MOPAB —  Monday Poster Session   (24-May-21   08:00—10:00)

Paper	Title	Page
MOPAB001	Power Deposition in Superconducting Dispersion Suppressor Magnets Downstream of the Betatron Cleaning Insertion for HL-LHC	37
	A. Waets, C. Bahamonde Castro, E. Belli, R. Bruce, N. Fuster-Martínez, A. Lechner, A. Mereghetti, S. Redaelli, M. Sabaté-Gilarte, E. Skordis CERN, Meyrin, Switzerland
	Funding: Research supported by the HL-LHC project The power deposited in dispersion suppressor magnets downstream of the Large Hadron Collider (LHC) betatron cleaning insertion is governed by off-momentum particles scattered out of the primary collimators. In order to mitigate the risk of magnet quenches during periods of short beam lifetime in future High-Luminosity (HL-LHC) operation, new dispersion suppressor (DS) collimators are considered for installation (one per beam). In this paper, we present FLUKA simulations for both protons and Pb ions at 7 TeV, predicting the power deposition in the DS magnets, including the new higher-field dipoles 11T which are needed to integrate the collimator in the cold region next to the cleaning insertion. The simulated power deposition levels for the adopted HL-LHC collimator configuration and settings are used to assess the quench margin by comparison with the present estimated quench levels.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB001
About •	paper received ※ 19 May 2021       paper accepted ※ 07 July 2021       issue date ※ 16 August 2021
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MOPAB002	Risk of Halo-Induced Magnet Quenches in the HL-LHC Beam Dump Insertion	41
	J.B. Potoine, A. Apollonio, E. Belli, C. Bracco, R. Bruce, M. D’Andrea, R. García Alía, A. Lechner, G. Lerner, S. Morales Vigo, S. Redaelli, V. Rizzoglio, E. Skordis, A. Waetspresenter CERN, Meyrin, Switzerland F. Wrobel IES, Montpellier, France
	Funding: Research supported by the HL-LHC project After the High Luminosity (HL-LHC) upgrade, the LHC will be exposed to a higher risk of magnet quenches during periods of short beam lifetime. Collimators in the extraction region (IR6) assure the protection of magnets against asynchronous beam dumps, but they also intercept a fraction of the beam halo leaking from the betatron cleaning insertion. In this paper, we assess the risk of quenching nearby quadrupoles during beam lifetime drops. In particular, we present an empirical analysis of halo losses in IR6 using LHC Run 2 (2015-2018) beam loss monitor measurements. Based on these results, the halo-induced power density in magnet coils expected in HL-LHC is estimated using FLUKA Monte Carlo shower simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB002
About •	paper received ※ 19 May 2021       paper accepted ※ 13 July 2021       issue date ※ 22 August 2021
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MOPAB003	Machine Learning Analysis of Electron Cooler Operation for RHIC	45
	X. Gu, A.V. Fedotov, D. Kayran BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. A regression machine learning algorithm was applied to analyze the operation data of RHIC with electron cooler LEReC during the 2020 physics run. After constructing a black-box surrogate model from the XGBoost algorithm and plotting their partial dependency plots for different operation parameters, we can find the effects of an individual parameter on the RHIC luminosity and optimize it accordingly offline.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB003
About •	paper received ※ 14 May 2021       paper accepted ※ 25 May 2021       issue date ※ 11 August 2021
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MOPAB004	JSPEC - A Simulation Program for IBS and Electron Cooling	49
	H. Zhang, S.V. Benson, M.W. Bruker, Y. Zhang JLab, Newport News, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. Intrabeam scattering is an important collective effect that can deteriorate the properties of a high-intensity beam, and electron cooling is a method to mitigate the IBS effect. JSPEC (JLab Simulation Package for Electron Cooling) is an open-source program developed at Jefferson Lab, which simulates the evolution of the ion beam under the IBS and/or the electron cooling effect. JSPEC has been benchmarked with BETACOOL and experimental data. In this report, we will introduce the features of JSPEC, including the friction force calculation, the IBS expansion rate and electron cooling rate calculation, and the beam-dynamic simulations for the electron cooling process; explain how to set up the simulations in JSPEC; and demonstrate the benchmarking results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB004
About •	paper received ※ 19 May 2021       paper accepted ※ 21 May 2021       issue date ※ 27 August 2021
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MOPAB005	Studies for an LHC Pilot Run with Oxygen Beams	53
	R. Bruce, R. Alemany-Fernández, H. Bartosik, M.A. Jebramcik, J.M. Jowett, M. Schaumann CERN, Geneva, Switzerland
	Motivated by the study of collective effects in small systems with oxygen-oxygen (O-O) collisions, and improvements to the understanding of high-energy cosmic ray interactions from proton-oxygen (p-O) collisions, a short LHC oxygen run during Run 3 has been proposed. This article presents estimates for the obtainable luminosity performance in these two running modes based on simulations of a typical fill. The requested integrated luminosity, projected beam conditions, data-taking and commissioning times are considered and a running scenario is proposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB005
About •	paper received ※ 17 May 2021       paper accepted ※ 25 May 2021       issue date ※ 19 August 2021
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MOPAB006	Optics Configurations for Improved Machine Impedance and Cleaning Performance of a Multi-Stage Collimation Insertion	57
	R. Bruce, R. De Maria, M. Giovannozzi, N. Mounet, S. Redaelli CERN, Geneva, Switzerland
	For a two-stage collimation system, the betatron phase advance between the primary and secondary stages is usually set to maximise the absorption of secondary particles outscattered from the primary. Another constraint is the contribution to the ring impedance of the collimation system, which can be decreased through an optimized insertion optics, featuring large values of the beta functions. In this article we report on first studies of such an optics for the CERN LHC. In addition to a gain in impedance, we show that the cleaning efficiency can be improved thanks to the large beta functions, even though the phase advance is not set at the theoretical optimum.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB006
About •	paper received ※ 17 May 2021       paper accepted ※ 28 May 2021       issue date ※ 11 August 2021
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MOPAB007	Prospect for Interaction Region Local Coupling Correction in the LHC Run 3	61
	F. Soubelet, T.H.B. Persson, R. Tomás García CERN, Geneva, Switzerland O. Apsimon, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom O. Apsimon, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) and CERN. Successful operation of large scale particle accelerators depends on the precise correction of unavoidable magnet field or alignment errors present in the machine. In the LHC Run 2, local linear coupling in the Interaction Regions (IR) has been proven to have a severe impact on beam size and hence the luminosity - up to a 50% decrease -, making its handling a target for Run 3 and High Luminosity LHC (HL-LHC). However, current measurement methods are not optimised for local IR coupling. In this contribution, an approach to accurately minimise IR local coupling based on correlated external variables such as the |C-| is proposed. The validity of the method is demonstrated through simulations and benchmarked against theoretical values, such as Resonance Driving Terms (RDTs) and Ripken parameters.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB007
About •	paper received ※ 17 May 2021       paper accepted ※ 23 July 2021       issue date ※ 19 August 2021
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MOPAB008	Exploiting the Beam-Beam Wire Demonstrators in the Next LHC Run 3	65
	A. Poyet Université Grenoble Alpes, Grenoble, France S.D. Fartoukh, N. Karastathis, Y. Papaphilippou, A. Rossi, G. Sterbini CERN, Geneva, Switzerland K. Skoufaris University of Crete, Heraklion, Crete, Greece
	After the successful experiments performed during the LHC Run 2 with the Beam-Beam Wire demonstrators installed, on Beam 2, in the frame of the HL-LHC project, two of the four wire demonstrators were moved to Beam 1. The objective is to gain operational experience with the wire compensation also on that beam and therefore fully exploit the demonstrators’ potential. This paper proposes a numerical validation of the wire implementation using Run 3 scenarios and explores the optimization of those devices in that respect.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB008
About •	paper received ※ 17 May 2021       paper accepted ※ 24 May 2021       issue date ※ 11 August 2021
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MOPAB009	Review of the Fixed Target Operation at RHIC in 2020	69
	C. Liu, P. Adams, E.N. Beebe, S. Binello, I. Blackler, M. Blaskiewicz, K.A. Brown, D. Bruno, B.D. Coe, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, K. Hock, H. Huang, R.L. Hulsart, T. Kanesue, D. Kayran, N.A. Kling, B. Lepore, Y. Luo, D. Maffei, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, J. Morris, C. Naylor, S. Nemesure, M. Okamura, I. Pinayev, S. Polizzo, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, P. Thieberger, M. Valette, A. Zaltsman, I. Zane, K. Zeno, W. Zhang BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. As part of the Beam Energy Scan (BES) physics program, RHIC operated in Fixed Target mode at various beam energies in 2020. The fixed target experiment, achieved by scraping the beam halo of the circulating beam on a gold ring inserted in the beam pipe upstream of the experimental detectors, extends the range of the center-of-mass energy for BES. The machine configuration, control of rates, and results of the fixed target experiment operation in 2020 will be presented in this report.
	Poster MOPAB009 [2.913 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB009
About •	paper received ※ 16 May 2021       paper accepted ※ 17 August 2021       issue date ※ 23 August 2021
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MOPAB010	RHIC Beam Energy Scan Operation with Electron Cooling in 2020	72
	C. Liu, P. Adams, E.N. Beebe, S. Binello, I. Blackler, M. Blaskiewicz, K.A. Brown, D. Bruno, B.D. Coe, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, K. Hock, H. Huang, R.L. Hulsart, T. Kanesue, D. Kayran, N.A. Kling, B. Lepore, Y. Luo, D. Maffei, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, J. Morris, C. Naylor, S. Nemesure, M. Okamura, I. Pinayev, S. Polizzo, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, P. Thieberger, M. Valette, A. Zaltsman, I. Zane, K. Zeno, W. Zhang BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. RHIC provided Au-Au collisions at beam energies of 5.75 and 4.59 GeV/nucleon for the physics program in 2020 as a part of the Beam Energy Scan II experiment. The operational experience at these energies will be reported with emphasis on their unique features. These unique features include the addition of a third harmonic RF system to enable a large longitudinal acceptance at 5.75 GeV/nucleon, the application of additional lower frequency cavities for alleviating space charge effects, and the world-first operation of cooling with an RF-accelerated bunched electron beam.
	Poster MOPAB010 [3.523 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB010
About •	paper received ※ 17 May 2021       paper accepted ※ 29 July 2021       issue date ※ 10 August 2021
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MOPAB012	Energy Deposition Study of the CERN HL-LHC Optics v1.5 in the ATLAS and CMS Insertions	76
	M. Sabaté-Gilarte, F. Cerutti CERN, Meyrin, Switzerland
	Funding: Research supported by the HL-LHC project The High Luminosity Large Hadron Collider (HL-LHC) is the approved CERN project aiming at further increasing the integrated luminosity of the LHC by a factor 10. As such, it implies a complete redesign of the experimental high-luminosity insertions of ATLAS and CMS. The progressive evolution of the new layout and optics requires a continuous analysis of the radiation environment, to which magnets and other equipment are exposed to. This is assured by means of Monte Carlo simulations of the collision debris on the evolving machine model. The latter featured several developments, such as the explicit inclusion of the cold protection diodes of the final focusing circuits as well as the crab cavities cryomodule. This work presents the most updated characterization of the radiation field with FLUKA and its impact in the insertion region and the dispersion suppressor of Point 1 and 5, for the HL-LHC optics v1.5 released in 2019. Various optimization and mitigation studies are highlighted, providing key information for maximizing the lifetime of new and present magnets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB012
About •	paper received ※ 18 May 2021       paper accepted ※ 25 May 2021       issue date ※ 21 August 2021
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MOPAB013	Radiation to Electronics Impact on CERN LHC Operation: Run 2 Overview and HL-LHC Outlook	80
	Y.Q. Aguiar, A. Apollonio, F. Cerutti, S. Danzeca, R. García Alía, G. Lerner, D. Prelipcean, M. Sabate-Gilartepresenter CERN, Geneva 23, Switzerland
	Funding: Research supported by the HL-LHC project After the mitigation measures implemented during Run 1 (2010-2012) and Long Shutdown 1 (LS1, 2013-2014), the number of equipment failures due to radiation effects on electronics (R2E) leading to LHC beam dumps and/or machine downtime has been sufficiently low as to yield a minor impact on the accelerator performance. During Run 2 (2015-2018) the R2E related failures per unit of integrated luminosity remained below the target value of 0.5 events/fb-1, with the sole exception of the 2015 run during which the machine commissioning took place. However, during 2018, an increase in the failure rate was observed, linked to the increased radiation levels in the dispersion suppressors of the ATLAS and CMS experimental insertions, significantly affecting the Quench Protection System located underneath the superconducting magnets in the tunnel. This work provides an overview of the Run 2 R2E events during LHC proton-proton operation, putting them in the context of the related radiation levels and equipment sensitivity, and providing an outlook for Run 3 and HL-LHC operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB013
About •	paper received ※ 19 May 2021       paper accepted ※ 23 July 2021       issue date ※ 23 August 2021
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MOPAB014	First High Spin-Flip Efficiency for High Energy Polarized Protons	84
	H. Huang, J. Kewisch, C. Liu, A. Marusic, W. Meng, F. Méot, P. Oddo, V. Ptitsyn, V.H. Ranjbar, T. Roser BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In order to minimize the systematic errors for the Relativistic Heavy Ion Collider (RHIC) spin physics experiments, flipping the spin of each bunch of protons during the stores is needed. Experiments done with single RF magnet at energies less than 2 GeV have demonstrated a spin-flip efficiency over 99%. At high energy colliders with Siberian snakes, a single magnet spin flipper does not work because of the large spin tune spread and the generation of multiple, overlapping resonances. Over past decade, RHIC spin flipper design has evolved and a sophisticated spin flipper, constructed of nine-dipole magnets, was developed to flip the spin in RHIC. A special optics choice was also used to make the spin tune spread very small. In recent experiment, 97% spin-flip efficiency was measured at both 24 and 255 GeV for the first time. The results show that efficient spin flipping can be achieved at high energies.
	Poster MOPAB014 [0.984 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB014
About •	paper received ※ 16 May 2021       paper accepted ※ 08 June 2021       issue date ※ 20 August 2021
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MOPAB015	Feasibility of Polarized Deuteron Beam in the EIC	87
	H. Huang, F. Méot, V. Ptitsyn, V.H. Ranjbar, T. Roser BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The physics program in the EIC calls for polarized neutron beam at high energies. The best neutron carriers are 3He nuclei and deuterons. Both neutron carries are expected to be used by spin physics program in the EIC. Due to the small magnetic moment anomaly of deuteron particles, much higher magnetic fields are required for spin rotation, so full Siberian snake is not feasible. However, the resonance strength is in general weak and the number of resonances is also small. It is possible to deal with individual resonances with conventional methods, such as betatron tune jump for intrinsic depolarizing resonances; and a weak partial snakes for imperfection resonances. The study shows that accelerating polarized deuteron beyond 100GeV/n is possible in the EIC.
	Poster MOPAB015 [0.977 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB015
About •	paper received ※ 16 May 2021       paper accepted ※ 28 May 2021       issue date ※ 13 August 2021
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MOPAB016	Small Longitudinal Emittance Setup in Injectors with Gold Beam for Beam Energy Scan in RHIC	90
	H. Huang, C.J. Gardner, C. Liu, V. Schoefer, K. Zeno BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In recent years, RHIC physics program calls for gold beam collisions with energies at and lower than the nominal RHIC injection energy. To get shorter bunches at the three higher energies (9.8GeV/c, 7.3GeV/c and 4.75GeV/c), RHIC 28MHz cavities were used. The longitudinal emittance out of injectors needs to fit in the 28MHz cavities in RHIC. At two lower energies (4.6 and 3.85 GeV/c), the 9MHz RF cavities were used, which set different requirements from injectors. Extensive beam studies were carried out to establish needed beam parameters, such as bunch intensities and longitudinal emittances. In general, enough intensity can be provided for all energies within the longitudinal emittance constraint. This paper summarizes the recent injector operation experiences for various energies.
	Poster MOPAB016 [2.641 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB016
About •	paper received ※ 16 May 2021       paper accepted ※ 17 August 2021       issue date ※ 01 September 2021
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MOPAB017	Influence of Injection Kicker Post-pulses on Storage of Ion Stack in NICA Collider	93
	E. Syresin, A. Tuzikov, N.O. Zagibin JINR, Dubna, Moscow Region, Russia
	The peculiarity of the injection kicker power supply in NICA collider is related to same post pulse of the magnetic field which is appeared after a regular injection pulse. The magnetic field of this post pulse became to an increase of the stack ion angle spread during each injection cycle. When the stack ion angles reaches the acceptance angle the ions are lost in the collider. Influence of the injection kicker post pulse on the storage of the ion stack is considered in this paper in presence of the electron cooling and ion electron recombination losses.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB017
About •	paper received ※ 17 May 2021       paper accepted ※ 20 May 2021       issue date ※ 13 August 2021
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MOPAB018	SASE Gain-Curve Measurements with MCP-Based Detectors at the European XFEL	96
	E. Syresin, O.I. Brovko, A.Yu. Grebentsov JINR, Dubna, Moscow Region, Russia W. Freund, J. Grünert, J. Liu, Th. Maltezopoulos, D. Mamchyk EuXFEL, Schenefeld, Germany M.V. Yurkov DESY, Hamburg, Germany
	Radiation detectors based on microchannel plates (MCP) are used for characterization of the Free-Electron Laser (FEL) radiation and measurements of the Self-amplified spontaneous emission (SASE) gain curve at the European XFEL. Photon pulse energies are measured by the MCPs with an anode and by a photodiode. There is one MCP-based detector unit installed in each of the three photon beamlines downstream of the SASE1, SASE2, and SASE3 undulators. MCP detectors operate in a wide dynamic range of pulse energies, from the level of spontaneous emission up to FEL saturation. Their wavelength operation range overlaps with the whole range of radiation wavelengths of SASE1 and SASE2 (from 0.05 nm to 0.4 nm), and SASE3 (from 0.4 nm to 5 nm). In this paper we present results of SASE gain-curve measurements by the MCP-based detectors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB018
About •	paper received ※ 18 May 2021       paper accepted ※ 17 August 2021       issue date ※ 23 August 2021
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MOPAB019	Possible Application of Round-to-Flat Hadron Beam Creation Using 3rd Order Coupling Resonances for the Electron-Ion Collider	99
	J. Kallestrup PSI, Villigen PSI, Switzerland X. Gu BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. An Electron-Ion Collider (EIC) is planned to be built in Brookhaven National Laboratory with the contribution from Jefferson National Laboratory. To have a high luminosity, both the EIC ion bunch and the EIC electron bunch are designed to be flat during their collision. The existing injector source provides a round beam of width 2.5 um rad transverse emittances. In this paper we investigate the option of dynamically crossing the 2Qx-Qy coupling resonance in order to create a flat-beam with emittance ratio Ex/Ey of up to 4. Furthermore, we explore the possibility of using a pulsed- or AC skew sextupole magnets to achieve a similar effect. Using one of these methods for flat beam creation will help lower the ion beam cooling time.
	Poster MOPAB019 [0.323 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB019
About •	paper received ※ 19 May 2021       paper accepted ※ 02 June 2021       issue date ※ 24 August 2021
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MOPAB020	Improvements to the SLS Booster Synchrotron Performance Towards SLS 2.0	103
	J. Kallestrup, M. Aiba PSI, Villigen PSI, Switzerland
	The Swiss Light Source (SLS) storage ring will undergo a major upgrade to a multi-bend achromat lattice. The existing injector complex will be reused with few modifications. However, the SLS booster synchrotron has not been studied since the initial commissioning in years 2000-2001. We plan to apply an emittance exchange in the booster to lower the horizontal emittance, which is a critial parameter for the injection. Here, we present improvements to the SLS booster as a preparation for SLS 2.0 upgrade project. The vertical beam size is decreased by 50\% by the use of vertical orbit correctors without beam position monitors, leading also to suppression of vertical dispersion and a factor 10 reduction of the transverse coupling coefficient. The emittance exchange reflected these improvements in the horizontal emittance, achieving a factor of 9-10 reduction. Lastly, a fast head-tail instability limiting the injection rate into the storage ring is discovered and subsequently suppressed by correcting the chromaticities.
	Poster MOPAB020 [0.380 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB020
About •	paper received ※ 19 May 2021       paper accepted ※ 01 June 2021       issue date ※ 30 August 2021
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MOPAB021	A Dispersive Quadrupole Scan Technique for Transverse Beam Characterization	107
	J. Kallestrup, M. Aiba PSI, Villigen PSI, Switzerland N. Carmignani, T.P. Perron ESRF, Grenoble, France
	Quadrupole scans are one of the standard techniques to characterize the transverse beam properties in transfer lines or linacs. However, in the presence of dispersion the usage of regular quadrupole scans will lead to erroneous estimates of the beam parameters. The standard solution to this problem is to measure the dispersion and then subtract it in the post-analysis of the quadrupole scan measurements assuming the design energy spread. Here we show that the dispersive contribution to the beam size can be included in the quadrupole scan procedure, forming a linear system of equations that can be solved to obtain both the betatronic and dispersive beam parameters. The method is tested at both the SLS and ESRF booster-to-ring transfer lines leading to reasonable estimates of the beam parameters.
	Poster MOPAB021 [0.447 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB021
About •	paper received ※ 19 May 2021       paper accepted ※ 02 June 2021       issue date ※ 19 August 2021
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MOPAB022	FailSim: A Numerical Toolbox for the Study of Fast Failures and Their Impact on Machine Protection at the CERN Large Hadron Collider	111
	C. Hernalsteens, G. Sterbini, O.K. Tuormaa, C. Wiesner, D. Wollmann CERN, Meyrin, Switzerland
	The High Luminosity LHC (HL-LHC) foresees to reach a nominal, levelled luminosity of 5·1034 cm-2 s−1 through a higher beam brightness and by using new equipment, such as larger aperture final focusing quadrupole magnets. The HL-LHC upgrade has critical impacts on the machine protection strategy, as the stored beam energy reaches 700 MJ for each of the two beams. Some failure modes of the novel active superconducting magnet protection system of the inner triplet magnets, namely the Coupling-Loss Induced Quench (CLIQ) systems, have been identified as critical. This paper reports on FailSim, a Python-language framework developed to study the machine protection impact of failure cases and their proposed mitigation. It provides seamless integration of the successive phases required by the simulation studies, i.e., verifying the optics, preparing and running a MAD-X instance for multiple particle tracking, processing and analysing the simulation results and summarising them with the relevant plots to provide a solid estimate of the beam losses, their location and time evolution. The paper also presents and discusses the result of its application on the spurious discharge of a CLIQ unit.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB022
About •	paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 18 August 2021
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MOPAB023	Experimental Test of a New Method to Verify Retraction Margins Between Dump Absorbers and Tertiary Collimators at the LHC	115
	C. Wiesner, W. Bartmann, C. Bracco, R. Bruce, J. Molson, M. Schaumann, C. Staufenbiel, J.A. Uythoven, M. Valette, J. Wenninger, D. Wollmann, M. Zerlauth CERN, Meyrin, Switzerland
	The protection of the tertiary collimators (TCTs) and the LHC triplet aperture in case of a so-called asynchronous beam dump relies on the correct retraction between the TCTs and the dump region absorbers. A new method to validate this retraction has been proposed, and a proof-of-principle experiment was performed at the LHC. The method uses a long orbit bump to mimic the change of the beam trajectory caused by an asynchronous firing of the extraction kickers. It can, thus, be performed with circulating beam. This paper reports on the performed beam measurements, compares them with expectations and discusses the potential benefits of the new method for machine protection.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB023
About •	paper received ※ 19 May 2021       paper accepted ※ 25 August 2021       issue date ※ 24 August 2021
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MOPAB024	Efficient Coupling of Hydrodynamic and Energy-Deposition Codes for Hydrodynamic-Tunnelling Studies on High-Energy Particle Accelerators	119
	C. Wiesner, F. Carra, J. Kruse-Hansen, M. Masci, D. Wollmann CERN, Meyrin, Switzerland Y. Nie KIT, Karlsruhe, Germany
	The machine-protection evaluation of high-energy accelerators comprises the study of beyond-design failures, including the direct beam impact onto machine elements. In case of a direct impact, the nominal beam of the Large Hadron Collider (LHC) would penetrate more than 30 meters into a solid copper target. The penetration depth due to the time structure of the particle beam is, thus, significantly longer than predicted from purely static energy-deposition simulations with 7 TeV protons. This effect, known as hydrodynamic tunnelling, is caused by the beam-induced density depletion of the material at the target axis, which allows subsequent bunches to penetrate deeper into the target. Its proper simulation requires, therefore, to sequentially couple an energy-deposition code and a hydrodynamic code for the different target densities. This paper describes a method to efficiently couple the simulations codes Autodyn and FLUKA based on automatic density assignment and input file generation, and presents the results achieved for a sample case.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB024
About •	paper received ※ 19 May 2021       paper accepted ※ 05 July 2021       issue date ※ 28 August 2021
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MOPAB025	First Experiments with Accelerated Ion Beams in the Booster of NICA Accelerator Complex	123
	A.V. Butenko, V. Andreev, A.M. Bazanov, O.I. Brovko, D.E. Donets, A.V. Eliseev, I.V. Gorelyshev, A.V. Konstantinov, S.A. Kostromin, O.S. Kozlov, K.A. Levterov, A. Nesterov, A.V. Philippov, D.O. Ponkin, G.S. Sedykh, I.V. Shirikov, A.O. Sidorin, E. Syresin, A. Tuzikov, V. Volkov JINR/VBLHEP, Dubna, Moscow region, Russia N.N. Agapov, A.V. Alfeev, A.A. Baldin, A.A. Fateev, A.R. Galimov, B.V. Golovenskiy, E.V. Gorbachev, A. Govorov, E.V. Ivanov, V. Karpinsky, V.D. Kekelidze, H.G. Khodzhibagiyan, A. Kirichenko, A.G. Kobets, S.A. Korovkin, V. Kosachev, A.D. Kovalenko, G. Kunchenko, I.N. Meshkov, V.A. Mikhailov, V.A. Monchinsky, D. Nikiforov, R.V. Pivin, S. Romanov, A.A. Shurygin, A.I. Sidorov, A.N. Svidetelev, G.V. Trubnikov, B. Vasilishin JINR, Dubna, Moscow Region, Russia G.A. Fatkin Cosylab Siberia, Novosibirsk, Russia
	The NICA accelerator complex in JINR consist of two linear injector chains, a 578 MeV/u superconducting (SC) Booster synchrotron, the existing SC synchrotron Nuclotron, and a new SC collider that has two storage rings. The construction of the facility is based on the Nuclotron technology of SC magnets with an iron yoke and hollow SC cable. Assembly of the Booster synchrotron was finished in autumn of 2020 and first machine Run and experiments with ion beams were successfully done in December 2020. The results of this Run are discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB025
About •	paper received ※ 16 May 2021       paper accepted ※ 07 September 2021       issue date ※ 15 August 2021
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MOPAB026	RHIC Delayed Abort Experiments	126
	M. Valette, D. Bruno, K.A. Drees, K.M. Hartmann, G. Heppner, K. Mernick, C. Mi, J.-L. Mi, R.J. Michnoff, J. Morris, F. Orsatti, E. Rydout, T. Samms, J. Sandberg, V. Schoefer, C. Schultheiss, T.C. Shrey, C. Theisen BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. For RHIC to operate at its top energy (100 GeV/n) while protecting the future sPHENIX detector, spontaneous and asynchronous firing of abort kicker modules (pre-fires) have to be avoided. A new triggering circuit for the abort kickers was implemented with relatively slow mechanical relays in series with the standard fast thyratron tubes. The relays prevents unwanted pre-fires during operation, but comes at the expense of a long latency - about 7 milliseconds - between the removal of beam permit and the actual firing of the abort kickers. Protection considerations of RHIC’s superconducting magnets forbid delaying energy extraction from the main dipoles and quadrupoles for too long after a quench. The beam has thus to circulate in both RHIc rings for a few milliseconds as the current in dipole and quadrupole circuit is being extracted. We present the results of delayed abort experiments conducted in July 2018 with the analysis of fast orbit and tune measurements and discuss the safety implications of this implementation for future RHIC operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB026
About •	paper received ※ 19 May 2021       paper accepted ※ 26 May 2021       issue date ※ 23 August 2021
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MOPAB027	Improving the Luminosity Burn-Off Estimate by Considering Single-Diffractive Effects	130
	F.F. Van der Veken, H. Burkhardt, M. Giovannozzi, V.K.B. Olsen CERN, Geneva, Switzerland
	Collisions in a high-luminosity collider result in a continuous burn-off of the circulating beams that is the dominant effect that reduces the instantaneous luminosity over time. In order to obtain a good estimate of the luminosity evolution, it is imperative to have an accurate understanding of the burn-off. Typically, this is calculated based on the inelastic cross-section, as it provides a direct estimate of the number of protons that participate in inelastic collisions, and are hence removed. Likewise, protons that participate in elastic collisions will remain in the machine acceptance, still contributing to luminosity. In between these two regimes lie diffractive collisions, for which the protons have a certain probability to remain in the machine acceptance. Recent developments of the SixTrack code allow it to interface with Pythia, thus allowing for more precise simulations to obtain a better estimate of the diffractive part of the cross-section. In this paper, we will mainly concentrate on slowly-drifting protons that are close to the acceptance limit, resulting from single-diffractive scattering.
	Poster MOPAB027 [1.193 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB027
About •	paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 11 August 2021
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MOPAB028	Using Machine Learning to Improve Dynamic Aperture Estimates	134
	F.F. Van der Veken, M. Giovannozzi, E.H. Maclean CERN, Geneva, Switzerland C.E. Montanari Bologna University, Bologna, Italy G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	The dynamic aperture (DA) is an important concept in the study of nonlinear beam dynamics. Several analytical models used to describe the evolution of DA as a function of time, and to extrapolate to realistic time scales that would not be reachable otherwise due to computational limitations, have been successfully developed. Even though these models have been quite successful in the past, the fitting procedure is rather sensitive to several details. Machine Learning (ML) techniques, which have been around for decades and have matured into powerful tools ever since, carry the potential to address some of these challenges. In this paper, two applications of ML approaches are presented and discussed in detail. Firstly, ML has been used to efficiently detect outliers in the DA computations. Secondly, ML techniques have been applied to improve the fitting procedures of the DA models, thus improving their predictive power.
	Poster MOPAB028 [1.764 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB028
About •	paper received ※ 18 May 2021       paper accepted ※ 25 May 2021       issue date ※ 12 August 2021
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MOPAB029	Burn-Off with Asymmetric Interaction Points	138
	R. Tomás García, I. Efthymiopoulos, G. Iadarola CERN, Geneva, Switzerland
	LHC can host above 2700 proton bunches per ring providing collisions in the ATLAS, CMS, LHCb and ALICE interaction points. ATLAS and CMS are placed symmetrically so that they feature the same colliding bunch pairs. However this is not the case for LHCb, hence introducing unwanted bunch-by-bunch variations of the bunch intensity as the physics fill evolves. We present first analytical derivations, numerical simulations and experimental data in different bunch train collision configurations.
	Poster MOPAB029 [1.502 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB029
About •	paper received ※ 13 May 2021       paper accepted ※ 25 May 2021       issue date ※ 27 August 2021
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MOPAB030	Research and Development Progress of CEPC RF Shield Bellows	142
	J.M. Liu, Y.H. Guan, S.M. Liu, B. Tan, P.C. Wang DNSC, Dongguan, People’s Republic of China H. Dong, Y. Ma IHEP, Beijing, People’s Republic of China H.Y. He, T. Huang IHEP CSNS, Guangdong Province, People’s Republic of China
	The circular electron positron collider (CEPC) is a candidate for the next-generation electron positron collider, which can be used to accurately measure the Higgs and electroweak bosons. The RF shield bellow is a vacuum component necessary for the construction of CEPC. Therefore, a RF shield bellow model machine with an elliptical cross-section was designed and processed for technical verification. Based on the traditional interdigital structure, a special contact force testing device was also designed to reduce measurement errors. The on-off status of the circuit was used by the device to determine whether the spring finger was pulled up, thus reducing the influences of human factors in the measurement process. It can be known from the measurement results of the model machine that the contact force of the spring finger is between 120g and 130g, which can satisfy the technical requirements.
	Poster MOPAB030 [1.467 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB030
About •	paper received ※ 19 May 2021       paper accepted ※ 20 May 2021       issue date ※ 13 August 2021
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MOPAB031	Development and Operation of Vacuum System for Rapid Cycling Synchrotron to Target Beam Transfer Line of China Spallation Neutron Source	145
	J.M. Liu, Y.H. Guan, S.M. Liu, B. Tan, P.C. Wang DNSC, Dongguan, People’s Republic of China H. Dong IHEP, Beijing, People’s Republic of China H.Y. He, T. Huang IHEP CSNS, Guangdong Province, People’s Republic of China
	China Spallation Neutron Source (CSNS) is a major scientific project during the National Eleventh Five-Year Plan. It consists of a negative hydrogen ion linear accelerator, a rapid cycling synchrotron ( RCS), a linac to RCS beam transfer line (LRBT), an RCS to target beam transfer line (RTBT), and a target station. As an important part of CSNS, the RTBT connects the rapid cycling synchrotron and the target window. This paper described the design requirements, technical solutions, and operating conditions of the vacuum system for the CSNS RCS to target beam transfer line. In addition, the fast valve protection system and its verification results were also expounded. The CSNS has been in operation for over three years, during this period, the beam power has been gradually improved from 10KW to 100KW, and the vacuum system for RTBT has been operating stably.
	Poster MOPAB031 [0.581 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB031
About •	paper received ※ 19 May 2021       paper accepted ※ 24 May 2021       issue date ※ 25 August 2021
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MOPAB032	Estimates of Collective Effects for the FCC-e⁺e⁻ Pre-Booster Ring	148
	O. Etisken, F. Antoniou, K. Oide, Y. Papaphilippou, F. Zimmermann CERN, Geneva, Switzerland A.K. Çiftçi Izmir University of Economics, Balçova/Izmir, Turkey
	The FCC-e+e− injector complex needs to produce and to transport high-intensity e+ and e- beams at a fast repetition rate for topping up the collider at its collision energy. Two different options are under consideration as pre-accelerator before the bunches are transferred to the high-energy booster: either using the existing SPS machine or designing a completely new ring. The purpose of this paper is to present the studies of collective effects with analytical estimates for both the pre-booster ring design options including space charge (SC), longitudinal micro-wave instability (LMI), transverse mode coupling instability (TMCI), ion effects, electron cloud (e-cloud), coherent synchrotron radiation (CSR), and intra-beam scattering (IBS).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB032
About •	paper received ※ 17 May 2021       paper accepted ※ 27 May 2021       issue date ※ 15 August 2021
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MOPAB033	Monochromatization of e⁺e⁻ Colliders with a Large Crossing Angle	152
	V.I. Telnov BINP SB RAS, Novosibirsk, Russia
	The relative center-of-mass energy spread at e+e− colliders is much larger than the widths of narrow resonances, which greatly lowers the resonance production rates of J/Psi, Psi-prime, Upsililon(nS), n=1-3. Thus, a significant reduction of the center-of-mass energy spread would open up great opportunities in the search for new physics in rare decays of narrow resonances, the search for new narrow states with small partial e+e− width. The existing monochromatization scheme is only suitable for head-on collisions, while e+e− colliders with crossing angles (the so-called Crab Waist collision scheme) can provide much higher luminosity. In this report, a new monochromatization method for colliders with a large crossing angle is discussed*. The contribution of the beam energy spread to the spread of the center-of-mass energy is canceled by introducing an appropriate energy-angle correlation at the interaction point; the relative RMS mass spread of about (3-5)10-6 seems possible. Limitations of the proposed method are also considered. This monochromatization scheme is very attractive for the Upsilon-meson region and below. * V.I.Telnov, Monochromatization of e+e− colliders with a large crossing angle, arXiv:2008.13668
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB033
About •	paper received ※ 22 May 2021       paper accepted ※ 26 May 2021       issue date ※ 31 August 2021
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MOPAB034	VEPP-4M Collider Operation at High Energy	155
	P.A. Piminov, G.N. Baranov, A.V. Bogomyagkov, V.M. Borin, V.L. Dorokhov, S.E. Karnaev, K.Yu. Karyukina, V.A. Kiselev, E.B. Levichev, O.I. Meshkov, S.I. Mishnev, I.A. Morozov, I.N. Okunev, E.A. Simonov, S.V. Sinyatkin, E.V. Starostina, A.N. Zhuravlev BINP SB RAS, Novosibirsk, Russia
	VEPP-4M is an electron positron collider equipped with the universal KEDR detector for HEP experiments in the beam energy range from 1 GeV to 6 GeV. A unique feature of VEPP-4M is the high precision beam energy calibration by resonant polarization technique which allows conducting of interesting experiments despite the low luminosity of the collider. Recently we have started new luminosity acquisition run above 2 GeV. The hadron cross section was measured from 2.3 GeV to 3.5 GeV has been done. The luminosity run for gamma-gamma physics has been started. The luminosity at ψ(1S)-meson has been obtained. For the beam energy calibration the laser polarimeter is used. The paper discusses recent results from VEPP-4M collider.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB034
About •	paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 22 August 2021
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MOPAB035	Modified Lattice of the Compact Storage Ring in the cSTART Project at Karlsruhe Institute of Technology	159
	A.I. Papash, E. Bründermann, B. Härer, A.-S. Müller, R. Ruprecht, J. Schäfer, M. Schuh KIT, Karlsruhe, Germany
	A very large acceptance compact storage ring (VLA-cSR) is under design at the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT, Germany). The combination of a compact storage ring and a laser wakefield accelerator (LWFA) might be the basis for future compact light sources and advancing user facilities. Meanwhile, the post-LWFA beam should be adapted for storage and accumulation in a dedicated storage ring. Modified geometry and lattice of a VLA-cSR operating at 50 MeV energy range have been studied in detailed simulations. The main features of a new model are described here. The new design, based on 45° bending magnets, is suitable to store the post-LWFA beam with a wide momentum spread (1% to 2%) as well as ultra-short electron bunches in the fs range from the Ferninfrarot Linac- Und Test- Experiment (FLUTE). The DBA-FDF lattice with relaxed settings, split elements, and higher-order optics of tolerable strength allows improving the dynamic aperture to an acceptable level. This contribution discusses the lattice features in detail and different possible operation schemes of a VLA-cSR.
	Poster MOPAB035 [1.405 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB035
About •	paper received ※ 10 May 2021       paper accepted ※ 27 May 2021       issue date ※ 24 August 2021
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MOPAB036	Different Operation Regimes at the KIT Storage Ring KARA (Karlsruhe Research Accelerator)	163
	A.I. Papash, M. Brosi, E. Huttel, A. Mochihashi, A.-S. Müller, R. Ruprecht, P. Schreiber, M. Schuh, N.J. Smale KIT, Karlsruhe, Germany
	The KIT storage ring KARA operates in a wide energy range from 0.5 to 2.5 GeV. Different operation modes have been implemented at KARA, so far, the double-bend achromat (DBA) lattice with non-dispersive straight sections, the theoretical minimum emittance (TME) lattice with distributed dispersion, different versions of low-compaction factor optics with highly stretched dispersion function. Short bunches of a few ps pulse width are available at KARA. Low-alpha optics has been simulated, tested and implemented in a wide operational range of the storage ring and is now routinely used at 1.3 GeV for studies of beam bursting effects caused by coherent synchrotron radiation in the THz frequency range. Different non-linear effects, in particular residual high-order components of the magnetic field, generated in high-field superconducting wigglers have been studied and cured. Based on good agreement between computer simulations and experiments, a new operation mode at high vertical tune was implemented. The beam performance during user operation as well as at low-alpha regimes has been improved. A specific optic with negative compaction factor was simulated, tested and is in operation.
	Poster MOPAB036 [1.477 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB036
About •	paper received ※ 13 May 2021       paper accepted ※ 08 June 2021       issue date ※ 29 August 2021
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MOPAB037	On Possibility of Alpha-buckets Detecting at the KIT Storage Ring KARA (Karlsruhe Research Accelerator)	167
	A.I. Papash, T. Boltz, M. Brosi, A.-S. Müller, R. Ruprecht, P. Schreiber, M. Schuh, N.J. Smale KIT, Karlsruhe, Germany
	Computer studies of longitudinal motion have been performed with the objective to estimate the possibility of detection of alpha-buckets at the KIT storage ring KARA (Karlsruhe Research Accelerator). The longitudinal equations of motion and the Hamiltonian were expanded to high order terms of the energy deviation of particles in a beam. Roots of third order equation for three leading terms of momentum compaction factor and free energy independent term were derived in a form suitable for analytical estimations. Averaged quadratic terms of closed orbit distortions caused by misalignment of magnetic elements in a ring lead to orbit lengthening independent of particle energy deviation. Particle transverse excursions were estimated and are taken into account. Simulations have been bench-marked on existing experiments at Metrology Light Source (MLS) in Berlin (Germany) and SOLEIL (France). Parameters of three simultaneous beams and alpha buckets at MLS and SOLEIL have been reproduced with high accuracy. A computer model of KARA was used to predict behavior and the dynamics of possible simultaneous beams in the ring.
	Poster MOPAB037 [1.269 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB037
About •	paper received ※ 11 May 2021       paper accepted ※ 28 May 2021       issue date ※ 29 August 2021
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MOPAB038	Robustness Studies and First Commissioning Simulations for the SOLEIL Upgrade Lattice	171
	D. Amorim, A. Loulergue, L.S. Nadolski, R. Nagaoka SOLEIL, Gif-sur-Yvette, France
	Diffraction limited light sources will use very strong focusing elements to achieve their emittance goal. The beam will therefore be more sensitive to magnet field and alignment errors. Impact of errors on the lattice proposed for the SOLEIL upgrade was studied with the Accelerator Toolbox (AT) code. The performance achieved with the imperfect lattice will be presented. In particular the effect of girders misalignment was also accounted for. As the lattice uses a large number of permanent magnets for the beam bending as well as the focusing, challenges arise in terms of beam correction. The correctors and BPMs location and number will be investigated to maximize their efficiency, and corrector magnet strength required to obtain a closed orbit will be studied. The commissioning strategy, and in particular the method used to achieve the first turns and a stored beam in the machine will also be exposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB038
About •	paper received ※ 19 May 2021       paper accepted ※ 31 May 2021       issue date ※ 16 August 2021
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MOPAB039	Amplitude-Dependent Shift of Betatron Tunes and Its Relation to Long-Term Circumference Variations at NSLS-II	175
	L.H. Yu, G. Bassi, Y. Hidaka, B. Podobedov, V.V. Smaluk, G.M. Wang, X. Yang BNL, Upton, New York, USA
	The comparison of amplitude tune dependence measured for NSLSII lattices with models indicated the large change of amplitude tune dependence over time apparently can not be solely explained by magnets variation or beta function changes, but it seems can be explained by energy changes. On the other hand, the energy change required by fitting with the amplitude tune dependence change is too large to be explained by the RF frequency change and the change of the sum of correctors in the period of the measurements. To explain this apparent contradiction, our analysis shows the long term storage ring circumference change can explain the apparent energy change. Our data indeed shows a seasonal change of the amplitude tune dependence over long term observation. This clearly also indicated a relation to long term closed orbit drift. Hence the current work indicates a new strategy to study how to use amplitude tune dependence as a guideline to analyze long term lattice parameter shifts and closed orbit drift, and improve the orbit and machine performance stability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB039
About •	paper received ※ 09 May 2021       paper accepted ※ 26 May 2021       issue date ※ 26 August 2021
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MOPAB040	Gain of Hard X-Ray Fel at 3 GeV and Required Parameters	178
	L.H. Yu BNL, Upton, New York, USA
	We develop a tool for the calculation to study the conditions for a hard x-ray FEL oscillator based on an electron beam in the medium energy range from 3 to 4.5 GeV. We show that the approach developed by K.J. Kim et al. for the small-signal low gain formula can be modified so that the gain can be derived without taking the "no focusing approximation" adopted in the approach so that a strong focusing can be applied. We also derive the formula to allow for the gain calculation of harmonic lasing. The gain in this formula can be cast in the form of a product of two factors with one of them only depends on the harmonic number, undulator period, and gap. Thus this factor can be used to show that it is favorable to use harmonic lasing to achieve hard x-ray FEL working in the medium energy range and in the small-signal low gain regime.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB040
About •	paper received ※ 09 May 2021       paper accepted ※ 26 May 2021       issue date ※ 10 August 2021
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MOPAB041	Convergence Map with Action-Angle Variables Based on Square Matrix for Nonlinear Lattice Optimization	182
	L.H. Yu, Y. Hidaka, F. Plassard, V.V. Smaluk BNL, Upton, New York, USA Y. Hao FRIB, East Lansing, Michigan, USA
	We apply square matrix method to obtain in high speed a "convergence map", which is similar but different from frequency map. The convergence map is obtained from solving nonlinear dynamical equation by iteration of perturbation method and study the convergence. The map provides information about the stability border of dynamical aperture. We compare the map with frequency map from tracking. The result indicates the new method may be applied in nonlinear lattice optimization, taking the advantage of the high speed (about 10~50 times faster) to explore x, y and the off-momentum phase space.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB041
About •	paper received ※ 09 May 2021       paper accepted ※ 26 May 2021       issue date ※ 18 August 2021
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MOPAB042	Beam Dynamics Investigation for a New Project of Compton Back Scattering Photon Source at NRNU MEPhI	186
	V.S. Dyubkov, I.A. Ashanin, M. Gusarova, Yu.D. Kliuchevskaia, M.V. Lalayan, S.M. Polozov, A.I. Pronikov, V.I. Rashchikov MEPhI, Moscow, Russia
	Funding: This project is supported by Russian Foundation for Basic Research, Grant no. 19-29-12036. The activities on physical models design of a compact monochromatic radiation source in the x-ray range based on inverse Compton scattering are started at NRNU MEPhI. There are comparison of two schemes of the photon source here: one of them is considered to be based on linac with variable energy of 20-60 MeV only and the other one is considered as accelerator complex where linac is supposed to be used as injector to medium size storage ring (energy up to 60 MeV). Preliminary results of linac structures and storage ring design as well as electron dynamics simulation are discussed
	Poster MOPAB042 [0.962 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB042
About •	paper received ※ 13 May 2021       paper accepted ※ 20 May 2021       issue date ※ 10 August 2021
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MOPAB043	Validation of APS-U Beam Dynamics Using 6-GeV APS Beam	189
	L. Emery, P.S. Kallakuri, R.R. Lindberg, A. Xiao ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Several beam measurements at the Advanced Photon Sources were done with a lowered-energy beam of 6 GeV in order to verify or validate calculation codes and some predictions for the APS-U. Though the APS lattice is obviously different from that of the APS-U some aspects of the beams at 6 GeV are similar, for example, the synchrotron radiation damping rate. At 6 GeV, one can also store more current and run with a higher rf bucket allowing the characterization of larger momentum aperture lattices. We report measurements (or plans of measurements) on general instabilities thresholds, lifetime, and other subtle effects. The important topic of ion instabilities at 6 GeV is covered in a separate paper by J. Calvey at this conference.
	Poster MOPAB043 [0.829 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB043
About •	paper received ※ 20 May 2021       paper accepted ※ 23 June 2021       issue date ※ 10 August 2021
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MOPAB044	Gas Bremsstrahlung Measurements in the Advanced Photon Source Storage Ring	193
	J.C. Dooling, A.R. Brill, J.R. Calvey ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357. In the Advanced Photon Source Upgrade storage ring (SR), small-aperture vacuum chambers provide limited conductance for pumping. Non-evaporable getter (NEG) coatings will be used in the SR to support the vacuum. Ion pumps and cold-cathode gauges are typically located away from the vacuum chamber transporting the beam. Measuring gas bremsstrahlung (GB) photons in low-conductance chambers provides a method to determine the pressure at the beam location. We report on GB measurements made in the ID-25 beamline. A Pb:Glass calorimeter radiator generates Cherenkov radiation when high-energy photons cause pair-production within the glass. A photomultiplier tube converts the light pulses to electrical signals. Data was obtained during normal machine operations starting in January 2020. Data collection was facilitated using a 4-channel ITech Beam Loss Monitor FPGA that allows for control of thresholds and attenuation settings in both counting and pulse-height acquisition modes. Count rates and spectra were recorded for the three primary fill patterns typically used during SR operations as well as during gas injection experiments; results of these measurements will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB044
About •	paper received ※ 22 May 2021       paper accepted ※ 28 May 2021       issue date ※ 25 August 2021
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MOPAB045	Measurements and Simulations of High Charge Beam in the APS Booster	197
	J.R. Calvey, J.C. Dooling, K.C. Harkay, K.P. Wootton, C. Yao ANL, Lemont, Illinois, USA
	For the APS-Upgrade, swap-out injection will require the booster to support up to 17 nC bunch charge, several times what is used in the present APS. Booster injection efficiency drops sharply at high charge, and is the present bottleneck limiting high charge transport through the injectors. Particle tracking simulations have been used to understand what causes are limiting the injection efficiency, and to guide plans for improving it. In particular, bunch length blowup in the injected beam and beam loading in the RF cavities have been identified as the biggest factors. Simulations and measurements have also been done to characterize beam properties along the booster energy ramp. So far, a bunch charge of 12 nC has been successfully extracted from the booster.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB045
About •	paper received ※ 19 May 2021       paper accepted ※ 26 July 2021       issue date ※ 16 August 2021
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MOPAB046	Plan for Operating the APS-Upgrade Booster with a Frequency Sweep	201
	J.R. Calvey, T.G. Berenc, A.R. Brill, L. Emery, T. Fors, K.C. Harkay, T.J. Madden, N. Sereno, U. Wienands ANL, Lemont, Illinois, USA A. Gu UCB, Berkeley, California, USA
	The APS-Upgrade presents several challenging demands to the booster synchrotron. Swap-out injection requires the booster to capture a high charge bunch (up to 17 nC), accelerate it to 6 GeV, and maintain a low emittance at extraction for injection into the storage ring. To accommodate these conflicting demands, the RF frequency will be ramped between injection and extraction. However, the RF cavity tuners will remain static, which means the couplers will need to withstand a high reflected power at extraction. This paper presents a plan for a system that will meet the requirements for injection efficiency, extracted emittance, and equivalent power at the coupler. Results from tracking simulations and beam studies with a frequency ramp will also be shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB046
About •	paper received ※ 28 May 2021       paper accepted ※ 02 June 2021       issue date ※ 26 August 2021
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MOPAB047	A CAD Tool for Linear Optics Design: A Use Case Approach	205
	J. Bengtsson HZB, Berlin, Germany T.J.R. Nichollspresenter, W.A.H. Rogers DLS, Oxfordshire, United Kingdom
	The formula relevant for linear optics design of synchrotrons are derived systematically from first principles, i.e., an exercise in Hamiltonian dynamics. Equipped with these, the relevant use cases are then captured; for a streamlined approach. To enable professionals, i.e., software engineers, to efficiently prototype & architect a CAD tool available to mechanical engineers since the mid-1960s. In other words, robust design of a modern synchrotron is an exercise in/pursuit of the art of Engineering-Science.
	Poster MOPAB047 [1.059 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB047
About •	paper received ※ 17 May 2021       paper accepted ※ 28 May 2021       issue date ※ 15 August 2021
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MOPAB048	Robust Design and Control of the Nonlinear Dynamics for BESSY-III	209
	J. Bengtsson, M. Abo-Bakr, P. Goslawski, A. Jankowiak, B.C. Kuske HZB, Berlin, Germany
	The design philosophy for a robust prototype lattice design for BESSY III, i.e., that is insensitive to small parameter changes, e.g. engineering tolerances - based on a higher-order-achromat, a la: SLS, NSLS-II, MAX IV, and SLS 2 - is outlined & presented. As usual, a well optimized design requires a clear understanding of the end-user requirements and close collaboration between the linear optics designer and nonlinear dynamics specialist for a systems approach.
	Poster MOPAB048 [1.202 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB048
About •	paper received ※ 17 May 2021       paper accepted ※ 24 May 2021       issue date ※ 27 August 2021
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MOPAB049	Gyroresonant Acceleration of Electrons by an Axisymmetric Transverse Electric Field	213
	E.A. Orozco, O. Otero Olartepresenter UIS, Bucaramanga, Colombia
	The acceleration of electrons using gyromagnetic autoresonance consist on the sustaint of the electron cyclotron resonant condition through of a magnetic field which increase on time, this scheme was propose by K. S. Golovanivsky. In this work, we considerer the gyroresonant acceleration of electrons using an axisymmetric transverse electric field and its limitations. The 2D acceleration of electrons by a TE011 cylindrical mode is studied numerically. The trajectory, energy and phase-shift between the electron transverse velocity and the electric field are determined by the numerical solution of the relativistic Newton-Lorentz equation using a finite difference scheme. The growth rate of the magnetic field obtained is such that it maintains the phase difference within the acceleration band. The study includes the evolution of the energy for electrons initially ubicated in diferents initial points. For an electron that starts from rest and located at the radial midpoint of the transverse central plane of the cavity, it is reaches an energy close to 560 keV in 625 cycles of the microwave field using an electric field amplitude of 1 kV/cm and a frequency of 2.45 GHz.
	Poster MOPAB049 [3.541 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB049
About •	paper received ※ 17 May 2021       paper accepted ※ 14 June 2021       issue date ※ 23 August 2021
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MOPAB050	Spatial Autoresonant Acceleration of Electrons by an Axysimmetric Transverse Electric Field	217
	E.A. Orozco, O. Otero Olartepresenter UIS, Bucaramanga, Colombia
	In this research, The autoresonance acceleration of electrons by an axisymmetric transverse electric field in presence of a stationary inhomogeneous magnetic field is studied. The dynamics of electrons is determined by the numerical solution of the relativistic Newton-Lorentz equation using a finite difference scheme. The inhomogeneous external magnetic field is generated with a three-coil system and calculated using the Biot-Savart law. The electrons move along a TE011 cylinder cavity in a stationary magnetic field whose axis coincides with the cavity axis. The magnetic field profile obtained is such that it keeps the phase difference between the electric field vector of the microwave mode and the velocity vector of the particle within the acceleration band. For an electron injected longitudinally with an energy of 1 keV and that starts at the radial midpoint of the cavity, it is accelerated up to an energy of about 185 keV using an electric field amplitude of 14 kV/cm and a frequency of 2.45 GHz at a distance of 14 cm.
	Poster MOPAB050 [3.298 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB050
About •	paper received ※ 17 May 2021       paper accepted ※ 15 June 2021       issue date ※ 30 August 2021
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MOPAB051	Operation of the ESRF Booster with the New EBS Storage Ring	221
	N. Carmignani, L.R. Carver, S.M. Liuzzo, T.P. Perron, S.M. White ESRF, Grenoble, France
	The Extremely Brilliant Source (EBS) has replaced the old ESRF Storage Ring (SR) during the 2019 one-year shutdown. The injector chain, composed of a Linac, a booster synchrotron, and two transfer lines, was not replaced. Nevertheless, some major hardware upgrades were anticipated prior to the long shutdown to ensure its long-term reliability. The shutdown interventions focused on reducing the machine circumference to cope with the new RF frequency of the SR. The status of the upgraded booster will be presented with a focus on the strategy used to lower horizontal emittance especially via emittance exchange.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB051
About •	paper received ※ 14 May 2021       paper accepted ※ 28 May 2021       issue date ※ 25 August 2021
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MOPAB052	Study of Beam Transmission Efficiency in Injection and Ramping Process of the HEPS Booster	225
	Y.M. Peng, Z. Duan, Y. Jiaopresenter, C. Meng IHEP, Beijing, People’s Republic of China
	A high-bunch-charge mode, with a bunch charge of approximately 14.4 nC at 200 mA, has been proposed for the storage ring of High Energy Photon Source (HEPS). In order to reduce the bunch charge requirement to the injector, high-energy accumulation in the HEPS booster is proposed to combine with the on-axis swap-out injection. This allows reducing the requirement of bunch charge accelerated in HEPS booster (500 MeV-6 GeV) from over 14.4 nC to about 5 nC. It is expected that the overall transmission efficiency during the low energy injection and ramping process of the booster should be higher than 80% to fulfill the requirement. In this paper, we present the simulation results of transmission efficiency and potential improvement measures.
	Poster MOPAB052 [0.362 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB052
About •	paper received ※ 13 May 2021       paper accepted ※ 26 May 2021       issue date ※ 15 August 2021
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MOPAB053	Progress of Lattice Design and Physics Studies on the High Energy Photon Source	229
	Y. Jiao, Y. Bai, X. Cui, C.C. Du, Z. Duan, Y.Y. Guo, P. He, X.Y. Huang, D. Ji, H.F. Ji, S.C. Jiang, B. Li, C. Li, J.Y. Li, N. Li, X.Y. Li, P.F. Liang, C. Meng, W.M. Pan, Y.M. Peng, Q. Qin, H. Qu, S.K. Tian, J. Wan, B. Wang, J.Q. Wang, N. Wang, Y. Wei, G. Xu, H.S. Xu, F. Yan, C.H. Yu, Y.L. Zhao IHEP, Beijing, People’s Republic of China X.H. Lu IHEP CSNS, Guangdong Province, People’s Republic of China
	Funding: Work supported by High Energy Photon Source (HEPS), a major national science and technology infrastructure and NSFC (11922512) The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. The HEPS construction started in mid-2019. While the physics design has been basically determined, modifications on the HEPS accelerator physics design have been made since 2019, in order to deal with challenges emerging from the technical and engineering designs. In this paper, we will introduce the new storage ring lattice and injector design, and also present updated results of related physics issues, including impedance and collective effects, lattice calibration, insertion device effects, injection design studies, etc.
	Poster MOPAB053 [0.699 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB053
About •	paper received ※ 10 May 2021       paper accepted ※ 24 May 2021       issue date ※ 17 August 2021
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MOPAB054	Start-to-End Simulation of a Free-Electron Laser Driven by a Laser-Plasma Wakefield Accelerator	233
	W. Liu, Y. Jiaopresenter, S. Wang IHEP, Beijing, People’s Republic of China
	The rapid development of laser-plasma wakefield accelerator (LPA) has opened up a new possible way to achieve ultra-compact free-electron laser (FEL). To this end, LPA experts have made many efforts to generate electron beams with sub-micrometer emittance and low energy spread. Recently, a new laser modulation method was proposed for generating EUV coherent pulse in an LPA-driven FEL. The simulation demonstration of this scheme is based on the Gaussian beam. However, the distribution of the LPA beam is not Gaussian. To further verify the feasibility of the method mentioned above, a start-to-end simulation is required.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB054
About •	paper received ※ 18 May 2021       paper accepted ※ 27 May 2021       issue date ※ 22 August 2021
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MOPAB055	Generation of Coherent Attosecond X-ray Pulses in the Southern Advanced Photon Source	237
	W. Liu, Y. Zhao IHEP CSNS, Guangdong Province, People’s Republic of China Y. Jiaopresenter, S. Wang IHEP, Beijing, People’s Republic of China
	Southern Advanced Photon Source (SAPS) is a fourth-generation storage ring light source that has been considered for construction in Guangdong province of China, adjacent to the China Spallation Neutron Source. As a low-emittance storage ring, the natural emittance of SAPS is below 100 pm. One of the benefits is that the brightness is about 2 orders high than 3rd generation light sources. However, like many other storage ring-based light sources, the time resolution is limited by the electron bunch length in the range of picoseconds. In this work, we propose a new scheme for the generation of coherent attoseconds X-ray pulses with a high repetition rate in SAPS. A numerical demonstration of the scheme is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB055
About •	paper received ※ 17 May 2021       paper accepted ※ 26 May 2021       issue date ※ 26 August 2021
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MOPAB056	Optimization of a TBA with Stable Optics and Minimal Longitudinal Dispersion and CSR-Induced Emittance Growth	241
	C. Zhang, Y. Jiaopresenter IHEP, Beijing, People’s Republic of China C.-Y. Tsai HUST, Wuhan, People’s Republic of China
	Funding: National Natural Science Foundation of China (No. 11922512), Youth Innovation Promotion Association of Chinese Academy of Sciences (No. Y201904), National Key R&D Program of China (No. 2016YFA0401900) In the beam transfer line which often consists of dipoles to deflect the beam trajectory, longitudinal dispersion effect and emission of coherent synchrotron radiation (CSR) will lead to beam phase space distortion, thus degrading the machine performance. In this study, optimizations of a triple-bend achromat (TBA) cell are conducted using the multi-objective particle swarm optimization (MOPSO) method to suppress the CSR-induced emittance growth and minimize the longitudinal dispersion functions up to high orders, simultaneously. For the longitudinal dispersion function, results of three optimization settings are reported, which makes the TBA design first-order, second-order, and higher-order isochronous. Furthermore, we study the shortest possible beamline length of the higher-order isochronous TBA design, which may pave the way to designing a more compact beam transfer line.
	Poster MOPAB056 [0.366 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB056
About •	paper received ※ 12 May 2021       paper accepted ※ 28 May 2021       issue date ※ 15 August 2021
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MOPAB057	Evaluation of Pulsed Septum Leakage Fields and Compensation for the Advanced Photon Source Upgrade	245
	M. Borland, M.S. Jaski, J. Wang ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The Advanced Photon Source upgrade is considering two options for injection: vertical-plane injection with a DC Lambertson septum and horizontal-plane injection with a pulsed septum. In the latter case, pulsed leakage fields are a concern as they will cause transient beam motion and emittance dilution. In this paper, we describe results of modeling the effect of such leakage fields on the beam. We also evaluate methods of compensating for the leakage fields, including the limited time response of correction elements. Several septum drive-pulse shapes are considered and compared.
	Poster MOPAB057 [2.066 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB057
About •	paper received ※ 17 May 2021       paper accepted ※ 26 May 2021       issue date ※ 02 September 2021
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MOPAB058	Swap-Out Safety Tracking for the Advanced Photon Source Upgrade	249
	M. Borland, J.S. Downey, M.S. Jaski ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The Advanced Photon Source upgrade will operate in swap-out mode, which is similar to top-up but involves complete replacement of individual depleted bunches in a single shot. As with top-up, safety is a concern given that this process will take place with beamline shutters open. We describe the methods used to model swap-out safety, including creation and validation of a full ring lattice based on 3D field maps. We also describe a new method of implementing complex, intersecting channels for electron beams and photon beams, as well as a method of easily identifying potentially dangerous stray particles. Numerous potential errors (e.g., magnet shorts) were modeled, giving a reliable indication of performance of proposed stored beam and magnet interlocks.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB058
About •	paper received ※ 14 May 2021       paper accepted ※ 28 May 2021       issue date ※ 29 August 2021
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MOPAB059	Tools for Use of Generalized Gradient Expansions in Accelerator Simulations	253
	M. Borland, R.R. Lindberg, R. Soliday, A. Xiao ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. A common assumption in simulation of accelerators is that the magnets can be approximated using a hard-edge model, perhaps with some edge effects implemented in an impulse approximation. This is usually a good assumption but ignores details of the longitudinal variation of the magnetic fields, which makes it straightforward to implement symplectic tracking. Use of generalized gradient expansions* provides an alternative approach that can suppress numerical deficiencies that may be present in computed or measured 3D field maps. However, the computation of the expansions is not particularly straightforward. In this note, we describe several recently-developed tools that make this process fairly painless and allow tracking with such expansions in the program ELEGANT**. We show several examples of using the tools for simulations related to the Advanced Photon Source Upgrade. * M. Venturini et al., NIM A 427, 387 (1999). ** M. Borland, Advanced Photon Source LS-287, September 2000
	Poster MOPAB059 [4.311 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB059
About •	paper received ※ 17 May 2021       paper accepted ※ 26 May 2021       issue date ※ 18 August 2021
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MOPAB061	Comparison Simulation Results of the Collimator Aperture in HEPS Storage Ring	257
	Y.L. Zhao, Y. Jiao, N. Lipresenter IHEP, Beijing, People’s Republic of China
	The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring light source, which is under construction and planned to be in operation in 2025. To protect the sensitive elements from being damaged and reduce the radiation level of the site, collimators will be installed in the storage ring to localize the particle losses. The Touschek scattering is the main cause of particle losses during daily nominal operations. Based on the elegant simulations, we evaluate the physical design of the collimators, especially analysis the collimator performance with different collimator apertures. The simulation results will be introduced in this paper.
	Poster MOPAB061 [0.701 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB061
About •	paper received ※ 13 May 2021       paper accepted ※ 17 August 2021       issue date ※ 21 August 2021
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MOPAB062	A Single Dipole Source for Broad-Band Soft Photon Beamlines in Diamond-II	261
	M. Apollonio, G. Cinque, H. Ghasem, A.N. Jury, I.P.S. Martin, R. Rambo DLS, Oxfordshire, United Kingdom
	Diamond-II is a project based at Diamond Light Source for an upgrade towards a Storage Ring characterized by a reduction of a factor 20 in its natural emittance and a doubling of the number of straight sections. At Diamond-II the majority of existing beamline capacity should be maintained, while enhancing their performance thanks to the increase in brightness at the source points. The substantial modification of the lattice imposes a likewise re-design of the broad-band sources, presently based on standard dipoles. In this paper we discuss a possible solution for the IR/THz beamline B22 operating within a photon energy range between 1meV and 1eV. This proposal, ideal for low critical energy and single source point sources, entails the insertion of a dipole in one of the newly created mid-cell straights of the machine, while reducing the bending power of the nearby gradient dipoles. After performing the linear matching of the lattice, reproducing a comparable phase advance in the modified cell, we studied the non-linear dynamics of the system. Comparison of the main observables (Dynamic Aperture, Injection Efficiency and Lifetime) with the baseline case is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB062
About •	paper received ※ 18 May 2021       paper accepted ※ 28 May 2021       issue date ※ 12 August 2021
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MOPAB063	Commissioning Strategy for Diamond-II	265
	M. Apollonio, R.T. Fielder, H. Ghasem, I.P.S. Martin DLS, Oxfordshire, United Kingdom
	At Diamond Light Source we are working on the upgrade towards a machine aimed at a factor 20 reduction in emittance and an increase of the capacity for beamlines. Crucially the success of the programme depends on the ability to inject and capture the electrons in the storage ring, and finally reach control of beam alignment and the linear optics. The paper presents the series of strategies adopted to achieve the commissioning of the machine, from the threading procedure ensuring the first turn of the electron beam, to the orbit corrections in the storage ring. Beam based alignment of the quadrupoles and skew quadrupoles is illustrated and restoration of the linear optics (LOCO) for the storage ring is presented. Main performance parameters (Dynamic Apertures, Injection Efficiency and Lifetime) are calculated to evaluate the performance of the commissioned lattices.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB063
About •	paper received ※ 18 May 2021       paper accepted ※ 28 May 2021       issue date ※ 14 August 2021
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MOPAB065	Optimization of the Lattice Replacement Options for the Next Generation Australian Synchrotron	269
	R. Auchettl, R.T. Dowd, Y.E. Tan AS - ANSTO, Clayton, Australia
	The design of a next generation Australian Synchrotron replacement lattice is a multi-objective and multi-constrained problem. Our group was tasked to produce a low emittance design while re-using the existing tunnel infrastructure and injector system. Our objectives coupled with the set infrastructure constraints are not straightforward to achieve with manual design. Several variables act at cross-purposes to one-another, leading to a conflicting trade-off between objectives. Recently we have investigated replacement options for the Australian Synchrotron containing longitudinal gradient and reverse bends in the form of a 4BA (4-bend achromat) lattice. In this work, optimise the lattice design for a potential fourth generation Australian Synchrotron facility. We outline the baseline 4BA solution to the lowest emittance lattice that can reuse the existing tunnels and injector system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB065
About •	paper received ※ 19 May 2021       paper accepted ※ 28 May 2021       issue date ※ 19 August 2021
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MOPAB066	Dual Octupole Emittance Growth Correction of the CompactLight XFEL Bunch Compressors	272
	R. Auchettl, R.T. Dowd AS - ANSTO, Clayton, Australia
	An optimized CompactLight X-Ray Free Electron Laser (FEL) bunch compressor design is presented. In this work, we insert an octupole into the center of the two sequential bunch compressors. We show how this scheme can adjust the compression, while correcting the undesirable peak current profile and emittance growth.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB066
About •	paper received ※ 24 May 2021       paper accepted ※ 28 May 2021       issue date ※ 24 August 2021
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MOPAB068	Collective Effects Studies for the SOLEIL Upgrade	274
	A. Gamelin, D. Amorim, P. Brunelle, W. Foosang, A. Loulergue, L.S. Nadolski, R. Nagaoka, R. Ollier, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	The SOLEIL upgrade project aims to replace the actual SOLEIL storage ring by a 4th generation light source. The project has just finished its conceptual design report (CDR) phase*. Compared to the SOLEIL storage ring, the upgraded storage ring design includes many new features of 4th generation light sources that will impact collective effects, such as reduced beam pipe apertures, a smaller momentum compaction factor and the presence of harmonic cavities (HC). To mitigate them, we rely on several damping mechanisms provided by the synchrotron radiation, the transverse feedback system, and the HC (Landau damping and bunch lengthening). This article presents a first estimate of the collective effects impact of the upgraded design. * Conceptual Design Report: Synchrotron SOLEIL Upgrade, 2021, in press.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB068
About •	paper received ※ 17 May 2021       paper accepted ※ 02 June 2021       issue date ※ 12 August 2021
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MOPAB069	Equilibrium Bunch Density Distribution with Multiple Active and Passive RF Cavities	278
	A. Gamelin SOLEIL, Gif-sur-Yvette, France N. Yamamoto KEK, Ibaraki, Japan
	This paper describes a method to get the equilibrium bunch density distribution with an arbitrary number of active or passive RF cavities in uniform filling. This method is an extension of the one presented by M. Venturini which assumes a passive harmonic cavity and no beam loading in the main RF cavity*. *M. Venturini, "Passive higher-harmonic rf cavities with general settings and multibunch instabilities in electron storage rings," Physical Review Accelerators and Beams, 2018.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB069
About •	paper received ※ 17 May 2021       paper accepted ※ 23 June 2021       issue date ※ 23 August 2021
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MOPAB070	mbtrack2, a Collective Effect Library in Python	282
	A. Gamelin, W. Foosang, R. Nagaoka SOLEIL, Gif-sur-Yvette, France
	This article introduces mbtrack2, a collective effect library written in python3. The idea behind mbtrack2 is to build a coherent object-oriented framework to work on collective effects in synchrotrons. mbtrack2 is composed of different modules allowing to easily write scripts for single bunch or multi-bunch tracking using MPI parallelization in a transparent way. The base of the tracking model of mbtrack2 is inspired by mbtrack, a C multi-bunch tracking code initially developed at SOLEIL*. In addition, many tools to prepare or analyse tracking simulations are included. * R. Nagaoka, R. Bartolini, and J. Rowland, Studies of Collective Effects in SOLEIL and Diamond Using the Multiparticle Tracking Codes SBTRACK and MBTRACK, in Proc. PAC’09, 2009.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB070
About •	paper received ※ 17 May 2021       paper accepted ※ 06 July 2021       issue date ※ 16 August 2021
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MOPAB071	Progress with the Booster Design for the Diamond-II Upgrade	286
	I.P.S. Martin, C. Christou, M.P. Cox, R.T. Fielder, J. Kallestrup, A. Shahveh, W. Tizzano DLS, Oxfordshire, United Kingdom A.D. Brynes, J.K. Jones, B.D. Muratori, H.L. Owen STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Efficient injection into the Diamond-II storage ring [*, **] will require an emittance and bunch length substantially below the values produced from the existing booster. Whilst an earlier design for a replacement based on TME cells was able to meet the target values of <30 nm.rad and <40 ps respectively [***, ****], several technical constraints have led to a rethink of this solution. The revised booster lattice utilises a larger number of cells based on combined-function magnets with lower peak fields that still meets the emittance and bunch length goals. In addition, the new ring has been designed to have low impedance to maximise the extracted charge per shot. In this paper we describe the main features of the lattice, present the status of the engineering design and quantify the expected performance. *Diamond-II Conceptual Design Report, Diamond Light Source **H. Ghasem et al, these proceedings ***I. Martin, R. Bartolini, J.Phys.:Conf. Ser., 1067, 032005 ****I. Martin et al, IPAC 2019, WEPMP042
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB071
About •	paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 02 September 2021
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MOPAB072	Single-Bunch Thresholds for the Diamond-II Storage Ring	290
	T. Olsson, R.T. Fielder DLS, Oxfordshire, United Kingdom
	The proposed Diamond Light Source upgrade will see the storage ring replaced with a multibend achromat lattice, increasing the capacity of the facility whilst reducing the emittance and providing higher brightness for the users. As part of the design work, tracking studies have been performed to determine the single-bunch thresholds including both the resistive-wall and geometric contributions to the impedance. As the machine design also foresees a third order harmonic cavity, the paper also provides an initial assessment of the effects of bunch lengthening on the single-bunch thresholds.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB072
About •	paper received ※ 18 May 2021       paper accepted ※ 01 June 2021       issue date ※ 23 August 2021
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MOPAB073	Beam Loss Simulations During Beam Dumping in Heps	294
	X. Cui, Y. Jiaopresenter, Y.L. Zhao IHEP, Beijing, People’s Republic of China
	The High Energy Photon Source (HEPS) is a 6 GeV storage ring light source under construction in China. Several collimators installed in the vacuum chamber will be used as beam dump in the storage ring operation. Preliminary simulations showed that the temperature rise caused by the beam power deposited on the collimators will far exceed the melting point of the collimator material. In order to cure this problem, special kickers are proposed to be installed in the ring to modulate the beam during beam dumping, thereby increasing the size of the beam hit on the collimators. In this article, some simulation results of the density of particles on the collimators during beam dumping for different HEPS lattice and different kicker parameters are shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB073
About •	paper received ※ 17 May 2021       paper accepted ※ 07 June 2021       issue date ※ 31 August 2021
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MOPAB074	Preliminary Study of Design Method for Hybrid MBA Lattice	297
	J.J. Tan, Z.H. Bai, Z.L. Ren, J.H. Xu USTC/NSRL, Hefei, Anhui, People’s Republic of China Q. Zhang INEST, Hefei, People’s Republic of China
	Nonlinear optimization of hybrid multi-bend-achromat (HMBA) lattice is a difficult task due to its quite limited variables of multipole magnets. As a result, it is necessary to consider nonlinear potential of the lattice in its linear design. Nonlinear dynamics can be estimated by nonlinear driving terms and detuning terms. In this paper, we propose a design method for HMBA lattice. In this method, objective functions include emittance and two indicators of nonlinear dynamics, which consist of nonlinear driving terms and detuning terms. As an example, an HMBA lattice for a 2.2 GeV storage ring with circumference of 460.8 m was designed to demonstrate the method.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB074
About •	paper received ※ 19 May 2021       paper accepted ※ 21 May 2021       issue date ※ 21 August 2021
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MOPAB075	Proposal of the Southern Advanced Photon Source and Current Physics Design Study	300
	S. Wang, J. Chen, L. Huang, Y. Jiao, B. Li, Z.P. Li, W. Liu, S.Y. Xu IHEP, Beijing, People’s Republic of China Y. Han, X.H. Lu, Y. Zhao IHEP CSNS, Guangdong Province, People’s Republic of China X. Liu Department of Energy Sciences, Tokyo Institute of Technology, Yokohama, Japan
	It has been considered to build a mid-energy fourth-generation storage ring light source neighbouring the China Spallation Neutron Source, in Guangdong Province, the south of China. The light source is named the Southern Advanced Photon Source (SAPS). Preliminary physics design studies on the SAPS have been implemented for a few years. In this paper, we will describe considerations of technical roadmap and key parameter choice for this light source, and introduce the up-to-date lattice designs and related physics studies on the SAPS.
	Poster MOPAB075 [1.689 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB075
About •	paper received ※ 12 May 2021       paper accepted ※ 20 May 2021       issue date ※ 21 August 2021
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MOPAB077	Anomaly Detection in Accelerator Facilities Using Machine Learning	304
	A. Das Stanford University, Stanford, California, USA M. Borland, L. Emery, X. Huang, H. Shang, G. Shen ANL, Lemont, Illinois, USA D.F. Ratner SLAC, Menlo Park, California, USA R.M. Smith, G.M. Wangpresenter BNL, Upton, New York, USA
	Synchrotron light sources are user facilities and usually run about 5000 hours per year to support many beamlines operations in parallel. Reliability is a key parameter to evaluate machine performance. Even many facilities have achieved >95% beam reliability, there are still many hours of unscheduled downtime and every hour lost is a waste of operation costs along with a big impact on individual scheduled user experiments. Preventive maintenance on subsystems and quick recovery from machine trips are the basic strategies to achieve high reliability, which heavily depends on experts’ dedication. Recently, SLAC, APS, and NSLS-II collaborated to develop machine-learning-based approaches aiming to solve both situations, hardware failure prediction and machine failure diagnosis to find the root sources. In this paper, we report our facility operation status, development progress, and plans.
	Poster MOPAB077 [1.240 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB077
About •	paper received ※ 16 May 2021       paper accepted ※ 14 June 2021       issue date ※ 01 September 2021
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MOPAB079	Experience of the First Six Years Operations and Plans in NSlS-II	308
	G.M. Wang BNL, Upton, New York, USA
	NSLS-II is a 3 GeV third-generation synchrotron light source at BNL. The storage ring was commissioned in 2014 and began its routine operations in the December of the same year. Since then, we have been continuously installing and commissioning new insertion devices, their front-ends, and beamlines. At this point, the facility hosts 28 operating beamlines from various radiation sources, including damping wiggler, IVU, EPU, 3PW, and bending magnets for infrared beamlines. Over the past six years, the storage ring performance continuously improved, including 500 mA with limited insertion devices close due to RF power limitation and routinely 400 mA top off operation, >95% operation reliability, maintenance of beam motion short- and long-term stability. In this paper, we report NSLS-II accelerator operations experience and plans for future facility developments.
	Poster MOPAB079 [2.064 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB079
About •	paper received ※ 17 May 2021       paper accepted ※ 21 June 2021       issue date ※ 25 August 2021
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MOPAB081	Feasibility Study of Using Multipole Injection Kicker (MIK) and Sextupole for TPS Injection	312
	C.-S. Fann, C.K. Chan, C.-C. Chang, H.-P. Chang, Y.-S. Cheng, M.-S. Chiu, Y.L. Chu, K.T. Hsu, S.Y. Hsu, K.H. Hu, J.C. Huang, C.-S. Hwang, S.H. Lee, K.-K. Lin, C.Y. Wu, C.S. Yang NSRRC, Hsinchu, Taiwan S.-Y. Lee Indiana University, Bloomington, Indiana, USA
	Feasibility of applying MIK/sextupole injection at TPS is evaluated in this study. This study adopts layout similar to MAX IV injection scheme and their collaboration project with SOLEIL for MIK. Although the light source service fulfills present user needs, yet the increasing demands for a transparent injection is inevitable in the foreseeable future. Notice that this preliminary study is constrained under routine user operation, the optional pinger ceramic chamber, located between existing injection kicker-3 and kicker-4, is chosen for the purpose. Kick strength requirement of the MIK is estimated with minor trajectory adjustment upstream at the booster to storage ring transfer line. Since the realization of MIK fabrication takes time, therefore a fast-built sextupole is prepared to examine the proposed injection scheme beforehand. The test result will be described in this report.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB081
About •	paper received ※ 17 May 2021       paper accepted ※ 20 May 2021       issue date ※ 21 August 2021
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MOPAB082	Implementation of Using IGBT Switch Based Pulser for TPS Booster Extraction Kicker	315
	C.-S. Fann, H.-P. Chang, C.L. Chen, Y.-S. Cheng, K.T. Hsu, S.Y. Hsu, K.-K. Lin, K.L. Tsai, C.Y. Wu NSRRC, Hsinchu, Taiwan
	A pair of thyratron-switch-based pulse-forming-network (PFN) pulser has been operating successfully in the past 5 years for TPS booster extraction kickers. In order to improve the flattop of drive-current pulse and to extend possible electron bunch train adjusting knob required, an IGBT-switch-based pulser has been designed, fabricated, and installed onto the TPS booster for its characteristics verification. In this report, the overall technical considerations for the pulser upgrade is described and its beam commissioning results is given for illustration purpose.
	Poster MOPAB082 [0.621 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB082
About •	paper received ※ 20 May 2021       paper accepted ※ 27 May 2021       issue date ※ 13 August 2021
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MOPAB084	Acceptance Tests and Installation of the IVU and Front End for the XAIRA Beamline of ALBA	318
	J. Campmany, J. Marcos, V. Massana ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	XAIRA is a new beamline being built at ALBA synchrotron for macromolecular crystallography (MX) devoted to the study of small bio crystals. It aims at providing a full beam with a size of 3x1 µm2 FWHM (hxv) and flux of >3·1012 ph/s (250 mA in Storage Ring) at 1 Å wavelength (12.4 keV) to tackle MX projects for which only tiny (<10 μm) or imperfect crystals are obtained. Besides, XAIRA aims at providing photons at low energies, down to 4 keV, to support MX experiments exploiting the anomalous signal of the metals naturally occurring in proteins (native phasing), which is enhanced in the case of small crystals and long wavelengths. To this end, an in-vacuum undulator has been built by a consortium between Kyma and Research Instruments companies. In this paper, we present the results of the Site Acceptance Tests made at ALBA using a new bench developed to measure closed structures, and also the steps done for its installation in the ALBA tunnel.
	Poster MOPAB084 [1.715 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB084
About •	paper received ※ 11 May 2021       paper accepted ※ 20 May 2021       issue date ※ 25 August 2021
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MOPAB085	Design and Fabrication of a Short Multipole Wiggler and the Front End for the New ALBA Beamline FAXTOR	321
	J. Campmany, J. Marcos, V. Massana ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	FAXTOR is a new hard XR tomography beam line that is being built at ALBA in order to fulfil the needs that cannot be currently covered by the MISTRAL VUV and soft XR beamline. This beam line needs a small source size as well higher than 1012 Photons per second through an aperture of 4x1 mm2 in the whole range 5 to 60 keV, for a current of 250 mA in Storage Ring with source size maintained below 310 µm horizontal and 25 µm vertical. The contract was awarded to AVS-US Company. In this paper we present the design finally selected as well as the preliminary design carried out by manufacturer to implement the conceptual model designed by ALBA.
	Poster MOPAB085 [1.879 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB085
About •	paper received ※ 11 May 2021       paper accepted ※ 20 May 2021       issue date ※ 31 August 2021
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MOPAB086	Design of Front End and a 3-Pole-Wiggler as a Photon Source for BEATS Beamline at SESAME	324
	J. Campmany, J. Marcos ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain M. Al Nadjawi, M. Attal, G. Lori SESAME, Allan, Jordan I. Cudin Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy S. Guiducci INFN/LNF, Frascati, Italy P. Van Vaerenbergh ESRF, Grenoble, France
	BEATS is an international collaboration funded by EU in order to design and implement an XR tomography beam line in SESAME Jordanian synchrotron. ALBA contribution consists in the design of the photon source and the Front End elements. In this paper we present the conceptual designs of both the 3-pole wiggler uses as photon source as well as the Front End elements designed for the beamline.
	Poster MOPAB086 [2.306 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB086
About •	paper received ※ 11 May 2021       paper accepted ※ 21 May 2021       issue date ※ 17 August 2021
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MOPAB087	Design of a Multi-Bunch Feedback Kicker in SPEAR3	327
	K. Tian, J.B. Langton, NL. Parry, J.A. Safranek, J.J. Sebek SLAC, Menlo Park, California, USA
	The new Multi-bunch feedback kickers have been designed to replace the current device loaned from ALS. In this paper, we first present the specification of the kickers based on the beam physics requirements. Then the mechanical design of the kicker is elaborated. Numerical simulations, both in time domain and in frequency domain, are conducted for evaluating the shunt impedance and beam coupling impedance of the kicker. Surface heating induced from the beam or the external source is estimated from the numerical results as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB087
About •	paper received ※ 19 May 2021       paper accepted ※ 11 June 2021       issue date ※ 01 September 2021
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MOPAB088	Beam-Based Measurement on the Performance of Ferrite Dampers in an In-Vacuum Undulator	331
	K. Tian, A. Ringwall, J.J. Sebek SLAC, Menlo Park, California, USA
	In this paper, we first present the tracking studies for SPEAR3 with the new BL17 ID and estimate its impact on the dynamic aperture of the low emittance lattice. Then the ferrite dampers installations in the device is briefly reviewed. After that, we will show that, based on beam-based measurements, the performance of the dampers is as being expected from earlier numerical studies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB088
About •	paper received ※ 19 May 2021       paper accepted ※ 18 June 2021       issue date ※ 24 August 2021
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MOPAB089	Effect of Different Models of Combined-function Dipoles on the HEPS Parameters	335
	Y.Y. Guo, Y. Jiaopresenter, N. Li IHEP, Beijing, People’s Republic of China
	The high energy photon source (HEPS) is a 6 GeV, kilometer-scale storage ring light source being built in Beijing, China. In the current ring lattice, the combined-function dipoles are used and assumed to have constant dipole field. However, in the actual magnet design, an eccentrically placed quadrupole is adopted, in which the bending field along the trajectory is not constant. In this paper, we will present the effect of the two models of combined-function dipoles on the parameters of the storage ring.
	Poster MOPAB089 [0.590 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB089
About •	paper received ※ 13 May 2021       paper accepted ※ 25 May 2021       issue date ※ 27 August 2021
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MOPAB090	Status of HEPS Insertion Devices Design	339
	X.Y. Li, Y. Jiaopresenter, H.H. Lu, S.K. Tian IHEP, Beijing, People’s Republic of China
	HEPS is a 4th generation light source with the energy of 6 GeV and ultralow emittance of 34 pm.rad. A total of 14 beamlines with 19 insertion devices has been planned in the first phase, including 6 cryogenic undulators, 5 in-vacuum undulators, and two special non-planar IDs. The schemes and parameters of all the IDs are planned to be determined in this year. We report on the status of the design of these IDs and their effects on beam dynamics.
	Poster MOPAB090 [0.633 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB090
About •	paper received ※ 13 May 2021       paper accepted ※ 01 July 2021       issue date ※ 10 August 2021
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MOPAB091	Injection Section Upgrading with the Septum-Magnet Replacement in KEK-PF Ring	342
	C. Mitsuda, K. Harada, N. Higashi, T. Honda, Y. Kobayashi, H. Miyauchi, S. Nagahashi, N. Nakamura, T. Nogami, T. Obina, M. Tadano, R. Takai, H. Takaki, Y. Tanimoto, T. Uchiyama, A. Ueda KEK, Ibaraki, Japan
	In 2015, the water leakage happened at the cooling pipe of the in-vacuum septum magnet installed into the injection point. Because the maintenance of the leakage needed the total replacement of the magnet, the water circulation was stopped permanently, and accordingly, the light absorber was installed upstream in the storage ring to prevent the synchrotron light of the bending magnet from coming to the septum wall. This treatment temporally worked well, but the beam injection efficiency was decreased to about 30% due to the physical aperture narrowed by the absorber. With the desired replacement of septum magnet to maintainable out-vacuum type, the injection section upgrading was simultaneously planned to recover and improve the injection efficiency. In this upgrade, the injection beam is closed to the stored beam more than before by adapting the thinner septum structure as a way to improve the injection efficiency. And some new ideas are introduced in the part of monitor and beam duct, for example, realtime beam monitor, thinner Inconel duct. The detailed design of the upgraded injection section and technical points will be reviewed in this conference.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB091
About •	paper received ※ 19 May 2021       paper accepted ※ 26 May 2021       issue date ※ 02 September 2021
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MOPAB092	Project of Wuhan Photon Source	346
	H.H. Li, Y. Deng, J.H. He, Y. Nie, L. Tang, J. Wang, Y.X. Zhu IAS, Wuhan City, People’s Republic of China
	Wuhan Photon Source (WHPS) has been designed as a fourth-generation light source, which consists of a low energy storage ring (1.5 GeV), a medium energy storage ring (4.0 GeV), and a linac working as a full energy injector. It has been planned to build the low energy light source first as the Phase I project, and then the medium energy light source after its completion. The low energy storage ring has been optimized with the main design parameters as following: An 8-cell, 500 mA storage ring, with a circumference of 180 m and nature emittance 238.4 pm-rad. Based on hybrid-7BA lattice structure, it reaches the soft X-ray diffraction limit. And at the middle of each cell, a 3.5 T superB magnet is used to extend the photon energy to the hard X-ray region. The swap-out injection is chosen due to the small dynamic aperture and a full energy S-band LINAC will be used as its injector. A 3rd harmonic cavity is designed for bunch lengthening to keep a sufficient lifetime. More details of the WHPS phase I project will be described in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB092
About •	paper received ※ 10 June 2021       paper accepted ※ 23 June 2021       issue date ※ 24 August 2021
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MOPAB093	Operational Status of Photon Factory Light Sources	350
	T. Honda, Y. Kobayashi, C. Mitsuda, S. Nagahashi, R. Takai, H. Takaki KEK, Ibaraki, Japan
	One of the recent topics of Photon Factory light sources, PF-ring and PF-AR, is a construction of a GeV-class beamline for testing detectors at the PF-AR. The bremsstrahlung photons generated by a thin carbon wire are brought to a copper target to generate e+e− pairs. Sufficient count rates can be expected when the thin wire touching halo of the stored beam, and the test beamline can be used without disturbing the synchrotron radiation experiments. In addition to the usual 6.5-GeV operation, a low-energy operation at 5-GeV was started recently at PF-AR to secure operation time by saving electricity costs. At the PF-ring, the injection section has been upgraded with the septum-magnet replacement. By the top-up injection and improved bunch feedback, the hybrid-fill mode operation has become convenient for both single-bunch users and multi-bunch users, and about 30% or 40% of the user time is scheduled as the hybrid-fill mode now.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB093
About •	paper received ※ 21 May 2021       paper accepted ※ 25 May 2021       issue date ※ 13 August 2021
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MOPAB095	Concept Design for the CLS2 Accelerator Complex	354
	M.J. Boland, P.J. Hunchak University of Saskatchewan, Saskatoon, Canada C.K. Baribeau, D. Bertwistle, J.M. Patel, H. Shaker, X. Shen, M.J. Sigrist CLS, Saskatoon, Saskatchewan, Canada F. Le Pimpec EuXFEL, Schenefeld, Germany E.J. Wallén LBNL, Berkeley, California, USA
	The Canadian Light Source has been in operation since 2005 and is now looking at a design concept to upgrade to a fourth generation storage ring. A brief overview is given of a possible accelerator complex layout, including some details on the lattice design and injection system. A full energy linac is being explored as an option for top-up injection and to future proof the facility for a potential FEL upgrade in the future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB095
About •	paper received ※ 23 May 2021       paper accepted ※ 28 July 2021       issue date ※ 13 August 2021
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MOPAB096	Rocking Curve Imaging Experiment at SSRL 10-2 Beamline	357
	A. Halavanau, R. Arthur, B. Johnson, J.P. MacArthur, G. Marcus, R.A. Margraf, Z. Qu, T. Rabedeau, T. Sato, C.J. Takacs, D. Zhu SLAC, Menlo Park, California, USA
	Stanford Synchrotron Radiation Lightsource (SSRL) serves a wide scientific community with its variety of X-ray capabilities. Recently, we have employed a wiggler source located at beamline 10-2 to perform high resolution rocking curve imaging (RCI) of diamond and silicon crystals. In-house X-ray RCI capability is important for the upcoming cavity-based x-ray source development projects at SLAC, such as cavity-based XFEL (CBXFEL) and X-ray laser oscillator (XLO). In this proceeding, we describe theoretical considerations, and provide experimental results, validating the design of our apparatus. We also provide a plan for future improvements of the RCI@SSRL program.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB096
About •	paper received ※ 19 May 2021       paper accepted ※ 27 July 2021       issue date ※ 10 August 2021
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MOPAB097	Two Color Grating design for Soft X-Ray Self-Seeding at LCLS-II	361
	A. Halavanau, D. Cocco, E. Hemsing, G. Marcus, D.S. Morton SLAC, Menlo Park, California, USA G.R. Wilcox Cornell University, Ithaca, New York, USA
	A new grating design is examined for the soft x-ray self-seeding system (SXRSS) at LCLS-II to ultimately produce stable two-color XFEL pulses. The grating performance is analyzed with Fourier optics methods. The final XFEL performance is assessed via full numerical XFEL simulations that substantiate the feasibility of the proposed design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB097
About •	paper received ※ 19 May 2021       paper accepted ※ 27 July 2021       issue date ※ 21 August 2021
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MOPAB098	LCLS Multi-Bunch Improvement Plan	365
	A. Halavanau, S. Carbajo, F.-J. Decker, A.K. Krasnykh, A.A. Lutman, A. Marinelli, C.E. Mayes, D.C. Nguyen SLAC, Menlo Park, California, USA
	Current and future experiments at LCLS require XFEL pulse trains of variable time separation. The cavity based XFEL (CBXFEL) project requires multiple pulses separated by 220 ns, the X-ray Laser Oscillator (XLO) uses 15 ns spaced pulse trains and Matter under Extreme Conditions (MEC) experiments need a shortly spaced (less than 5 ns) pulse trains. In this proceeding, we discuss the LCLS multi-bunch improvement plan and report on its recently status and progress.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB098
About •	paper received ※ 19 May 2021       paper accepted ※ 27 July 2021       issue date ※ 20 August 2021
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MOPAB099	Intensity Fluctuations Reduction in the Double-Bunch FEL at LCLS	369
	G. Zhou, A. Halavanaupresenter, C. Pellegrini SLAC, Menlo Park, California, USA
	In this paper we explore the possibility of reducing the intensity fluctuations of a hard X-ray double-bunch free-electron laser (DBFEL) by using an ultra-short, high peak current electron bunch to generate the seed signal, as studied recently for soft X-ray single bunch self-seeding. The ultra-short, nearly single-spike, SASE pulse is amplified to saturation, where a four-crystal monochromator selects a narrow bandwidth seed for the second bunch. Start-to-end simulation results for 7 keV photon energy are presented here for a DBFEL already studied for LCLS using the HXR undulator. We show that using this enhanced DBFEL (EDBFEL) system; the seed signal intensity fluctuations can be reduced from 85% to about 30%, and the second bunch intensity fluctuation at saturation to about 15%.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB099
About •	paper received ※ 24 May 2021       paper accepted ※ 16 July 2021       issue date ※ 31 August 2021
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MOPAB100	Progress Report on Population Inversion-Based X-Ray Laser Oscillator	373
	A. Halavanau, R. Alonso-Mori, A. Aquila, U. Bergmann, D. DePonte, F.-J. Decker, F. Fuller, M. Liang, A.A. Lutman, C. Pellegrini SLAC, Menlo Park, California, USA M. Doyle UCB, Berkeley, USA
	The population inversion X-ray Laser Oscillator (XLO) is a fully coherent, transform limited hard X-ray source. It operates by repetitively pumping inner-shell atomic transitions with an XFEL, in a closed Bragg cavity. XLO will produce very bright monochromatic X-ray pulses for applications in quantum optics, X-ray interferometry and metrology. We report the progress to build the first XLO operating at the copper alpha line, using LCLS 9 keV SASE X-ray pulses as a pump.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB100
About •	paper received ※ 20 May 2021       paper accepted ※ 29 July 2021       issue date ※ 02 September 2021
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MOPAB101	Hollow and Flat Electron Beam Generation at FACET-II	376
	A. Halavanau, S.J. Gessner, C.E. Mayes SLAC, Menlo Park, California, USA J.B. Rosenzweig UCLA, Los Angeles, California, USA
	In this proceeding, we investigate hollow and flat electron beam generation at FACET-II facility. We focus on the case of a circular beamlet arrangement, also known as ’necklace’ beams. We study, via numerical simulations, the resulting e-beam dynamics in the FACET-II photoinjector, beam propagation through the high energy section, as well as possible experimental applications of the ’necklace’ beams. Finally, we evaluate the feasibility of high charge flat beam generation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB101
About •	paper received ※ 23 May 2021       paper accepted ※ 27 July 2021       issue date ※ 23 August 2021
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MOPAB102	CSR Impedance in HEPS Storage Ring	379
	H.S. Xu, X.Y. Li, N. Wang IHEP, Beijing, People’s Republic of China
	High Energy Photon Source (HEPS) is under construction in Beijing, China. The relatively complete impedance model has been built up based on the element-by-element impedance calculation. However, Coherent Synchrotron Radiation (CSR) impedance, which might affect the longitudinal performance of the beam, was not included in the impedance model of the HEPS storage ring in the preliminary design stage. For completeness, we would like to take the CSR impedance into consideration. The most important contributions to the total CSR impedance come from the bending magnets and insertion devices. We therefore calculate the CSR impedance from both above mentioned elements in HEPS storage ring. The influence of the CSR impedance on the microwave instability threshold is studied and presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB102
About •	paper received ※ 17 May 2021       paper accepted ※ 18 June 2021       issue date ※ 27 August 2021
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MOPAB103	Study of Transverse Oscillation Coupling and Possibility of Its Minimization in SKIF (Novosibirsk)	383
	D. Leshenok BINP, Novosibirsk, Russia G.N. Baranov, E.B. Levichev, S.A. Nikitin BINP SB RAS, Novosibirsk, Russia
	The vertical emittance and, in general, the vertical beam size and angular divergence are of paramount importance in the SKIF (Russian acronym for Siberian Circular Photon Source) project developed in Novosibirsk. Therefore, a detailed simulation of the corresponding influence of possible errors in the storage ring was carried out with cross-validation by different methods. Variants of cross-coupling correction are proposed and modeled to obtain a vertical emittance of the order of one picometer simultaneously with minimizing vertical dispersion.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB103
About •	paper received ※ 18 May 2021       paper accepted ※ 17 August 2021       issue date ※ 19 August 2021
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MOPAB106	Enhancing the MOGA Optimization Process at ALS-U with Machine Learning	387
	Y. Lu, M.P. Ehrlichman, T. Hellert, S.C. Leemann, H. Nishimura, C. Sun, M. Venturini LBNL, Berkeley, California, USA
	Funding: This research is funded by the US Department of Energy(BES & ASCR Programs), and supported by the Director of the Office of Science of the US Department of Energy under Contract No. DEAC02-05CH11231. The bare lattice optimization for the linear and nonlinear ALS-U storage ring lattice, even without reverse bending, comprises 11 degrees of freedom (DoF) and is therefore a very complex and highly time-consuming process. This design process relies heavily on multi-objective genetic algorithms (MOGA), usually requiring many months of experienced scientists’ time. The main problem lies in having to evaluate numbers of candidate lattices due to the stochastic process of MOGA. Although almost all of these candidates are eventually rejected, they nevertheless require extensive particle tracking to arrive at a Pareto front. We therefore propose a novel Machine Learning (ML) pipeline that nonlinear tracking is replaced by two well-trained neural networks (NNs) to predict dynamic aperture (DA) and momentum aperture (MA) for any lattice candidate. Initial training of these models takes only several minutes on conventional CPUs while predictions are then rendered near instantaneously. We present this novel method and demonstrate the resulting orders of magnitude speedup of the ML-enhanced MOGA process on a 2-DoF problem as well as first results on a more complex 11-DoF problem.
	Poster MOPAB106 [0.918 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB106
About •	paper received ※ 19 May 2021       paper accepted ※ 01 June 2021       issue date ※ 18 August 2021
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MOPAB107	RF Plans for the Diamond-II Upgrade	391
	C. Christou, P. Gu, P.J. Marten, S.A. Pande, A.F. Rankin DLS, Oxfordshire, United Kingdom
	The RF system for the proposed Diamond-II upgrade will be based on normal-conducting EU HOM-damped cavities powered by high powered solid state amplifiers and controlled by digital low level RF systems built on the microTCA platform. Reasons for these design choices are discussed, and experience of the selected technologies in the Diamond-I ring are reviewed. The storage ring will also include a third harmonic cavity, and the different design options for this device are discussed. RF design of the booster ring is presented, and details are given of an upgraded linac and gun design intended to improve the charge delivered for top-up.
	Poster MOPAB107 [1.703 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB107
About •	paper received ※ 18 May 2021       paper accepted ※ 20 May 2021       issue date ※ 12 August 2021
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MOPAB108	ESRF-EBS 352.37 MHz Radio Frequency System	395
	J. Jacob, P.B. Borowiec, A. D’Elia, G. Gautier, V. Serrière ESRF, Grenoble, France
	The ESRF 352 MHz Radio Frequency (RF) system has been upgraded and tailored to the new 4th Generation Extremely Brilliant Source EBS, that was installed in 2019 and commissioned in 2020. The five former five-cell cavities were replaced with 13 single cell strongly HOM damped cavities that were developed in house, 10 of which are powered from existing 1 MW klystron transmitters. The remaining three cavities are individually fed by three 150 kW solid state amplifiers. All this required a reconstruction in record time of an elaborate WR2300 waveguide network. The low level RF system as well as the cavity and transmitter control system have been rebuilt. The RF design, commissioning and operation experience will be reported, including plans for a 4th harmonic RF system for bunch lengthening to further improve the performance of the new EBS ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB108
About •	paper received ※ 19 May 2021       paper accepted ※ 27 May 2021       issue date ※ 02 September 2021
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MOPAB109	A Lattice for PETRA IV Based on the Combination of Different Arc Cell Designs	399
	J. Keil, I.V. Agapov, R. Brinkmann DESY, Hamburg, Germany
	The 6 GeV synchrotron light source PETRA III at DESY is in user operation since 2009. In 2016 investigations of upgrading PETRA III into a diffraction limited storage ring at 10 keV have been started. The ambitious goal is to achieve an emittance in the range of 10-30 pm*rad. For the conceptual design report (CDR) of PETRA IV a lattice based on hybrid multi-bend achromats (HMBA) has been chosen. It consists of eight arcs connected by eight long straight sections whereas each arc consists of eight HMBA cells. While this lattice variant has an advantage in terms of simplicity of magnet and girder design it is challenging in regards of multipole strengths and beam dynamic properties. However, only a part of all eight arcs will be used for undulator beamlines. This offers the possibility to choose a more relaxed optics design in the arcs without undulators while preserving the ultra-low emittance. In addition, the use of reverse bends in the undulator cells allows smaller beta functions at the undulators for an increased brilliance. The design and the beam dynamic properties of this combi lattice are discussed in this paper and compared to the lattice based on HMBA cells.
	Poster MOPAB109 [1.338 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB109
About •	paper received ※ 18 May 2021       paper accepted ※ 28 May 2021       issue date ※ 30 August 2021
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MOPAB110	An Electron Synchrotron Lattice Based on Theoretic Minimal Emittance Cell	403
	H.C. Chao DESY, Hamburg, Germany
	A design of an electron synchrotron featuring the theoretic minimal emittance (TME) cells is presented. It has 32 superperiods and the circumference is around 300 m. It offers versatile functions with the equilibrium emittance less than 10 nm-rad at 6 GeV. The beam energy can go up to 7 GeV. Locations with proper phase advances are found to form effective vertical orbit bumps, which can be used for the injections and extraction. A tune scan study shows the sweet spot for the working point. Some discussions of other usages and studies of synchro-betatron coupling effects are also included in this article.
	Poster MOPAB110 [0.777 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB110
About •	paper received ※ 11 May 2021       paper accepted ※ 28 May 2021       issue date ※ 30 August 2021
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MOPAB112	A Modified Hybrid 6BA Lattice for the HALF Storage Ring	407
	Z.H. Bai, G.Y. Feng, T.L. He, W. Li, W.W. Li, G. Liu, Z.L. Ren, L. Wang, P.H. Yang, S.C. Zhang, T. Zhang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	In this paper, we propose a modified hybrid 6BA lattice as the baseline lattice of the Hefei Advanced Light Facility (HALF) storage ring. Similar to the Diamond-II lattice, the proposed lattice cell has one long straight section and one mid-straight section; but the two bend units adjacent to the mid-straight are LGB/RB units (LGB: longitudinal gradient bend, RB: reverse bend), which can give both lower emittance and shorter damping times. The designed HALF storage ring, with an energy of 2.2 GeV and 20 lattice cells, has a natural emittance of about 85 pm·rad.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB112
About •	paper received ※ 15 May 2021       paper accepted ※ 20 May 2021       issue date ※ 01 September 2021
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MOPAB113	A Low-emittance Booster Lattice Design for the SOLEIL Upgrade	410
	M.-A. Tordeux, A. Loulergue, R. Nagaoka SOLEIL, Gif-sur-Yvette, France Z.H. Baipresenter, G. Liu, T. Zhang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	The SOLEIL storage ring upgrade will require an injected beam with small transverse and longitudinal sizes. To meet this requirement, the present booster also needs to be upgraded, aiming to reduce the emittance below 10 nm·rad. A multi-bend achromat lattice is designed in this context for the booster upgrade, which consists of two superperiods to respect the present race-track configuration. The lattice is a 16BA HOA (Higher-Order Achromat) type lattice, composed of 14 unit cells, 2 matching cells and a long straight section, and combined-function bending magnets are used in the unit cells to both save space and reduce the emittance. The natural emittance of the designed booster is 5.2 nm·rad at the final energy of 2.75 GeV. This paper presents the general constraints, linear lattice design and nonlinear dynamics optimization for the booster upgrade.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB113
About •	paper received ※ 19 May 2021       paper accepted ※ 28 May 2021       issue date ※ 26 August 2021
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MOPAB114	Development of a Decoherence Kicker for the ALS Upgrade Project (ALS-U)	414
	C. Sun, S. De Santis, M.P. Ehrlichman, T. Hellert, T. Oliver, G. Penn, C. Steier, M. Venturini, W.L. Waldron LBNL, Berkeley, California, USA
	The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is upgrading the existing storage-ring lattice to a nine-bend-achromat lattice with on-axis swap-out injection. The upgraded storage ring will provide a highly focused beam of about 10 um in both horizontal and vertical directions with a single bunch train energy of about 60 J at 2.0 GeV. Such a small and intense beam could cause damage to the transfer line vacuum chambers in case of extraction element failures or damage to the storage ring vacuum chamber in case of RF failures. To mitigate these potential damages, a fast kicker magnet (so-called decoherence kicker) will be installed in the ALS-U storage ring and activated to dilute the beam charge density either on a train to be swapped out a few 100s turns before extraction or on the whole beam after RF failures. In this paper, we will present both physics and engineering designs of this decoherence kicker.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB114
About •	paper received ※ 19 May 2021       paper accepted ※ 27 May 2021       issue date ※ 20 August 2021
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MOPAB115	ATS/STA Transfer Line Design for the ALS Upgrade Project (ALS-U)	417
	C. Sun, M.P. Ehrlichman, T. Hellert, M. Juchno, J.-Y. Jung, M. Mardenfeld, J.R. Osborn, G. Penn, C. Steier, C.A. Swenson, M. Venturini LBNL, Berkeley, California, USA
	At the Advanced Light Source Upgrade (ALS-U), an on-axis swap-out injection will be used to replenish depleted bunches in the storage ring with refreshed bunches from the full energy accumulator ring. To implement this scheme, two transfer lines are required between the storage ring and the accumulator ring: the accumulator-to-storage-ring (ATS) transfer line and the storage-ring-to-accumulator (STA) transfer line. The design of the ATS/STA transfer lines is a challenging task as they must fit within a tight injection region while also accommodating the storage and accumulator rings at different elevations. Moreover, the ATS/STA design needs to meet both the boundary conditions and optics requirements. In this paper, we will present a design option for these ATS/STA transfer lines.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB115
About •	paper received ※ 19 May 2021       paper accepted ※ 27 May 2021       issue date ※ 15 August 2021
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MOPAB116	A Flexible Injection Scheme for the ESRF-EBS	421
	S.M. White, N. Carmignani, L.R. Carver, M. Dubrulle, L. Hoummi, S.M. Liuzzo, M. Morati, T.P. Perron ESRF, Grenoble, France
	The ESRF-EBS storage ring light source started commissioning in 2019 and successfully resumed users operation in 2020. Due to the smaller emittance and consequently reduced lifetime frequent injections are required that can potentially disturb beam lines experiments. In addition, operating the machine with low beta straight section and reduced insertion devices (ID) gaps are considered, therefore reducing the vertical aperture of the machine. Alternatives to the standard off-axis injection scheme allowing for efficient injection in reduced apertures with minimized perturbations are explored. A flexible layout for potential integration in the ESRF-EBS lattice is proposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB116
About •	paper received ※ 11 May 2021       paper accepted ※ 27 May 2021       issue date ※ 24 August 2021
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MOPAB117	Single Bunch Collective Effects in the EBS Storage Ring	425
	L.R. Carver, E. Buratin, N. Carmignani, F. Ewald, L. Hoummi, S.M. Liuzzo, T.P. Perron, B. Roche, S.M. Whitepresenter ESRF, Grenoble, France
	The ESRF storage ring (SR) has been dismantled and replaced by the Extremely Brilliant Source (EBS) which has now been commissioned. Beam based measurements have been performed to characterise the impedance of the new machine and to make a first comparison with predictions. The results from instability threshold scans and tune shift measurements will be presented, as well as bunch length and position variation with current and microwave threshold measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB117
About •	paper received ※ 11 May 2021       paper accepted ※ 31 May 2021       issue date ※ 25 August 2021
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MOPAB118	The Impact of Short-Range Wakes on Injection Into the ALS-U Accumulator Ring	429
	G. Penn, M.P. Ehrlichman, T. Hellert, C. Steier, C. Sun, M. Venturini, D. Wang LBNL, Berkeley, California, USA
	Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DEAC02-05CH11231. As part of the ALS-U design, bunches with small charge will be added to the accumulator ring in a manner that initially leaves both the stored and injected bunches displaced from the nominal orbit. While the beam current is below instability thresholds, transient effects due to the combination of short-range wake fields and large initial displacements can have an impact on injection efficiency. In this paper, the impact of wake fields on the two bunches is detailed using the elegant simulation code, and different techniques to optimize the injection efficiency are explored.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB118
About •	paper received ※ 19 May 2021       paper accepted ※ 31 May 2021       issue date ※ 12 August 2021
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MOPAB119	Comparisons Between AT and Elegant Tracking	432
	G. Penn, T. Hellert, M. Venturini LBNL, Berkeley, California, USA
	Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DEAC02-05CH11231. The simulation codes Elegant* and Accelerator Toolbox (AT)** are both in common use for the study of particle accelerators and light sources. They use different software platforms and have different capabilities, so there is a strong motivation to be able to switch from one version to another to achieve different goals. In addition, it is useful to directly compare results for benchmarking studies. We discuss differences in tracking methods and results for various elements, and explore the impact on simulations performed with lattices designed for the ALS-U. In addition to single-particle tracking, global properties such as chromaticity, dynamics aperture, momentum aperture and beam lifetime are also investigated. We have also developed scripts to translate AT lattices into elegant lattice files to facilitate comparisons. * M. Borland, Advanced Photon Source LS-287, September 2000. ** A. Terebilo, Particle Accelerators Conference 2001, p. 3203.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB119
About •	paper received ※ 20 May 2021       paper accepted ※ 31 May 2021       issue date ※ 30 August 2021
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MOPAB120	Update on Injector for the New Synchrotron Light Source in Thailand	435
	T. Chanwattana, S. Chunjarean, N. Juntong, K. Kittimanapun, S. Klinkhieo, P. Sudmuang SLRI, Nakhon Ratchasima, Thailand K. Manasatitpong Synchrotron Light Research Institute (SLRI), Muang District, Thailand
	Design of the new 3-GeV synchrotron light source in Thailand, Siam Photon Source II (SPS-II), has been updated. The SPS-II accelerator complex consists of a 150-MeV injector linac, a 3-GeV booster synchrotron and a 3-GeV storage ring. The RF system of both storage ring and booster is based on a frequency of 119 MHz. In this paper, design considerations and specifications of the SPS-II injector linac are presented. A study on the injector linac in multi-bunch mode (MBM) and single-bunch mode (SBM) was done to get appropriate parameters for top-up injection and different filling patterns in the storage ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB120
About •	paper received ※ 18 May 2021       paper accepted ※ 20 May 2021       issue date ※ 24 August 2021
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MOPAB121	Progress Towards Soft X-Ray Beam Position Monitor Development	438
	B. Podobedov, C. Eng, S. Hulbert, C. Mazzoli BNL, Upton, New York, USA D. Donetski, K. Kucharczyk, J. Liupresenter, R. Lutchman Stony Brook University, Stony Brook, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. X-ray beam position monitors (BPMs) are instrumental for storage ring light sources, where they reliably provide positional measurements of high-power beams in hard X-ray beamlines. However, despite a growing need, coming especially from coherent soft X-ray beamlines, non-invasive soft X-ray BPMs have not been demonstrated yet. We are presently working on a funded R&D proposal to develop a non-invasive soft X-ray BPM with micron-scale resolution for high-power white beams. In our approach, multi-pixel GaAs detector arrays are placed into the beam halo and beam position is inferred from the pixel photocurrent levels. Presently, the first detector array prototypes have been manufactured and are being prepared for low-power beam tests. The mechanical design of a BPM test-stand, which will be installed in the 23-ID canted soft X-ray undulator beamline at NSLS-II, is well under way. In addition, we are developing new algorithms of beam position calculation which take full advantage of extended multi-pixel detector arrays. In this paper we will review our design choices and discuss recent progress.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB121
About •	paper received ※ 03 June 2021       paper accepted ※ 13 July 2021       issue date ※ 28 August 2021
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MOPAB122	Present Status of HiSOR	442
	M. Katoh UVSOR, Okazaki, Japan K. Goto, M. Katoh, M. Shimada HSRC, Higashi-Hiroshima, Japan H. Miyauchi KEK, Ibaraki, Japan
	HiSOR is a compact synchrotron light source of 700MeV. The circumference is 22m. The ring has two straight sections for undulators, which provide high brilliance VUV radiation. Two 180 bending magnets have 2.7 T field strength, which provide broadband radiation in VUV and soft X-ray range. The injector is a 150 MeV microtron. The beam injection is made twice a day with a 5 hour interval. Although the accelerators are being operated stably, the large emittance of 400nm makes it difficult to compete with high brilliance light sources of new generations. The compactness of the configuration makes it difficult to introduce new technologies. We have started seeking possible upgrades.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB122
About •	paper received ※ 18 May 2021       paper accepted ※ 20 May 2021       issue date ※ 30 August 2021
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MOPAB123	Radiation Safety Considerations For The APS Upgrade Injector	445
	K.C. Harkay, J.R. Calvey, S. Chitra, G.I. Fystro, M.J. Henry, E.E. Heyeck, B.J. Micklich, K.P. Wootton ANL, Lemont, Illinois, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The Advanced Photon Source Upgrade (APS-U) is a high-performance fourth-generation storage ring light source based on multibend achromat optics. As such, APS-U will require on-axis injection. The injectors will need to supply full-current bunch replacement in the ring; therefore, the injected bunch charge will be up to five times higher than what is typical for APS. A program was conducted to measure the radiation dose above the injector transport line to the APS storage ring for both normal operation conditions and controlled loss scenarios. Standard survey meters were used to record the dose. A review of the dose data identified opportunities to minimize the potential dose under normal APS-U high charge operation and fault conditions; these include improving the supplemental shielding and adding engineered controls. In addition, the dose data provide a benchmark for evaluating new radiation monitors for APS-U.
	Poster MOPAB123 [1.317 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB123
About •	paper received ※ 18 May 2021       paper accepted ※ 24 May 2021       issue date ※ 12 August 2021
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MOPAB124	APS Booster Injection Horizontal Trajectory Control Upgrade	449
	C. Yao, J.R. Calvey, G.I. Fystro, A.F. Pietryla, H. Shangpresenter ANL, Lemont, Illinois, USA
	Funding: * Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-ACO2-O6CH11357. The APS booster is a 7-GeV electron synchrotron with a 0.5-second cycle. The booster runs a set of injection control programs that correct the beam trajectory in the horizontal and longitudinal planes, and the betatron tunes. Recently we developed a single-turn BPM controllaw program for horizontal trajectory control to replace the previous FFT based horizontal controllaw program. We present the system configuration and results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB124
About •	paper received ※ 15 May 2021       paper accepted ※ 27 May 2021       issue date ※ 21 August 2021
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MOPAB126	BESSY III & MLS II - Status of the Development of the New Photon Science Facility in Berlin	451
	P. Goslawski, M. Abo-Bakr, F. Andreas, M. Arlandoo, J. Bengtsson, V. Dürr, K. Holldack, J.-G. Hwang, A. Jankowiak, B.C. Kuske, J. Li, A.N. Matveenko, T. Mertens, A. Meseck, E.C.M. Rial, M. Ries, M.K. Sauerborn, A. Schälicke, M. Scheer, P. Schnizer, L. Shi, J. Viefhaus HZB, Berlin, Germany J. Lüning UPMC, Paris, France
	HZB operates and develops two synchrotron radiation sources at Berlin Adlershof. The larger one, BESSY II with an energy of 1.7 GeV and 240 m circumference is optimized for soft-X rays and in operation since 1999. The smaller one is the MLS (Metrology Light Source), owned by the Physikalische Technische Bundesanstalt (PTB) - Germany’s National Metrology Institute. It is designed to fulfill the special metrology needs of the PTB with an energy of 0.6 GeV and 48 m circumference, covering the spectral range from THz and IR to EUV/VUV. In 2020 a discussion process has been started to define the requirements for successors of BESSY II and MLS and to study the possibilities integrate them into a new photon science facility in Berlin Adlershof. Here, we give a status report and present a first envisaged parameter space to both machines (see also MOPAB262, MOPAB220, MOPAB048, MOPAB242).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB126
About •	paper received ※ 18 May 2021       paper accepted ※ 24 June 2021       issue date ※ 18 August 2021
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MOPAB127	Construction of an Impedance Model for Diamond-II	455
	R.T. Fielder, T. Olsson DLS, Oxfordshire, United Kingdom
	Impedance models for accelerators have traditionally been presented in a static form, usually as tables or spreadsheets which must be read manually. As part of the Diamond-II upgrade work, we have developed an impedance model using a lattice structure. This allows more direct integration with simulation codes while keeping important information easily human readable. We present here a description of this implementation method, along with an overview of the Diamond-II impedance model derived from the latest engineering design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB127
About •	paper received ※ 18 May 2021       paper accepted ※ 20 May 2021       issue date ※ 11 August 2021
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MOPAB128	Operational Use of Pinger Magnets to Counter Stored Beam Oscillations During Injection at Diamond Light Source	459
	R.T. Fielder, M. Apollonio, I.P.S. Martin DLS, Oxfordshire, United Kingdom
	Diamond uses a four kicker bump injection scheme. Due to a variety of factors it has become more difficult to perfectly match the four kicks while maintaining injection efficiency, resulting in some disturbance to the stored beam during top-up. This has consequences for beamlines which may see degraded beam quality during injections. A gating signal is provided, but this is not appropriate for all experiments, and in any case ideally would not be required. The disturbance to the stored beam can be partly controlled using the existing diagnostic pinger magnets installed in the storage ring. We present here a comparison of different compensation schemes and tests with beamlines, along with initial experiences operating during user beam time. Use of these magnet also provides proof of principle for any future, purpose-built compensation kickers.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB128
About •	paper received ※ 18 May 2021       paper accepted ※ 20 May 2021       issue date ※ 01 September 2021
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MOPAB131	Synchrotron SOLEIL Upgrade Project	463
	A. Nadji SOLEIL, Gif-sur-Yvette, France
	To remain competitive in the future, SOLEIL is also working on an upgrade project plan based on Multi-Bend Achromat (MBA) lattices. The Technical Design Report of the project is expected to start in early 2021 immediately after the completion of the Conceptual Design Report (CDR) phase. The achieved equilibrium emittance in the CDR reference lattice (80 pm-rad) is about 50 times smaller than that of the existing storage ring (4000 pm-rad). By operating on a linear coupling resonance, round beam sizes in Insertion Devices straight sections of less than 10 microns RMS in both planes can be produced. These performances rely on the use of a 10 mm inner diameter circular copper vacuum chamber with NEG-coating allowing reaching strong quadrupole gradients and very strong sextupole and octupole strengths. As all these technical challenges are pushing the engineering technology to the limits, they are being investigated through an intensive R&D program based on extensive numerical simulations, prototyping, and measurement with the beam. Extensive use of the pure permanent magnet technology beyond what has been done so far in the other similar projects is considered in this project.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB131
About •	paper received ※ 22 May 2021       paper accepted ※ 27 July 2021       issue date ※ 30 August 2021
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MOPAB132	The Multi-Mega-Watt Target Station for the European Spallation Source Neutrino Super Beam	466
	E. Baussan, E. Bouquerel, L. D’Alessi, M. Dracos, P. Poussot, J. Thomas, J. Wurtz, V. Zeter IPHC, Strasbourg Cedex 2, France P. Cupial, M. Koziol, L.J. Lacny, J. Snamina AGH University of Science and Technology, Kraków, Poland I. Efthymiopoulos CERN, Meyrin, Switzerland T. Tolba University of Hamburg, Hamburg, Germany
	Funding: This project has received funding from the European Union Horizon 2020 research and innovation program under grant agreement No 777419 and also by the Deutsche Forschungsgemeinschaft No 423761110. One of the next challenges in fundamental physics is to understand the origin of matter/antimatter asymmetry in the Universe. In particular, intense neutrinos could play an important role to elucidate this mystery and better understand the expansion of the Universe. The ESSnuSB collaboration proposes to use the proton linac of the European Spallation Source currently under construction in Lund (Sweden) to produce a very intense neutrino super beam, in parallel with the spallation neutron production. A very challenging part of the proposed facility is the Target Station which will have to afford 5 MW proton beam power. This poster will present the hadronic collector and the whole facility to produce the next generation of neutrino superbeam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB132
About •	paper received ※ 20 May 2021       paper accepted ※ 27 May 2021       issue date ※ 18 August 2021
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MOPAB133	Recovering the Positron Beam After Muon Production in the Lemma Muon Source	470
	I. Drebot INFN-Milano, Milano, Italy M.E. Biagini, O.R. Blanco-García, A. Giribono, S. Guiducci, C. Vaccarezza, A. Variola INFN/LNF, Frascati, Italy S.M. Liuzzo ESRF, Grenoble, France
	In the LEMMA muon source proposal* a positron beam at 45 GeV is used to produce muons at threshold by interaction with some targets. In order to release the required intensity on the main positron source, orders of magnitude higher than the state of the art, the possibility to recover the primary positron beam after the interaction with the targets was studied. The particles distribution, with a strongly degraded energy spread after the interac- tion, was injected back into a low emittance, large energy acceptance 45 GeV ring. Studies of injection efficiency were performed. The possibility of compressing the beam in a linac before injection was also studied. As a result, even without compression, about 80% of the disrupted e+ beam can be injected back into the ring. * D. Alesini et al, "Positron driven muon source for a muon collider", arXiv:1905.05747v2 [physics.acc-ph], May 2019
	Poster MOPAB133 [4.171 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB133
About •	paper received ※ 17 May 2021       paper accepted ※ 24 May 2021       issue date ※ 20 August 2021
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MOPAB134	Normalized Transverse Emittance Reduction via Ionization Cooling in MICE ’Flip Mode’	474
	P.B. Jurj Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	Low emittance muon beams are central to the development of a Muon Collider and can significantly enhance the performance of a Neutrino Factory. The international Muon Ionization Cooling Experiment (MICE) has recorded several million individual muon tracks passing through a liquid hydrogen or a lithium hydride absorber and has demonstrated the ionization cooling of muon beams. Previous analysis used a restricted data set, and the beam matching was not perfect. In this analysis, beam sampling routines were employed to account for imperfections in beam matching at the entrance into the cooling channel and enable an improvement of the cooling measurement. A study of the normalized transverse emittance change in the MICE cooling channel set up in a flipped polarity magnetic field configuration is presented. Additionally, the evolution of the canonical angular momentum across the absorber is shown and the characteristics of the cooling effect are discussed.
	Poster MOPAB134 [1.821 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB134
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 27 August 2021
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MOPAB137	Interaction Region Design for DWA Experiments at FACET-II	478
	O. Williams, G. Andonian, A. Fukasawa, W.J. Lynn, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, Y. Sakai, M. Yadav, Y. Zhuang UCLA, Los Angeles, California, USA C.I. Clarke, M.J. Hogan, B.D. O’Shea, D.W. Storey, V. Yakimenko SLAC, Menlo Park, California, USA M. Ruelas RadiaBeam, Santa Monica, California, USA M. Yadav The University of Liverpool, Liverpool, United Kingdom
	Funding: DOE HEP Grant DE-SC0009914 The extremely intense beam generated at FACET-II provides the unique opportunity to investigate the effects of beam-driven GV/m fields in dielectrics exceeding meter-long interaction lengths. The diverse range of phenomena to be explored, such as material response in the terahertz regime, suppression of high-field pulse damping effects, advanced geometry structures, and methods for beam break up (BBU) mitigation, all within a single UHV vacuum vessel, requires flexibility and precision in the experimental layout. We present here details of the experimental design for the dielectric program at FACET-II. Specifically, consideration is given to the alignment of the dielectric structures due to the extreme fields associated with the electron beam, as well as implementation of electron beam and Cherenkov radiation-based diagnostics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB137
About •	paper received ※ 19 May 2021       paper accepted ※ 17 August 2021       issue date ※ 29 August 2021
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MOPAB138	Dielectric Wakefield Acceleration with a Laser Injected Witness Beam	481
	G. Andonian, T.J. Campese RadiaBeam, Santa Monica, California, USA N.M. Cook RadiaSoft LLC, Boulder, Colorado, USA D.S. Doran, G. Ha, J.G. Power, J.H. Shao, E.E. Wisniewski ANL, Lemont, Illinois, USA W.J. Lynn, N. Majernik, J.B. Rosenzweig, V.S. Yu UCLA, Los Angeles, California, USA
	Funding: Work supported by DOE grant DE-SC0017690 The plasma photocathode concept, whereby a two-species gas mixture is used to generate a beam -driven accelerating wakefield and a laser-ionized generation of a witness beam, was recently experimentally demonstrated. In a variation of this concept, a beam-driven dielectric wakefield accelerator is employed, filled with a neutral gas for laser-ionization and creation of a witness beam. The dielectric wakefields, in the terahertz regime, provide comparatively modest timing requirements for the injection phase of the witness beam. In this paper, we provide an update on the progress of the experimental realization of the hybrid dielectric wakefield accelerator with laser injected witness beam at the Argonne Wakefield Accelerator (AWA), including engineering considerations for gas delivery, and preliminary simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB138
About •	paper received ※ 19 May 2021       paper accepted ※ 17 June 2021       issue date ※ 31 August 2021
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MOPAB139	High Resolution Imaging Design Using Permanent Magnet Quadrupoles at BNL UEM	485
	G. Andonian, T.J. Campese, I.I. Gadjev, M. Ruelas RadiaBeam, Marina del Rey, California, USA M.G. Fedurin, K. Kusche, X. Yang, Y. Zhu BNL, Upton, New York, USA C.C. Hall RadiaSoft LLC, Boulder, Colorado, USA
	Ultrafast electron microscopy techniques have demonstrated the potential to reach very high combined spatio-temporal resolution. In order to achieve high resolution, strong focusing magnets must be used as the objective and projector lenses. In this paper, we discuss the design and development of a high-resolution objective lens for use in the BNL UEM. The objective lens is a quintuplet array of permanent magnet quadrupoles, which in sum, provide symmetric focusing, high magnification, and control of higher order aberration terms. The application and design for a proof-of-concept experiment using a calibrated slit for imaging are presented. The image resolution is monitored as a function of beam parameters (energy, energy spread, charge, bunch length, spot size), and quintuplet lens parameters (drifts between lenses).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB139
About •	paper received ※ 26 May 2021       paper accepted ※ 28 May 2021       issue date ※ 18 August 2021
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MOPAB140	Gas Sheet Ionization Diagnostic for High Intensity Electron Beams	489
	N.P. Norvell, G. Andonian, T.J. Campese, A.-L.M.S. Lamure, M. Ruelas, A.Yu. Smirnov RadiaBeam, Santa Monica, California, USA N.M. Cook RadiaSoft LLC, Boulder, Colorado, USA J.K. Penney UCLA, Los Angeles, California, USA C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: Work supported by DOE grant DE-SC0019717 The characterization of high intensity charged particle beams in a minimally interceptive, and non-destructive manner is performed using an ionization diagnostic. In this application, a neutral gas is tailored into a thin sheet, or curtain-like, distribution at the interaction point with an electron beam. The electron beam ionizes the neutral gas in localized space, leaving a footprint of the beam transverse distribution. The ion cloud is subseqeuntly imaged with a series of electrostatic lenses to a detector plane. The resultant image is used in a reconstruction algorithm to reconstruct the beam profile at the interaction point. In this paper, we present progress on the development of this diagnostic for the characterization of high charge, 10GeV electron beams with small transverse distributions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB140
About •	paper received ※ 20 May 2021       paper accepted ※ 10 June 2021       issue date ※ 01 September 2021
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MOPAB141	Terahertz Driven Compression and Time-Stamping Technique for Single-Shot Ultrafast Electron Diffraction	492
	M.A.K. Othman, A.E. Gabriel, M.C. Hoffmann, F. Ji, E.A. Nanni, X. Shen, E.J.C. Snively, X.J. Wang SLAC, Menlo Park, California, USA
	Funding: This research has been supported by the U.S. Department of Energy (DOE) under Contract No. DE-AC02-76SF00515 and DE-AC02-05-CH11231. Ultrafast structural dynamics are well understood through pump-probe characterization using ultrafast electron diffraction (UED). Advancements in electron diffraction and spectroscopy techniques open new frontiers for scientific discovery through interrogation of ultrafast phenomena, such as quantum phase transitions. Previously, we have demonstrated that strong-field THz radiation can be utilized to efficiently manipulate and compress ultrafast electron probes *, and also offer temporal diagnostics with sub-femtosecond resolution ** enabled by the inherent phase locking of THz radiation to the photoemission optical drive. In this work, we demonstrate a novel THz compression and time-stamping technique to probe solid-state materials at time scales previously inaccessible with standard UED. A high-frequency THz generation method using the organic OH-1 crystals is employed to enable a threefold reduction in the electron probes length and overall timing jitter. These time-stamped probes are used to demonstrate a substantial enhancement in the UED temporal resolution using pump-probe measurement in both photoexcited single crystal and polycrystalline samples. * E. C. Snively et al., Phys. Rev. Lett, vol. 124, no. 6, p. 054801, 2020. ** R. K. Li et al., Phys. Rev. Accel. Beams, vol. 22, no. 1, p. 012803, Jan. 2019.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB141
About •	paper received ※ 20 May 2021       paper accepted ※ 21 June 2021       issue date ※ 19 August 2021
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MOPAB142	A Compact, Low-Field, Broadband Matching Section for Externally-Powered X-Band Dielectric-Loaded Accelerating Structures	495
	Y. Wei, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom H. Bursali Sapienza University of Rome, Rome, Italy N. Catalán Lasheras, S. Gonzalez Anton, A. Grudiev, R. Wegner, Y. Wei CERN, Meyrin, Switzerland B.T. Freemire, C.-J. Jing Euclid TechLabs, Solon, Ohio, USA J. Sauza-Bedolla Lancaster University, Lancaster, United Kingdom Y. Wei, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	It has been technically challenging to efficiently couple external radiofrequency (RF) power to cylindrical dielectric-loaded accelerating (DLA) structures. This is especially true when the DLA structure has a high dielectric constant. This contribution presents a novel design of a matching section for coupling the RF power from a circular waveguide to an X-band DLA structure with a dielectric constant εr=16.66 and a loss tangent \tanθ = 3.43× 10-5. It consists of a very compact dielectric disk with a width of 2.035 mm and a tilt angle of 60 degrees, resulting in a broadband coupling at a low RF field which has the potential to survive in the high-power environment. To prevent a sharp dielectric corner break, a 45-degree chamfer is added. Moreover, a microscale vacuum gap, caused by metallic clamping between the thin coating and the outer thick copper jacket, is studied in detail. Based on simulation studies, a prototype of the DLA structure with the matching sections was fabricated. Results from preliminary bench measurements and their comparison with design values will also be discussed.
	Poster MOPAB142 [2.617 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB142
About •	paper received ※ 11 May 2021       paper accepted ※ 21 May 2021       issue date ※ 19 August 2021
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MOPAB143	Simulations for MeV Energy Gain in Multi-Micron Vacuum Channel Dielectric Structures Driven by a CO₂ Laser	499
	G. Yadav, O. Apsimon, Y. Wei, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom O. Apsimon, C.P. Welsch, G.X. Xia Cockcroft Institute, Warrington, Cheshire, United Kingdom G.X. Xia The University of Manchester, Manchester, United Kingdom
	Funding: This work was supported by STFC LIV. DAT under grant agreement ST/P006752/1. This research used the resources of the Supercomputing Laboratory at KAUST in Thuwal, Saudi Arabia. Dielectric Laser Accelerators (DLAs) have been demonstrated as a novel scheme for producing high acceleration gradients (~1 GV/m) within the damage threshold of the dielectric. The compactness of the DLAs and the low emittance of the output electron beam make it an attractive candidate for future endoscopic devices to be used in tumor irradiation. However, due to the small accelerating distances(sub-mm), the total energy gain is limited to sub-MeV which remains an obstacle for its realistic applications. Also, these DLAs operate under solid-state lasers with wavelengths near IR (800 nm to 2 um), where required sub-micron vacuum channel at such wavelengths imposes major aperture restrictions for the amount of charge to be accelerated. Here, we present numerical simulation results for a dielectric structure excited by a CO2 laser with a wavelength of 10.6 um. Upon injecting a 50 MeV electron bunch through a 5.3 um diameter of vacuum channel width, our simulation suggests an energy gain beyond 1 MeV. These results are the initial steps for the realization of an mm-scale DLA capable of producing MeV energy electron beams.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB143
About •	paper received ※ 18 May 2021       paper accepted ※ 02 June 2021       issue date ※ 11 August 2021
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MOPAB144	Investigation of Optimization of Dielectric Terahertz Acceleration Structures	502
	A.E. Gabriel, E.A. Nanni SLAC, Menlo Park, California, USA
	Funding: This work was supported by the Department of Energy Contract No. DE-AC02-76SF00515 (SLAC) and by NSF Grant No. PHY-1734015. THz-frequency accelerating structures could provide the accelerating gradients needed for next generation particle accelerators with compact, GV/m-scale devices. Current THz accelerators are limited by significant losses during transport of THz radiation from the generating nonlinear crystal to the electron acceleration structure. In addition, the spectral properties of high-field THz sources make it difficult to couple THz radiation into accelerating structures. Dielectric accelerator structures reduce these losses because THz radiation can be coupled laterally into the structure, as opposed to metallic structures where THz radiation must be coupled along the beam path. In order to utilize these advantages, we are investigating the optimization of THz accelerating structures for comparison between metallic and dielectric devices. These results will help to inform future designs of improved dielectric THz acceleration structures.
	Poster MOPAB144 [6.524 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB144
About •	paper received ※ 20 May 2021       paper accepted ※ 27 May 2021       issue date ※ 22 August 2021
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MOPAB145	Acceleration and Focusing of Positron Bunch by Electron Bunch Wakefield in the Dielectric Waveguide Filled with Plasma	505
	G.V. Sotnikov, R.R. Kniaziev, P.I. Markov NSC/KIPT, Kharkov, Ukraine
	Funding: The National Research Foundation of Ukraine, program "Leading and Young Scientists Research Support" (project # 2020.02/0299) The results of the numerical PIC-simulation of accelerated positron bunch focusing in the plasma dielectric wakefield accelerator unit, filled with radially inhomogeneous plasma that has vacuum channel inside are presented. The Wakefield was created by drive electron bunch in quartz dielectric tube with external and internal diameters of 1.2 mm and 1.0 mm, respectively. The tube was embedded in cylindrical metal waveguide. The internal area of dielectric tube has been filled with different transverse density profiles of plasma: homogeneous density and inhomogeneous density created in capillary discharge. Drive bunch electrons energy was 5 GeV, drive bunch charge was 3 nC. The test positron bunch had the same parameters as the drive bunch except for the charge of 0.05 nC. Results of numerical PIC simulation have shown the possibility of simultaneous acceleration and focusing of test positron bunch in the wakefield excited by drive electron bunch. The dependence of transport and acceleration of positron bunch on size of vacuum channel is studied.
	Poster MOPAB145 [2.003 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB145
About •	paper received ※ 19 May 2021       paper accepted ※ 20 May 2021       issue date ※ 25 August 2021
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MOPAB146	Status of the C-Band Engineering Research Facility (CERF-NM) Test Stand Development at LANL	509
	D. Gorelov Private Address, Los Alamos, USA R.L. Fleming, S.K. Lawrence, J.W. Lewellen, D. Perez, M.E. Schneider, E.I. Simakov, T. Tajima LANL, Los Alamos, New Mexico, USA M.E. Middendorf ANL, Lemont, Illinois, USA
	Funding: LDRD-DR Project 20200057DR C-Band structures research is of increasing interest to the accelerator community. The RF frequency range of 4-6 GHz gives the opportunity to achieve significant increase in the accelerating gradient, and having the wakefields at the manageable levels, while keeping the geometric dimensions of the structure technologically convenient. Strong team of scientists, including theorists researching properties of metals under stressful thermal conditions and high electromagnetic fields, metallurgists working with copper as well as alloys of interest, and accelerator scientists developing new structure designs, is formed at LANL to develop a CERF-NM facility. A 50 MW, 5.712 GHz Canon klystron, was purchased in 2019, and laid the basis for this facility. As of Jan-21, the construction of the Test Stand has been finished and the high gradient processing of the waveguide components has been started. Future plans include high gradient testing of various accelerating structures, including benchmark C-band accelerating cavity, a proton ß=0.5 cavity, and cavities made from different alloys. An upgrade to the facility is planned to allow for testing accelerator cavities at cryogenic temperatures.
	Poster MOPAB146 [3.778 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB146
About •	paper received ※ 17 May 2021       paper accepted ※ 26 May 2021       issue date ※ 19 August 2021
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MOPAB147	Efficient, High Power Terahertz Radiation Outcoupling From a Beam Driven Dielectric Wakefield Accelerator	513
	M. Yadav, G. Andonian, C.E. Hansel, W.J. Lynn, N. Majernik, B. Naranjo, J.B. Rosenzweig, O. Williams UCLA, Los Angeles, California, USA G. Andonian RadiaBeam, Santa Monica, California, USA C.P. Welsch The University of Liverpool, Liverpool, United Kingdom C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by DE-SC0009914 (UCLA) and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. Wakefields in dielectric structures are a useful tool for beam diagnostics and manipulation with applications including acceleration, shaping, chirping, and THz radiation generation. It is possible to use the produced THz radiation to diagnose the fields produced during the DWA interaction but, to do so, it is necessary to effectively out-couple this radiation to free space for transport to diagnostics such as a bolometer or interferometer. To this end, simulations have been conducted using CST Studio for a 10 GeV beam with FACET-II parameters in a slab-symmetric, dielectric waveguide. Various termination geometries were studied including flat cuts, metal horns, and the "Vlasov antenna". Simulations indicate that the Vlasov antenna geometry is optimal and detailed studies were conducted on a variety of dielectrics including quartz, diamond, and silicon. Multiple modes were excited and coherent Cherenkov radiation (CCR) was computationally generated for both symmetric and asymmetric beams. Finally, we include witness beams to study transport and acceleration dynamics as well as the achievable field gradients.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB147
About •	paper received ※ 24 May 2021       paper accepted ※ 29 August 2021       issue date ※ 28 August 2021
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MOPAB148	Liénard-Wiechert Numerical Radiation Modeling for Plasma Acceleration Experiments at FACET-II	517
	M. Yadav, G. Andonian, C.E. Hansel, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, O. Williams, Y. Zhuang UCLA, Los Angeles, California, USA G. Andonian RadiaBeam, Marina del Rey, California, USA O. Apsimon, A. Perera, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom O. Apsimon, A. Perera, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by DE-SC0009914 (UCLA) and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. Future plasma acceleration experiments at FACET-II will measure betatron radiation in order to provide single-shot non-destructive beam diagnostics. We discuss three models for betatron radiation: a new idealized particle tracking code with Liénard-Wiechert radiation, a Quasi-Static Particle-in-Cell (PIC) code with Liénard-Wiechert radiation, and a full PIC code with radiation computed via a Monte-Carlo QED Method. Predictions of the three models for the E-310 experiment are presented and compared. Finally, we discuss beam parameter reconstruction from the double differential radiation spectrum.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB148
About •	paper received ※ 24 May 2021       paper accepted ※ 01 June 2021       issue date ※ 17 August 2021
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MOPAB149	Ion Motion in Flat Beam Plasma Accelerators	521
	M. Yadav, C.E. Hansel, J.B. Rosenzweig UCLA, Los Angeles, California, USA O. Apsimon, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom O. Apsimon, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by UCLA and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. This work is done on SCARF Cluster. Intense beams, such as those in proposed plasma based linear colliders, can not only blow out electrons to form a bubble but can also attract ions towards the beam. This violates the assumption that the ions are stationary on the timescale of the beam, which is a common assumption for shorter and less intense beams. While some research has been done on understanding the physics of ion motion in blowout Plasma Wakefield Accelerators (PWFAs), this research has almost exclusively focused on cylindrically symmetric beams, rather than flat asymmetric emittance beams which are often used in linear colliders in order to minimize beamstrahlung at the final focus. This contribution investigates both analytically and computationally ion motion of a flat beam scenario in order to understand the basic physics as well as how to mitigate emittance growth, beam hosing and quadrupole.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB149
About •	paper received ※ 24 May 2021       paper accepted ※ 17 June 2021       issue date ※ 11 August 2021
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MOPAB150	Optimization of the Gain Medium Delivery System for an X-Ray Laser Oscillator	524
	M. Yadav, N. Majernik, P. Manwani, B. Naranjo, C. Pellegrini, J.B. Rosenzweig UCLA, Los Angeles, California, USA E.C. Galtier, A. Halavanau, C. Pellegrini SLAC, Menlo Park, California, USA A. Malinouski ASC HMTI, Minsk, Belarus
	Funding: This work was supported by DE-SC0009914. X-ray laser oscillator, dubbed XLO, is a recently proposed project at SLAC to build the first population inversion X-ray laser. XLO utilizes a train of XFEL SASE pulses to pump atomic core-states. The resulting amplified spontaneous emission radiation is recirculated in a backscattering Bragg cavity and subsequently amplified. XLO could provide fully coherent, transform-limited X-ray pulses with 50 meV bandwidth and 1e10 photons. Currently, XLO is being considered for operation at the copper K-alpha line at 8048 eV. In this work, we focus on the optimization of gain medium delivery in the XLO cavity. We consider a fast, subsonic jet of copper nitrate solution, moving through a cylindrical nozzle. We focus on the nozzle geometry optimization and possible diagnostics of the jet-XFEL interaction point.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB150
About •	paper received ※ 24 May 2021       paper accepted ※ 18 June 2021       issue date ※ 27 August 2021
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MOPAB151	A Stable Drive Beam for High Gradient Dielectric Wakefield Acceleration	528
	T.J. Overton, Y.M. Saveliev, G.X. Xia Cockcroft Institute, Warrington, Cheshire, United Kingdom T.J. Overton, G.X. Xia The University of Manchester, Manchester, United Kingdom T.H. Pacey, Y.M. Saveliev STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: Science and Technology Funding Council (STFC) student grant. A high accelerating gradient, with stable beam transport, is necessary for the next generation of particle accelerators. Dielectric wakefield accelerators are a potential solution to this problem. In these proceedings, we present simulation studies of electron bunches in the self-wake regime inside a planar dielectric structure. This is analogous to driving beams in a dielectric wakefield accelerator. The transverse and longitudinal wake fields are investigated for dielectric plate gaps, various transverse beam sizes, and longitudinal bunch profiles. The effects of these on the stability of drive bunches, and acceleration of a witness bunch, are discussed in the context of electron bunches that can be produced with conventional linac RF technology.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB151
About •	paper received ※ 13 May 2021       paper accepted ※ 07 June 2021       issue date ※ 24 August 2021
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MOPAB152	High Power Tests of Brazeless Accelerating Structures	532
	S.P. Antipov, P.V. Avrakhov, C.-J. Jing, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA V.A. Dolgashev SLAC, Menlo Park, California, USA D.S. Doran, W. Liu, J.G. Power, J.H. Shao, E.E. Wisniewski ANL, Lemont, Illinois, USA
	Funding: DOE SBIR Grant #DE-SC0017749 A typical accelerating structure is a set of copper resonators brazed together. This multi step process is expensive and time consuming. In an effort to optimize production process for rapid prototyping and overall reduction of accelerator cost we developed a split block brazeless accelerating structure. In such structure the vacuum is sealed by the use of knife edges, similar to an industry standard conflat technology. In this paper we present high power tests of several different brazeless structures. First, an inexpensive 1 MeV accelerator powered by radar magnetron. Second, a high gradient power extractor tested at Argonne Wakefield Accelerator Facility. In this experiment a high charge electron beam generated a 180 MW peak power pulse. Finally, we report on high power testing of a brazeless x-band accelerating structure at SLAC.
	Poster MOPAB152 [0.783 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB152
About •	paper received ※ 20 May 2021       paper accepted ※ 24 June 2021       issue date ※ 31 August 2021
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MOPAB153	Laser Microfabrication for Accelerator Applications	535
	S.P. Antipov, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA A.A. Vikharev IAP/RAS, Nizhny Novgorod, Russia
	Laser microfabrication allows high precision ablation of materials at sub-mm scale. When laser pulse length is shorter than about 10 picoseconds the heat affected zone is minimized and ablation occurs without melting. Work-pieces processed in this fashion exhibit less structural damage and are expected to have a higher damage thresholds. In this paper we will review several case studies of laser-microfabricated components for accelerator and x-ray applications. Ablated materials include diamond, quartz, tungsten, copper, YAG:Ce and silicon.
	Poster MOPAB153 [2.781 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB153
About •	paper received ※ 20 May 2021       paper accepted ※ 01 July 2021       issue date ※ 29 August 2021
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MOPAB154	Multi-Cell Accelerating Structure Driven by a Lens-Focused Picosecond THz Pulse	537
	S.P. Antipov, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA A.A. Vikharev IAP/RAS, Nizhny Novgorod, Russia
	Recently, gradients on the order of 1 GV/m level have been obtained in a form of a single cycle (~1 ps) THz pulses produced by conversion of a high peak power laser radiation in nonlinear crystals (~1 mJ, 1 ps, up to 3% conversion efficiency). Such high-intensity radiation can be utilized for charged particle acceleration. However, these pulses are short in time (~1ps) and broadband, therefore a new accelerating structure type is required. In this paper, we propose a novel structure based on focusing of THz radiation in accelerating cell and stacking such cells to achieve a long-range interaction required for an efficient acceleration process. We present an example in which a 100 microJoule THz pulse produces a 600 keV energy gain in 5 mm long 10 cell accelerating structure for an ultra-relativistic electron. This design can be readily extended to non-relativistic particles. Such structure had been laser microfabricated and appropriate dimensions were achieved.
	Poster MOPAB154 [1.283 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB154
About •	paper received ※ 27 May 2021       paper accepted ※ 05 July 2021       issue date ※ 14 August 2021
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MOPAB155	Magnetic Breakdowns in Side-Coupled X-Band Accelerating Structures	540
	S.P. Antipov, P.V. Avrakhov, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA V.A. Dolgashev SLAC, Menlo Park, California, USA C. Jing Euclid Beamlabs, Bolingbrook, USA
	Funding: DOE SBIR Side coupled accelerating structures are popular in the industrial realizations of linacs due to their high shunt impedance and ease of tuning. We designed and fabricated a side-coupled X-band accelerating structure that achieved 133 MOhm/m shut impedance. This structure was fabricated out of two halves using a novel brazeless approach. The two copper halves are joined together using a stainless steel joining piece with knife edges that bite into copper. This structure had been tested at high power at SLAC National Accelerator Laboratory. The performance of the structure had been limited by magnetic breakdowns on the side-coupling cells. In this paper we will present results of the high gradient tests and after-test analysis. Scanning electron microscopy images show a typical magnetic-field induced breakdown.
	Poster MOPAB155 [1.069 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB155
About •	paper received ※ 20 May 2021       paper accepted ※ 23 June 2021       issue date ※ 01 September 2021
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MOPAB156	Wakefields and Transverse Bunch Dynamics Studies of a Plasma-Dielectric Accelerating Structure	542
	K. Galaydych, I.N. Onishchenko, G.V. Sotnikov NSC/KIPT, Kharkov, Ukraine
	Funding: The National Research Foundation of Ukraine, programme "Leading and Young Scientists Research Support" (grant agreement n. 2020.02/0299). A theoretical investigation of a wakefield excitation in a plasma-dielectric accelerating structure by a drive electron bunch in the case of an off-axis bunch injection is carried out. The structure under investigation is a round dielectric-loaded metal waveguide with channel for the charged particles, filled with homogeneous cold plasma. In this paper we focus on the spatial distribution of the bunch-excited wakefield components, which act on both the drive and test bunches, and on transverse bunch dynamics. Dependence of the drive bunch propagation distance on its offset is studied.
	Poster MOPAB156 [2.042 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB156
About •	paper received ※ 19 May 2021       paper accepted ※ 18 June 2021       issue date ※ 14 August 2021
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MOPAB159	Matching of an RFQ and Multicusp Ion Source with Compact LEBT	546
	L.H. Waites, J.M. Conrad, J. Smolsky, D. Winklehner MIT, Cambridge, Massachusetts, USA
	Funding: NSF provided funding for RFQ-DIP project, Draper Laboratory provided fellowship for graduate studnets The IsoDAR project is a neutrino experiment that requires a high current H2+ beam at 60 MeV/amu, which will be produced by a cyclotron. A critical aspect of the design is the injection, which comprises an ion source, a compact low energy beam transport section (LEBT), and a radio-frequency quadrupole (RFQ) buncher embedded in the cyclotron yoke. The LEBT is optimized to match the desired input Twiss parameters of the RFQ. Here we report on the latest results from the ion source commissioning, and on the design and optimization of the LEBT with matching to the RFQ. With this ion source, we have demonstrated a 76% H2+ fraction at a current density of 11 mA/cm2 in DC mode. The design of the LEBT includes a chopper, steering elements, and focusing elements, to achieve the desired matching, which according to our simulations leads to ~95% transmission from the ion source to the exit of the RFQ.
	Poster MOPAB159 [0.851 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB159
About •	paper received ※ 15 May 2021       paper accepted ※ 24 June 2021       issue date ※ 13 August 2021
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MOPAB160	Tools for the Development and Applications of the IsoDAR Cyclotron	550
	L.H. Waites, J.R. Alonso, J.M. Conrad, D. Koser, D. Winklehner MIT, Cambridge, Massachusetts, USA
	Funding: NSF provided funding for the RFQDIP project, Draper laboratory provided a fellowship for the graduate student The IsoDAR cyclotron is a 60 MeV cyclotron designed to output 10mA of protons in order to be a driver for a neutrino experiment. However, this high power can be used in other useful and important applications outside of particle physics. The IsoDAR cyclotron accelerates H2+, which allows the beam to be highly versatile and important for the development of high-power targets. This could help alleviate a huge bottleneck in the medical isotope community. IsoDAR could also be used for the development of materials. The accelerator system uses many new tools, including novel methods of applying machine learning, as well as several of the uses of this new technology. With these applications and tools, the IsoDAR cyclotron can have an important impact on the accelerator, medical, and physics communities.
	Poster MOPAB160 [0.424 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB160
About •	paper received ※ 15 May 2021       paper accepted ※ 24 June 2021       issue date ※ 13 August 2021
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MOPAB162	The First Trial of XY-Coupled Beam Phase Space Matching for Three-Dimensional Spiral Injection	553
	M.A. Rehman, K. Furukawa, H. Hisamatsu, T. Mibe, H. Nakayama, S. Ohsawa, N. Saito, K. Sasaki KEK, Ibaraki, Japan H. Hirayama, H. Iinuma, K. Oda Ibaraki University, Ibaraki, Japan R. Matsushita The University of Tokyo, Graduate School of Science, Tokyo, Japan N. Saito J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Funding: Work supported by "Grant in Aid" for Scientific Research, JSPS (KAKENHI# 26287055, KAKENHI#19H00673) The most recent measurement of muon g-2 results in a 3.8σ discrepancy with the equally precise theoretical prediction. The J-PARC muon g-2/EDM experiment (E34) is in preparation to decipher this discrepancy and unravel the new physics beyond the standard model. The precision goal for g-2 is 0.1 ppm. To achieve this precision goal a novel 3-D spiral injection scheme has been devised to inject and store the beam into a small diameter MRI-type storage magnet for E34. The new injection scheme features smooth injection with high storage efficiency for the compact magnet. However, the spiral injection scheme is an unproven idea, therefore, a Spiral Injection Test Experiment (SITE) at KEK Tsukuba Campus is underway to establish this injection scheme. Due to the axial symmetric field of the solenoid magnet, a strongly XY-coupled beam is required. To produce the required phase space for the solenoid-type storage magnet, a beam transport line consisting of three rotatable quadrupole magnets has been designed and built for SITE. The vertical beam size reduction by means of phase space matching and other geometrical information has been successfully measured by the wire scanners.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB162
About •	paper received ※ 20 May 2021       paper accepted ※ 28 May 2021       issue date ※ 01 September 2021
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MOPAB163	First Synchronous Measurement of Single-Bunched Electron and Positron Beams with a Wideband Feedthrough-BPM at the Positron Capture Section of the SuperKEKB Injector Linac	557
	M.A. Rehman, F. Miyahara, T. Suwada KEK, Ibaraki, Japan
	The SuperKEKB is an asymmetric e−/e+ collider with 40 times higher luminosity than the KEKB project, to explore the new physics beyond the standard model. For the SuperKEKB, the positrons are created by striking the accelerated electrons at a tungsten target. The secondary electrons are also produced during the positron creation process and accelerated in the capture section. Because of phase slipping in the capture section, the secondary electron bunch is only  ∼ 180 ps away from the positron. Conventional stripline-type BPM cannot detect such closely spaced and opposite polarity signals due to slow frequency response and high cable losses. Therefore, a new wideband feedthrough-type beam position monitor was developed. It was successfully employed at the positron capture section of the SuperKEKB injector linac for the first synchronous measurement of the electron and positron beams. The cable losses effect also has been de-embedded to reveal correct signal properties. This paper describes the initial results of synchronous measurement of e−/e+ transverse position.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB163
About •	paper received ※ 20 May 2021       paper accepted ※ 27 May 2021       issue date ※ 16 August 2021
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MOPAB164	Miniature, High Strength Transport Line Design for Laser Plasma Accelerator-Driven FELs	561
	S. Fatehi, A. Bernhard, A.-S. Müller, M.S. Ning KIT, Karlsruhe, Germany
	Funding: This work is supported by the BMBF project 05K19VKA PlasmaFEL (Federal Ministry of Education and Research). Laser-plasma acceleration is an outstanding candidate to drive the next-generation compact light sources and FELs. To compensate large chromatic effects using novel compact beam optic elements in the beam transport line is required. We aim at designing miniature, high strength, normal conducting and superconducting transport line magnets and optics for capturing and matching LPA-generated electron bunches to given applications. Our primary application case is a demonstration experiment for transverse gradient undulator (TGU) FELs, to be performed at the JETI laser facility, Jena, Germany. In this contribution, we present the current design of the beam transport line magnets and the beam optics calculations. Laser Plasma Accelerators, FELs, Magnets, Beam Dynamics, Superconductivity, transverse gradient undulator
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB164
About •	paper received ※ 19 May 2021       paper accepted ※ 25 May 2021       issue date ※ 20 August 2021
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MOPAB165	Identical Focusing of Train of Relativistic Positron Gaussian Bunches in Plasma	565
	D.S. Bondar KhNU, Kharkov, Ukraine V.I. Maslov, I.N. Onishchenko NSC/KIPT, Kharkov, Ukraine
	Funding: The study is supported by the National Research Fundation of Ukraine under the program "Leading and Young Scientists Research Support" (project # 2020.02/0299). Focusing of both electron and positron bunches in an electron-positron collider is necessary. The focusing mechanism in the plasma, in which all electron bunches are focused identically, has been proposed earlier*. This mechanism is considered for positron bunches by using simulation with LCODE**. Three types of lenses with different trains of cosine profile positron bunches are considered depending on the bunch length, the distance between bunches, and their charge. It has been shown that all positron bunches are focused identically at special parameters of the first positron bunch, wherein the middle of bunches are focused weaker than their fronts. * V. I. Maslov et al. PAST. 3(2012) 159. ** K. V. Lotov, Phys. Plas. 5 (1998) 785.
	Poster MOPAB165 [2.272 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB165
About •	paper received ※ 17 May 2021       paper accepted ※ 20 May 2021       issue date ※ 17 August 2021
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MOPAB166	Wakefield Excitation by a Sequence of Laser Pulses in Plasma	568
	D.S. Bondar KhNU, Kharkov, Ukraine V.I. Maslov, I.N. Onishchenko NSC/KIPT, Kharkov, Ukraine
	Funding: The study is supported by the National Research Fundation of Ukraine under the program "Leading and Young Scientists Research Support" (project # 2020.02/0299). PIC simulation by means of 2.5D UMKA code * of the wakefield excitation by a sequence of three Gaussian laser pulses in plasma was carried out. The dependence of excited wakefield intensity on power and width of laser pulses was investigated. It was shown the coherent addition of wakefield, excited by each laser pulse of the sequence, for linear case, while for the nonlinear case the coherency was destroyed. The profiled sequence of laser pulses was also considered. The possibility to obtain the same total wakefield excited by the profiled sequence of laser pulses with decreasing intensity, as for the uniform sequence was studied. * G. I. Dudnikova et al. Comp. Techn. 10 (2005) 37.
	Poster MOPAB166 [2.638 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB166
About •	paper received ※ 17 May 2021       paper accepted ※ 20 May 2021       issue date ※ 15 August 2021
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MOPAB167	Wakefield Excitation in Plasma of Metallic Density by a Laser Pulse	571
	D.S. Bondar KhNU, Kharkov, Ukraine V.I. Maslov, I.N. Onishchenko NSC/KIPT, Kharkov, Ukraine
	Funding: The study is supported by the National Research Foundation of Ukraine under the program "Leading and Young Scientists Research Support" (project # 2020.02/0299). Recently the proposal to use X-ray Exawatt pulse for particle acceleration in a crystal has been declared *. Short X-ray high-power pulse excites wakefield in electron plasma of metallic density which can be used for high gradient acceleration of charged particles. This wakefield is suited for laser wakefield acceleration. In this paper there are simulated with PIC code UMKA: excitation of the large wakefield amplitude up to several TV/m in electron plasma of metallic density by a powerful X-ray laser pulse; laser-plasma wakefield acceleration of self-injected electron bunch in such setup; combined acceleration by plasma wakefield driven by a laser pulse (LPWA) and by self-injected electron bunch (PWFA). * T.Tajima. Eur. Phys. J. Special Topics 223 (2014) 1037.
	Poster MOPAB167 [2.054 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB167
About •	paper received ※ 17 May 2021       paper accepted ※ 21 May 2021       issue date ※ 22 August 2021
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MOPAB168	Nanoplasmonic Accelerators Towards Tens of TeraVolts per Meter Gradients Using Nanomaterials	574
	A.A. Sahai, M. Golkowski, V. Harid CU Denver, Denver, Colorado, USA C. Joshi UCLA, Los Angeles, California, USA T.C. Katsouleas Duke ECE, Durham, North Carolina, USA A. Latina, F. Zimmermann CERN, Geneva, Switzerland J. Resta-López Cockcroft Institute, Warrington, Cheshire, United Kingdom P. Taborek UCI, Irvine, California, USA A.G.R. Thomas University of Michigan, Ann Arbor, Michigan, USA
	Funding: University of Colorado Denver Ultra-high gradients which are critical for future advances in high-energy physics, have so far relied on plasma and dielectric accelerating structures. While bulk crystals were predicted to offer unparalleled TV/m gradients that are at least two orders of magnitude higher than gaseous plasmas, crystal-based acceleration has not been realized in practice. We have developed the concept of nanoplasmonic crunch-in surface modes which utilizes the tunability of collective oscillations in nanomaterials to open up unprecedented tens of TV/m gradients. Particle beams interacting with nanomaterials that have vacuum-like core regions, experience minimal disruptive effects such as filamentation and collisions, while the beam-driven crunch-in modes sustain tens of TV/m gradients. Moreover, as the effective apertures for transverse and longitudinal crunch-in wakes are different, the limitation of traditional scaling of structure wakefields to smaller dimensions is significantly relaxed. The SLAC FACET-II experiment of the nano2WA collaboration will utilize ultra-short, high-current electron beams to excite nonlinear plasmonic modes and demonstrate this possibility. * doi:10.1109/ACCESS.2021.3070798 ** doi:10.1142/S0217751X19430097 *** indico.fnal.gov/event/19478/contributions/52561 **** indico.cern.ch/event/867535/contributions/3716404
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB168
About •	paper received ※ 11 May 2021       paper accepted ※ 08 June 2021       issue date ※ 20 August 2021
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MOPAB169	Generating 510 MW of X-Band Power for Structure-Based Wakefield Acceleration Using a Metamaterial-Based Power Extractor	578
	J.F. Picard, I. Mastovsky, M.A. Shapiro, R.J. Temkin MIT/PSFC, Cambridge, Massachusetts, USA M.E. Conde, D.S. Doran, J.G. Power, J.H. Shao, E.E. Wisniewski ANL, Lemont, Illinois, USA C.-J. Jing Euclid TechLabs, Solon, Ohio, USA X. Lu Northern Illinois University, DeKalb, Illinois, USA
	Funding: Research sponsored under Award No. DE-SC0015566 by U.S. Department of Energy, Office of Science, Office of High Energy Physics and Contract No. DE-AC02-06CH11357 by the Office of Science. We present our recent results generating 510 MW of power at 11.7 GHz using a metamaterial-based metallic power-extractor for application in structure-based wakefield acceleration (SWFA). SWFA is a novel acceleration scheme in which high-charge electron bunches are passed through a power extractor structure to produce a high-intensity wakefield. This wakefield can then be used to accelerate a witness bunch in the same beamline or passed to a separate acceleration beamline. MIT’s approach uses a specialized metamaterial for the power extractor design. By using a metamaterial, we can overcome some of the challenges faced by other SWFA techniques. Here, we discuss the Stage 3 experiment. The Stage 1 and Stage 2 experiments successfully demonstrated the functionality of the metamaterial approach by generating high power RF pulses using the 65 MeV electron beam at the Argonne Wakefield Accelerator (AWA) facility. The 510 MW result from Stage 3 experiment is the highest power generated to-date for SWFA at AWA, and was enable by significant design improvements, including an all-copper structure, fully-symmetric coupler design, and breakdown risk-reduction treatment.
	Poster MOPAB169 [8.882 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB169
About •	paper received ※ 08 May 2021       paper accepted ※ 16 July 2021       issue date ※ 25 August 2021
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MOPAB171	Numerical Simulation on Plasma-Based Beam Dumps Using Smilei	582
	S. Kumar, C. Davut, G.X. Xiapresenter UMAN, Manchester, United Kingdom A. Bonatto, C. Davut, L. Liang The University of Manchester, Manchester, United Kingdom A. Bonatto Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil B.S. Nunes IF-UFRGS, Porto Alegre, Brazil R.P. Nunes UFRGS, Porto Alegre, Brazil
	The active plasma beam dump utilizes a laser to generate a plasma wakefield and decelerate an externally injected beam to low energy. We use the particle-in-cell code "Smi-lei" for the investigation of electron beam energy loss in plasma. In this research work, we optimize the laser and plasma parameters to investigate the active plasma beam dump scheme. In doing so, most of the beam energy will be deposited in the plasma. The optimization strategy for the beam energy loss in plasma is presented. *A. Bonatto, C. B. Schroeder et al., Physics of Plasmas 22 (8) 083106 (2015). *G. Xia, A. Bonatto et al., Instruments 4 (2) 10 (2020). *A Bonatto et al., J. Phys.: Conf. Ser. 1596 012058, 2020.
	Poster MOPAB171 [0.756 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB171
About •	paper received ※ 15 May 2021       paper accepted ※ 24 May 2021       issue date ※ 26 August 2021
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MOPAB173	Physics Program and Experimental for AWAKE Run 2	586
	P. Muggli MPI, Muenchen, Germany
	Run 1 experimental results demonstrate many characteristics of the self-modulation (SM) in plasma of a long, 400GeV SPS proton bunch*. Externally injected, 19MeV electrons were accelerated to 2GeV**. Based on these results, we are assembling a physics and experiment program aiming at producing a multi-GeV electron bunch with emittance and energy spread sufficiently low for possible early applications to high-energy physics experiments. Plans include two plasmas, the first for SM, the second for acceleration, and of scalable length, separated by an injection region. The first plasma includes a density step to maintain large-amplitude wakefields after saturation of the SM process. Seeding of the SM process may be obtained from an electron bunch. The 150MeV witness electron bunch from an S-band gun, X-band linac has parameters that produce plasma electron blow out and loading of the wakefields in order to minimize final energy spread and emittance***. We are studying the possibility of using a helicon plasma source for the accelerator, a source that can in principle be very long (100s of m). *AWAKE, PRL 122, 054802 (2019), Turner, PRL 122, 054801 (2019), Turner, PRAB 23, 081302, (2020), Braunmueller PRL 125, 264801 (2020) **AWAKE, Nature 561, 363 (2018) ***Olsen, PRAB 21, 011301 (2018)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB173
About •	paper received ※ 18 May 2021       paper accepted ※ 28 May 2021       issue date ※ 02 September 2021
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MOPAB174	Foil Hits Reduction by Minimizing Injection Beam Size at the Foil in J-PARC RCS	590
	P.K. Saha, H. Harada, K. Okabe, F. Tamura, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan H. Hotchi KEK, Tokai, Ibaraki, Japan
	Funding: Pranab Kumar Saha The uncontrolled beam loss caused by the foil scattering of the circulating beam during multi-turn charge-exchange injection is one of the main sources for high residual radiation at the injection area of J-PARC 3-GeV rapid cycling synchrotron. We studied to reduce foil hits of the circulating beam by minimizing the vertical injection beam size at the foil and using a smaller vertical foil size. The vertical foil size was reduced according to the injection beam size by maintaining the stripping efficiency. As a result, the number of circulating beam passing through foil was significantly reduced due to smaller foil size. The simulation and measurement results of the foil hits reduction are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB174
About •	paper received ※ 20 May 2021       paper accepted ※ 31 May 2021       issue date ※ 28 August 2021
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MOPAB175	Advanced Concepts and Technologies for Heavy Ion Synchrotrons	594
	P.J. Spiller, O. Boine-Frankenheim, L.H.J. Bozyk, S. Klammes, H. Kollmus, D. Ondreka, I. Pongrac, N. Pyka, C. Roux, K. Sugita, St. Wilfert, T. Winkler, D.F.A. Winters GSI, Darmstadt, Germany
	New concepts and technologies are developed to advance the performance of heavy ion synchrotrons. Besides fast ramping of superconducting magnets, extreme UHV technologies to stabilize dynamic vacuum and charge related loss, broad band MA cavities, space charge compensation by means of electron lenses and new cooling technologies, e.g. laser cooling, show great promise to advance the forefront of beam parameters. Several of these technologies and concepts are developed and tested at GSI/FAIR. Progress and plans will be reported.
	Poster MOPAB175 [1.367 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB175
About •	paper received ※ 11 May 2021       paper accepted ※ 21 May 2021       issue date ※ 20 August 2021
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MOPAB177	ELENA Commissioning and Status	598
	C. Carli, M.E. Angoletta, W. Bartmann, L. Bojtár, F. Butin, B. Dupuy, Y. Dutheil, M.A. Fraser, P. Freyermuth, D. Gamba, L.V. Jørgensen, B. Lefort, O. Marqversen, M. McLean, S. Ogur, S. Pasinelli, L. Ponce, G. Tranquille CERN, Geneva, Switzerland
	The Extra Low ENergy Antiproton ring ELENA is a small synchrotron recently constructed and commissioned to decelerate antiprotons injected from the Antiproton Decelerator AD with a kinetic energy of 5.3 MeV down to 100 keV. Controlled deceleration in the synchrotron, equipped with an electron cooler to reduce losses and generate dense bunches, allows the experiments, typically capturing the antiprotons in traps and manipulating them further, to improve the trapping efficiency by one to two orders of magnitude. During 2018, bunches with an energy of 100 keV with parameters close to nominal have been demonstrated, and first beams have been provided to an experiment in a new experimental zone. The magnetic transfer lines from the AD to the experiments have been replaced by electrostatic lines from ELENA. Commissioning of the new transfer lines and, in parallel, studies to better understand the ring with H− beams from a dedicated source, have started in autumn 2020. The first 100 keV antiproton physics run using ELENA will start in late summer 2021.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB177
About •	paper received ※ 18 May 2021       paper accepted ※ 14 June 2021       issue date ※ 23 August 2021
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MOPAB178	Systematic Effects Limiting the Sensitivity of "Magic Energy" Proton EDM Rings	602
	C. Carli, M. Haj Tahar CERN, Geneva, Switzerland
	Proposals to measure a possible Electric Dipole Moment (EDM) of protons in an electro-static storage ring are studied by a world-wide community. The machine is operated at the so-called "magic energy" to satisfy the "frozen spin" condition such that, without imperfections and with the well known magnetic moment of the particle, the spin is always oriented parallel to the direction of movement. The effect of a finite EDM is a build-up of a vertical spin component. Any effect, other than a finite EDM, leading as well to a build-up of a vertical spin limits the sensitivity of the experiment. Such "systematic effects" are caused by machine imperfections, such as magnetic fields inside the magnetic shield surrounding the ring, and misalignments of electro-static elements or of the RF cavity. Operation of the machine with counter-rotating beams helps mitigating some of the effects. The most dangerous effects are those, which cannot be disentangled from an EDM by combining measurements from both counter-rotating beams, such as an average residual radial magnetic field penetrating the magnetic shield or a combination of magnetic fields and misalignments of electric elements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB178
About •	paper received ※ 18 May 2021       paper accepted ※ 17 June 2021       issue date ※ 20 August 2021
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MOPAB179	Simulations of AGS Boosters Imperfection Resonances for Protons and Helions	606
	K. Hock, H. Huang, F. Méot, N. Tsoupas BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. As part of the effort to increase the polarization of the proton beam for the physics experiments at RHIC, a scan of orbit harmonic corrector strengths is performed in the Booster to ensure polarization transmission through the |G gamma|=3 and 4 imperfection resonances is optimized. These harmonic scans have been simulated using quadrupole alignment data and accurately match experimental data. The method used to simulate polarized protons is extended to polarized helions for crossing the |G gamma|=5 through |G gamma|=10 imperfection resonances and used to determine the corrector strength required to cross each resonance.
	Poster MOPAB179 [0.437 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB179
About •	paper received ※ 17 May 2021       paper accepted ※ 31 May 2021       issue date ※ 02 September 2021
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MOPAB180	AGS Dynamic Aperture at Injection of Polarized Protons and Helions	610
	K. Hock, H. Huang, F. Méot, N. Tsoupas BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Polarized helions are part of the physics program for the future EIC. An AC dipole has been installed in the AGS Booster to preserve polarization as helions are accelerated to |Ggamma|=10.5. Extraction from the AGS Booster at |Ggamma|=7.5 is possible but: would involve crossing an intrinsic resonance in the AGS, and would be the lowest rigidity beam injected into the AGS, and therefore experiences strong distortions of the optical functions because of the AGS two partial snakes. This lower rigidity would exacerbate the optical distortions from the snake, reducing the dynamic aperture. A comparison of the dynamic aperture of protons at Ggamma=4.5 to that of helions at |Ggamma|=7.5 and |Ggamma|=10.5 show that extraction at |Ggamma|=10.5 provides a larger dynamic aperture. This larger aperture would allow helions to be placed inside the spin tune gap generated by the two partial helices in AGS earlier in the cycle.
	Poster MOPAB180 [0.453 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB180
About •	paper received ※ 17 May 2021       paper accepted ※ 31 May 2021       issue date ※ 20 August 2021
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MOPAB181	Non-Delivery Time Reduction at MedAustron	613
	L. Adler, S. Danzinger, F. Farinon, F. Feichtinger, G. Guidoboni, N. Kahn, C. Kurfürst, D.A. Prokopovich, A. Wastlpresenter EBG MedAustron, Wr. Neustadt, Austria L.C. Penescu Abstract Landscapes, Montpellier, France
	Funding: Funding by the NÖ WIRTSCHAFTS- UND TOURISMUSFONDS under grant number WST3-F-5033232/001-2020. MedAustron is a cancer treatment center in Austria providing proton and carbon ion beams to three clinical and one non-clinical research beam lines. The slow extraction of particles from the synchrotron follows a third order resonance extraction scheme. Currently, for every change of extraction energy a new spill needs to be generated. Besides the beam-on time of the particle delivery, every spill is also comprised of non-delivery time components e.g. the multiturn injection, acceleration or magnet conditioning. For small tumor target volumes, this non-delivery time is the major contribution to the overall treatment time. A dedicated performance improvement project (supported with a grant from the state of lower Austria) was executed with the goal to reduce these non-delivery times without affecting important clinical beam parameters such as the beam size or penetration depth. The implemented reduction of the non-delivery time >50% could be achieved, resulting in beam-on time reductions for reference treatment plans between 25% (largest proton PTV) and 58% (smallest carbon PTV). Results of commissioning efforts, technical details and the achieved optimizations will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB181
About •	paper received ※ 14 May 2021       paper accepted ※ 28 May 2021       issue date ※ 25 August 2021
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MOPAB182	Automated Synchrotron Lattice Design and Optimisation Using a Multi-Objective Genetic Algorithm	616
	X. Zhang, S.L. Sheehy The University of Melbourne, Melbourne, Victoria, Australia E. Benedetto TERA, Novara, Italy E. Benedetto CERN, Meyrin, Switzerland
	Funding: This work is partially supported by the Australian Government Research Training Program Scholarship. As part of the Next Ion Medical Machine Study (NIMMS), we present a new method for designing synchrotron lattices. A step-wise approach was used to generate random lattice structures from a set of feedforward neural networks. These lattice designs are optimised by evolving the networks over many iterations with a multi-objective genetic algorithm (MOGA). The final set of solutions represent the most effi- cient and feasible lattices which satisfy the design constraints. It is up to the lattice designer to choose a design that best suits the intended application. The automated algorithm presented here randomly samples from all possible lattice layouts and reaches the global optimum over many iterations. The requirements of an efficient extraction scheme in hadron therapy synchrotrons impose stringent constraints on the lat- tice optical functions. Using this algorithm allows us to find the global optimum that is tailored to these constraints and to fully utilise the flexibilities provided by new technology.
	Poster MOPAB182 [6.006 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB182
About •	paper received ※ 15 May 2021       paper accepted ※ 23 June 2021       issue date ※ 14 August 2021
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MOPAB183	A Framework for Dynamic Aperture Studies for Colliding Beams in the High-Luminosity Large Hadron Collider	620
	S. Kostoglou, H. Bartosik, Y. Papaphilippou, G. Sterbini CERN, Geneva, Switzerland
	During the last physics run of the Large Hadron Collider (LHC), Dynamic Aperture (DA) studies have been successfully employed to optimize the accelerator’s performance by guiding the selection of the beam and machine parameters. In this paper, we present a framework for single-particle tracking simulations aiming to refine the envisaged operational scenario of the future LHC upgrade, the High-Luminosity LHC (HL-LHC), including strong non-linear fields such as beam-beam interactions. The impact of several parameters and beam processes during the cycle is initially illustrated with frequency maps and then quantified with DA studies.
	Poster MOPAB183 [2.789 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB183
About •	paper received ※ 17 May 2021       paper accepted ※ 06 July 2021       issue date ※ 23 August 2021
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MOPAB184	Unsupervised Learning Techniques for Tune Cleaning Measurement	624
	H. Garcia Morales Oxford University, Physics Department, Oxford, Oxon, United Kingdom E. Fol, R. Tomás García CERN, Meyrin, Switzerland
	Precise measurements of tune and its stability are crucial for various optics analyses in the LHC, e.g. for the determination of the beta star using K-modulation. LHC BBQ system provides tune measurements online and stores the tune data. We apply unsupervised machine learning techniques on BBQ tune data in order to provide an automatic outlier detection method for better measurements of tune shifts and unexpected tune jitters.
	Poster MOPAB184 [0.354 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB184
About •	paper received ※ 14 May 2021       paper accepted ※ 09 June 2021       issue date ※ 11 August 2021
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MOPAB185	HL-LHC Local Linear Optics Correction at the Interaction Regions	628
	H. Garcia Morales Oxford University, Physics Department, Oxford, Oxon, United Kingdom J.F. Cardona UNAL, Bogota D.C, Colombia R. Tomás García CERN, Geneva, Switzerland
	Magnetic imperfections of the HL-LHC inner triplet are expected to generate a significant \beta-beating. For that reason, improved local optics correction techniques at the low-\beta insertions is essential to ensure a high luminosity performance in the HL-LHC. In this study, we compare different strategies for local optics correction at the Interaction Regions with respect to their final performance in terms of residual \beta-beating. Supervised learning techniques are also explored to predict the inner triplet magnetic error contributions.
	Poster MOPAB185 [0.469 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB185
About •	paper received ※ 14 May 2021       paper accepted ※ 10 June 2021       issue date ※ 31 August 2021
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MOPAB186	Comparison of Segment-by-Segment and Action-Phase-Jump Techniques in the Calculation of IR Local Corrections in LHC	632
	H. Garcia Morales Oxford University, Physics Department, Oxford, Oxon, United Kingdom J.F. Cardona UNAL, Bogota D.C, Colombia R. Tomás García CERN, Geneva, Switzerland
	The correction of the local optics at the Interaction Regions of the LHC is crucial to ensure a good performance of the machine. In this paper, we compare two different techniques for local optics correction: Action-Phase Jump and Segment-by-Segment techniques. The comparison is made in view of future machine configurations such as Run 3 LHC optics and HL-LHC optics.
	Poster MOPAB186 [0.349 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB186
About •	paper received ※ 14 May 2021       paper accepted ※ 09 June 2021       issue date ※ 30 August 2021
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MOPAB187	Design and Calculation of the RF System of DC140 Cyclotron	636
	A.S. Zabanov, V.B. Zarubin JINR/FLNR, Moscow region, Russia J. Franko, G.G. Gulbekyan, I.V. Kalagin, N.Yu. Kazarinov, S.V. Mitrofanov, V.A. Sokolov, K. Verlamov JINR, Dubna, Moscow Region, Russia
	Flerov Laboratory of Nuclear Reaction of Joint Institute for Nuclear Research carries out the works under creating of FLNR JINR Irradiation Facility based on the cyclotron DC140. The facility is intended for SEE testing of microchip, for production of track membranes and for solving of applied physics problems. The main systems of DC140 are based on the DC72 cyclotron ones that now are under reconstruction. The DC140 cyclotron is intended for acceleration of heavy ions with mass-to-charge ratio A/Z within interval from 5 to 5.5 up to two fixed energies 2.124 and 4.8 MeV per unit mass. The intensity of the accelerated ions will be about 1 pmcA for light ions (A<86) and about 0.1 pmcA for heavier ions (A>132). The designed RF-system of the DC-72 cyclotron with a half-wave cavity is not suitable due to the big vertical size. For this reason, a new quarter-wave RF-system was developed for the DC140 cyclotron project. The results of calculating the parameters of the new RF-system are given in this work.
	Poster MOPAB187 [0.488 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB187
About •	paper received ※ 17 May 2021       paper accepted ※ 24 May 2021       issue date ※ 15 August 2021
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MOPAB189	Beam Commissioning of XiPAF Synchrotron	639
	H.J. Yao, X. Guan, Y. Li, X.Y. Liupresenter, M.W. Wang, X.W. Wang, Y. Yang, W.B. Ye, H.J. Zeng, S.X. Zheng TUB, Beijing, People’s Republic of China W.L. Liu, D. Wang, Z.M. Wang NINT, Shannxi, People’s Republic of China
	XiPAF (Xi’an 200MeV Proton Application Facility) is a project to fulfill the need for the experimental simulation of the space radiation environment. It comprises a 7 MeV H− linac, a 60-230 MeV proton synchrotron, and experimental stations. The Installation of the synchrotron, beamline and one experimental station were completed at the end of December 2019, and commissioning has just begun. Circulating beam around the synchrotron was observed on the first day of operation, and now 10-200 MeV proton beam directly extracted from the synchrotron had been transported to the experimental station for user experiments. The results of the commissioning and data analysis are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB189
About •	paper received ※ 18 May 2021       paper accepted ※ 21 May 2021       issue date ※ 17 August 2021
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MOPAB190	An 8 GeV Linac as the Booster Replacement in the Fermilab Power Upgrade	643
	D.V. Neuffer, S.A. Belomestnykh, M. Checchin, D.E. Johnson, S. Posen, E. Pozdeyev, V.S. Pronskikh, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. Increasing the Main Injector (MI) beam power above ~1.2 MW requires replacement of the 8 GeV Booster by a higher intensity alternative. Previously, rapid-cycling synchrotron (RCS) and Linac solutions were considered for this purpose. In this paper, we consider the Linac version that produces 8 GeV H− beam for injection into the Recycler Ring (RR) or Main Injector (MI). The Linac takes ~1 GeV beam from the PIP-II Linac and accelerates it to ~2 GeV in a cw SRF linac, followed by a ~2-8 GeV pulsed linac using 1300 MHz cryomodules. The linac components incorporate recent improvements in SRF technology. The linac configuration and beam dynamics requirements are presented. Injection options are discussed. Research needed to implement the Booster replacement is described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB190
About •	paper received ※ 15 May 2021       paper accepted ※ 28 May 2021       issue date ※ 10 August 2021
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MOPAB191	Method Development for Cavity Failure Compensation in a Superconducting Linac	647
	F. Bouly LPSC, Grenoble Cedex, France
	Reliability is a major challenge within the perspective of improving the performances and sustainability of MegaWatt class accelerators. To optimize the operational costs of such accelerators the availability requirements are becoming more and more challenging. These requirements are even more stringent in the case of Accelerator Driven systems (ADS). As an example, for the MYRRHA (Multipurpose Hybrid Research Reactor for High-tech Applications) ADS demonstrator, the actual availability limit is set to a maximum of 10 beam interruptions (longer than 3 seconds) over a 3-month operating cycle. For this purpose, the accelerator design is based on a redundant and fault-tolerant scheme to enable rapid mitigation of a cavity failure. The adopted strategy is to apply for local compensation: a failed cavity is compensated by several neighboring cavities. Beam dynamics studies and method developments to apply such a failure compensation scheme are here reviewed. First simulation results for superconducting linac retuning and potential future improvements will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB191
About •	paper received ※ 19 May 2021       paper accepted ※ 21 May 2021       issue date ※ 20 August 2021
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MOPAB192	LILac Energy Upgrade to 13 MeV	651
	B. Koubek, S. Altürk, M. Busch, H. Höltermann, J.D. Kaiser, H. Podlech, U. Ratzinger, M. Schuett, M. Schwarz, W. Schweizer, D. Strehl, R. Tiede, C. Trageser BEVATECH, Frankfurt, Germany A. Brunzel, P. Nonn, H. Schlarb DESY, Hamburg, Germany A.V. Butenko, D.E. Donets, B.V. Golovenskiy, A. Govorov, K.A. Levterov, D.A. Lyuosev, A.A. Martynov, V.A. Monchinsky, D.O. Ponkin, K.V. Shevchenko, I.V. Shirikov, E. Syresin JINR, Dubna, Moscow Region, Russia
	In the frame of the NICA (Nuclotron-based Ion Collider fAcility) ion collider upgrade a new light ion LINAC for protons and ions will be built in collaboration between JINR and BEVATECH GmbH. While ions with a mass-to-charge ratio up to 3 will be fed into the NUCLOTRON ring with an energy of 7 MeV/u, protons are supposed to be accelerated up to an energy of 13 MeV using a third IH structure. This energy upgrade comprises a third IH structure, a dual-use Debuncher cavity as well as an extension of the LLRF control system built on MicroTCA technology.
	Poster MOPAB192 [4.914 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB192
About •	paper received ※ 11 May 2021       paper accepted ※ 31 May 2021       issue date ※ 20 August 2021
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MOPAB194	First 3D Printed IH-Type Linac Structure - Proof-of-Concept for Additive Manufacturing of Linac rf Cavities	654
	H. Hähnel, U. Ratzinger IAP, Frankfurt am Main, Germany
	Additive manufacturing (or "3D printing") has become a powerful tool for rapid prototyping and manufacturing of complex geometries. As technology is evolving, the quality and accuracy of parts manufactured this way is ever improving. Especially interesting for the world of particle accelerators is the process of 3D printing of stainless steel (and copper) parts. We present the first fully functional IH-type drift tube structure manufactured by metal 3D printing. A 433 MHz prototype cavity has been constructed to act as a proof-of-concept for the technology. The cavity is designed to be UHV capable and includes cooling channels reaching into the stems of the DTL structure. We present the first experimental results for this prototype.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB194
About •	paper received ※ 18 May 2021       paper accepted ※ 01 June 2021       issue date ※ 02 September 2021
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MOPAB195	Development of a Disk-and-Washer Cavity for the J-PARC Muon g-2/EDM Experiment	658
	Y. Takeuchi, J. Tojo Kyushu University, Fukuoka, Japan E. Cicek, K. Futatsukawa, N. Kawamura, T. Mibe, M. Otani, T. Yamazaki, M. Yoshida KEK, Ibaraki, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan R. Kitamura, Y. Kondo, T. Morishita JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan Y. Nakazawa Ibaraki University, Hitachi, Ibaraki, Japan N. Saito J-PARC, KEK & JAEA, Ibaraki-ken, Japan Y. Sue, K. Sumi, M. Yotsuzuka Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan H.Y. Yasuda University of Tokyo, Tokyo, Japan
	At J-PARC, an experiment using muons accelerated by a linac is planned to measure the anomalous magnetic moment of muons and to search for the electric dipole moment. A 1296 MHz disk and washer (DAW) coupled cavity linac (CCL) is being developed for use in the middle beta section of the muon linac. The DAW CCL consists of 14 tanks with 11 cells each. All tanks are connected by bridge couplers and electromagnetic quadrupole doublets for focusing are installed in each bridge coupler. The basic design of the DAW cavity has already been completed, and now detailed cavity design studies and manufacturing process studies are underway. In this poster, we will report about these studies and the preparation status of manufacturing the DAW cavity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB195
About •	paper received ※ 20 May 2021       paper accepted ※ 01 June 2021       issue date ※ 23 August 2021
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MOPAB196	Field tuning of the 1 MeV/n RFQ at KOMAC	662
	H.-J. Kwon, Y.-S. Cho, J.J. Dang, W.-H. Jung, D.-H. Kim, H.S. Kim, K.H. Kim, S. Lee Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
	Funding: This work was supported by the Korea Multi-purpose Accelerator Complex (KOMAC) operation funds through Ministry of Science and ICT (MIST) of Korean Government. A 1 MeV/n Radio-frequency Quadrupole (RFQ) is under development at Korea Multi-purpose Accelerator Complex (KOMAC), the purposes of which are swift ion beam irradiation and compact neutron source. The RFQ was designed to accelerate ions with mass to charge (A/q) ratio up to 2.5. The designed peak current was 10 mA with 10% duty ratio. The RFQ is four vane structure resonated at 200 MHz. It has total 40 frequency tuners. There are no dipole rods and resonant coupling plate because the mode separation was large enough and the length of the RFQ was only two times of the wavelength. In this paper, the development status and field tuning results of the 1 MeV/n RFQ are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB196
About •	paper received ※ 19 May 2021       paper accepted ※ 28 May 2021       issue date ※ 20 August 2021
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MOPAB198	Study on Magnet Sorting of the CSNS/RCS Dipoles	665
	Y. Li, Y.W. An IHEP, Beijing, People’s Republic of China Z.P. Lipresenter, S.Y. Xu DNSC, Dongguan, People’s Republic of China
	The 1.6GeV rapid cycling synchrotron (RCS) of the China Spallation Neutron Source (CSNS) is a high-power pulsed proton machine aiming for 500kW output beam power. Now, the routine output beam power has been increased to 100kW. However, the horizontal bare orbit in the ring is large (15mm) and the number of correctors is small, which brings great challenges to the ramp-up of beam power. It is found that the bare orbit in AC mode is 3-4mm larger than that in DC mode. The reason is that the AC dipoles field error is larger than DC dipoles field error. Therefore, it is proposed to sort dipoles again according to the AC dipoles field error. In order to reduce the risk of beam commissioning, fewer magnets should to be moved to achieve smaller orbit. The best results of moving two to six magnets were calculated. After sorting, the orbit can be reduced by 3-4mm, which reduces the difficulty of orbit correction.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB198
About •	paper received ※ 16 May 2021       paper accepted ※ 21 May 2021       issue date ※ 14 August 2021
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MOPAB200	Parameters Measurements of Proton Beam Extracted from CSNS/RCS	668
	Z.P. Li, Y.W. An, M.Y. Huang IHEP, Beijing, People’s Republic of China Y. Li, S.Y. Xu DNSC, Dongguan, People’s Republic of China H.Y. Liu IHEP CSNS, Guangdong Province, People’s Republic of China
	In order to study the emittance evolution of the circulating beam in the fast-cycling synchrotron (RCS) of the Chinese Spallation Neutron Source (CSNS), parameter measurements of the beam extracted at different times were carried out. The measurements were mainly based on wire-scanners mounted in RCS to target transport line (RTBT) for beam profile measurement, and different methods were applied in the solution processes. The emittance and C.S parameters of the extracted beam at different times were obtained and studied, which provided an important reference basis for the beam commissioning of RCS. The beam envelope along the RTBT has been matched and re-measured, which was in good agreement with the design optics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB200
About •	paper received ※ 19 May 2021       paper accepted ※ 21 May 2021       issue date ※ 25 August 2021
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MOPAB203	Benchmark of Superconducting Cavity Models at SNS Linac	671
	A.P. Shishlo ORNL, Oak Ridge, Tennessee, USA
	Funding: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC0500OR22725 with the U.S. Department of Energy. A benchmark of superconducting cavity models against Time-of-Flight measurements at the SNS linac is presented. The superconducting part of SNS linac (SCL) includes 81 RF cavities that accelerates H− beam from 185.6 MeV to the final energy of 1 GeV. During the operation some of cavities can become unstable, and its amplitudes should be reduced, or they should be completely switched off. In this case, the SCL is retuned by using a linac simulation code. This simulation tool relay on an accuracy of the superconducting cavity model. This paper describes the comparison of the measured beam acceleration by one of the SCL cavities and simulations of this process. Different cavity models are used in simulations. The subject of this study is limited to the longitudinal beam dynamics, so no effects on transverse beam characteristics have been considered.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB203
About •	paper received ※ 14 May 2021       paper accepted ※ 20 May 2021       issue date ※ 24 August 2021
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MOPAB205	Minerva (MYRRHA Phase 1) RFQ Beam Commissioning	675
	A. Gatera, J. Belmans, F. Davin, W. De Cock, F. Doucet, L. Parez, F. Pompon, A. Ponton, D. Vandeplassche SCK•CEN, Mol, Belgium F. Bouly LPSC, Grenoble Cedex, France C. Joly, L. Perrot Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France H. Podlech IAP, Frankfurt am Main, Germany J. Tamura JAEA/J-PARC, Tokai-mura, Japan C. Zhang GSI, Darmstadt, Germany
	Funding: Part of this work was supported by the European Commission Framework Programme H2020, MYRTE project nr. 662186 The MYRRHA project aims at coupling a 600 MeV proton accelerator to a subcritical fission core operating at a thermal power of 60 MW. The nominal proton beam for this ADS has an intensity of 4 mA and is delivered in a quasi-CW mode. Phase 1 of the project will realize a 100 MeV, 4 mA superconducting linac with the mission of ensuring the ADS requirements in terms of reliability and fault tolerance. As part of the reliability optimization program the integrated prototyping of the MINERVA injector is ongoing. The front-end of the injector is composed of an ECR proton source, a 2.6 m long LEBT (low energy beam transport line) and a four-rod RFQ accelerating the beam to 1.5 MeV. The present contribution focuses on the current beam tests on the RFQ, including beam matching, RF conditioning, assessment of the cavities’ performances and accelerated beam characterisation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB205
About •	paper received ※ 19 May 2021       paper accepted ※ 31 May 2021       issue date ※ 24 August 2021
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MOPAB206	The RF Parameters of Heavy Ions Linac	679
	A. Sitnikov, G. Kropachev, T. Kulevoypresenter, D.N. Selesnev, A.I. Semennikov ITEP, Moscow, Russia M.L. Smetanin, A.V. Telnov, N.V. Zavyalov VNIIEF, Sarov, Russia
	The new linac for A/Z = 8, output energy 4 MeV/u and 3 mA current is under development at NRC "Kurchatov Institute"-ITEP. The linac consists of Radio-Frequency Quadrupole (RFQ) with operating frequency 40 MHz and two sections of Drift Tube Linac (DTL) with operating frequency 80 and 160 MHz, correspondently. Both DTL has a modular structure and consists of separated individually phased resonators with focusing magnetic quadrupoles located between the cavities. The DTL1 is based on the quarter-wave resonators meanwhile DTL2 is based on IH 5-gap resonators. The 6D beam matching between RFQ and DTLs is provided by magnetic quadrupole lenses and 2-gaps RF-bunchers. The paper presents results of the radio-frequency (RF) design of linac accelerating structures.
	Poster MOPAB206 [0.559 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB206
About •	paper received ※ 14 May 2021       paper accepted ※ 01 July 2021       issue date ※ 29 August 2021
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MOPAB207	Design Guideline for Minimizing Space-Charge-Induced Emittance Growth	682
	C. Zhang GSI, Darmstadt, Germany
	Space-charge-induced emittance growth is a big concern for designing low-energy and high-intensity linacs. The Equipartitioning Principle was introduced to minimize space-charge-induced emittance growth by removing free energy between the transverse and longitudinal degrees of freedom. In this study, a different design guideline is being proposed. It suggests holding the ratio of longitudinal emittance to transverse emittance around one and take advantage of low emittance transfer for minimizing emittance growth. Using a high-intensity RFQ accelerator as an example, a comparison between the two design methods has been made.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB207
About •	paper received ※ 17 May 2021       paper accepted ※ 21 May 2021       issue date ※ 01 September 2021
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MOPAB208	LLRF Measurements and Cu-plating at the First-of-Series Cavity Section of the Alvarez 2.0 at GSI	686
	M. Heilmann, T. Dettinger, X. Du, L. Groening, S. Mickat, A. Rubin GSI, Darmstadt, Germany
	The Alvarez 2.0 will replace the existing post-stripper DTL of the GSI UNILAC. Today’s GSI comprises the UNILAC and the synchrotron SIS18 and is going to serve as the injector chain for the Facility of Antiproton and Ion Research (FAIR). The new Alvarez-type DTL is operated at 108.4 MHz providing acceleration from 1.4 MeV/u to 11.4 MeV/u along a total length of 55 meters. The first-of-series (FoS) cavity section has 12 RF-gaps along a total length of 1.9 m. It is the first cavity section of the new DTL. All main components were delivered in 2019, followed by successful SAT and installation of the 11 drift tubes and copper-plating. Completion of first low level RF-measurements prior to copper plating and the subsequent plating are major project milestones. These proceedings report on the results and compares them to simulation using CST Microwave Studio.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB208
About •	paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 22 August 2021
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MOPAB209	Commissioning of SANAEM RFQ Accelerator	690
	B. Yasatekin, A. Alacakir, A.S. Bolukdemir, I. Kilic, Y. Olgac TENMAK-NUKEN, Ankara, Turkey E. Cicek KEK, Ibaraki, Japan E. Cosgun UNIST, Ulsan, Republic of Korea
	The former SANAEM RFQ is upgraded with a newly manufactured cavity, made of oxygen-free copper (OFC), having the capability of accelerating protons from 20 keV to 1.3 MeV. In the assembling of cavity vanes, flanges, etc., indium wire is preferred over the brazing process providing a more flexible and easy method for vacuum sealing. After assembling the cavity, argon plasma cleaning is performed for the final cleaning and RF pre-conditioning. Vacuum tests revealed that levels of 2·10-7 mbar could be achieved quite easily. RF power conditioning of the RFQ cavity is successfully completed with the observation of quite few sparks. In the commissioning tests with the proton beam, a magnetic analyzer is used to measure the energy of the particles. This paper presents the strategy and the results concerning the commissioning of the proton beam with special emphasis on the RFQ cavity.
	Poster MOPAB209 [5.076 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB209
About •	paper received ※ 19 May 2021       paper accepted ※ 14 June 2021       issue date ※ 22 August 2021
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MOPAB210	High-Gradient Booster for Enhanced Proton Radiography at LANSCE	693
	S.S. Kurennoy, Y.K. Batygin LANL, Los Alamos, New Mexico, USA
	Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV improves radiography resolution ~10 times. We propose accomplishing this energy boost with a compact cost-effective linac based on cryo-cooled normal conducting high-gradient RF accelerating structures. High-gradient structures exceeding 100 MV/m have been developed for electron acceleration and operate with short RF pulse lengths below 1 us. Though such parameters are unusual for typical proton linacs, they fit perfectly for proton radiography (pRad) applications. The pRad limits contiguous trains of beam micro-pulses to less than 80 ns to prevent blur in images. For a compact pRad booster at LANSCE, we develop a staged design: a short section to capture and compress the 800-MeV proton beam followed by the main high-gradient linac. Our beam dynamics study addresses the beam magnetic focusing and minimizing its energy spread, which are challenging in high-gradient structures but very important for successful pRad operation.
	Poster MOPAB210 [0.809 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB210
About •	paper received ※ 10 May 2021       paper accepted ※ 17 August 2021       issue date ※ 11 August 2021
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MOPAB211	Beam Coupling Impedances of Ferrite-Loaded Cavities: Calculations and Measurements	696
	S.S. Kurennoy, R.C. McCrady LANL, Los Alamos, New Mexico, USA
	We have developed an efficient method of calculating impedances in cavities with dispersive ferrite dampers. The ferrite dispersive properties in the frequency range of interest are fitted in CST, which allows using both wakefield and lossy eigenmode solvers. A simple test cavity with or without ferrite inserts is explored both numerically and experimentally. The resonance frequencies and beam coupling impedances at cavity resonances are calculated with CST to understand the mode structure. The cavity transverse coupling impedances are also measured on a test stand using a two-wire method. We compare results of impedance calculations and measurements for a few different configurations, with and without ferrites, to ensure a complete understanding of the cavity resonances and their damping with ferrite. These results are important to provide adequate damping of undesired transverse modes in induction-linac cells.
	Poster MOPAB211 [1.105 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB211
About •	paper received ※ 10 May 2021       paper accepted ※ 21 May 2021       issue date ※ 19 August 2021
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MOPAB212	3-D Quantum Lifetime	700
	H. Zhao, M. Blaskiewicz BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The quantum lifetime of electron beam in storage rings is defined by the particle loss that caused by the aperture limitation. Based on the equilibrium beam distribution produced by radiation damping and quantum excitation, the 1-d quantum lifetime has been well studied by A. Piwinski. In this paper, we give the derivation of the 3-d quantum lifetime, which can be applied to the machines with elliptical aperture and momentum acceptance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB212
About •	paper received ※ 04 June 2021       paper accepted ※ 21 June 2021       issue date ※ 16 August 2021
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MOPAB213	Characterization of Linear Optics and Beam Parameters for the APS Booster with Turn-by-Turn BPM Data	703
	X. Huang, H. Shang, C. Yao ANL, Lemont, Illinois, USA
	We take turn-by-turn (TBT) BPM data on the energy ramp of the APS Booster, and analyze the data with the independent component analysis. The extraction kicker was used to excite the betatron motion. The linear optics of the machine is characterized with the TBT BPM data. We also analyze the decoherence pattern of the kicked beam, from which we are able to derive beam distribution parameters, such as the momentum spread.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB213
About •	paper received ※ 13 May 2021       paper accepted ※ 11 June 2021       issue date ※ 19 August 2021
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MOPAB214	Linear Optics Measurement for the APS Ring with Turn-by-Turn BPM Data	707
	X. Huang, V. Sajaev, Y.P. Sun, A. Xiao ANL, Lemont, Illinois, USA
	We measure the linear optics of the APS storage ring from turn-by-turn BPM data taken when the beam is excited with an injection kicker. Decoherence due to chromaticity and amplitude-dependent detuning is observed and compared to theoretic predictions. Independent component analysis is used to analyze the data, which separates the betatron normal modes and synchrotron motion, despite contamination of bad BPMs. The beta functions and phase advances are subsequently obtained. The method is used to study the linear optics perturbation of an insertion device.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB214
About •	paper received ※ 12 May 2021       paper accepted ※ 09 June 2021       issue date ※ 01 September 2021
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MOPAB215	Using ICA for Retrieving Teng Parameters	711
	A. Lauterbach IAP, Frankfurt am Main, Germany G. Franchetti GSI, Darmstadt, Germany
	The blind source separation (BSS) method of Independent Component Analysis (ICA) is explored as a new approach for the reconstruction of the transfer matrix of Linear Coupling Parameterization. ICA is a method to detangle independent signals out of several measurements of their mixtures. In BSS-calculations, it is usually not possible to retrieve the mixing matrix, for the source signals, as well as the matrix, are unknown. Combining the parameterization model of D.A. Edwards and L.C. Teng with the standard ICA approach, it is though possible to retrieve the mixing matrix, as the form of the original uncoupled motion is known. At the same time arises the possibility to recalculate the parameters of Edwards and Teng through a system of equations of the one turn map components. It can be shown as a proof of concept, that the parameters can be reconstructed up to high accuracy for a simulated, non-perturbed signal.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB215
About •	paper received ※ 10 May 2021       paper accepted ※ 31 May 2021       issue date ※ 23 August 2021
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MOPAB216	20-24 GeV FFA CEBAF Energy Upgrade	715
	S.A. Bogacz, J.F. Benesch, R.M. Bodenstein, B.R. Gamage, G.A. Krafft, V.S. Morozov, Y. Roblin JLab, Newport News, Virginia, USA J.S. Berg, S.J. Brooks, D. Trbojevic BNL, Upton, New York, USA D. Douglas Douglas Consulting, York, Virginia, USA G.H. Hoffstaetter Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177 A proposal was formulated to increase the CEBAF energy from the present 12 GeV to 20-24 GeV by replacing the highest-energy arcs with Fixed Field Alternating Gradient (FFA) arcs. The new pair of arcs would provide six or seven new beam passes, going through this magnet array, allowing the energy to be nearly doubled using the existing CEBAF SRF cavity system. One of the immediate accelerator design tasks is to develop a proof-of-principle FFA arc magnet lattice that would support simultaneous transport of 6-7 passes with energies spanning a factor of two. We also examine the possibility of using combined function magnets to configure a cascade, six-way beam split switchyard. Finally, a novel multi-pass linac optics based on a weakly focusing lattice is being explored.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB216
About •	paper received ※ 19 May 2021       paper accepted ※ 02 June 2021       issue date ※ 29 August 2021
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MOPAB217	A Storage Ring for MESA	719
	C.P. Stoll, A. Meseck KPH, Mainz, Germany B. Ledroit HIM, Mainz, Germany
	The Mainz Energy-recovering Superconducting Accelerator (MESA) is an Energy Recovery Linac (ERL) facility under construction at the Johannes Gutenberg-University in Mainz. It provides the opportunity for precision physics experiments with a 1 mA c.w. electron beam in its initial phase. In this phase experiments with unpolarised, high density 1019 atoms cm2 gas jet targets are foreseen at the Mainz Gas Internal Target Experiment (MAGIX). To allow experiments with thin polarised gas targets with sufficiently high interaction rates in a later phase, the beam current has to be increased to up to 100 mA, which would pose significant challenges to the existing ERL machine. Thus, it is proposed here to use MESA in pulsed operation with a repetition rate of several kHz to fill a storage ring, providing a quasi c.w. beam current to a thin gas target. For this purpose, the existing optics need to be extended and adapted, a suitable injection and extraction scheme is necessary and beam target interaction must be investigated. First considerations on these topics are presented here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB217
About •	paper received ※ 18 May 2021       paper accepted ※ 08 June 2021       issue date ※ 21 August 2021
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MOPAB220	Towards Deterministic Design of MBA-Lattices	722
	B.C. Kuske HZB, Berlin, Germany
	Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of the Helmholtz Association Since the pioneering work of MAX IV *, multi-bend achromat (MBA) lattices have become the standard in lattice design for 4th generation lights sources as well as upgrades of 3rd generation storage rings. The distribution of the bending angle to many weak dipoles enables to reach unprecedented low emittance and highest brightness. In their most basic form, MBA-lattices consist of a repetitive unit cell and two identical matching cells on either end of the achromatic arc. The simplicity of both cells allows for a unique determination of the linear lattice parameters in dependence on boundary conditions defined by the design goals. Those might be the emittance, momentum compaction factor, chromaticity, as well as phase advances with respect to achieving higher-order achromatic structures. A scan of optional lattice prototypes is quickly obtained. We demonstrate this concept and apply it in the design of the first candidates for the lattice of BESSY III, a green-field 4th generation storage ring being currently planned at HZB, Berlin, Germany. * https://www.maxiv.lu.se/accelerators-beamlines/accelerators/accelerator-documentation/max-iv-ddr/
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB220
About •	paper received ※ 17 May 2021       paper accepted ※ 23 July 2021       issue date ※ 26 August 2021
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MOPAB221	Developments of a Pulse Kicker System for the Three-Dimensional Spiral Beam Injection of the J-PARC Muon g-2/EDM Experiment	726
	K. Oda, H. Hirayama, H. Iinuma, Y. Sato, M. Sugita Ibaraki University, Ibaraki, Japan M. Abe, K. Furukawa, T. Mibe, H. Nakayama, S. Ohsawa, M.A. Rehman, N. Saito, K. Sasaki KEK, Ibaraki, Japan R. Matsushita The University of Tokyo, Graduate School of Science, Tokyo, Japan
	The J-PARC muon g-2/EDM experiment aims to perform ultra-precise measurements of anomalous magnetic moments (g-2) and electric dipole moments (EDM) from the spin precession of muons in a precise magnetic field and to explore new physics beyond the Standard Model. On experimental requirements, the beam must be stored in a compact storage orbit with a diameter of 66 cm, which is about 1/20th smaller than that of the previous experiment. To be realized, we adopt an unprecedented injection technique called the three-dimensional spiral injection scheme. In this scheme, the beam is injected from upward of the solenoidal storage magnet. The vertical beam motion along the solenoid axis is controlled by a few 100 ns pulse kicker. Once the beam is guided into the center fiducial storage volume, the muon beam is stored by the weak focusing magnetic field. Therefore, stable and accurate control of the pulse kicker is one of the major technical challenges to realize the ultra-precise measurement of the muon spin precession. In this presentation, we discuss the performance of the prototype pulse kicker device and future plan for installation of it to our test bench with an electron beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB221
About •	paper received ※ 20 May 2021       paper accepted ※ 31 May 2021       issue date ※ 15 August 2021
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MOPAB224	Optimization and Error Studies for the USSR HMBA Lattice	730
	L. Hoummi, N. Carmignani, L.R. Carver, S.M. Liuzzo, T.P. Perron, S.M. White ESRF, Grenoble, France I.A. Ashanin, S.M. Polozov MEPhI, Moscow, Russia T. Kulevoy ITEP, Moscow, Russia T. Kulevoy NRC, Moscow, Russia
	Several new accelerator facilities will be built in Russia in the next few years. One of those facilities is a 6 GeV storage ring (SR) light source, the Ultimate Source of Synchrotron Radiation (USSR) to be built in Protvino, near Moscow. The Cremlin+ project aims to incorporate in this activity the best experience of European Accelerator Laboratories. The optimization of such optics including realistic errors and a commissioning-like sequence of corrections, using Multi-Objective Genetic Algorithms (NSGA-II) is presented. Several corrections schemes are also tested.
	Poster MOPAB224 [1.164 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB224
About •	paper received ※ 12 May 2021       paper accepted ※ 01 June 2021       issue date ※ 13 August 2021
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MOPAB225	A HMBA Lattice Design Study for the 4 GeV Light Source	734
	S.W. Jang, E.-S. Kim KUS, Sejong, Republic of Korea
	The 4th generation storage ring (4GSR) project will start from 2022 in South Korea. We proposed HMBA (Hybrid Multi-Bend Achromatic) lattice for 4GSR with super-bend at the center of the lattice. The 4GSR lattice is designed to combined HMBA lattice with a 4 GeV, 53 pm-rad emittance and 843m. The storage ring including 32 long with 5.65m, 16 short straight with 1.3m sections for IDs and 16 super-bend sections for more different type of beam line experiments. A calculated dynamic aperture is more larger than 15mm in both direction and the beam life time is expected to 4.7 hour. In this paper, we will describe the study results of the HMBA lattice design with a 4GeV light source.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB225
About •	paper received ※ 20 May 2021       paper accepted ※ 24 May 2021       issue date ※ 30 August 2021
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MOPAB226	Analytical Description of the Steerer Parameters in the Bilinear-Exponential Model at DELTA	737
	S. Kötter DELTA, Dortmund, Germany
	At DELTA, a 1.5 GeV synchrotron radiation source operated by the TU Dortmund University, an analytical description of the steerer parameters in the bilinear-exponential (BE) model has been developed. The BE model describes the coupled orbit response in a storage ring. It is used in the closed-orbit bilinear-exponential analysis (COBEA) algorithm to decompose orbit response matrices into beta function, betatron phase, and a scaled dispersion. After introducing the BE model and the analytical steerer parameters, a simulation-based comparison of the BE model and another coupled orbit response model is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB226
About •	paper received ※ 19 May 2021       paper accepted ※ 08 June 2021       issue date ※ 11 August 2021
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MOPAB228	Introducing two Energy-Correction Schemes at DELTA	740
	S. Kötter DELTA, Dortmund, Germany
	At DELTA, a 1.5 GeV synchrotron light source operated by the TU Dortmund University, two methods to correct the beam energy of the storage ring have been tested. The first one is capable of maintaining the current beam energy. The second method is used to find the optimal orbit length. Here, the ideas behind both methods are explained and first test results are presented. Numerical studies are shown together with measurement results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB228
About •	paper received ※ 19 May 2021       paper accepted ※ 02 June 2021       issue date ※ 29 August 2021
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MOPAB229	Compensations of Third-Order Resonances in J-PARC MR	744
	T.Y. Yasui, S. Igarashi, T. Koseki, Y. Kurimoto, Y. Morita, K. Ohmi, Y. Sato, T. Shimogawa KEK, Tokai, Ibaraki, Japan
	The main ring synchrotron (MR) of the Japan Proton Accelerator Research Complex (J-PARC) provides high-power proton beams for the neutrino and hadron experiments. In the fast extraction (FX) operation, the beams are injected with the energy of 3 GeV and the intensity of 3.3 × 1013 protons per bunch, and accelerated to 30 GeV. Most of the beam losses are observed in the low-energy period, because the space charge tune spread is large, and crosses various kinds of resonances. In this study, the compensations of the third-order resonances are performed. The present operation tune is (νx, νy) = (21.35, 21.43) in FX operation. The nearest third-order structure resonance is νx-2νy=-21. It was clearly compensated by optimizing the phase advances in the arc sections. The compensation was confirmed by the aperture survey simulations and demonstrated by the three different experiments. The third-order nonstructure resonances near the operation tune are 3νx=64 and νx+2νy=64. They are simultaneously compensated by introducing four trim coils of the sextupole magnets. The beam loss was successfully reduced by adopting the compensations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB229
About •	paper received ※ 20 May 2021       paper accepted ※ 02 June 2021       issue date ※ 29 August 2021
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MOPAB230	The Optics Design for the Final Focus System of CLIC 380 GeV	748
	A. Pastushenko, R. Tomás García CERN, Geneva, Switzerland A. Faus-Golfe Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
	The first stage of the Compact Linear Collider (CLIC) is planned to be at the center-of-mass energy of 380 GeV. The final focus system (FFS) was re-optimized for this energy and for L* of 6 m (distance between the Interaction Point (IP) and the last quadrupole, QD0). Furthermore, the FFS optics was optimized for the vertical beta-function of 70 microns to approach the Hourglass effect limit. This paper reports the exploration of shortening the Final Doublet (FD) within the FFS to reduce the chromaticity. In addition, an alternative optics design is investigated with a different dispersion profile along the FFS, which outperforms the previous optics with the same β*, increasing luminosity by 5 %.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB230
About •	paper received ※ 19 May 2021       paper accepted ※ 14 June 2021       issue date ※ 11 August 2021
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MOPAB231	Tunability Study of the Ultra-Low β* Optics at ATF2 with New Octupole Setup and Tuning Knobs	752
	A. Pastushenko, R. Tomás García CERN, Geneva, Switzerland A. Faus-Golfe Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France K. Kubo, S. Kuroda, T. Naito, T. Okugi, N. Terunuma, R.J. Yang KEK, Ibaraki, Japan
	The main goal of the Accelerator Test Facility 2 (ATF2) is to demonstrate the feasibility of future linear colliders’ final focus systems. The Ultra-low β* optics of ATF2 is designed to have the same chromaticity level as CLIC. To ease the tuning procedure, a pair of octupoles was installed in ATF2 in 2017. This paper reports the optimizations performed to the octupoles’ setup for Ultra-low β* optics including the new alignment technique, based on the waist shift and the new tunning knobs constructed for this optics. The full tuning procedure including the static errors is simulated for this setup.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB231
About •	paper received ※ 19 May 2021       paper accepted ※ 28 July 2021       issue date ※ 12 August 2021
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MOPAB232	Observation of Polarization-Dependent Changes in Higher-Order Mode Responses as a Function of Transverse Beam Position in Tesla-Type Cavities at FAST	756
	R.M. Thurman-Keup, D.R. Edstrom, A.H. Lumpkin, P.S. Prieto, J. Ruan Fermilab, Batavia, Illinois, USA J.A. Diaz Cruz UNM-ECE, Albuquerque, USA J.A. Diaz Cruz, B.T. Jacobson, J.P. Sikora, F. Zhou SLAC, Menlo Park, California, USA
	Funding: FNAL supported by U.S. Department of Energy, Office of Science, under contract DE-AC02-07CH11359. SLAC supported by U.S. Department of Energy, Office of Science, under contract DE-AC02-76SF00515. Higher-order modes (HOMs) in superconducting rf cavities present problems for an electron bunch traversing the cavity in the form of long-range wakefields from previous bunches. These may dilute the emittance of the macropulse average, especially with low emittance beams at facilities such as the European X-ray Free-electron Laser (XFEL) and the upgraded Linac Coherent Light Source (LCLS-II). Here we present observations of HOMs driven by the beam at the Fermilab Accelerator Science and Technology (FAST) facility. The FAST facility features two independent TESLA-type cavities (CC1 and CC2) after a photocathode rf gun followed by an 8-cavity cryomodule. The HOM signals were acquired from cavities using bandpass filters of 1.75 ± 0.15 GHz, 2.5 ± 0.2 GHz, and 3.25 ± 0.2 GHz and recorded using an 8-GHz, 20 GSa/s oscilloscope. The frequency resolution obtained is sufficient to separate polarization components of many of the HOMs. These HOM signals were captured from CC1 and cavities 1 and 8 of the cryomodule for various initial trajectories through the cavities, and we observe correlations between trajectory, HOM signals, and which polarization component of a mode is affected.
	Poster MOPAB232 [2.144 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB232
About •	paper received ※ 20 May 2021       paper accepted ※ 25 May 2021       issue date ※ 10 August 2021
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MOPAB234	Analysis of the Chromatic Vertical Focusing Effect of Dipole Fringe Fields	760
	K. Hwang, C.E. Mitchell, R.D. Ryne LBNL, Berkeley, California, USA
	Funding: U.S. Department of Energy under Contract No. DE-AC02-05CH11231 There have been questions regarding the impact of the dipole fringe-field models (used by accelerator codes including ELEGANT and MADX) on vertical chromaticity. Here, we analyze the cause of the disagreement among codes and suggest a correction.
	Poster MOPAB234 [0.486 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB234
About •	paper received ※ 20 May 2021       paper accepted ※ 01 June 2021       issue date ※ 23 August 2021
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MOPAB235	Transverse 2d Phase-Space Tomography Using Beam Position Monitor Data of Kicked Beams	763
	K. Hwang, C.E. Mitchell, R.D. Ryne LBNL, Berkeley, California, USA
	Funding: U.S. Department of Energy under Contract No. DE-AC02-05CH11231 The time-series Beam Position Monitor (BPM) data of kicked beam is a function of lattice parameters and beam parameters including phase-space density. The decoherence model using the first-order detuning parameter has an exact solution when the beam is Gaussian. We parameterize the beam phase-space density by multiple Gaussian kernels of different weights, means, and sizes to formulate the inverse problem for 2D phase-space tomography. Numerical optimization and Bayesian inference are used to infer the beam density.
	Poster MOPAB235 [1.253 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB235
About •	paper received ※ 20 May 2021       paper accepted ※ 02 June 2021       issue date ※ 01 September 2021
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MOPAB236	Ion Beam Dynamics in Linac-100 Facility at Jinr	767
	S.M. Polozov, V.S. Dyubkov, Y. Lozeev, T.A. Lozeevapresenter, A.V. Samoshin MEPhI, Moscow, Russia
	The heavy-ion linac LINAC-100 is a superconducting driver-accelerator proposed as one of the prospective projects at JINR. Its goal is to accelerate primary stable isotope CW high-intensity beams to energies up to 100 MeV/u*. This linac is discussed as the first stage of a new rare isotope facility DERICA (Dubna Electron-Radioactive Ion Collider fAcility), being under development at JINR since 2017**. LINAC-100 is supposed to work with a wide range of beams with A/Z 3.5/7, Uranium U34+ being the heaviest. Its concept has undergone many changes, mostly considering stripping cells to increase accelerator efficiency. During the latest investigations of various stripping cells [***, ****], Uranium beam stripping at the energy 10 MeV/u and utilizing three adjacent charge states 59-61+ resulted in 60% output beam intensity preservation (or 30 pA overall output current). The current layout of the LINAC-100 is the following: one or two (separately for light and heavy ions) normal conducting front-end linacs, gas stripper cell at 10 MeV/u, and the SC section. In this paper three charge state Uranium beam dynamics in the current version of SC LINAC-100 section is presented. *S Polozov 2020 PhysScr 95 084006 **A S Fomichev Phys Usp 62(7) 675-690 2019 ***Tolstikhina I 2018 Basic At Int of Acc H Ions in Matter 98 1 **** W Barth J Phys Conf Ser 1350:012096
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB236
About •	paper received ※ 20 May 2021       paper accepted ※ 17 August 2021       issue date ※ 26 August 2021
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MOPAB239	Simulation and Optimization of the Spin Coherence Time of Protons in a Prototype EDM Ring	771
	M. Vitz, A. Lehrach FZJ, Jülich, Germany R. Shankar INFN-Ferrara, Ferrara, Italy
	The matter-antimatter asymmetry might be understood by investigating the EDM (Electric Dipole Moment) of elementary charged particles. A permanent EDM of a subatomic particle violates time-reversal and parity symmetry at the same time and would be, with the currently achievable experimental accuracy, a strong indication for physics beyond the Standard Model. The JEDI-Collaboration (Jülich Electric Dipole moment Investigations) in Jülich is preparing a direct EDM measurement for protons and deuterons: first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. A prototype EDM ring is an intermediate step before building the final storage ring to demonstrate sufficient beam lifetime and SCT (Spin Coherence Time) in a pure electrostatic ring as well as in a storage ring with combined electric and magnetic bending elements. In order to study the effect of E-B-deflectors on the orbit and the spin motion, the software library Bmad is used. The first results of the optics and spin simulations, with a focus on the optimization of the SCT, towards the prototype EDM ring will be discussed.
	Poster MOPAB239 [0.560 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB239
About •	paper received ※ 17 May 2021       paper accepted ※ 09 June 2021       issue date ※ 23 August 2021
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MOPAB240	Estimates of Damped Equilibrium Energy Spread and Emittance in a Dual Energy Storage Ring	774
	B. Dhital, G.A. Krafft ODU, Norfolk, Virginia, USA Y.S. Derbenev, D. Douglas, A. Hutton, G.A. Krafft, F. Lin, V.S. Morozov, Y. Zhang JLab, Newport News, Virginia, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, and Office of Nuclear Physics under Contracts DE-AC05-06OR23177 and DE-AC02-06CH11357. / Jefferson Lab EIC Fellowship2020. A dual energy storage ring design consists of two loops at markedly different energies. As in a single-energy storage ring, the linear optics in the ring design may be used to determine the damped equilibrium emittance and energy spread. Because the individual radiation events in the two rings are different and independent, we can provide analytical estimates of the damping times in a dual energy storage ring. Using the damping times, the values of damped energy spread, and emittance can be determined for a range of parameters related to lattice design and rings energies. We present analytical calculations along with simulation results to estimate the values of damped energy spread and emittance in a dual energy storage ring. We note that the damping time tends to be dominated by the damping time of the high energy ring in cases where the energy of the high energy rings is significantly greater than that of the low energy ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB240
About •	paper received ※ 17 May 2021       paper accepted ※ 27 May 2021       issue date ※ 13 August 2021
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MOPAB241	Design of the Proton and Electron Transfer Lines for AWAKE Run 2c	778
	R.L. Ramjiawan JAI, Oxford, United Kingdom S. Döbert, E. Gschwendtner, P. Muggli, F.M. Velotti, L. Verra CERN, Meyrin, Switzerland J.P. Farmer MPI-P, München, Germany P. Muggli MPI, Muenchen, Germany
	The AWAKE Run 1 experiment achieved electron acceleration to 2 GeV using plasma wakefield acceleration driven by 400 GeV, self-modulated proton bunches from the CERN SPS. The Run 2c phase of the experiment aims to build on these results by demonstrating acceleration to ~10 GeV while preserving the quality of the accelerated electron beam. To realize this, there will be an additional plasma cell, to separate the proton bunch self-modulation and the electron acceleration. A new 150 MeV beamline is required to transport and focus the witness electron beam to a beam size of several microns at the injection point. This specification is designed to preserve the beam emittance during acceleration, also requiring micron-level stability between the driver and witness beams. To facilitate these changes, the Run 1 proton transfer line will be reconfigured to shift the first plasma cell 40 m downstream. The Run 1 electron beamline will be adapted and used to inject electron bunches into the first plasma cell to seed the proton bunch self-modulation. Proposed adjustments to the proton transfer line and studies for the designs of the two electron transfer lines are detailed in this contribution.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB241
About •	paper received ※ 18 May 2021       paper accepted ※ 02 June 2021       issue date ※ 17 August 2021
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MOPAB242	A Six-Bend-Achromat Lattice for a 2.5 GeV Diffraction-Limited Storage Ring	782
	J. Li, M. Abo-Bakr, P. Goslawski HZB, Berlin, Germany Z.H. Bai USTC/NSRL, Hefei, Anhui, People’s Republic of China
	HZB has proposed a 2.5 GeV diffraction-limited storage ring as the upgrade of BESSY II. A Six-Bend-Achromat lattice based on Higher-Order Achromat, as one of the possible solutions, has been designed to meet the requirements of low emittance, compact layout, large dynamic aperture and large momentum acceptance. The linear lattice design and the nonlinear performance are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB242
About •	paper received ※ 18 May 2021       paper accepted ※ 09 June 2021       issue date ※ 17 August 2021
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MOPAB245	Theoretical Analysis of the Conditions for an Isochronous and CSR-Immune Triple-Bend Achromat with Stable Optics	786
	C. Zhang, Y. Jiao IHEP, Beijing, People’s Republic of China C.-Y. Tsaipresenter HUST, Wuhan, People’s Republic of China
	Funding: National Natural Science Foundation of China (No. 11922512), Youth Innovation Promotion Association of Chinese Academy of Sciences (No. Y201904), National Key R&D Program of China (No. 2016YFA0401900) Transport of high-brightness beams with minimum degradation of the phase space quality is pursued in modern accelerators. For the beam transfer line which commonly consists of bending magnets, it would be desirable if the transfer line can be isochronous and coherent synchrotron radiation (CSR)-immune. For multi-pass transfer line, the achromatic cell designs with stable optics would bring great convenience. In this paper, based on the transfer matrix formalism and the CSR point-kick model, we report the detailed theoretical analysis and derive the condition for a triple-bend achromat with stable optics in which the first-order longitudinal dispersion (i.e., R56) and the CSR-induced emittance growth can be eliminated. The derived condition suggests a new way of designing the bending magnet beamline that can be applied to the free-electron laser (FEL) spreader and energy recovery linac (ERL) recirculation loop.
	Poster MOPAB245 [0.530 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB245
About •	paper received ※ 12 May 2021       paper accepted ※ 08 June 2021       issue date ※ 27 August 2021
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MOPAB246	Design of the MEBT for the JAEA-ADS Project	790
	B. Yee-Rendón, Y. Kondo, F.M. Maekawa, S.I. Meigo, J. Tamura JAEA/J-PARC, Tokai-mura, Japan
	The Medium Energy Beam Transport (MEBT) will transport a CW proton beam with a current of 20 mA and energy of 2.5 MeV from the exit of the normal conducting Radiofrequency Quadrupole (RFQ) to the superconducting Half-Wave resonator (HWR) section. The MEBT must provide a good matching between the RFQ and HWR, effective control of the emittance growth and the halo formation, enough space for all the beam diagnostics devices, among others. This work reports the first lattice design and the beam dynamics studies for the MEBT of the JAEA-ADS.
	Poster MOPAB246 [0.827 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB246
About •	paper received ※ 10 May 2021       paper accepted ※ 02 June 2021       issue date ※ 19 August 2021
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MOPAB247	Multipacting Studies for the JAEA-ADS Five-Cell Elliptical Superconducting RF Cavities	793
	B. Yee-Rendón, Y. Kondo, F.M. Maekawa, S.I. Meigo, J. Tamura JAEA/J-PARC, Tokai-mura, Japan E. Cicek KEK, Ibaraki, Japan
	The Five-cell Elliptical Superconducting Radio-Frequency Cavities (SRFC) provide the final acceleration in the JAEA-ADS linac (from 208 MeV to 1.5 GeV); thus, their performance is essential for the success of the JAEA-ADS project. After their optimization of the cavity geometry to achieve a high acceleration gradient with lower electromagnetic peaks, the next step in the R&D strategy is the accurate estimation of beam-cavity effects which can affect the performance of the cavities. To this end, multipacting studies were developed to investigate its effect in the cavity operation regimen and find countermeasures. The results of this study will help in the development of the SRFC models and in the consolidation of the JAEA-ADS project.
	Poster MOPAB247 [0.599 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB247
About •	paper received ※ 10 May 2021       paper accepted ※ 07 June 2021       issue date ※ 28 August 2021
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MOPAB248	Injection Schemes for the SOLEIL Upgrade	796
	M.-A. Tordeux, P. Alexandre, R. Ben El Fekih, P. Brunelle, L. Hoummi, A. Loulergue, L.S. Nadolski, R. Nagaoka SOLEIL, Gif-sur-Yvette, France
	Injection into the SOLEIL upgrade storage ring is much more challenging compared to the case of the current ring. Thanks to the experience gained in the development, manufacture and commissioning of a Multipole Injection Kicker (MIK) on the MAX IV 3 GeV storage ring, the SOLEIL pulsed magnet team is currently developing new MIK magnets that will serve as the basis for the injection schemes in the upgrade storage ring. We then propose two kinds of injections: firstly, a betatron off-axis injection that should be compatible with the full-coupling storage ring tuning, and secondly, a synchrotron on-axis injection by creating a large horizontal dispersion bump at the injection point.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB248
About •	paper received ※ 19 May 2021       paper accepted ※ 21 May 2021       issue date ※ 26 August 2021
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MOPAB253	Comparison of Transfer Map Derivation Methods for Static Magnetic Fields	799
	J.A. Crittenden, S. Wang Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This work is supported by National Science Foundation award numbers DMR-1829070 and PHY-1757811. We compare methods for deriving transfer maps for static magnetic fields, including field-map tracking and tracking elements defined by multipole content. Building on prior work on quantitative evaluation of the accuracy of finite-element models used to produce field maps, we assess the tradeoffs between computing time and fidelity to the underlying magnetic field, including fringe fields, of the various approximate methods. We illustrate our approach using the example of electromagnets in the south arc of the 6-GeV Cornell High Energy Synchrotron Source, which have been operating since 2019.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB253
About •	paper received ※ 19 May 2021       paper accepted ※ 18 June 2021       issue date ※ 13 August 2021
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MOPAB254	Measurement of Horizontal Beam Size Using Sextupole Magnets	802
	J.A. Crittenden, K.E. Deitrick, H.X. Duan, G.H. Hoffstaetter, V. Khachatryan, D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This work is supported by National Science Foundation award number DMR-1829070. The quadratic dependence of sextupole fields on position results in a beam-size-dependent kick on a beam traversing a sextupole magnet. A change in sextupole strength changes the closed orbit and the tune of the beam in a storage ring. Measuring both therefore allows conclusions about the beam size in the sextupole. Here we derive the pertinent formula and discuss the applicability to storage rings. In particular we investigate the measurement accuracy that can be achieved at the Cornell High Energy Synchrotron Source. The Cornell Electron-positron Storage Ring underwent a major upgrade in 2018 with the goal of reducing the emittance by a factor of four. A variety of beam size measurement methods have been developed to monitor the positron beam size, including visible synchrotron light and interferometry. We investigate the sensitivity of the sextupole method and compare to other measurement techniques. The design horizontal emittance of the 6-GeV positron beam is about 30 nm-rad with typical beam sizes of about 1 mm, setting the scale for the required accuracy in the beam-size measurement.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB254
About •	paper received ※ 19 May 2021       paper accepted ※ 22 June 2021       issue date ※ 01 September 2021
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MOPAB255	Demonstration of a Novel Longitudinal Phase Space Linearization Method without Higher Harmonics	805
	R. Stark University of Hamburg, Hamburg, Germany K. Flöttmann, M. Hachmann DESY, Hamburg, Germany F.J. Grüner Center for Free-Electron Laser Science, Universität Hamburg, Hamburg, Germany B. Zeitler CFEL, Hamburg, Germany
	Nonlinear correlations in the longitudinal phase space of electron bunches can be a decisive limitation to the achievable bunch length compression and attainability of small energy spreads. To overcome the restrictions imposed by nonlinear distortions, the longitudinal phase space distribution must be linearized. Previously, a novel linearization procedure based on the controlled expansion of the bunch between two radio frequency cavities operated at the same fundamental frequency has been presented in *. A demonstration of this linearization method is presented in this work. *B. Zeitler, K. Floettmann, and F. Grüner, "Linearization of the longitudinal phase space without higher harmonic field," Phys. Rev. ST Accel. Beams, vol. 18, p. 120102, 2015.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB255
About •	paper received ※ 18 May 2021       paper accepted ※ 02 June 2021       issue date ※ 16 August 2021
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MOPAB256	Development of Pulsed Beam System for the Three Dimensional Spiral Injection Scheme in the J-PARC muon g-2/EDM Experiment	809
	R. Matsushita The University of Tokyo, Graduate School of Science, Tokyo, Japan M. Abe, K. Hurukawa, T. Mibe, H. Nakayama, S. Ohsawa, M.A. Rehman, N. Saito, K. Sasaki KEK, Ibaraki, Japan H. Hirayama, H. Iinuma, K. Oda, Y. Sato, M. Sugita Ibaraki University, Ibaraki, Japan N. Saito J-PARC, KEK & JAEA, Ibaraki-ken, Japan T. Takayanagi JAEA/J-PARC, Tokai-mura, Japan
	The J-PARC muon g-2/EDM experiment aims to measure the anomalous magnetic moment(g-2) and electric dipole moment(EDM) of the muon with higher precision than the previous BNL E821 experiment. A brand-new three-dimensional spiral injection scheme is employed to inject and store muon beam into a 66 cm diameter of storage magnet. Feasibility studies are ongoing by use of 80 keV electron beam at KEK test bench, to develop skills on control transverse beam motion; so-called X-Y coupling, with DC beam. As a next step, towards store the beam by use of a kicker system, a pulsed beam should be generated from the DC beam with an intended time structure to meet a pulse kicker’s duration time, without changing transverse phase space characteristics. In this presentation, the development of a beam chopper device and the evaluation of pulse beam profile are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB256
About •	paper received ※ 20 May 2021       paper accepted ※ 15 June 2021       issue date ※ 16 August 2021
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MOPAB257	Effects of Mode Launcher on Beam Dynamics in Next Generation High Brightness C-Band Guns	813
	A. Giribono, D. Alesini, F. Cardelli, G. Di Raddo, M. Ferrario, A. Gallo, J. Scifo, C. Vaccarezza, A. Vannozzi INFN/LNF, Frascati (Roma), Italy G. Castorina AVO-ADAM, Meyrin, Switzerland L. Ficcadenti INFN-Roma, Roma, Italy G. Muti Sapienza University of Rome, Rome, Italy G. Pedrocchi SBAI, Roma, Italy
	High-brightness RF photo-injectors plays nowadays a crucial role in the fields of radiation generation and advanced acceleration schemes. A high gradient C-band photoinjector consisting of a 2.5 cell gun followed by TW sections is here proposed as an electron source for radiation user facilities. The paper reports on beam dynamics studies in the RF injector and illustrates the effects on the beam quality of the mode launcher with a focus on the compensation of the quadrupole RF components.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB257
About •	paper received ※ 19 May 2021       paper accepted ※ 08 June 2021       issue date ※ 16 August 2021
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MOPAB258	Corrections of Non-Linear Field Errors with Asymmetric Optics in LHC and HL-LHC Insertion Regions	817
	J. Dilly, E.H. Maclean, R. Tomás García CERN, Geneva, Switzerland
	Funding: Research supported by the HL-LHC project, CERN and the german Federal Ministry of Education and Research. Existing correction schemes to locally suppress resonance driving terms in the error-sensitive high-beta regions of the LHC and HL-LHC have operated on the assumption of symmetric beta-functions of the optics in the two rings. As this assumption can fail for a multitude of reasons, such as inherently asymmetric optics and unevenly distributed errors, an extension of this correction scheme has been developed removing the need for symmetry by operating on the two separate optics of the beams at the same time. Presented here is the impact of this novel approach on dynamic aperture as an important measure of particle stability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB258
About •	paper received ※ 10 May 2021       paper accepted ※ 23 July 2021       issue date ※ 16 August 2021
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MOPAB259	Corrections of Feed-Down of Non-Linear Field Errors in LHC and HL-LHC Insertion Regions	821
	J. Dilly, E.H. Maclean, R. Tomás García CERN, Geneva, Switzerland
	Funding: Research supported by the HL-LHC project, CERN and the german Federal Ministry of Education and Research. The optics in the insertion regions of the LHC and its upgrade project the High Luminosity LHC (HL-LHC) are very sensitive to local magnetic errors, due to the extremely high beta-functions present. In collision optics, the non-zero closed orbit in the same region leads to a "feed-down" of high-order errors to lower orders, causing additional effects detrimental to beam lifetime. An extension to the proven method for correcting these errors by locally suppressing resonance driving terms has been undertaken, not only taking this feed-down into account, but also adding the possibility of utilizing it such that the powering of higher-order correctors will compensate for lower order errors. The impact of these corrections on measures of particle stability, namely dynamic aperture and amplitude detuning are presented in this contribution.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB259
About •	paper received ※ 10 May 2021       paper accepted ※ 23 July 2021       issue date ※ 15 August 2021
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MOPAB260	Optics Corrections with LOCO on Sirius Storage Ring	825
	M.B. Alves LNLS, Campinas, Brazil
	Sirius is a 4th generation 3GeV synchrotron light source at the Brazilian Center for Research in Energy and Materials (CNPEM). In this work, we report the results of linear optics and coupling corrections during the commissioning of Sirius storage ring, using the Linear Optics from Closed Orbits (LOCO) algorithm. Beam-based measurements were performed to verify independently the impact of corrections on storage ring parameters.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB260
About •	paper received ※ 19 May 2021       paper accepted ※ 02 June 2021       issue date ※ 30 August 2021
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MOPAB261	NSLS-II Storage Ring Lattice Analysis using Response Matrices	829
	J. Choi BNL, Upton, New York, USA
	Funding: Work supported by the U.S. Department of Energy (DOE) under contract No. DE-SC0012704. Affected from various sources, the NSLS-II storage ring lattice is slightly changing operation to operation and, for the operational performance, we are continually optimizing the lattice and maintaining the response matrices for the feedback and lattice analysis. Because not all sources are identified, we are investing efforts to identify as many as possible. As one of such efforts, we also study the measured response matrices. In this paper, we present the results of lattice studies using a pair of recently measured response matrices.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB261
About •	paper received ※ 20 May 2021       paper accepted ※ 02 June 2021       issue date ※ 19 August 2021
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MOPAB262	First Thoughts on Lattices for a possible Metrology Light Source 2	833
	M. Arlandoo, M. Abo-Bakr, P. Goslawski, J. Li HZB, Berlin, Germany
	The Physikalisch-Technische Bundesanstalt (PTB), in cooperation with the Helmholtz-Zentrum Berlin (HZB), operates the Metrology Light Source (MLS), which is a low-energy electron storage ring. The MLS can be operated in a low-alpha mode to produce coherent synchroton ration in the far-IR and THz spectral range. In the scope of the Conceptual Design process for a BESSY II successor, the PTB also requested for an MLS successor to cover their increasing demands on synchrotron radiation. A combination of two different machines, one optimized for low emittance (BESSY III) and one for flexible timing capabilities (MLS II), would provide best radiation capabilities for our user community. In this paper, we discuss the demands on the MLS II and propose first lattice candidates which may meet the needs of the PTB and HZB. Currently, we focus on linear lattices for standard user mode with first steps towards nonlinear optimization.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB262
About •	paper received ※ 18 May 2021       paper accepted ※ 02 June 2021       issue date ※ 17 August 2021
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MOPAB263	Preliminary Beam Dynamics Studies for 200 MeV Superconducting Linac Planned at KOMAC	837
	S. Lee, J.J. Dang, H.S. Kim, H.-J. Kwon Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea Y.-S. Cho KAERI, Daejon, Republic of Korea
	Funding: This work has been supported through KOMAC operation fund of KAERI by the Korea government (MSIT). Korea Multi-purpose Accelerator Complex (KOMAC) is planning an energy upgrade of the existing 100 MeV proton linac to 200 MeV using a superconducting Half Wave Resonator (HWR) operating at 350 MHz. A cryomodule is planned to house four HWR cavities with a warm doublet focusing lattice structure. Matching between the already existing DTL section and HWR section is designed and studied. We report the preliminary study of the beam dynamics of the 200 MeV superconducting linac carried out at KOMAC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB263
About •	paper received ※ 20 May 2021       paper accepted ※ 01 July 2021       issue date ※ 24 August 2021
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MOPAB264	Commissioning of the DESIR High-Resolution Separator at CENBG	841
	J. Michaud, P. Alfaurt, A. Balana, B. Blank, L. Daudin, T. Kurtukian-Nieto, S. Leblanc, L.S. Serani CENBG, Gradignan, France F. Méot BNL, Upton, New York, USA F. Varenne GANIL, Caen, France
	DESIR is the low-energy part of the SPIRAL2 ISOL facility under construction at GANIL. The high-resolution mass separator (HRS) included in DESIR is a 180 degree symmetric online separator with two 90 degree magnetic dipole sections arranged with electrostatic quadrupoles, sextupoles and a multipole on the mid plane. The HRS is now completely mounted at CENBG and under commissioning for the next 2 to 3 years before its transfer at the entrance of the DESIR facility. The objective is to test, characterise and correct all HRS elements contributing to the higher order aberration by performing experimental measurements and comparing them with the results from different simulation tools. The recently mounted pepperpot-type emittance-meter will allow us to observe the emittance figures and dynamically tune the multipole to improve the optical parameters of the HRS. We will present the first results concerning the hexapolar correction with the multipole, the associated emittance measurements and the resolution currently achieved.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB264
About •	paper received ※ 19 May 2021       paper accepted ※ 08 June 2021       issue date ※ 10 August 2021
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MOPAB266	Start-to-End Study on Laser and RF Jitter Effects for MAX-IV SXL	844
	S.P. Pirani, B.S. Kyle MAX IV Laboratory, Lund University, Lund, Sweden F. Curbis, M.A. Pop, S. Werin Lund University, Lund, Sweden W. Qin DESY, Hamburg, Germany
	A Soft X-ray free electron laser (FEL) for the MAX IV Laboratory is currently in the design phase and it will use the existing 3 GeV linac. Present stability limits in the RF and the photocathode laser will affect the performance of the FEL. One of the critical elements for the design of a FEL is to have an estimation on jitter effects of the accelerator parameters on the X-ray radiation. In this regard, we implemented a start-to-end study using Astra, Elegant and Genesis in order to assess possible variations in pulse energy, photon pulse length and spectral width in the Soft X-ray Laser (SXL) radiation. This investigation provides insights on the final SXL performance variation due to RF and laser related jitter affecting the electron beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB266
About •	paper received ※ 19 May 2021       paper accepted ※ 26 July 2021       issue date ※ 24 August 2021
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MOPAB267	End to End Simulations of Antiproton Transport and Degradation	847
	S. Padden, E. Kukstas, P. Pusa, V. Rodin, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom K. Nordlund HIP, University of Helsinki, Finland V. Rodin, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The ELENA ring decelerates anti-protons to 100 keV down from 5.3 MeV with transport to experiments handled by electrostatic transfer lines. Even at 100 keV antiprotons are still too high in energy for direct injection into an ion trap, and this is why degrader foils are used to further lower the energy. This contribution presents full end-to-end simulations from the point of extraction until passing through the foil using realistic beam transport simulations coupled with accurate simulations of degrader foils via the use of density functional theory and molecular dynamics. Particles are tracked from the point of extraction until their injection into the trap with full physical modeling at all time steps. The results of this study provide a versatile platform for the optimization of low energy ion experiments towards specific targets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB267
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 24 August 2021
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MOPAB268	Design of a Continuous Wave Heavy Ion RFQ for BISOL	851
	S. Liu, M.Y. Han, Y.R. Lu, Q.Y. Tan, Z. Wang PKU, Beijing, People’s Republic of China
	The Beijing isotope separation online (BISOL) facility will be used to study the new physics and technologies at the limit of the nuclear stability. The post accelerator for BISOL facility aims to accelerate radioactive beams to 150MeV/u. As an injector for the downstream superconducting linac, a 4-vane RFQ operating at 81.25MHz is needed to accelerate high-charge-state ions such as 132Sn22+ from 3keV/u to 500keV/u in CW mode. We have compared two kinds of beam dynamics of BISOL RFQ with and without a Multi-Harmonic Buncher (MHB) bunching the continuous wave beam up-stream of the RFQ. The results indicate that it is possible to keep transverse emittance growth within tolerable limits while the longitudinal emittance is much smaller than the design without an external buncher. The acceleration of multi-charge beams simultaneously in the RFQ is also discussed in this paper.
	Poster MOPAB268 [1.829 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB268
About •	paper received ※ 19 May 2021       paper accepted ※ 25 May 2021       issue date ※ 16 August 2021
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MOPAB269	Three Approaches for Complete Measurement of the Transverse Beam Optics Along the Fermilab Muon Campus Extraction Line	854
	B.D. Simons, M.J. Syphers Northern Illinois University, DeKalb, Illinois, USA D. Stratakis, M.J. Syphers Fermilab, Batavia, Illinois, USA
	Funding: This work was supported through grant DE-SC0020379 with the United States Department of Energy. Traditionally, the process of measuring the optical parameters of a beamline has employed the use of one of two standard methods, namely the three-screen method or a quadrupole magnet scan. Both require either an area of zero dispersion to perform the measurements or knowledge of the dispersion function and momentum spread beforehand in order to provide accurate results. There is however a third method that can be used to measure the standard optical parameters, the beam parameters, the dispersion function, and the momentum spread simultaneously. This method, aptly named the six-screen method, is an extension of the more standard three-screen method. Utilizing the simulation environment of G4beamline, we simulated the 8 GeV proton beam in the M4 beamline and measured the optical and beam parameters using the two standard approaches. Those results were then used as a reference to check the viability of employing the less standard six-screen method in the M4 line. If shown to be a viable option, the six-screen method could be used to retrieve the dispersion function and momentum spread of the beam without needing to change the energy of the beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB269
About •	paper received ※ 20 May 2021       paper accepted ※ 07 June 2021       issue date ※ 12 August 2021
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MOPAB270	Beam Dynamics Studies in a Standing Wave Ka-band Linearizer	857
	J. Scifo, M. Behtouei, L. Faillace, M. Ferrario, A. Giribono, B. Spataro, C. Vaccarezza INFN/LNF, Frascati, Italy M. Migliorati INFN-Roma1, Rome, Italy M. Migliorati Sapienza University of Rome, Rome, Italy G. Torrisi INFN/LNS, Catania, Italy
	Next-generation FEL user facilities require high-quality electron beams with kA peak current. The combination of a high brightness RF injector and a magnetic compression stage represents a very performant solution in terms of electron beam emittance and peak current. One of the important issues is the design of a proper device that acts as a linearizer for the beam longitudinal phase space. Recently, the design of a SW Ka band RF accelerating structure has been proposed with promising results. The paper reports on electron beam dynamics studies in the described RF structure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB270
About •	paper received ※ 19 May 2021       paper accepted ※ 29 August 2021       issue date ※ 26 August 2021
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MOPAB272	Consideration the Prospects of Beam Diagnostic System Upgrade in the Transport Channels of Injection Complex VEPP-5	860
	K.V. Astrelina, F.A. Emanov BINP SB RAS, Novosibirsk, Russia F.A. Emanov NSU, Novosibirsk, Russia
	Transport electron and positron channels from linear accelerator to storage ring of Injection Complex VEPP-5 (BINP, Novosibirsk) have complicated 3D configuration and equipped only with luminophore screens as a beam test. For the regular machine operations the non-destructive beam diagnostic system is required to adjust the electron and positron beam trajectories and minimize the beam losses. The proposal of new beam position monitors (BPM) assembling is considered. Newly added BPMs allow one to control the beam trajectory during operations. Collecting beam position data in several points makes it possible to calculate and correct the beamline parameters: Twiss parameters, dispersion, beam energy variations. The possible configuration of the new BPMs placing is suggested and the rate of beam loss reducing due the additional diagnostics is estimated.
	Poster MOPAB272 [1.164 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB272
About •	paper received ※ 20 May 2021       paper accepted ※ 02 June 2021       issue date ※ 02 September 2021
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MOPAB273	Nonlinear Coupling Resonances in X-Y Coupled Betatron Oscillations Near the Main Coupling Resonance in VEPP-2000 Collider	863
	S.A. Kladov, E. Perevedentsev BINP SB RAS, Novosibirsk, Russia S.A. Kladov, E. Perevedentsev NSU, Novosibirsk, Russia
	In the vicinity of the linear coupling resonance where the working point of the collider is positioned, we study the effect of nonlinear coupling resonances on the single-particle phase space, beam sizes and the waveform of coherent beam motion. The latter is interesting for diagnostics of the nonlinear dynamics.
	Poster MOPAB273 [1.142 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB273
About •	paper received ※ 19 May 2021       paper accepted ※ 28 May 2021       issue date ※ 21 August 2021
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MOPAB274	Two-Stream Effects in Coherent Beam-Beam Oscillations in VEPP-2000 Collider Near the Linear Coupling Resonance	866
	S.A. Kladov, E. Perevedentsev BINP SB RAS, Novosibirsk, Russia S.A. Kladov, E. Perevedentsev NSU, Novosibirsk, Russia
	Synchro-betatron motion of colliding bunches may cause limitations of the high-luminosity performance. For a round beam collider operated near the linear coupling resonance, we present theoretical predictions of the beam-beam coherent synchro-betatron oscillation behavior under the influence of x-y coupling.
	Poster MOPAB274 [0.968 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB274
About •	paper received ※ 19 May 2021       paper accepted ※ 02 June 2021       issue date ※ 02 September 2021
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MOPAB275	Study on Supports of BPM Displacement Measurement System for HLS	870
	C.H. Wang, P. Lu, B.G. Sun, T.Y. Zhou USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Funding: National Synchrotron Radiation Laboratory HLS is the second-generation light source with energy of 800 MeV and emittance of less than 40 nm-rad. In order to improve the beam orbit stability and correct the errors introduced in the orbital feedback system due to movement of the vacuum chamber and BPM, a system for measuring BPM displacement will be built. It requires a high degree of mechanical and thermal stability for its supports. The support should have a higher eigen-frequency to minimize the amplification of ground vibration. In this paper, a series of simulation, including finite element analysis (FEA), measurement and analysis have been done upon the support to make sure it can meet the requirements of the stability of the BPM displacement measurement system.
	Poster MOPAB275 [1.025 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB275
About •	paper received ※ 18 May 2021       paper accepted ※ 21 May 2021       issue date ※ 26 August 2021
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MOPAB276	Investigation on the injection of the Arronax Cyclotron 70XP	873
	F. Poirier, F. Bulteau-Harel, T. Durand, X. Goiziou, C. Koumeir, C. Lassalle, H. Trichet Cyclotron ARRONAX, Saint-Herblain, France F. Haddad SUBATECH, Nantes, France
	Funding: This work is supported by grants from the ANR program "Investissements d’Avenir", n°ANR-11-EQPX-0004, n°ANR-11-LABX-18-01 and n°ANR-16-IDE-0007 and by a PhD scholarship from CNRS/IN2P3. A 70 MeV cyclotron is being used at the Arronax GIP (Interest Public Group), France, for various types of R&D on nuclear, biological and chemical reactions with beams and radioisotopes production. In order to adapt its usage for experiments and users demands of high peak intensity, above an equivalent average of a few µA, the injection is being adapted. Several studies are thus being performed in this section. These include the newly installed chopper-based system and the injection collimator. This paper details the various studies, specifically the signal purity obtained in the pulsed mode. A mode particularly adapted for flash irradiation.
	Poster MOPAB276 [2.522 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB276
About •	paper received ※ 19 May 2021       paper accepted ※ 23 June 2021       issue date ※ 15 August 2021
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MOPAB277	Installation, Use and Follow-Up of an Emittance-Meter at the Arronax Cyclotron 70XP	877
	F. Poirier, R. Bellamy, F. Bulteau-Harel, C. Castel, T. Durandpresenter, X. Goiziou, F. Haddad, C. Koumeir, R. Lelièvre, G. Mechin, L. Perrigaud, J. Poudevigne, H. Trichet Cyclotron ARRONAX, Saint-Herblain, France T. Adam, P.G. Graehling, M. Heine, C. Maazouzi, F.R. Osswald, E.K. Traykov IPHC, Strasbourg Cedex 2, France A. Dinkov, S. Wurth IJCLab, ORSAY, France F. Haddad SUBATECH, Nantes, France
	Funding: This work is supported by grants from the ANR program "Investissements d’Avenir", n°ANR-11-EQPX-0004, n°ANR-11-LABX-18-01 and n°ANR-16-IDE-0007 and by a PhD scholarship from CNRS/IN2P3. The 70 MeV cyclotron group of the Arronax GIP (Interest Public Group), France, foresees to increase its beam intensity on target. For this, several beam studies are being performed in the various sections of the accelerator including the injection. Thus, an Allison-type emittance-meter has been installed in this section above the cyclotron and downstream a quadrupole triplet. Installation and the first results of a campaign of measurements are presented including high intensity runs, up to 1 mA for 40 keV H− ions. The emittance-meter is expected to be used with several accelerators throughout the world. Therefore, a strategy on the follow-up of the activation of sample materials used in the equipment is being established and is described in the paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB277
About •	paper received ※ 17 May 2021       paper accepted ※ 27 May 2021       issue date ※ 12 August 2021
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MOPAB278	Prototype of the Bunch Arrival Time Monitor for SHINE	881
	X.Q. Liu, L.W. Lai SARI-CAS, Pudong, Shanghai, People’s Republic of China Y.B. Leng, R.X. Yuan, N. Zhang, Y.M. Zhou SSRF, Shanghai, People’s Republic of China
	Funding: Youth Innovation Promotion Association, CAS (Grant No. 2019290) Bunch arrival time monitor (BAM) is an important tool to investigate the temporal characteristic of electron bunch in free electron lasers (FEL). Since the timing jitter of electron bunch will affect the FEL’s stability and the resolution of time-resolved experiment at FELs, it is nec-essary to precisely measure the electron bunch’s arrival time information to stabilize the electron bunch’s timing jitter using beam-based feedback. The BAM based on electro-optic modulator (EOM) is currently being devel-oping for Shanghai high-repetition-rate XFEL and Ex-treme light facility (SHINE). And the first BAM prototype has been installed on SXFEL for beam test. The beam test result shows that the estimated resolution of the pro-totype is about 27.5 fs rms.
	Poster MOPAB278 [1.166 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB278
About •	paper received ※ 20 May 2021       paper accepted ※ 23 June 2021       issue date ※ 30 August 2021
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MOPAB279	Non-Invasive Beam Profile Monitoring for the HL-LHC Hollow Electron Lens	884
	A. Salehilashkajani, N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom M. Ady, N.S. Chritin, N. Jens, O.R. Jones, R. Kersevan, T. Lefèvre, S. Mazzoni, G. Papazoglou, A. Rossi, G. Schneider, R. Veness CERN, Geneva, Switzerland P. Forck, S. Udrea GSI, Darmstadt, Germany N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 and the STFC Cockcroft core grant No. ST/G008248/1. A Hollow Electron Lens (HEL) is currently under development for the High-Luminosity upgrade of the Large Hadron Collider (HL-LHC). In this device, a hollow electron beam co-propagates with a central proton beam and provides active halo control in the LHC. To ensure the concentricity of the two beams, a non-invasive diagnostic instrument is currently being commissioned. This instrument is a compact version of an existing prototype that leverages beam induced fluorescence with supersonic gas curtain technology. This contribution includes the design features of this version of the monitor, recent progress, and future plans for tests at the Cockcroft Institute and the electron lens test stand at CERN.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB279
About •	paper received ※ 18 May 2021       paper accepted ※ 15 June 2021       issue date ※ 02 September 2021
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MOPAB280	Split Ring Resonator Experiment - Simulation Results	888
	J. Schäfer, B. Härer, A. Malygin, A.-S. Müller, M. Nabinger, M.J. Nasse, T. Schmelzer, M. Schuh, T. Windbichler KIT, Karlsruhe, Germany
	Funding: Supported by "Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology (KSETA)" and European Union’s Horizon 2020 Research and Innovation programme. FLUTE (Ferninfrarot Linac- Und Test-Experiment) is a compact linac-based test facility for accelerator and diagnostics R&D. An example for a new accelerator diagnostics tool currently studied at FLUTE is the split-ring-resonator (SRR) experiment, which aims to measure the longitudinal bunch profile of fs-scale electron bunches. Laser-generated THz radiation is used to excite a high frequency oscillating electromagnetic field in the SRR. Particles passing through the SRR gap are time-dependently deflected in the vertical plane, which allows a vertical streaking of an electron bunch. This principle allows a diagnosis of the longitudinal bunch profile in the femtosecond time domain and will be tested at FLUTE. This contribution presents an overview of the SRR experiment and the results of various tracking simulations for different scenarios as a function of laser pulse length and bunch charge. Based on these results possible working points for the experiments at FLUTE will be proposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB280
About •	paper received ※ 19 May 2021       paper accepted ※ 21 June 2021       issue date ※ 01 September 2021
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MOPAB281	Research on Resolution Evaluation of Stripline BPM at SXFEL-UF	892
	B. Gao, J. Chen, Y.B. Leng SSRF, Shanghai, People’s Republic of China
	48 stripline BPMs are installed in the injection section and linear acceleration section of Shanghai X-ray Free Electron Laser (SXFEL) for electron beam position measurement. These two sections require resolution of 20 µm@100pC. Resolution evaluation is an important step in BPM installation and commissioning. This paper presents BPM resolution evaluation methods based on correlation analysis. Experimental methods, data processing and result analysis will be discussed
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB281
About •	paper received ※ 19 May 2021       paper accepted ※ 27 May 2021       issue date ※ 02 September 2021
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MOPAB282	Development of a Multi-Camera System for Non-Invasive Intense Ion Beam Investigations	895
	A. Ateş, H. Hähnel, U. Ratzinger, K. Volk, C. Wagner IAP, Frankfurt am Main, Germany
	The continued popularity of miniaturized cameras integrated into smartphones is leading to further research for more advanced CMOS camera sensors. This made CMOS technology even superior to scientific CCD cameras. Due to the lower power consumption and high flexibility, a multicamera system can be developed more effectively. At the Institute of Applied Physics at Goethe University Frankfurt (IAP) a prototype of a beam induced rest gas fluorescence monitor (BIF) was developed and tested successfully. The BIF consists of x and y single board cameras integrated into the vacuum chamber. A multi-camera system was installed in the LEBT area of the FRANZ project at the IAP within the first diagnostic chamber. This system consists of six cameras. With this equipment it is possible to investigate the beam along a 484 mm path in x and y direction. The developments on the reconstruction and image processing methods are in progress.
	Poster MOPAB282 [1.139 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB282
About •	paper received ※ 12 May 2021       paper accepted ※ 08 June 2021       issue date ※ 24 August 2021
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MOPAB283	Simulations of Space-Charge and Guiding Fields Effects on the Performance of Gas Jet Profile Monitoring	898
	O. Sedláček, N. Kumar, A. Salehilashkajani, C.P. Welsch, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom P. Forck, S. Udrea GSI, Darmstadt, Germany N. Kumar, A. Salehilashkajani, O. Sedláček, C.P. Welsch, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom S. Mazzoni, O. Sedláček CERN, Geneva, Switzerland
	Gas jet based profile monitors inject a usually curtain shaped gas jet across a charged particle beam and exploit the results of the minimally invasive beam-gas interaction to provide information about the beam’s transversal profile. Such monitor will be installed as part of the High Luminosity LHC upgrade at CERN in the Hollow Electron Lens (HEL). The HEL represents a new collimation stage increasing the diffusion rate of halo particles by placing a high intensity hollow electron beam concentrically around the LHC beam. The gas jet monitor will use the fluorescence radiation resulting due to the beam-gas interaction to create an image of the profiles of both hollow electron and LHC beams However, the high beam space-charge and strong guiding magnetic field of the electron beam cause significant displacements of the excited molecules, as they are also ionized, and thus image distortions. This work presents preliminary simulation results showing expected fluorescence images of the hollow electron profile as affected by space-charge and guiding fields using simulation tools such as IPMsim. The influence of the estimated electron beam and gas jet curtain parameters are investigated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB283
About •	paper received ※ 18 May 2021       paper accepted ※ 28 July 2021       issue date ※ 19 August 2021
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MOPAB284	Status of the Dedicated Electron Diagnostic Beamline at AXSIS	902
	H. Dinter, R.W. Aßmann, F. Burkart, M.J. Kellermeier DESY, Hamburg, Germany C. Lechner EuXFEL, Schenefeld, Germany
	Funding: The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. 609920. AXSIS (Attosecond X-ray Science: Imaging and Spectroscopy) is a compact, accelerator-driven X-ray source currently under construction at DESY Hamburg. It comprises a THz-powered electron gun and THz-driven linac for all-optical electron extraction and acceleration to several MeV with the goal of providing X-rays generated by inverse Compton scattering for photon science experiments. For the commissioning and characterisation of the THz gun and linac the facility includes a dedicated accelerator testing area, for which an electron diagnostic beamline has been designed and is currently under construction. The challenges imposed by the AXSIS project on the development of the diagnostics beamline are the wide ranges of bunch charge (15 fC to 3 pC) and energy (5 MeV to 20 MeV) expected from the THz-driven accelerator as well as the limited available space of only ca. 2.5 metres length. In this contribution we present an overview of the design and the current commissioning status of the electron diagnostic beamline as well as plans for future steps.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB284
About •	paper received ※ 19 May 2021       paper accepted ※ 18 June 2021       issue date ※ 25 August 2021
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MOPAB286	Towards a Data Science Enabled MeV Ultrafast Electron Diffraction System	906
	M.A. Fazio, S. Biedron, M. Martínez-Ramón, D.J. Monk, S.I. Sosa Guitron UNM-ECE, Albuquerque, USA M. Babzien, K.A. Brown, M.G. Fedurin, J.J. Li, M.A. Palmer, J. Tao BNL, Upton, New York, USA S. Biedron, T. Talbott UNM-ME, Albuquerque, New Mexico, USA J. Chen, A.J. Hurd, N.A. Moody, R. Prasankumar, C. Sweeney LANL, Los Alamos, New Mexico, USA D. Martin, M.E. Papka ANL, Lemont, Illinois, USA
	Funding: US DOE, SC, BES, MSE, award DE-SC0021365 and DOE NNSA award 89233218CNA000001 through DOE’s EPSCoR program in Office of BES with resources of DOE SC User Facilities BNL’s ATF and ALCF. A MeV ultrafast electron diffraction (MUED) instrument is a unique characterization technique to study ultrafast processes in materials by a pump-probe technique. This relatively young technology can be advanced further into a turn-key instrument by using data science and artificial intelligence (AI) mechanisms in conjunctions with high-performance computing. This can facilitate automated operation, data acquisition and real time or near- real time processing. AI based system controls can provide real time feedback on the electron beam which is currently not possible due to the use of destructive diagnostics. Deep learning can be applied to the MUED diffraction patterns to recover valuable information on subtle lattice variations that can lead to a greater understanding of a wide range of material systems. A data science enabled MUED facility will also facilitate the application of this technique, expand its user base, and provide a fully automated state-of-the-art instrument. We will discuss the progress made on the MUED instrument in the Accelerator Test Facility of Brookhaven National Laboratory.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB286
About •	paper received ※ 20 May 2021       paper accepted ※ 09 June 2021       issue date ※ 25 August 2021
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MOPAB287	The Development of Single Pulse High Dynamic Range BPM Signal Detector Design at AWA	909
	E.M. Siebert, S. Baturin Northern Illinois University, DeKalb, Illinois, USA D.S. Doran, G. Ha, W. Liu, P. Piot, J.G. Power, J.H. Shao, C. Whiteford, E.E. Wisniewski ANL, Lemont, Illinois, USA
	Funding: the US Department of Energy, Office of Science Single pulse high dynamic range BPM signal detector has been on the most wanted list of Argonne Wakefield Accelerator (AWA) Test Facility for many years. Unique capabilities of AWA beamline require BPM instrumentation with an unprecedented dynamic range, thus cost effective solution could be challenging to design and prototype. Our most recent design, and the results of our quest for a solution, are shared in this paper.
	Poster MOPAB287 [1.372 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB287
About •	paper received ※ 19 May 2021       paper accepted ※ 23 June 2021       issue date ※ 13 August 2021
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MOPAB288	Real-Time Edge AI for Distributed Systems (READS): Progress on Beam Loss De-Blending for the Fermilab Main Injector and Recycler	912
	K.J. Hazelwood, M.R. Austin, M.A. Ibrahim, V.P. Nagaslaev, A. Narayanan, D.J. Nicklaus, A.L. Saewert, B.A. Schupbach, K. Seiya, R.M. Thurman-Keup, N.V. Tran Fermilab, Batavia, Illinois, USA H. Liu, S. Memik, R. Shi, M. Thieme Northwestern University, Evanston, Illinois, USA A. Narayanan Northern Illinois University, DeKalb, Illinois, USA
	The Fermilab Main Injector enclosure houses two accelerators, the Main Injector and Recycler. During normal operation, high intensity proton beams exist simultaneously in both. The two accelerators share the same beam loss monitors (BLM) and monitoring system. Beam losses in the Main Injector enclosure are monitored for tuning the accelerators and machine protection. Losses are currently attributed to a specific machine based on timing. However, this method alone is insufficient and often inaccurate, resulting in more difficult machine tuning and unnecessary machine downtime. Machine experts can often distinguish the correct source of beam loss. This suggests a machine learning (ML) model may be producible to help de-blend losses between machines. Work is underway as part of the Fermilab Real-time Edge AI for Distributed Systems Project (READS) to develop a ML empowered system that collects streamed BLM data and additional machine readings to infer in real-time, which machine generated beam loss.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB288
About •	paper received ※ 19 May 2021       paper accepted ※ 29 July 2021       issue date ※ 13 August 2021
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MOPAB289	Machine Learning Training for HOM reduction and Emittance Preservation in a TESLA-type Cryomodule at FAST	916
	J.A. Diaz Cruz UNM-ECE, Albuquerque, USA J.A. Diaz Cruz, A.L. Edelen, B.T. Jacobson, J.P. Sikora SLAC, Menlo Park, California, USA D.R. Edstrom, A.H. Lumpkin, R.M. Thurman-Keup Fermilab, Batavia, Illinois, USA
	Low emittance electron beams are of high importance at facilities like the LCLS-II at SLAC. Emittance dilution effects due to off-axis beam transport for a TESLA-type cryomodule (CM) have been shown at the Fermilab Accelerator Science and Technology facility. The results showed the correlation between the electron beam-induced cavity high-order modes (HOMs) and submacropulse centroid slewing and oscillation downstream of the CM. Mitigation of emittance dilution can be achieved by reducing the HOM signals and the variances in the submacropulse beam positions downstream of the CM. Here we present a Machine Learning based optimization and model construction for HOM signal level reduction using Neural Networks and Gaussian Processes. To gather training data we performed experiments using single bunch and 50 bunch electron beams with charges up to 125 pC/b. We measured HOM signals of all cavities and beam position with a set of BPMs downstream of the CM. The beam trajectory was changed using V/H125 corrector set located upstream of the CM. The results presented here will inform the LCLS-II injector commissioning and will serve as a prototype for HOM reduction and emittance preservation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB289
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 14 August 2021
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MOPAB290	Machine Learning-Based LLRF and Resonance Control of Superconducting Cavities	920
	J.A. Diaz Cruz, S. Biedron, M. Martínez-Ramón UNM-ECE, Albuquerque, USA J.A. Diaz Cruz SLAC, Menlo Park, California, USA R. Pirayesh UNM-ME, Albuquerque, New Mexico, USA S. Sosa ODU, Norfolk, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics, under award number DE-SC0019468. Superconducting radio frequency (SRF) cavities with high loaded quality factors that operate in continuous wave (CW) and low beam loading are sensitive to microphonics-induced detuning. Cavity detuning can result in an increase of operational power and/or in a cavity quench. Such SRF cavities have bandwidths on the order of 10 Hz and detuning requirements can be as tight as 10 Hz. Passive methods to mitigate vibration sources and their impact in the cryomodule/cavity environment are widely used. Active resonance control techniques that use stepper motors and piezoelectric actuators to tune the cavity resonance frequency by compensating for microphonics detuning have been investigated. These control techniques could be further improved by applying Machine Learning (ML), which has shown promising results in other particle accelerator control systems. In this paper, we describe a Low-level RF (LLRF) and resonance control system based on ML methods that optimally and adaptively tunes the control parameters. We present simulations and test results obtained using a low power test bench with a cavity emulator.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB290
About •	paper received ※ 03 June 2021       paper accepted ※ 11 June 2021       issue date ※ 29 August 2021
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MOPAB291	Design of Cavity BPM Pickup for EuPRAXIA@SPARC_LAB	924
	Sh. Bilanishvili INFN/LNF, Frascati (Roma), Italy
	EuPRAXIA@SPARC_LAB will make available at LNF a unique combination offering three different options. A high-brightness electron beam with 1 GeV energy generated in a novel X-band RF linac; A PW-class laser system, and a compact light-source directly driven by a plasma accelerator*. Plasma and conventional RF linac driven FEL provide beam with parameters of 30- 200pC charge range, 10-100Hz repetition rate, and 1 GeV electron energy**. The control of the charge and the trajectory monitoring at a few pC and a few um is mandatory in this machine. Particularly in the plasma interaction region, where the pickup resolution under 1 um is required. As a possible solution, a cavity beam position monitor (cBPM) is proposed. A prototype in the C-band frequency range has been designed. The pickup was optimized for low charge and single-shot bunches. The poster presents the process to achieve the required specifications. The simulations were performed to study RF properties and the electromagnetic response of the device. Finally, the overall performance of the pickup is discussed, and theoretical resolution is approximated. * https://www.researchgate.net/publication/335459394FromSPARCLABtoEuPRAXIASPARC_LAB **http://www.lnf.infn.it/sis/preprint/detail-new.php?id=5416
	Poster MOPAB291 [16.718 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB291
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 23 August 2021
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MOPAB293	Electro-Optical Diagnostics at KARA and FLUTE - Results and Prospects	927
	G. Niehues, E. Bründermann, M. Caselle, S. Funkner, A.-S. Müller, M.J. Nasse, M.M. Patil, R. Ruprecht, M. Schuh, M. Weber, C. Widmann KIT, Karlsruhe, Germany
	Funding: S.F. was funded by BMBF contract No. 05K16VKA, C. W. by BMBF contract number 05K19VKD. G.N. and E.B. acknowledge support by the Helmholtz President’s strategic fund IVF "Plasma Accelerators". Electro-optical (EO) methods are nowadays well-proven diagnostic tools, which are utilized to detect THz fields in countless experiments. The world’s first near-field EO sampling monitor at an electron storage ring was developed and installed at the KIT storage ring KARA (Karlsruhe Research Accelerator) and optimized to detect longitudinal bunch profiles. This experiment with other diagnostic techniques builds a distributed, synchronized sensor network to gain comprehensive data about the phase-space of electron bunches as well as the produced coherent synchrotron radiation (CSR). These measurements facilitate studies of physical conditions to provide, at the end, intense and stable CSR in the THz range. At KIT, we also operate FLUTE (Ferninfrarot Linac- und Test-Experiment), a new compact versatile linear accelerator as a test facility for novel techniques and diagnostics. There, EO diagnostics will be implemented to open up possibilities to evaluate and compare new techniques for longitudinal bunch diagnostics. In this contribution, we will give an overview of results achieved, the current status of the EO diagnostic setups at KARA and FLUTE and discuss future prospects.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB293
About •	paper received ※ 19 May 2021       paper accepted ※ 07 July 2021       issue date ※ 17 August 2021
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MOPAB294	Implementing Electro-Optical Diagnostics for Measuring the CSR Far-Field at KARA	931
	C. Widmann, E. Bründermann, M. Caselle, S. Funkner, A.-S. Müller, M.J. Nasse, G. Niehues, M.M. Patil, C. Sax, J.L. Steinmann, M. Weber KIT, Karlsruhe, Germany C. Mai DELTA, Dortmund, Germany
	Funding: This work was supported by BMBF ErUM-Pro project 05K19 STARTRAC, C.W. was funded under contract No. 05K19VDK, C.M. under contract No. 05K19PEC, S.F. under contract No. 05K16VKA. For measuring the temporal profile of the coherent synchrotron radiation (CSR) at the KIT storage ring KARA (Karlsruhe Research Accelerator) an experimental setup based on electro-optical spectral decoding (EOSD) is currently being implemented. The EOSD technique allows single-shot, phase-sensitive measurements of the far-field radiation on a turn-by-turn basis at rates in the MHz range. Therefore, the resulting THz radiation from the dynamics of the bunch evolution, e.g. the microbunching, can be observed with high temporal resolution. This far-field setup is part of the distributed sensor network at KARA. Additionally to the information acquired from the near-field EOSD spectral decoding and the horizontal bunch profile monitor, it enables to monitor the longitudinal phase-space of the bunch. In this contribution, the characterization of the far-field setup is summarized and its implementation is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB294
About •	paper received ※ 19 May 2021       paper accepted ※ 07 June 2021       issue date ※ 18 August 2021
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MOPAB295	Simulation Study of Emittance Measurement Using a Genetic Algorithm for Space Charge Dominated Beams	935
	H.D. Zhang, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom
	Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 under and the STFC Cockcroft core grant No. ST/G008248/1. The quadrupole scan method is one of the traditional ways to measure beam emittance in an accelerator. The required devices are simple: several quadrupole magnets and a beam profile monitor. Beam sizes are measured from the beam profile monitor with different quadrupole settings to bring the beam through its waist and then fitted to a quadratic equation to determine the Twiss parameters. measured data from a quadrupole scan taking the beam through its waist is fitted to a quadratic equation and this allows determining the Twiss parameters. However, with increasing beam intensity, the transfer function becomes non-linear and this causes a deviation of the fitted emittance from its real value, making it no longer useful. In this contribution, a genetic algorithm is applied to find the optimum quadrupole scan fit in space-charge dominated electron beams. Results from simulations using different space charge levels are presented and scenarios identified where this method can be applied.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB295
About •	paper received ※ 19 May 2021       paper accepted ※ 28 May 2021       issue date ※ 02 September 2021
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MOPAB296	Statistical Analysis of 2D Single-Shot PPRE Bunch Measurements	939
	M. Koopmans, J.-G. Hwang, A. Jankowiak, M. Ries, A. Schälicke, G. Schiwietz HZB, Berlin, Germany
	The pulse picking by resonant excitation (PPRE) method* is used to realize pseudo single-bunch radiation from a complex filling pattern at the BESSY II storage ring. The PPRE bunch is excited in the horizontal plane by a quasi-resonant incoherent perturbation to increase the emittance of this bunch**. Therefore, the synchrotron light of the PPRE bunch can be separated by collimation from the radiation of the main bunch train at dedicated beamlines for timing users. The properties of the PPRE bunch depend on the storage ring settings and on the excitation parameters. It is not trivial to distinguish between the wanted intrinsic bunch broadening and an additional position fluctuation of the PPRE bunch. Using the potential of the new diagnostics beamline with the possibility to observe an additional spatial dimension with a fast streak camera, we introduce a new method to study the properties of the PPRE bunch***. Applying a statistical analysis to a series of single-turn images enables distinguishing between horizontal orbit motion and the broadening of the bunch due to the excitation. Measurements are presented and the results are compared with data from the BPM system. * K. Holldack et al., Nature Commun. 5 (2014) 4010. ** J.-G. Hwang et al., Nucl. Instrum. Methods A940 (2019) 387. *** G. Schiwietz et al., Nucl. Instrum. Methods A990 (2021) 164992.
	Poster MOPAB296 [2.074 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB296
About •	paper received ※ 19 May 2021       paper accepted ※ 02 June 2021       issue date ※ 23 August 2021
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MOPAB299	STRUCTURAL OPTIMIZATION DESIGN OF FARADAY CUP FOR BEAM COMMISSIONING OF CSNS	943
	A.X. Wang, L. Kang, M. Meng, J.L. Sun IHEP, Beijing, People’s Republic of China J.X. Chenpresenter, H.Y. He, L. Liu, R.H. Liu, X.J. Nie, C.J. Ning, R.Y. Qiu, G.Y. Wang, T. Yang, J.B. Yu, Y.J. Yu, J.S. Zhang, D.H. Zhu IHEP CSNS, Guangdong Province, People’s Republic of China
	Faraday cup is used to absorb and stop the beam during the two phases of beam commissioning, such as the front end (FE) system and the temporary line after the drift tube linac (DTL) at the Chinese Spallation Neutron Source (CSNS). According to the beam physical parameters, graphite is selected to stop the beam directly, and oxygen-free copper which is just behind the graphite as the thermal conductive material. By the analysis and comparison of the target type and cooling efficiency, the single slant target is adopted. The incident angle between the target surface and the beam is set as 10°, meanwhile a new waterfall type water-cooling structure with parallel tunnels is designed to improve the cooling efficiency. The finite element software ANSYS is used for thermal analysis of the model, by which the diameter and interval of water cooling tunnels are optimized. The faraday cup discussed in this paper is finally successfully installed in the beam commissioning line and went well.
	Poster MOPAB299 [1.113 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB299
About •	paper received ※ 13 May 2021       paper accepted ※ 08 July 2021       issue date ※ 19 August 2021
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MOPAB300	Description of the Beam Diagnostics Systems for the SOCIT, SODIT and SODIB Applied Research Stations Based on the NICA Accelerator Complex	946
	A. Slivin, A. Agapov, A.A. Baldin, A.V. Butenko, G.A. Filatov, K.N. Shipulin, E. Syresin, G.N. Timoshenko, A. Tuzikov JINR, Dubna, Moscow Region, Russia D.V. Bobrovskiy, A.I. Chumakov, S. Soloviev MEPhI, Moscow, Russia I.L. Glebov, V.A. Luzanov GIRO-PROM, Dubna, Moscow Region, Russia A.S. Kubankin BelSU, Belgorod, Russia T. Kulevoy, Y.E. Titarenko ITEP, Moscow, Russia
	Within the framework of the NICA project an Innovation Block is being constructed. It includes an applied research station for microchips with a package for Single Event Effects (SEE) testing (energy range of 150-500 MeV/n, the SODIT station), an applied research station for testing of decapsulated microchips (ion energy up to 3,2 MeV/n, the SOCIT station), and an applied research station for space radiobiological research and modelling of influence of heavy charged particles on cognitive functions of the brain of small laboratory animals and primates (energy range 500-1000 MeV/n, the SODIB station). The systems for diagnostics and control of the beam characteristics during the certification and adjustment as well as the systems for online diagnostics and control of the beam characteristics of the SOCIT, SODIT and SODIB applied research stations are described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB300
About •	paper received ※ 19 May 2021       paper accepted ※ 27 May 2021       issue date ※ 23 August 2021
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MOPAB301	A Concept for Reconstruction of the Capsulated Microchip Structure Using Its Interaction with High-Energy Ion Beams of the NICA Accelerator Complex	949
	A. Slivin, A.V. Butenko, G.A. Filatov, E. Syresin, A. Tuzikov, A. Zhemchugov JINR, Dubna, Moscow Region, Russia
	Within the framework of the NICA project an applied research station for irradiation by long-range ions (SODIT) is being constructed for testing radiation hardness of semiconductor micro- and nanoelectronics products in the energy range of 150-350 MeV/n. Calculations for the interaction of high-energy gold ions with the microchip and strip detector structures are performed using the GEANT4 simulation toolkit. A concept was developed for reconstruction of the capsulated microchip structure in terms of depth and in terms of cross-section using interaction with high-energy ions at the technical station for irradiation by long-range ions. The possibility of localizing the radiation-vulnerable area of the microchip is evaluated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB301
About •	paper received ※ 19 May 2021       paper accepted ※ 20 May 2021       issue date ※ 17 August 2021
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MOPAB302	Characterization of the Full Transverse Phase Space of Electron Bunches at ARES	952
	S. Jaster-Merz, R.W. Aßmann, R. Brinkmann, F. Burkart, H. Dinter, W. Kuropka, F. Mayet, T. Vinatier DESY, Hamburg, Germany R.W. Aßmann INFN/LNF, Frascati, Italy S. Jaster-Merz University of Hamburg, Hamburg, Germany
	The ARES linear accelerator at the SINBAD facility (DESY) is dedicated to perform accelerator R&D studies with sub-fs short electron bunches to test novel acceleration techniques and diagnostics devices. Currently, the commissioning of the linac is ongoing and first experiments are being performed. For this, the knowledge of the full phase space of the particle beams is of high interest to, for example, optimize the accelerator performance and identify possible errors in the beam line. Tomographic methods can be used to gain insight into the full 4D transverse phase space and its correlations. Here, simulation results and first experimental preparations of a 4D transverse phase-space tomography of electron bunches at ARES are presented and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB302
About •	paper received ※ 17 May 2021       paper accepted ※ 16 June 2021       issue date ※ 30 August 2021
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MOPAB303	Design of the X-Ray Beam Size Monitor for the Advanced Photon Source Upgrade	956
	K.P. Wootton, F.K. Anthony, K. Belcher, J.S. Budz, J. Carwardine, W.X. Cheng, S. Chitra, G. Decker, S.J. Izzo, S.H. Lee, J. Lenner, Z. Liu, P. McNamara, H.V. Nguyen, F.S. Rafael, C. Roehrig, J. Runchey, N. Sereno, G. Shen, J.B. Stevens, B.X. Yang ANL, Lemont, Illinois, USA
	Funding: This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. A beam size monitor provides an intuitive display of the status of the beam profile and motion in an accelerator. In the present work, we outline the design of the X-ray electron beam size monitor for the Advanced Photon Source Upgrade. Components and anticipated performance characteristics of the beam size monitor are outlined.
	Poster MOPAB303 [0.577 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB303
About •	paper received ※ 18 May 2021       paper accepted ※ 02 June 2021       issue date ※ 24 August 2021
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MOPAB304	Beam Diagnostics for Multi-Objective Bayesian Optimization at the Argonne Wakefield Accelerator Facility	960
	J.P. Gonzalez-Aguilera, Y.K. Kim University of Chicago, Chicago, Illinois, USA W. Liu, P. Piot, J.G. Power, E.E. Wisniewski ANL, Lemont, Illinois, USA R.J. Roussel Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
	Particle accelerators must achieve certain beam quality objectives for use in different experiments. Usually, optimizing certain beam objectives comes at the expense of others. Additionally, there are many input parameters and a limited number of diagnostics. Therefore, accelerator tuning becomes a multi-objective optimization problem with a limited number of observations. Multi-objective Bayesian optimization was recently proposed as an efficient method to find the Pareto front for an online accelerator tuning problem with reduced number of observations. In order to experimentally test the multi-objective Bayesian optimization method, a novel accelerator diagnostic is being designed to measure multiple beam quality metrics of an electron beam at the Argonne Wakefield Accelerator Facility. Here, we present a design consisting in a pepper-pot mask, a dipole magnet and a scintillation screen, which allows a simultaneous measurement of the electron beam energy spread and vertical emittance. Additionally, a surrogate model for the vertical emittance was constructed with only 60 observations and without prior knowledge of the objective function nor diagnostics constraints.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB304
About •	paper received ※ 18 May 2021       paper accepted ※ 08 June 2021       issue date ※ 26 August 2021
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MOPAB310	Vertical Phase Space Measurement Progress at Canadian Light Source	963
	Y. Yousefi Sigari, D. Bertwistle, M.J. Boland CLS, Saskatoon, Saskatchewan, Canada M.J. Boland University of Saskatchewan, Saskatoon, Canada
	A key feature of third-generation light sources is their small vertical opening angle, which is difficult to measure experimentally. To reconstruct the vertical phase space, one can scan the beam’s position using X-ray synchrotron radiation (XSR) and a pinhole camera. The XSR diagnostic beamline, operational in the wavelength region of 0.05 - 0.15 nm, in Canadian Light Source (CLS) is qualified to measure the beam position with X-ray radiation. Using the corrector magnets in CLS lattice made of 12 identical double-bend achromats (DBA) cells, vertical iterations can be executed parallel to the beam’s original orbit. The outcomes of this experiment are: 1) the vertical beam positions that are monitored by BPMs, and 2) the X-ray image of the beam that is projected through the pinhole. The bumps were simulated using Matlab Middle Layer (MML) for Accelerator control systems to get an insight of the source point’s position in the XSR’s bending magnet. The simulation shows the position of the source point depends on which corrector sets are chosen.
	Poster MOPAB310 [0.328 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB310
About •	paper received ※ 19 May 2021       paper accepted ※ 28 July 2021       issue date ※ 13 August 2021
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MOPAB313	Argonaut - A Robotic System for Cryogenic Environments	966
	W. Pellico, N.M. Curfman, M. Wong-Squires Fermilab, Batavia, Illinois, USA
	Funding: Department of Energy Fermilab and the HEP community invest significant resources into liquid argon detectors. The largest and most expensive of these detectors will be located in the Deep Underground Neutrino Experiment (DUNE). However, recent experiences have shown that there are limited avenues of monitoring, intervention, and interaction in the internal liquid environment. This proposal shows a technological path that could provide a valuable tool to ensure or at least improve the management of these HEP detectors. The development of a robotic system named Argonaut will demonstrate several technologies including 1) demonstration of suitable mobility of a small robotic device at liquid argon temperatures, 2) demonstration of wireless communication, 3) demonstration of improved diagnostics capabilities - such as tunable optics with motion control, 4) demonstration of interconnectivity of a robotic system with hardware residing within the detector. This initial research will be a seed for extended development in cold robotics and associated technologies. This work will allow FNAL to contribute a significant technology capability to recent efforts to cryogenic detector operations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB313
About •	paper received ※ 19 May 2021       paper accepted ※ 21 May 2021       issue date ※ 25 August 2021
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MOPAB314	Surrogate Modeling for MUED with Neural Networks	970
	D.J. Monk, S. Biedron, M.A. Fazio, M. Martínez-Ramón, S.I. Sosa Guitron UNM-ECE, Albuquerque, USA M. Babzien, K.A. Brown, M.A. Palmer, J. Tao BNL, Upton, New York, USA D. Martin, M.E. Papka ANL, Lemont, Illinois, USA T. Talbott UNM-ME, Albuquerque, New Mexico, USA
	Electron diffraction is among the most complex and influential inventions of the last century and contributes to research in many areas of physics and engineering. Not only does it aid in problems like materials and plasma research, electron diffraction systems like the MeV ultra-fast electron diffraction(MUED) instrument at the Brookhaven National Lab(BNL) also present opportunities to explore/implement surrogate modeling methods using artificial intelligence/machine learning/deep learning algorithms. Running the MUED system requires extended periods of uninterrupted runtime, skilled operators, and many varying parameters that depend on the desired output. These problems lend themselves to techniques based on neural networks(NNs), which are suited to modeling, system controls, and analysis of time-varying/multi-parameter systems. NNs can be deployed in model-based control areas and can be used simulate control designs, planned experiments, and to simulate employment of new components. Surrogate models based on NNs provide fast and accurate results, ideal for real-time control systems during continuous operation and may be used to identify irregular beam behavior as they develop.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB314
About •	paper received ※ 20 May 2021       paper accepted ※ 07 June 2021       issue date ※ 15 August 2021
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MOPAB315	Beam Diagnostics for Commissioning and Operation of the FAIR Proton Linac	972
	T. Sieber, P. Forck, S. Udrea GSI, Darmstadt, Germany J. Herranz, A. Vizcaino-de-Julian Proactive Research and Development, Sabadell, Spain
	For the planned antiproton experiments at FAIR a dedicated proton injector Linac is currently under construction. It will be connected via the old UNILAC transfer beamline to SIS18 and has a length of ~30 m. The Linac will accelerate protons up to a final energy of 68 MeV, at a pulse length of 35 µs and a maximum repetition rate of 4 Hz. It will operate at 325 MHz and consists of a new so called "Ladder" RFQ type, followed by a chain of CH-cavities, partially coupled by rf-coupling cells. We have worked out a diagnostics system, which allows detailed measurement and study of all beam parameters during commissioning and later during regular operation. The diagnostics devices will - in a first step - be installed on a diagnostics testbench for stepwise commissioning. We present the concepts for Linac and testbench with some special emphasis on energy measurements with spectrometer and SEM Grid profile measurements.
	Poster MOPAB315 [3.149 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB315
About •	paper received ※ 14 May 2021       paper accepted ※ 24 June 2021       issue date ※ 30 August 2021
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MOPAB316	Commissioning the New CERN Beam Instrumentation Following the Upgrade of the LHC Injector Chain	976
	F. Roncarolo, S. Bart Pedersen, J.M. Belleman, D. Belohrad, M. Bozzolan, C. Bracco, S. Di Carlo, J. Emery, A. Goldblatt, A. Guerrero, S. Levasseur, A. Navarro Fernandez, E. Renner, H.S. Sandberg, J.W. Storey, J. Tan, J. Tassan-Viol CERN, Geneva, Switzerland A. Navarro Fernandez UPC, Barcelona, Spain E. Renner TU Vienna, Wien, Austria
	The LHC injectors Upgrade (LIU) program has been fully implemented during the second long shutdown (LS2), which took place in 2019-20. In this context, new or upgraded beam instrumentation was developed to cope with H− beam in LINAC4 and the new Proton Synchrotron Booster (PSB) injection systems which would provide high brightness proton beams in the rest of the injector complex. After a short overview of the newly installed diagnostics, the main focus of this paper will move to the instruments already commissioned with the beam. This will include LINAC4 diagnostics, the PSB H0/H− monitor, the PSB Trajectory Measurement System, and the PS beam gas ionization monitor. In addition, particular emphasis will be given to the first operational experience with the new generation of fast wire scanners installed in all injector synchronous.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB316
About •	paper received ※ 19 May 2021       paper accepted ※ 17 June 2021       issue date ※ 14 August 2021
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MOPAB318	Beam Characterization of Five Electrode ECR Ion Source	980
	H.M. Kewlani, S. Gharat, S. Krishnagopal, J.V. Mathew, S.V.L.S. Rao BARC, Mumbai, India B. Dikshit, H.M. Kewlani, S. Krishnagopal Homi Bhbha National Institute (HBNI), DAE, Mumbai, India
	A five electrode ECR Ion Source (ECRIS) was developed for the Low Energy High-Intensity Proton Accelerator (LEHIPA) at BARC. The ECRIS is operated at the energy of 50 keV with a beam current of 20 mA. The ECRIS characterization is done for the beam current, beam emittance, and proton fraction in continuous and pulse beam operation. The pulsed beam operation of the ion source starting from 500 µs to 200 ms of pulse on time with a repetition rate of 1 to 10 Hz. The transverse beam emittance measurement is done by using an Allison scanner. The beam emittance characterization experiments are conducted by varying applied microwave power to the plasma, operating gas pressure of plasma and puller voltage. The measured beam emittance is in the range of 0.3 pi.mm. mrad to 0.4 pi.mm. mrad for 50 keV beam. In this paper beam emittance experiment setup and results are discussed.
	Poster MOPAB318 [2.496 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB318
About •	paper received ※ 19 May 2021       paper accepted ※ 10 June 2021       issue date ※ 16 August 2021
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MOPAB319	Development of a Fast Betatron Tune and Chromaticity Measurement System for COSY	983
	P.J. Niedermayer, C. Böhme, B. Breitkreutz, V. Kamerdzhiev, A. Lehrach FZJ, Jülich, Germany A. Lehrach RWTH, Aachen, Germany
	A fast tune measurement is developed for the Cooler Synchrotron COSY at the Institut für Kernphysik of Forschungszentrum Jülich. Betatron oscillations of the beam are excited with a band-limited RF signal via a stripline kicker. Resonant transverse oscillations are then observed using capacitive beam position monitors. Based on the bunch-by-bunch beam position data the betatron tune is determined. The usage of bunch-by-bunch data is characteristic of the new system. It allows for a discrete tune measurement within a few milliseconds, as well as continuous tune monitoring during beam acceleration. The high precision tune measurement also enables determination of the beam chromaticity. Therefore, the beam momentum is varied by means of the RF frequency and the subsequent tune change is determined. For routine use during beam operation and experiments, the developed method is integrated into the control system.
	Poster MOPAB319 [1.209 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB319
About •	paper received ※ 19 May 2021       paper accepted ※ 16 June 2021       issue date ※ 12 August 2021
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MOPAB320	The CMS ECAL Enfourneur: A Gigantic Machine with a Soft Touch	986
	V. Pettinacci INFN-Roma, Roma, Italy
	The electromagnetic calorimeter (ECAL) of the CMS experiment at the LHC is composed of 75848 scintillating lead tungstate crystals arranged in a barrel section and two endcaps. The barrel part is made of 36 supermodules (SM), 2.7 tons each, and is installed inside the CMS magnet. There are 18 SMs on each side of CMS, with each SM containing 1700 crystals. During Long Shutdown 3, all ECAL SMs must be extracted to refurbish the electronics in preparation for HL-LHC. A dedicated machine called the "Enfourneur" is used to extract and re-insert the SMs inside CMS, with a required accuracy of about 1mm. In order to speed up the extraction and insertion process, two Enfourneurs will be employed, operating in parallel on both sides. In view of the purchase of the second Enfourneur, the design has been improved, starting from the feedback of past operations. The improvements to the new Enfourneur design include increased space for the operators, optimization of the operations and the controls with the use of electric motors, and an updated alignment system. Handling plans inside the CMS cavern have been defined in order to be compliant with the rest of CMS structures and procedures.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB320
About •	paper received ※ 11 May 2021       paper accepted ※ 17 August 2021       issue date ※ 20 August 2021
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MOPAB321	Schlieren Imaging for Flow Visualisation of Gas Jet in Vacuum for Accelerator Applications	989
	S. Rosily, B. Dikshit, S. Krishnagopal Homi Bhbha National Institute (HBNI), DAE, Mumbai, India S. Krishnagopal, S. Rosily BARC, Mumbai, India
	Schlieren imaging was explored for flow visualising of a gas jet in vacuum for beam profile monitor application. In supersonic gas jet based beam profile monitors, the high density jet flows through various differentially pumped skimmer stages before being shaped into a sheet. Schlieren imaging is a well known technique used in aerodynamic studies to visualise gas flow. This technique is explained in the paper along with a gist of other flow visualisation techniques. An Z-type schlieren imaging setup used to view the high density flow features of a pulsed supersonic gas jet inside vacuum is described in detail. Flow around a Pitot probe in supersonic flow was simulated and the resultant density profile obtained was compared with the image obtained using schlieren imaging. The flow features including a detached shock around the tip of the probe was observable at medium and high vacuum after processing the image. Image processing algorithms and tools useful for this application are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB321
About •	paper received ※ 20 May 2021       paper accepted ※ 26 May 2021       issue date ※ 29 August 2021
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MOPAB322	Electronics for Bead-pull Measurement of Radio Frequency Accelerating Structures in LEHIPA	993
	S. Rosily, S. Krishnagopal Homi Bhbha National Institute (HBNI), DAE, Mumbai, India S. Krishnagopal, S. Singh BARC, Mumbai, India
	For carrying out bead-pull characterisation of RFQ and DTL at the Low Energy High Intensity Proton Accelerator of BARC, a controller for simultaneous motion of 64 axis, tuners or post couplers, was developed. Also, a bead motion controller with integrated phase measurement sensor was developed. The paper discusses the requirements of the system, the architecture of the control systems, operation and results. The results obtained from the sensor was compared to that obtained using an independent USB VNA. The advantages of the system especially with addition of internal phase measurement sensor including minimising position error, flexibility in beadpull to selectively increase resolution at specified locations and ease of implementing auto-tuning algorithms are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB322
About •	paper received ※ 20 May 2021       paper accepted ※ 24 May 2021       issue date ※ 14 August 2021
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MOPAB323	Commissioning of the LCLS-II Prototype HOM Detectors with Tesla-Type Cavities at Fast	996
	J.P. Sikora, J.A. Diaz Cruz, B.T. Jacobson SLAC, Menlo Park, California, USA J.A. Diaz Cruz UNM-ECE, Albuquerque, USA D.R. Edstrom, A.H. Lumpkin, P.S. Prieto, J. Ruan, R.M. Thurman-Keup Fermilab, Batavia, Illinois, USA
	Funding: *Work supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. **Work supported by the U.S. Department of Energy, contract DE-AC02-76SF00515. Experiments at the Fermilab Accelerator Science and Technology* (FAST) facility detected electron beam-induced high order mode (HOM) signals from Tesla superconducting cavities. This paper describes some of the signal detection hardware used in this experiment, as well as measurements of the HOM signal magnitude versus beam trajectory. These measurements were made both with a single bunch and with a train of 50 bunches at bunch charges from 400 pC/b down to 10 pC/b. The detection hardware is designed for use with the Tesla superconducting cavities of LCLS-II at SLAC** and is based on a prototype already in use at Fermilab. The HOM signal passes through a bandpass filter that is centered on several cavity dipole modes and a zero bias Schottky diode detects its magnitude. Direct comparisons were made between the FNAL chassis and the SLAC prototype for identical beam steering conditions. To support measurements with bunch charges as low as 10 pC, the SLAC detector has RF amplification between the bandpass filter and the diode detector. With this hardware, usable HOM signal measurements are obtained with a single bunch of 10 pC in cryomodule cavities as will be needed for LCLS-II.
	Poster MOPAB323 [2.076 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB323
About •	paper received ※ 17 May 2021       paper accepted ※ 07 June 2021       issue date ※ 14 August 2021
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MOPAB324	High Voltage Design and Evaluation of Wien Filters for the CEBAF 200 keV Injector Upgrade	1000
	G.G. Palacios Serrano, P.A. Adderley, J.F. Benesch, D.B. Bullard, J.M. Grames, C. Hernandez-Garcia, A.S. Hofler, D. Machie, M. Poelker, M.L. Stutzman, R. Suleiman JLab, Newport News, Virginia, USA H. Baumgart, G.G. Palacios Serrano ODU, Norfolk, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. High-energy nuclear physics experiments at the Jefferson Lab Continuous Electron Beam Accelerator Facility (CEBAF) require highly spin-polarization electron beams, produced from strained super-lattice GaAs photocathodes, activated to negative electron affinity in a photogun operating at 130 kV dc. A pair of Wien filter spin rotators in the injector defines the orientation of the electron beam polarization at the end station target. An upgrade of the CEBAF injector to better support the upcoming MOLLER experiment requires increasing the electron beam energy to 200 keV, to reduce unwanted helicity correlated intensity and position systematics and provide precise control of the polarization orientation. Our contribution describes design, fabrication and testing of the high voltage system to upgrade the Wien spin rotator to be compatible with the 200 keV beam. This required Solidworks modeling, CST and Opera electro- and magnetostatic simulations, upgrading HV vacuum feedthroughs, and assembly techniques for improving electrode alignment. The electric and magnetic fields required by the Wien condition and the successful HV characterization under vacuum conditions are also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB324
About •	paper received ※ 19 May 2021       paper accepted ※ 24 May 2021       issue date ※ 29 August 2021
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MOPAB325	Development of Bunch Width Monitor with High Time Resolution for Low Emittance Muon Beam in the J-PARC Muon g-2 / EDM Experiment	1004
	M. Yotsuzuka, T. Iijima, K. Inami, Y. Sue, K. Sumi Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan T. Iijima KMI, Nagoya, AIchi Prefecture, Japan Y. Kondo JAEA, Ibaraki-ken, Japan T. Mibe KEK, Tsukuba, Japan Y. Nakazawa Ibaraki University, Ibaraki, Japan M. Otani, N. Saito J-PARC, KEK & JAEA, Ibaraki-ken, Japan Y. Takeuchi Kyushu University, Fukuoka, Japan H.Y. Yasuda University of Tokyo, Tokyo, Japan
	The J-PARC muon g-2/EDM experiment plans to measure the muon anomalous magnetic moment and electric dipole moment sensitive to new physics with high precision. This experiment uses a novel method using the low-emittance muon beam achieved by cooling and re-acceleration. In the muon linac consisting of four different accelerating cavities, the main cause of the emittance growth is the beam mismatch between the different cavities. Especially for the cavity in the low-beta section (ß=0.08-0.27), the longitudinal acceptance is narrow and beam mismatch has a significant impact. In order to perform beam matching in the low-beta cavity, a new beam monitor that can measure the low-emittance muon beam with high time resolution is required. Therefore, we developed a bunch width monitor (BWM) using a microchannel plate. The time resolution of the BWM was measured to be 40 picoseconds on the test bench using a picosecond pulse laser. It means that the BWM is possible to perform diagnosis with a phase accuracy of 1% for the acceleration phase of 324 MHz. We also evaluated factors that limit the current time resolution. In this presentation, the results of an evaluation of the BWM are reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB325
About •	paper received ※ 19 May 2021       paper accepted ※ 08 June 2021       issue date ※ 10 August 2021
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MOPAB326	Maximum Entropy Reconstruction of 4D Transverse Phase Space from 2D Projections: with Application to Laser Wire Measurements in the SNS HEBT	1008
	C.Y. Wong, A.P. Shishlo ORNL, Oak Ridge, Tennessee, USA
	We employ the principle of maximum entropy (MENT) to reconstruct 4D transverse phase space from its 2D projections. Emittance devices commonly measure two specific 2D projections, i.e. the horizontal and vertical phase space distributions. We show that: 1) given only these two 2D projections, their product is the analytic MENT solution to the 4D distribution; and 2) additional 2D projections provide information on inter-plane coupling in the MENT reconstruction of the 4D phase space which can be solved numerically. At the Spallation Neutron Source (SNS), laser wires in the high energy beam transport (HEBT) enable non-invasive two-slit type transverse phase space measurements. Laser wires play the role of the first slit whereas physical wires downstream of a drift act as the second slit. We reconstruct the 4D phase space in the HEBT using all four horizontal/vertical permutations of the two slits where: 1) the two configurations with parallel slits constitute ordinary 2D phase space measurements in either plane; and 2) the two configurations with perpendicular slits carry coupling information.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB326
About •	paper received ※ 20 May 2021       paper accepted ※ 19 July 2021       issue date ※ 17 August 2021
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MOPAB327	Beam Loss Diagnostics System for SKIF Synchrotron Light Source	1012
	X.C. Ma BINP, Novosibirsk, Russia S.V. Ivanenko, E.A. Puryga Budker Institute of Nuclear Physics, Novosibirsk, Russia A.D. Khilchenko, Yu.I. Maltseva, O.I. Meshkov BINP SB RAS, Novosibirsk, Russia Yu.I. Maltseva, O.I. Meshkov NSU, Novosibirsk, Russia
	The Siberian ring photon source (SKIF) is a new generation synchrotron light source designed and built by the Budker Institute of Nuclear Physics. The beam loss diagnostics system is a tool for monitoring beam loss information. It is widely used in modern large accelerators to provide a basis for diagnosing and locating machine faults, optimizing and debugging working beam parameters, and improving beam lifetime. Two types of beam loss monitor (BLM) will be applied on SKIF: fiber-based Cherenkov beam loss monitor (CBLM) and scintillator-based BLM (SBLM). Multi-mode silica fibers CBLM will be installed on linear accelerator and transfer lines. 128 SBLMs will be placed around the storage ring, dynamic ranges and sophisticated electronic equipment are employed to cover different SKIF operating modes. This article represents the details of design of beam loss diagnostics of SKIF, introduces the simulation and experimental studies of CBLM and SBLM.
	Poster MOPAB327 [4.893 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB327
About •	paper received ※ 19 May 2021       paper accepted ※ 26 May 2021       issue date ※ 30 August 2021
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MOPAB328	Beam Instrumentation for Linear Accelerator of SKIF Synchrotron Light Source	1016
	X.C. Ma BINP, Novosibirsk, Russia M.V. Arsentyeva, E.A. Bekhtenev, V.M. Borin, G.V. Karpov, Yu.I. Maltseva, O.I. Meshkov, D.A. Nikiforov, O.A. Pavlov, V.G. Tcheskidov, V. Volkov BINP SB RAS, Novosibirsk, Russia M.V. Arsentyeva, E.A. Bekhtenev, V.M. Borin, Yu.I. Maltseva, O.I. Meshkov, D.A. Nikiforov NSU, Novosibirsk, Russia V.M. Borin NSTU, Novosibirsk, Russia
	A new synchrotron light source SKIF of the 4th generation is under construction at BINP SB RAS (Novosibirsk, Russia). The linear accelerator is SKIF’s injector to provide 200 MeV electron beam. The set of diagnostics will be applied for tuning of the linear accelerator and measurements of beam parameters from electron RF gun to output of the accelerator. It includes 8 fluorescent screens for the beam transverse dimensions measurement, 2 Cherenkov probes for the beam duration measurement, magnetic spectrometer with range from 0.6 to 200 MeV, and some beam charge and current measurement devices, as Faraday cup, FCT, BPM along linear accelerator. Numerical simulations of diagnostics elements and results of beam dynamics simulations are introduced in paper. Brief description of the design and parameters of each diagnostics system is presented. Possible scenarios of linear accelerator tuning are also discussed.
	Poster MOPAB328 [2.324 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB328
About •	paper received ※ 19 May 2021       paper accepted ※ 21 May 2021       issue date ※ 31 August 2021
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MOPAB329	Operations of Copper Cavities at Cryogenic Temperatures	1020
	H. Wang, U. Ratzinger, M. Schuett IAP, Frankfurt am Main, Germany
	How the anomalous skin effect by copper affects the efficiency of copper- cavities will be studied in the experiment, especially at lower temperatures. The accurate quality factor Q and resonant frequency of three coaxial cavities will be measured over the temperature range from 300 to 22 K. The three coaxial cavities have the same structure, but different lengths, which correspond to resonant frequencies: around 100 MHz, 220 MHz and 340 MHz. The motivation is to check the feasibility of an efficient pulsed, liquid nitrogen cooled ion linac.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB329
About •	paper received ※ 19 May 2021       paper accepted ※ 07 June 2021       issue date ※ 02 September 2021
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MOPAB330	Production and Performance Evaluation of a Compact Deflecting Cavity to Measure the Bunch Length in the cERL	1023
	D. Naito, Y. Honda, T. Miyajima, N. Yamamoto KEK, Ibaraki, Japan
	At the KEK compact energy recovery linac, we try to generate an infrared free-electron laser (FEL). To generate the FEL, an electron bunch should be compressed along the longitudinal direction. The measurement of the bunch length is key to optimize the bunch compression. We plan to measure the bunch length by deflecting cavities in the burst mode. The deflecting cavities are required to be a time resolution of 33 fs in order to not only measure the bunch length but also resolve the structure inside the electron bunch. To achieve the requirement, we developed a c-band cavity whose RF input port is compact. The deflecting cavity is a single cell and normal conducting cavity. The deflection mode of the cavity is TM110. The 12 cavities will be located at the exit of undulators. In this presentation, we explain the design of our cavity and report the production of the first cavity. We also report the evaluation of the resonance frequency, the unloaded Q and the external Q of the cavity. From the measurements and simulations, the R/Q is estimated to be 1 mega orms. The time resolution of the cavity is expected to be 400 fs when the input RF power is 1 kW and the beam energy is 20 MeV.
	Poster MOPAB330 [12.920 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB330
About •	paper received ※ 12 May 2021       paper accepted ※ 08 June 2021       issue date ※ 28 August 2021
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MOPAB331	Design Consideration of a Longitudinal Kicker Cavity for Compensating Transient Beam Loading Effect in Synchrotron Light Sources	1027
	D. Naito, S. Sakanaka, T. Takahashi, N. Yamamoto KEK, Ibaraki, Japan T. Yamaguchi Sokendai, Ibaraki, Japan
	In ultra-low-emittance synchrotron light sources, bunch-lengthening using the combination of main and harmonic cavities is limited by the transient beam-loading (TBL) effect which is caused by gaps in the fill pattern. To manage this effect, we proposed a TBL compensation technique using a wide-band longitudinal kicker cavity*. In the future KEK-LS storage ring, for example, the kicker cavity should provide a compensation voltage of 50 kV with a -3dB bandwidth (BW) of about 5 MHz, as well as its higher-order modes (HOM) should be damped sufficiently. In this presentation, we report our conceptual design of the kicker cavity. We employed the single-mode (SM) cavity concept so that harmful HOMs are dumped by rf absorbers on the beam pipes. The distinctive feature of the SM cavity is its simple structure since it has no HOM damper on the cavity. Another feature is its low R/Q by which the TBL effect in the kicker cavity itself can be reduced significantly. We employed a frequency of 1.5 GHz (third-harmonic) and R/Q of 60 orms through optimizations. Using this kicker cavity with a double rf system, a bunch lengthening by a factor of 4.3 (i.e., 40.9 ps) is expected for the KEK-LS case. * N.Yamamoto et al., Phys. Rrev. Acc. Beams 21, 012001 (2018)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB331
About •	paper received ※ 19 May 2021       paper accepted ※ 11 June 2021       issue date ※ 01 September 2021
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MOPAB332	Design of 4th Harmonic RF Cavities for ESRF-EBS	1031
	A. D’Elia, J. Jacob, V. Serrière, X.W. Zhu ESRF, Grenoble, France
	Funding: European Union’s Horizon 2020 research and innovation program under grant #871072 An active 4th harmonic RF system for bunch lengthening is under study at the ESRF to improve the performance of the new EBS storage ring, mainly for few bunch operation with high currents per bunch, by reducing Touschek and intrabeam scattering, thereby increasing the lifetime and limiting the emittance growth. It will also reduce impedance heating of the vacuum chambers. The 4th Harmonic 1.41 GHz normal conducting cavity design takes inspiration from the KEK idea of using a TM020 mode exhibiting a reduced R/Q but a higher unloaded Q with respect to TM010. We propose to use multicell cavities for their compactness, the reduced number of required ancillaries and the ease of control for a reduced number of cavities. The drawback is the complexity of the model and the necessity to damp the lower order TM010 mode (LOM) as well as the higher order modes (HOM). The RF design of a 4th harmonic multicell damped cavity will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB332
About •	paper received ※ 19 May 2021       paper accepted ※ 17 August 2021       issue date ※ 16 August 2021
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MOPAB333	ESRF-EBS 352 MHz HOM Damped RF Cavities	1034
	A. D’Elia, J. Jacob, V. Serrière ESRF, Grenoble, France
	For the new ESRF-EBS Storage Ring (SR), HOM damped RF cavities were needed to cope with the reduced thresholds for Longitudinal Coupled Bunch Instabilities (LCBI). The 352 MHz cavities were designed at the ESRF based on an improved version of the 500 MHz EU/ALBA/BESSY structures. A short description of the cavity design will be presented as well as an overview of the fabrication, the preparation and the performance of 13 such cavities for the ESRF-EBS SR. A study of the impedance of a whole cavity equipped with its ancillaries (HOM absorbers, ion pump and tuner) will be presented. One of the three HOM absorbers, the smaller one on top of the cavity, was finally not installed on the machine. The reasons and a detailed analysis in terms of HOM impedances that justifies this choice will be reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB333
About •	paper received ※ 19 May 2021       paper accepted ※ 07 June 2021       issue date ※ 02 September 2021
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MOPAB334	Status and Recent Development of FAIR Ring RF Systems	1037
	U. Laier, R. Balß, C. Christoph, M. Frey, P. Hülsmann, H. Klingbeil, H.G. König, D.E.M. Lens, J.S. Schmidt, A. Stuhl, K.G. Thomin, T. Winnefeld GSI, Darmstadt, Germany H. Klingbeil TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: GSI Helmholtzzentrum für Schwerionenforschung GmbH Five different Ring RF Systems are required for the operation of FAIR (Facility for Antiproton and Ion Research). These systems have to operate at frequencies between 310 kHz and 3.2 MHz, with gap voltages up to 40 kVp and duty cycles from 5·10-4 up to cw. All systems will be realized using inductively loaded (ferrite or magnetic alloy) cavities driven by tetrode-based amplifiers fed by switch-mode power supplies. To stabilize the amplitude, resonance frequency and phase, versatile digital feedback and feedforward control will be used. This contribution will present the latest development on the power part and the LLRF of the four RF systems of the SIS100 (SIS100 Acceleration, SIS100 Bunch Compression, SIS100 Barrier Bucket and SIS100 Longitudinal Feedback) as well as the CR Debuncher system which is part of the Collector Ring. The progress of these systems varies by a large degree. This note will give an overview regarding the status of the design, procurement, realization, testing, optimization, commissioning and preparation for installation of these RF systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB334
About •	paper received ※ 18 May 2021       paper accepted ※ 07 June 2021       issue date ※ 12 August 2021
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MOPAB335	SNS Warm Linac Circulator Breakdown Considerations for the PPU Project	1041
	G.D. Toby, Y.W. Kang, S.-H. Kim, S.W. Lee, J.S. Moss ORNL, Oak Ridge, Tennessee, USA
	Funding: * This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract number DE-AC05-00OR22725. Multipacting in accelerating structures is a complex phenomenon about which there is much to be understood. While multipacting research efforts have primarily been focused on superconducting radio frequency (SRF) systems, normal conducting accelerating structures which have a higher thermal capacity, and a greater vacuum pressure tolerance could benefit from additional investigation. This research details multipacting simulation methods and the results of 3-D electromagnetic simulations of RF vacuum windows used on normal conducting linac (NCL) cavities. Benchmarking of the peak electric fields in these structures, benefits of material processing and possible techniques for reducing or eliminating multipacting activities are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB335
About •	paper received ※ 17 May 2021       paper accepted ※ 28 May 2021       issue date ※ 23 August 2021
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MOPAB336	Multipacting Analysis of Warm Linac RF Vacuum Windows	1044
	G.D. Toby, Y.W. Kang, S.-H. Kim, S.W. Lee, J.S. Moss ORNL, Oak Ridge, Tennessee, USA
	Funding: * This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract number DE-AC05-00OR22725. Multipacting in accelerating structures is a complex phenomenon with which there is much to be understood. While multipacting research efforts have primarily been focused on superconducting radio frequency (SRF) systems, normal conducting accelerating structures that have a higher thermal capacity and a greater vacuum pressure tolerance could benefit from additional investigation. This research details multipacting simulation methods and the results of 3-D electromagnetic simulations of RF vacuum windows used on normal conducting linac (NCL) cavities. Possible techniques for reducing and eliminating multipacting activities in these structures are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB336
About •	paper received ※ 17 May 2021       paper accepted ※ 28 May 2021       issue date ※ 29 August 2021
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MOPAB337	Design Study of the Spiral Buncher Cavities for the High Current Injector at IUAC	1048
	S. Kedia, R. Ahuja, R. Mehta, C.P. Safvan IUAC, New Delhi, India
	Two high energy beam transport (HEBT) cavities have been designed to provide the longitudinal beam bunching between drift tube linac and superconducting super-buncher of the superconducting linear (SC-LINAC) accelerator. The spiral type cavities were chosen over standard quarter wave-type geometry due to its higher shunt impedance. The TRACE-3D ion-optical codes have been used to determine the bunching voltage and physical location of the cavities. The two-gap RF cavity requires 80 kV/gap to provide the longitudinal beam bunching at the entrance of the superconducting buncher. The CST-MWS simulations were performed to design the spiral type bunching cavities. The various parameters including shunt impedance, quality factor, average accelerating field, and total power loss were determined using CST-MWS simulations. The ratio of drift tube radius to the gap was optimized to achieve the maximum effective electric field with minimum field penetration within the gap. The SolidWorks software has been used to prepare a mechanical model for the fabrication.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB337
About •	paper received ※ 15 May 2021       paper accepted ※ 26 May 2021       issue date ※ 26 August 2021
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MOPAB339	Design Of An X-band 3MeV Standing-wave Accelerating Structure with Nose-cone Structure Made From Two Halves	1051
	F. Liu, H.B. Chen, J. Shi, C.-X. Tang, H. Zha TUB, Beijing, People’s Republic of China
	This work presents an X-band 3MeV standing-wave accelerating structure with nose cones made from two halves. Milling two longitudinally split halves is one economic method to manufacture accelerating structure for decrease of welding, with increasing the difficulty in machining. This linear accelerator includes 4 buncher cavities and 4 accelerating cavities, and nose cone is applied to achieve high shunt impedance. A technical prototype is under fabrication to bring two milled halves manufacture way into practical application.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB339
About •	paper received ※ 19 May 2021       paper accepted ※ 26 May 2021       issue date ※ 15 August 2021
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MOPAB340	Experimental Tests with the First Segment of ESS-Bilbao RFQ Linac	1054
	J.L. Muñoz, I. Bustinduy, A. Conde, N. Garmendia, P.J. González, J. Martin, A. Zugazaga ESS Bilbao, Zamudio, Spain
	The ESS-Bilbao RFQ is an assembly of four segments, each one about 800 mm in length. The first segment has been manufactured before the others, so it could be thoroughly tested in order to validate the chosen technological approach for the RFQ, as it uses polymeric vacuum gaskets and bolts instead of brazing. In this paper we report on the tests run with the segment and their results. Vacuum tests, metrology measurements, low power RF tests as well as extensive tuning tests measuring the cavity resonant quadrupolar frequency as a function of cooling water temperature have been done. Experimental results are compared to the expected values obtained from numerical simulations. We describe the experimental set-ups for the measurements and the simulations. Results are analyzed with the aim of validating the design, and also to provide predictions for tuning and operation of the whole RFQ. As a consequence of the positive results of the tests reported here, the remaining segments have already been tendered.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB340
About •	paper received ※ 19 May 2021       paper accepted ※ 25 May 2021       issue date ※ 20 August 2021
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MOPAB341	First C-Band High Gradient Cavity Testing Results at LANL	1057
	E.I. Simakov, R.L. Fleming, D. Gorelov, T.A. Jankowski, M.F. Kirshner, J.W. Lewellen, J.D. Pizzolatto, M.E. Schneider, T. Tajima LANL, Los Alamos, New Mexico, USA X. Lu, E.A. Nanni, S.G. Tantawi SLAC, Menlo Park, California, USA M.E. Middendorf ANL, Lemont, Illinois, USA
	Funding: Los Alamos National Laboratory LDRD Program. This poster will report the results of high gradient testing of the two proton β=0.5 C-band accelerating cavities. The cavities for proton acceleration were fabricated at SLAC and tested at high gradient C-band accelerator test stand at LANL. One cavity was made of copper, and the second was made of a copper-silver alloy. LANL test stand was constructed around a 50 MW, 5.712 GHz Canon klystron and is capable to provide power for conditioning single cell accelerating cavities for operation at surface electric fields up to 300 MV/m. These β=0.5 C-band cavities were the first two cavities tested on LANL C-band test stand. The presentation will report achieved gradients, breakdown probabilities, and other characteristics measured during the high power operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB341
About •	paper received ※ 19 May 2021       paper accepted ※ 25 May 2021       issue date ※ 30 August 2021
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MOPAB342	Design, Fabrication, and Commissioning of the Mode Launchers for High Gradient C-Band Cavity Testing at LANL	1060
	E.I. Simakov, J.E. Acosta, D. Gorelov, M.F. Kirshner, J.W. Lewellen LANL, Los Alamos, New Mexico, USA P. Borchard Dymenso LLC, San Francisco, USA M.E. Schneider MSU, East Lansing, Michigan, USA
	Funding: Los Alamos National Laboratory LDRD Program. This poster will report on the design, fabrication, and operation status of the new high gradient C-band TM01 mode launchers for the high gradient C-band test stand at LANL. Modern applications require accelerators with optimized cost of construction and operation, naturally calling for high-gradient acceleration. At LANL we commissioned a test stand powered by a 50 MW, 5.712 GHz Canon klystron. The test is capable of conditioning single cell accelerating cavities for operation at surface electric fields up to 300 MV/m. The rf field is coupled into the cavity from a WR187 waveguide through a mode launcher that converts the fundamental mode of the rectangular waveguide into the TM01 mode of the circular waveguide. Several designs for mode launchers were considered and the final design was chosen based on a compromise between the field enhancements, bandwidth, and simplicity and cost of fabrication. Four mode launchers were fabricated and cold-tested. Two mode launchers with the best transmission characteristics were installed and conditioned to high power. The presentation will report achieved gradients, breakdown probabilities, and other characteristics measured during operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB342
About •	paper received ※ 19 May 2021       paper accepted ※ 25 May 2021       issue date ※ 19 August 2021
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MOPAB343	Optimization of the Parasitic-Mode Damping on the 1.5 GHz TM020-type Harmonic Cavity	1064
	T. Yamaguchi Sokendai, Ibaraki, Japan D. Naito, S. Sakanaka, T. Takahashi, N. Yamamoto KEK, Ibaraki, Japan
	Bunch-lengthening harmonic cavity is one of the essential tools to mitigate the intrabeam scattering in the 4th-generation synchrotron light sources. For this purpose, we proposed a normal-conducting 1.5 GHz harmonic cavity* of TM020-type**. Thanks to its low R/Q (68 ohms) and high unloaded Q (34, 000), bunch gap transient in the harmonic cavity can be reduced to ~20% as compared to that in a typical TM010 cavity. Furthermore, harmful parasitic modes in this cavity can be heavily damped by installing ferrites where no magnetic fields of TM020-mode exist. However, some of the parasitic modes, e.g. TM021 and TM120 modes, are difficult to damp because their field patterns are similar to that of the TM020 mode. To damp such modes effectively, we optimized the cavity inner shape by tailoring the curvature at the cavity equator, the shape of the nose cones, and introducing "bumps" on the inner wall. Our goals of the coupling impedances are fxR < 2.4[kohm GHz] and RT < 23 kohm/m in the longitudinal and the transverse planes, respectively. As a result of optimization, we almost achieved these goals. To confirm our simulation results, fabrication of a low-power test cavity is in progress. * N . Yamamoto et al., Phys. Rev. Acc. Beams 21, 012001 (2018). ** H. Ego et al., Proc. of the 11th Annual Meeting of Particle Accelerator Society of Japan (PASJ2014), MOOL14 (2014).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB343
About •	paper received ※ 19 May 2021       paper accepted ※ 26 May 2021       issue date ※ 01 September 2021
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MOPAB344	Machine Learning Models for Breakdown Prediction in RF Cavities for Accelerators	1068
	C. Obermair, A. Apollonio, T. Cartier-Michaud, N. Catalán Lasheras, L. Felsberger, W.L. Millar, W. Wuensch CERN, Geneva, Switzerland C. Obermair, F. Pernkopf TUG, Graz, Austria
	Radio Frequency (RF) breakdowns are one of the most prevalent limits in RF cavities for particle accelerators. During a breakdown, field enhancement associated with small deformations on the cavity surface results in electrical arcs. Such arcs degrade a passing beam and if they occur frequently, they can cause irreparable damage to the RF cavity surface. In this paper, we propose a machine learning approach to predict the occurrence of breakdowns in CERN’s Compact LInear Collider (CLIC) accelerating structures. We discuss state-of-the-art algorithms for data exploration with unsupervised machine learning, breakdown prediction with supervised machine learning, and result validation with Explainable-Artificial Intelligence (Explainable AI). By interpreting the model parameters of various approaches, we go further in addressing opportunities to elucidate the physics of a breakdown and improve accelerator reliability and operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB344
About •	paper received ※ 20 May 2021       paper accepted ※ 16 July 2021       issue date ※ 11 August 2021
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MOPAB345	Machine Learning with a Hybrid Model for Monitoring of the Protection Systems of the LHC	1072
	C. Obermair, A. Apollonio, Z. Charifoulline, M. Maciejewski, A.P. Verweij CERN, Geneva, Switzerland C. Obermair, F. Pernkopf TUG, Graz, Austria
	The LHC is the world’s largest particle accelerator and uses a complex set of sophisticated and highly reliable machine protection systems to ensure a safe operation with high availability for particle physics production. The data gathered during several years of successful operation allow the use of data-driven methods to assist experts in finding anomalies in the behavior of those protection systems. In this paper, we derive a model that can extend the existing signal monitoring applications for the LHC protection systems with machine learning. Our hybrid model combines an existing threshold-based system with a SVM by using signals, manually validated by experts. Even with a limited amount of data, the SVM learns to integrate the expert knowledge and contributes to a better classification of safety-critical signals. Using this approach, we analyze historical signals of quench heaters, which are an important part of the quench protection system for superconducting magnets. Particularly, it is possible to incorporate expert decisions into the classification process and to improve the failure detection rate of the existing quench heater discharge analysis tool.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB345
About •	paper received ※ 20 May 2021       paper accepted ※ 19 July 2021       issue date ※ 01 September 2021
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MOPAB346	Broadband Frequency Electromagnetic Characterisation of Coating Materials	1076
	A. Passarelli, C. Koral, M.R. Masullo INFN-Napoli, Napoli, Italy A. Andreone Naples University Federico II, Napoli, Italy M. De Stefano University of Naples, Naples, Italy V.G. Vaccaro Naples University Federico II and INFN, Napoli, Italy
	In the new generation of particle accelerators and storage rings, collective effects have to be carefully analyzed. In particular, the finite conductivity of the beam pipe walls is a major source of impedance and instabilities. A reliable electromagnetic (EM) characterisation of different coating materials is required up to hundreds of GHz due to very short bunches. We propose two different measurement techniques for an extended frequency characterization: (i) a THz time domain setup based on the signal transmission response of a tailored waveguide to infer the coating EM properties from 100 to 300 GHz or even further*.**. This technique has been tested both on NEG and amorphous Carbon films. (ii) a resonant method, based on dielectric cavities, to evaluate the surface resistance Rs of thin conducting samples at low (GHz) frequencies***. Due to its high sensitivity, Rs values can be obtained for very thin (nanometric) coatings or for copper samples with a laser treated surface, since they have an expected conductivity very close to bulk copper. *A. Passarelli et al., Phys. Rev. Accel. Beams, v.21, p.103101, 2018 **A. Passarelli et al., Cond. Matter, v.5, p.9, 2020 ***A. Andreone et al., Applied Physics Letters, v.91, n.7, p.072512, 2007
	Poster MOPAB346 [2.613 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB346
About •	paper received ※ 18 May 2021       paper accepted ※ 09 June 2021       issue date ※ 26 August 2021
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MOPAB347	High Power Coupler Conditioning for bERLinPro Energy Recovery Linac Injector	1080
	A. Neumann, W. Anders, F. Göbel, A. Heugel, S. Klauke, J. Knobloch, M. Schuster, Y. Tamashevich HZB, Berlin, Germany
	Funding: The work is funded by the Helmholtz-Association, BMBF, the state of Berlin and HZB. Helmholtz Zentrum Berlin is currently finalizing the construction of the demonstrator Energy Recovery Linac bERLinPro *. The first part, which will be commissioned, will be the injector consisting of a superconducting RF (SRF) photo-injector (Gun) and a Booster module made up of three two cell SRF cavities. For the latter the 2.3 MeV beam from the gun needs to be accelerated to 6.5 MeV, whereas one Booster cavity will be operated in zero-crossing mode for bunch-shortening. Thus, for the final stage with a 100 mA beam, the twin power couplers of the Booster cavity need to deliver up to 120 kW in travelling continous wave (CW) mode at 1.3 GHz each. To achieve that, a dedicated coupler conditioning setup was installed and commissioned. Here, we will present the first conditioning results with the bERLinPro Booster fundamental power couplers in pulsed and CW regime. * M. Abo-Bakr et al., in Proc. 9th Int. Particle Accelerator Conf. (IPAC’18), Vancouver, BC, Canada, Apr. 4,, pp. 4127-4130, doi:10.18429/JACoW-IPAC2018-THPMF034
	Poster MOPAB347 [3.256 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB347
About •	paper received ※ 18 May 2021       paper accepted ※ 08 June 2021       issue date ※ 14 August 2021
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MOPAB348	Portable 2.5 MeV X-Band Linear Accelerator Structure	1084
	A.V. Mishin, K. Brown, M. Denney, D. Fischer, N.P. Hanson, S. Proskin, J. Stammetti Varex Imaging, Salt Lake City, USA
	Two versions of 2.5 MeV X-Band linear accelerator structure have been designed and tested. The first is a traditional single input linac, and the other one is a dual input, two section linac with power input through a 3 dB coupler. The linac is designed for a portable linac system, which can be used for security screening, non-destructive testing, medical and industrial CT, and, perhaps, some other applications.
	Poster MOPAB348 [1.490 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB348
About •	paper received ※ 15 May 2021       paper accepted ※ 28 May 2021       issue date ※ 23 August 2021
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MOPAB349	New Accelerator Beam Centerline (ABC) Production Line at Varex Imaging Corporation	1087
	A.V. Mishin Varex Imaging, Salt Lake City, USA
	In January 2017, a Salt Lake City Component Division of Varian Medical (Varian)*, producer of X-ray tubes, detectors, and imaging panels has been spun off, giving birth to a new public company Varex Imaging Corporation (Varex)**, which also includes the Security and Inspection Products (SIP) linac producer in Las Vegas. Based on Varian asset acquisition of two small LLCs*** in May 2016, 8 months prior to the transition, a new business branch within Varex has been established, which included distribution of the betatrons and detector arrays as well as pilot production line for Accelerator Beam Centerlines (ABC). In 3 years, we moved ABC production from Fremont, CA to Salt Lake in Utah and improved it; several ABCs have been designed, produced, and qualified. A number of new products in energy range of 1-20 MeV are under development, based on the new ABCs used as components for SIP linear accelerator systems and ABCs sold to third parties for applications other than Security and NDT. The new products will brag broad energy and dose rate regulation, smooth and reliable operation, providing extended benefits to our customers. * - https://www.varian.com/ ** - https://www.vareximaging.com/ *** - both Thought One LLC and Radmedex LLC have been dissolved in 2018 upon completion of the transition process
	Poster MOPAB349 [2.182 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB349
About •	paper received ※ 13 May 2021       paper accepted ※ 27 May 2021       issue date ※ 21 August 2021
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MOPAB350	RF Buncher Cavity for Polarized He-3 Beam at BNL	1090
	T. Kanesue, S.M. Trabocchi BNL, Upton, New York, USA A. Murata TIT, Tokyo, Japan
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. A 100.625 MHz quarter wave resonator type rf buncher cavity was fabricated for polarized He-3 spin rotator beam line at BNL. This cavity will be installed in the existing EBIS-To-Booster beam line to provide effective voltage of more than 40 kV for 2 MeV/u 3He2+ beam. This cavity has a large drift tube inner diameter of 80 mm and small gap length of 5 mm. The buncher consists of 3 sections, which are a cavity main body including drift tube, stem, and inner wall, a lid with a power coupler, and a lid with an inductive tuner. The main body was machined from a bulk copper only by CNC machining. The result of low power test agreed well with rf simulation without any alignment. The difference between measured and calculated resonant frequency was <0.1 %, and measured Q value was 92 % of that in simulation. The cavity rf design and test results will be shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB350
About •	paper received ※ 26 May 2021       paper accepted ※ 28 May 2021       issue date ※ 12 August 2021
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MOPAB351	Using an RFQ to Transport Intense Heavy Ion Beams from an ECR Ion Source	1093
	G.O. Rodrigues IUAC, New Delhi, India R.W. Hamm R&M Technical Enterprises, Pleasanton, California, USA
	In the transport of high intensity, heavy ions from an ECR ion source through a low energy beam transport (LEBT) section, space charge can limit the transmission. It has been proposed to use a Radio Frequency Quadrupole (RFQ) to efficiently address this problem. The stray magnetic field of the ECR ion source can be used to provide focusing against the space charge blow-up when using the Direct Plasma Injection Scheme (DPIS) developed for laser ion sources. The RFQ will focus and transport the injected beam, eliminating most of the charge states extracted from the ECR ion source. This narrowing of the charge state distribution is a filter, reducing the low energy beam transport problem, as well as the emittance growth for the desired beam. A combined extraction/matching system has been designed for direct injection into a 48.5 MHz RFQ for the production of 238U40+ (0.52 mA) and 209Bi30+ (1.047 mA) beams. The IGUN code has been used to design the injection directly into the RFQ. The RFQ design has been modified with a pre-buncher built into the vanes to narrow the transmitted charge state distribution as much as possible. The design details of this system will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB351
About •	paper received ※ 20 May 2021       paper accepted ※ 17 August 2021       issue date ※ 15 August 2021
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MOPAB352	High Power Test of a Dielectric Disk Loaded Accelerator for a Two Beam Wakefield Accelerator	1096
	B.T. Freemire, C.-J. Jing, S. Poddar Euclid Beamlabs, Bolingbrook, USA M.E. Conde, D.S. Doran, G. Ha, W. Liu, J.G. Power, J.H. Shao, C. Whiteford, E.E. Wisniewski ANL, Lemont, Illinois, USA M.M. Peng TUB, Beijing, People’s Republic of China E.E. Wisniewski Illinois Institute of Technology, Chicago, Illinois, USA Y. Zhao Euclid TechLabs, Solon, Ohio, USA
	Funding: Small Business Innovation Research Contract No. DE-SC0019864 U.S. DOE Office of Science Contract No. DE-AC02-06CH11357 As part of the Argonne 500 MeV short pulse Two Beam Wakefield Acceleration Demonstrator, a single cell X-band dielectric disk loaded accelerator (DDA) has been designed, fabricated, and tested at high power at the Argonne Wakefield Accelerator. The DDA should provide a short pulse (~20 ns) high gradient (>300 MV/m) accelerator while maintaining a reasonable r/Q and high group velocity. This will allow a significantly larger RF-to-beam efficiency than is currently possible for conventional accelerating structures. A low loss barium titantate ceramic, µr = 50, was selected, and a low temperature brazing alloy chosen to preserve the dielectric properties of the ceramic during brazing. High power testing produced breakdown at the triple junction, resulting from the braze joint design. No evidence of breakdown was observed on the iris of the disk, indicating that the maximum surface electric field on the dielectric was not reached. An improved braze joint has been designed and is in production, with high power testing to follow.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB352
About •	paper received ※ 19 May 2021       paper accepted ※ 08 June 2021       issue date ※ 21 August 2021
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MOPAB353	Design of a compact Ka-Band Mode Launcher for High-gradient Accelerators	1100
	G. Torrisi, G.S. Mauro, G. Sorbello INFN/LNS, Catania, Italy M. Behtouei, L. Faillace, B. Spataro, A. Variola INFN/LNF, Frascati, Italy V.A. Dolgashev SLAC, Menlo Park, California, USA L. Faillace, M. Migliorati Sapienza University of Rome, Rome, Italy M. Migliorati INFN-Roma1, Rome, Italy J.B. Rosenzweig UCLA, Los Angeles, California, USA G. Sorbello University of Catania, Catania, Italy
	In this work, we present the RF design of a table-top Ka-Band mode launcher operating at 35.98 GHz. The structure consists of a symmetrical 4-port WR28 rectangular-TE10-to-circular-TM01 mode converter that is used to couple a peak output RF power of 5 MW (pulse length up to 50 ns and repetition rate up to 100 Hz) in Ka-Band linear accelerator able to achieve very high accelerating gradients (up to 200 MV/m). Numerical simulations have been carried out with the 3D full-wave commercial simulator Ansys HFSS in order to obtain a preliminary tuning of the accelerating field flatness at the operating frequency f0=35.98 GHz. The main RF parameters, such as reflection coefficient, transmission losses, and conversion efficiency are given together with a verification of the field azimuthal symmetry which avoids dipole and quadrupole deflecting modes. To simplify future manufacturing, reduce fabrication costs, and also reduce the probability of RF breakdown, the proposed new geometry has "open" configuration. This geometry eliminates the flow of RF currents through critical joints and allows this device to be milled from metal blocks.
	Poster MOPAB353 [3.131 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB353
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 27 August 2021
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MOPAB355	Multi-Objective Optimization of RF Structures	1103
	S.J. Smith, R. Apsimon, G. Burt, M.J.W. Southerbypresenter Cockcroft Institute, Lancaster University, Lancaster, United Kingdom S. Setiniyaz Cockcroft Institute, Warrington, Cheshire, United Kingdom S. Setiniyaz Lancaster University, Lancaster, United Kingdom
	In this work, we apply multi-objective optimization methods to single-cell cavity models generated using non-uniform rational basis splines (NURBS). This modeling method uses control points and a NURBS to generate the cavity geometry, which allows for greater flexibility in the shape, leading to improved performance. Using this approach and multi-objective genetic algorithms (MOGAs) we find the Pareto frontiers for the typical key quantities of interest (QoI) including peak fields, shunt impedance and the modified Poynting vector. Visualizing these results becomes increasingly more difficult as the number of objectives increases, therefore, in order to understand these frontiers, we provide several techniques for analyzing, visualizing and using multi-dimensional Pareto fronts specifically for RF cavity design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB355
About •	paper received ※ 19 May 2021       paper accepted ※ 15 July 2021       issue date ※ 30 August 2021
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MOPAB356	The ESS MEBT RF Buncher Cavities Conditioning Process	1107
	I. Bustinduy, N. Garmendiapresenter, P.J. González, A. Kaftoosian, S. Masa, I. Mazkiaran, L.C. Medina, J.L. Muñoz ESS Bilbao, Zamudio, Spain J. Etxeberria, J.P.S. Martins ESS, Lund, Sweden
	Funding: This work is part of FEDER-TRACKS project, co-funded by the European Regional Development Fund (ERDF) . As part of the 5 MW European Spallation Source (ESS), the Medium Energy Beam Transport (MEBT) was designed, assembled, and installed in the tunnel since May 2020 by ESS-Bilbao. This section of the accelerator is located between the Radio Frequency Quadrupole (RFQ) and the Drift Tube Linac (DTL). The main purpose of the MEBT is to match the incoming beam from the RFQ both transversely and longitudinally into the DTL. The longitudinal matching is achieved by three 352.209 MHz RF buncher cavities. In this paper, we focus on the RF conditioning process for each set of power coupler and buncher cavity. For this purpose, different tools were developed on EPICS and Python as well as electronics hardware such as Fast Interlock Module (FIM) and timing system. These tools served to automatize both the cavity frequency tuning and the power ramp-up process and will be described in detail in the following sections.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB356
About •	paper received ※ 18 May 2021       paper accepted ※ 09 June 2021       issue date ※ 25 August 2021
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MOPAB357	The New Design of the RF System for the SPS-II Light Source	1110
	N. Juntong, T. Chanwattana, S. Chunjarean, S. Krainara, T. Phimsen, T. Pulampong SLRI, Nakhon Ratchasima, Thailand K. Manasatitpong Synchrotron Light Research Institute (SLRI), Muang District, Thailand
	The new light source facility in Thailand, SPS-II, is a ring-based 3 GeV light source with a circumference of approximately 330 m. The target stored beam current is 300 mA with an emittance of below 1.0 nm rad. The injector has been changed from a full energy linac to a booster injector with 150 MeV linac. The main RF frequency has been reconsidered to a low-frequency range at 119 MHz. Low frequency is chosen with the benefit of low RF voltage for a high RF acceptance together with experience with the present ring RF system of 118 MHz. Details of RF frequency consideration will be discussed. The requirements and details of the RF systems in the booster ring and the storage ring will be presented.
	Poster MOPAB357 [1.696 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB357
About •	paper received ※ 17 May 2021       paper accepted ※ 08 June 2021       issue date ※ 14 August 2021
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MOPAB358	Design and Measurement of the 1.4 GHz Cavity for LEReC Linac	1113
	B.P. Xiao, J.C. Brutus, J.M. Fite, K. Hamdi, D. Holmes, K. Mernick, K.S. Smith, J.E. Tuozzolo, T. Xin, A. Zaltsman BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The Low Energy RHIC electron Cooler (LEReC) is the first electron cooler based on rf acceleration of electron bunches. To further improve RHIC luminosity for heavy ion beam energies below 10 GeV/nucleon, a normal conducting RF cavity at 1.4 GHz was designed and fabricated for the LINAC that will provide longer electron bunches for the LEReC. It is a single-cell cavity with an effective cavity length shorter than half of the 1.4 GHz wavelength. This cavity was fabricated and tested on-site at BNL to verify RF properties, i.e. the resonance frequency, FPC coupling strength, tuner system performance, and high power tests. In this paper, we report the RF test results for this cavity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB358
About •	paper received ※ 17 May 2021       paper accepted ※ 25 June 2021       issue date ※ 24 August 2021
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MOPAB359	Operational Experience and Redesign of the Tuner without Spring Fingers for the LEReC Warm Cavity	1116
	B.P. Xiao, J.M. Brennan, J.C. Brutus, K. Mernick, S. Polizzo, S.K. Seberg, F. Severino, K.S. Smith, A. Zaltsman BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. A folded coaxial tuner without spring fingers was designed for the Low Energy RHIC electron Cooler (LEReC) 2.1 GHz warm cavity. During RHIC run 2019, this tuner was found to cause cavity trips via different failure modes. After analyzing these failure modes, a new straight coaxial tuner without spring fingers was proposed and was installed. We show the operational experience of the new tuner in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB359
About •	paper received ※ 17 May 2021       paper accepted ※ 25 June 2021       issue date ※ 29 August 2021
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MOPAB360	Anomalous Skin Effect Study of Normal Conducting Film	1119
	B.P. Xiao, M. Blaskiewicz, T. Xin BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. For the radiofrequency (RF) applications of normal conducting film with large mean free path at high frequency and low temperature, the anomalous skin effect differs considerably from the normal skin effect with field decaying exponentially in the film. Starting from the relationship between the current and the electric field (E field) in the film, the amplitude of E field along the film depth is calculated, and is found to be non-monotonic. The surface impedance is found to have a minimum value at certain film thickness.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB360
About •	paper received ※ 17 May 2021       paper accepted ※ 25 June 2021       issue date ※ 17 August 2021
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MOPAB361	Threshold in Filling Failure of RF Cavity Caused by Beam Loading in Multipactor	1122
	J. Pang USTC/NSRL, Hefei, Anhui, People’s Republic of China Y. Dong Institute of Applied Physics and Computational Mathematics, People’s Republic of China Y. Du Institute of Fluid Physics,, China Academy of Engineering Physics, Mianyang, People’s Republic of China
	Funding: NSFC A pulsed RF cavity would be heavily detuned caused by beam loading of multipactor current in the RF filling process. Multipactor zone would be expended by several times than that in static states with assumptions of fixed voltage and no beam loading. The dynamic of multipactor in the RF filling process was simulated by coupling with parameters of external circuit with the developed simulation code, and test in experiments with a parallel-plate resonator. Threshold of RF voltage, which means the lower boundary of peak voltage of multipactor zone, had been quantified with different cavity parameters. When we increased the gap length, the measured threshold became larger due to the ionization in background gas. Then the secondary emission factor would be increased in simulation for consistence with the experiment results. Additionally, some multipactor phenomenon could not be predicted precisely because the simulation code did not take account of ionization. The hysteresis of phase and energy of ionization electrons would be a new driving factor for the growth of multipactor in certain conditions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB361
About •	paper received ※ 19 May 2021       paper accepted ※ 24 May 2021       issue date ※ 10 August 2021
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MOPAB362	Atomistic Modeling of the Coupling Between Electric Fields and Bulk Plastic Deformation in Rf Structures	1125
	S. Bagchi, D. Perez LANL, Los Alamos, New Mexico, USA
	Funding: LANL-LDRD A notable bottleneck in achieving high-gradient RF technology is dictated by the onset of RF breakdown. While bulk mechanical properties are known to significantly affect breakdown propensity, the underlying mechanisms coupling RF fields to bulk plastic deformation in experimentally relevant thermo-electrical loading conditions remain to be identified at the atomic scale. Here, we present results of large-scale molecular dynamics simulations (MD) to investigate possible modes of coupling. We consider the activation of Frank-Read (FR) sources, which leads to dislocation multiplication, under the action of bi-axial thermal stresses and surface electric-field. With a charge-equilibration formalism incorporated in a classical MD model, we show that a surface electric field acting on an either preexisting or dislocation-induced surface step, can generate a long-range resolved shear stress field inside the bulk of the sample. We investigate the feedback between step growth following dislocation emission and subsequent activations of FR sources and discuss the regimes of critical length-scales and densities of dislocations, where such a mechanism could promote RF breakdown precursors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB362
About •	paper received ※ 19 May 2021       paper accepted ※ 10 June 2021       issue date ※ 19 August 2021
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MOPAB363	Design, Characteristics and Dynamic Properties of Mobile Plunger-based Frequency Tuning System for Coaxial Half Wave Resonators	1129
	D. Bychanok, S. Huseu, S.A. Maksimenko, A.E. Sukhotski INP BSU, Minsk, Belarus A.V. Butenko, E. Syresin JINR, Dubna, Moscow Region, Russia M. Gusarova, M.V. Lalayan, S.M. Polozov MEPhI, Moscow, Russia V.S. Petrakovsky, A.I. Pokrovsky, A. Shvedov, S.V. Yurevich Physical-Technical Institute of the National Academy of Sciences of Belarus, Minsk, Belarus Y. Tamashevich HZB, Berlin, Germany
	The practical realization of a prototype of the frequency tuning system (FTS) for coaxial half-wave cavities (HWR) for the Nuclotron-based Ion Collider fAcility (NICA) injector is presented. The impact of FTS on electromagnetic parameters of copper HWR prototype is experimentally studied and discussed. The most important parameters like tuning range, tuning sensitivity, the dependence of the resonant frequency on the position of the plungers are estimated. The effective operation algorithms of the proposed FTS are discussed and analyzed. The dynamic characteristics of FTS are investigated and showed the ability to adjust the frequency with an accuracy of about 70 Hz.
	Poster MOPAB363 [3.597 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB363
About •	paper received ※ 18 May 2021       paper accepted ※ 09 June 2021       issue date ※ 11 August 2021
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MOPAB364	Shielded Pair Method for Cylindrical Surface Resistance Measurement at Cryogenic Temperature	1132
	K. Brunner, S. Calatroni, F. Caspers CERN, Geneva, Switzerland D. Barna Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary
	The shielded pair resonator method was already used in the past at CERN to measure the surface resistivity of the LHC beam screen both at room temperature and cryogenic temperature. We have refined and adapted the measurement to be able to measure other types of beam screens and also to operate in a strong dipolar magnetic field. This is necessary for testing the properties of HTS coated beam screens or the possible effects of coatings and surface treatments for e-cloud suppression. Several calibration runs were done at cryogenic temperatures (4.2 K) measuring the surface resistivity of a copper pipe to identify the precision, stability and reproducibility achievable using this method. This work describes the challenges of the measurement and ways to mitigate them.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB364
About •	paper received ※ 17 May 2021       paper accepted ※ 22 June 2021       issue date ※ 12 August 2021
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MOPAB365	Construction and First Test Results of the Barrier and Harmonic RF Systems for the NICA Collider	1136
	A.G. Tribendis, Y.A. Biryuchevsky, K.N. Chernov, A.N. Dranitchnikov, E. Kenzhebulatov, A.A. Kondakov, A.A. Krasnov, Ya.G. Kruchkov, S.A. Krutikhin, G.Y. Kurkin, A.M. Malyshev, A.Yu. Martynovsky, N.V. Mityanina, S.V. Motygin, A.A. Murasev, V.N. Osipov, V.M. Petrov, E. Pyata, E. Rotov, V.V. Tarnetsky, I.A. Zapryagaev, A.A. Zhukov BINP SB RAS, Novosibirsk, Russia O.I. Brovko, A.M. Malyshev, I.N. Meshkov, E. Syresin JINR, Dubna, Moscow Region, Russia I.N. Meshkov Saint Petersburg State University, Saint Petersburg, Russia E. Rotov NSU, Novosibirsk, Russia A.G. Tribendis NSTU, Novosibirsk, Russia A.V. Zinkevich Triada-TV, Novosibirsk, Russia
	This paper reports on the design features and construction progress of the three RF systems for the NICA collider being built at JINR, Dubna. Each of the two collider rings has three RF systems named RF1 to 3. RF1 is a barrier bucket system used for particles capturing and accumulation during injection, RF2 and 3 are resonant systems operating at 22nd and 66th harmonics of the revolution frequency and used for the 22 bunches formation. The RF systems are designed and produced by Budker INP. Solid state RF power amplifiers developed by the Triada-TV company, Novosibirsk, are used for driving the RF2 and three cavities. Two RF1 stations were already delivered to JINR, the prototypes of the RF2 and 3 stations were built and successfully tested at BINP. Series production of all eight RF2 and sixteen RF3 stations is in progress. The design modifications and test results are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB365
About •	paper received ※ 18 May 2021       paper accepted ※ 24 May 2021       issue date ※ 14 August 2021
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MOPAB366	Improving Magnetic Materials for RCS Cavity Tuners	1139
	R.L. Madrak, N.M. Curfman, G.V. Romanov, C.-Y. Tan, I. Terechkine Fermilab, Batavia, Illinois, USA G. Das, A.K. Samanta Ceramic Magnetics, Inc., National Magnetics Group, Inc., Bethlehem, USA
	Funding: United States Department of Energy, Contract No. DE-AC02-07CH11359 Within the Lab Directed R&D Program at Fermilab, and in partnership with National Magnetics, we have recently begun to study and attempt to improve the loss parameter in garnet material. This could be used for fast tuner applications such as in rapid cycling synchrotrons.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB366
About •	paper received ※ 19 May 2021       paper accepted ※ 25 May 2021       issue date ※ 15 August 2021
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MOPAB370	X-Band RF Spiral Load Optimization for Additive Manufacturing Mass Production	1143
	H. Bursali Sapienza University of Rome, Rome, Italy N. Catalán Lasheras, R.L. Gerard, A. Grudiev, O. Gumenyuk, P. Morales Sanchez, B. Riffaud CERN, Geneva, Switzerland J. Sauza-Bedolla Lancaster University, Lancaster, United Kingdom
	The CLIC main linac uses X-band traveling-wave normal conducting accelerating structures. The RF power not used for beam acceleration nor dissipated in the resistive wall is absorbed in two high power RF loads that should be as compact as possible to minimize the total footprint of the machine. In recent years, CERN has designed, fabricated and successfully tested several loads produced by additive manufacturing. With the current design, only one load can be produced in the 3D printing machine at a time. The aim of this study is optimizing the internal cross-section of loads in order to create a stackable design to increase the number of produced parts per manufacturing cycle and thus decrease the unit price. This paper presents the new design with an optimization of the internal vacuum part of the so-called RF spiral load. In this case, RF and mechanical designs were carried out in parallel. The new cross section has showed good RF reflection reaching less than -30 dB in simulations. The final load is now ready to be manufactured and high-power tested. This new load will not only provide cost saving but also faster manufacturing for mass production.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB370
About •	paper received ※ 18 May 2021       paper accepted ※ 26 May 2021       issue date ※ 23 August 2021
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MOPAB371	A Coupon Tester for Normal Conducting High-Gradient Materials	1147
	J.W. Lewellen, D. Gorelov, D. Perez, E.I. Simakov LANL, Los Alamos, New Mexico, USA M.E. Schneider Michigan State University, East Lansing, Michigan, USA
	Funding: Los Alamos National Laboratory LDRD Program A coupon tester is an RF structure used to subject a material sample to very high RF fields, with the fields on the sample, or coupon, being higher than elsewhere in the cavity. To date, most such cavities were originally intended to explore the RF properties of superconducting materials, and can expose the sample to strong magnetic fields, but weak to no electric fields. As part of a program to develop materials and structures for high-gradient (> 100 MV/m), low-breakdown-rate normal-conducting accelerators, we have designed a C-band (5.712 GHz) cavity intended to subject samples to both magnetic and electric fields comparable to those experienced in high-gradient structure designs, using a TM-mode cavity; the electric and magnetic fields along the sample coupon can be directly compared to the fields on the iris of high-gradient structures. This poster will present the design criteria for our coupon tester cavity, nominal operating parameters, and our structure concept. The cavity design will be refined over the next several months, and will be constructed and in service near the start of 2022.
	Poster MOPAB371 [0.764 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB371
About •	paper received ※ 17 May 2021       paper accepted ※ 26 May 2021       issue date ※ 30 August 2021
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MOPAB372	KARVE: A Nanoparticle Accelerator for Space Thruster Applications	1151
	J.W. Lewellen, L.R. Danielson, A. Essunfeld, J.A. Hollingsworth, M.A. Holloway LANL, Los Alamos, New Mexico, USA E.K. Lewis NASA Johnson Space Center, Houston, Texas, USA
	We present a concept for using RF-based acceleration of nanoparticles (NPs) as a means of generating thrust for future space missions: the Kinetic Acceleration & Resource Vector Engine (KARVE) thruster. Acceleration of nanoparticles (NPs) via DC accelerators has been shown to be feasible in dust accelerator labs such as the Heidelberg dust accelerator and the 3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies. In contrast, KARVE uses RF-driven acceleration of nanoparticles as the basis of a thruster design lying between chemical and ion engines in performance: more efficient than chemical engines in terms of specific impulse; and higher thrust than ion engines. The properties of multi-gap RF accelerators also allow an on-the-fly tradeoff between specific impulse and thrust.
	Poster MOPAB372 [0.694 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB372
About •	paper received ※ 19 May 2021       paper accepted ※ 27 May 2021       issue date ※ 10 August 2021
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MOPAB374	Creating Exact Multipolar Fields in Accelerating RF Cavities via an Azimuthally Modulated Design	1154
	L.M. Wroe, S.L. Sheehy JAI, Oxford, United Kingdom R. Apsimon Cockcroft Institute, Lancaster University, Lancaster, United Kingdom M. Dosanjh CERN, Meyrin, Switzerland S.L. Sheehy The University of Melbourne, Melbourne, Victoria, Australia
	In this paper, we present a novel method for designing RF structures with specifically tailored multipolar field contributions. This has a range of applications, including the suppression of unwanted multipolar fields or the introduction of wanted terms, such as for quadrupole focusing. In this article, we outline the general design methodology and compare the expected results to 3D CST simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB374
About •	paper received ※ 19 May 2021       paper accepted ※ 08 June 2021       issue date ※ 23 August 2021
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MOPAB376	Design and Fabrication of a Quadrupole Resonator for SRF R&D	1158
	R. Monroy-Villa, W. Hillert, M. Wenskat University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany S. Gorgi Zadeh, P. Putek Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany R. Monroy-Villa, D. Reschke, J.H. Thie DESY, Hamburg, Germany
	As Nb superconducting radio-frequency (SRF) cavities are now approaching the theoretical limits of the material, a variety of different surface treatments have been developed to further improve their performance; although no fully understood theory is yet available. Small superconducting samples are studied to characterize their material properties and their evolution under different surface treatments. To study the RF properties of such samples under realistic SRF conditions at low temperatures, a test cavity called quadrupole resonator (QPR) is currently being fabricated. In this work we report the status of the QPR at Universität Hamburg in collaboration with DESY. Our device is based on the QPRs operated at CERN and at HZB and its design will allow for testing samples under cavity-like conditions, i.e., at temperatures between 2K and 8 K, under magnetic fields up to 120mT and with operating frequencies of 433 MHz, 866 MHz and 1300 MHz. Fabrication tolerance studies on the electromagnetic field distributions and simulations of the static detuning of the device, together with a status report on the current manufacturing process, will be presented.
	Poster MOPAB376 [1.119 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB376
About •	paper received ※ 26 May 2021       paper accepted ※ 09 June 2021       issue date ※ 17 August 2021
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MOPAB379	Topological Optimization on SRF Cavities for Nuclear and High Energy Physics	1162
	H. Gassot Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
	Topology optimization has been developed for more than twenty years. The progress of additive manufacturing boosts the development in topological optimization since the design can be completely innovated and realized by 3D printing. The potential for cost reductions thanks to weight minimization give an interesting perspective for the small production of niobium superconducting radio-frequency cavities, commonly used in accelerators. The traditional manufacturing technologies of cavities are based on multi-stage processes while additive manufacturing technologies can built fully functional parts in a single operation. For modern accelerators that use superconducting linac, including energy recovery linacs (ERLs), it is particularly important to know the perspectives of additive manufacturing for SRF cavities. In this paper, we try to build a preliminary perception of topological optimization in superconducting cavities manufacturing innovation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB379
About •	paper received ※ 11 May 2021       paper accepted ※ 17 August 2021       issue date ※ 15 August 2021
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MOPAB380	Status and Progress of the RF System for High Energy Photon Source	1165
	P. Zhang, J. Dai, Z.W. Deng, L. Guo, T.M. Huang, D.B. Li, J. Li, Z.Q. Li, H.Y. Lin, Y.L. Luo, Q. Ma, F. Meng, Z.H. Mi, Q.Y. Wang, X.Y. Zhang, F.C. Zhao, H.J. Zheng IHEP, Beijing, People’s Republic of China
	Funding: This work was supported in part by High Energy Photon Source, a major national science and technology infrastructure in China and in part by the Chinese Academy of Sciences. High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited synchrotron light source currently under construction in Beijing. It adopts a double-frequency RF system with 166.6 MHz as fundamental and 499.8 MHz as third harmonic. The fundamental cavity is making use of a superconducting quarter-wave β=1 structure and the third harmonic is of superconducting elliptical single-cell geometry for the storage ring, while normal-conducting 5-cell cavities are chosen for the booster ring. A total of 900 kW RF power shall be delivered to the beam by the 166.6 MHz cavities and the third harmonic cavities are active. All cavities are driven by solid-state power amplifiers and the RF fields are regulated by digital low-level RF control systems. The cavity and ancillaries, high-power RF system and low-level RF control system are in the prototyping phase. This paper presents the current status and progress of the RF system for HEPS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB380
About •	paper received ※ 09 May 2021       paper accepted ※ 09 June 2021       issue date ※ 24 August 2021
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MOPAB382	Synchrotron Light Shielding for the 166 MHz Superconducting RF Section at High Energy Photon Source	1169
	X.Y. Zhang, Z.Q. Li, Q. Ma, P. Zhang IHEP, Beijing, People’s Republic of China
	Funding: This work was supported by High Energy Photon Source, a major national science and technology infrastructure in China. The High Energy Photo Source (HEPS) project has been under construction since 2019, and will be first diffraction-limited synchrotron light source in China. A 6 GeV electron beam with 200 mA current will be stored in the main ring. If synchrotron light produced from this energetic electron beam hits the superconducting cavity’s surface, it would cause thermal breakdown of the superconductivity. In the current lattice design, these lights cannot be fully blocked by the collimator in the upstream lattice cell, therefore a shielding scheme inside the rf section is required. This however brings great challenges to the already limited space. The design of the collimator has been focused on fulfilling shielding requirements while optimizing beam impedance, synchrotron light power density, thermal and mechanical stabilities. Shielding materials are subsequently chosen with dedicated cooling to ensure long-term stable operations. In this paper, a shielding scheme inside the rf section of the HEPS storage ring is presented. The synchrotron light mainly from the upstream bending magnet is successfully block. The sensitivity to beam position movement and installation error is also analyzed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB382
About •	paper received ※ 17 May 2021       paper accepted ※ 11 June 2021       issue date ※ 23 August 2021
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MOPAB383	Pressure Test for Large Grain and Fine Grain Niobium Cavities	1173
	M. Yamanaka, T. Dohmae, H. Inoue, T. Saeki, K. Umemori, Y. Watanabe, K. Yoshida KEK, Ibaraki, Japan K. Enami Tsukuba University, Ibaraki, Japan
	The pressure test was performed using a fine grain (FG) and a large grain (LG) niobium cavities. The cavity is 1.3 GHz 3-cell TESLA-like shape. The cavity was housed in a steel vessel. Water is supplied into the vessel and the cavity outside is pressurized. The applying pressure and the natural frequency of cavity were measured during the pressure test. The FG and LG cavities were deformed greatly and the pressure dropped suddenly at 3.4 MPa and 1.6 MPa, respectively. The frequency shifted up to 3.4 MHz and 1.3 MHz, respectively. There was no leak after the pressure test, so the cavity did not rupture under above pressure. The result of the pressure at LG cavity is less half than that of the FG cavity. We calculated the stress distribution in the structure by applying outer water pressure using a FEM. The maximum stress at cell when above test pressure is applied, are 146 MPa in FG and 73 MPa in LG, respectively. These stresses are similar to tensile strength of niobium specimen measure by ourselves. The result of pressure tests agrees well with the calculation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB383
About •	paper received ※ 19 May 2021       paper accepted ※ 22 June 2021       issue date ※ 28 August 2021
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MOPAB384	Nb₃Sn Coating of Twin Axis Cavity for Accelerator Applications	1175
	J.K. Tiskumara, S.U. De Silva, J.R. Delayen, H. Park ODU, Norfolk, Virginia, USA J.R. Delayen, H. Park, U. Pudasaini, C.E. Reece JLab, Newport News, Virginia, USA G.V. Eremeev Fermilab, Batavia, Illinois, USA
	Funding: Research supported by DOE Office of Science Accelerator Stewardship Program Award DE- SC0019399. Partially authored by Jefferson Science Associates under contract no. DEAC0506OR23177 A Superconducting twin axis cavity consisting of two identical beam pipes that can accelerate and decelerate beams within the same structure has been proposed for the Energy Recovery Linac (ERL) applications. There are two niobium twin axis cavities at JLab fabricated with the intention of later Nb3Sn coating and now we are progressing to coat them using vapor diffusion method. Nb3Sn is a potential alternate material for replacing Nb in SRF cavities for better performance and reducing operational costs. Because of advanced geometry, larger surface area, increased number of ports and hard to reach areas of the twin axis cavities, the usual coating approach developed for typical elliptical single-axis cavities must be evaluated and requires to be adjusted. In this contribution, we report the first results from the coating of a twin axis cavity and discuss current challenges with an outlook for the future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB384
About •	paper received ※ 19 May 2021       paper accepted ※ 24 May 2021       issue date ※ 27 August 2021
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MOPAB385	An Overview of RF Systems for the EIC	1179
	R.A. Rimmer, J.P. Preble JLab, Newport News, Virginia, USA K.S. Smith, A. Zaltsman BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under DOE Contract No. DE-SC0012704, by Jefferson Science Associates under contract DE-SC0002769, and by SLAC under Contract No. DE-AC02-76SF00515. The Electron Ion Collider (EIC) to be constructed at Brookhaven National Laboratory in the USA will be a complex system of accelerators providing high luminosity, high polarization, variable center of mass energy collisions between electrons and protons or ions. To achieve this a variety of RF systems are required. They must provide for capture, formation and storage of Ampere-class beams in the electron and hadron storage rings (ESR and HSR), fast acceleration of high-charge polarized electron bunches in the rapid cycling synchrotron (RCS), provision of cold high current electron bunches in the high-energy cooler ERL and precise high-gradient crabbing of electrons and hadrons either side of the interaction point. The challenges include strong HOM damping in the storage ring cavities and cooler ERL, very high fundamental mode power in the ESR and cooler injector, extremely stable low-noise operation of the crab cavities, mitigation of transient beam loading from gaps, and operating over a wide range of energies and beam currents. We describe the high-level system parameters and principal design choices made and progress on the R&D plan to develop these state of the art systems.
	Poster MOPAB385 [1.268 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB385
About •	paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 30 August 2021
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MOPAB386	Development of Nitrogen-Doping Technology for SHINE	1182
	Y. Zong, X. Huang, Z. Wang SINAP, Shanghai, People’s Republic of China J.F. Chenpresenter, H.T. Hou, D. Wang, J.N. Wu, Y.X. Zhang SARI-CAS, Pudong, Shanghai, People’s Republic of China P.C. Dong Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China Y.W. Huang ShanghaiTech University, Shanghai, People’s Republic of China J. Rong SSRF, Shanghai, People’s Republic of China
	The Shanghai HIgh repetition rate XFEL aNd Extreme light facility (SHINE) is under construction, which needs six hundred 1.3GHz cavities with high quality factor. In this paper, we present the newest studies on single cell cavities with nitrogen doping and cold EP treatment, showing an obvious improvement compared with the previous results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB386
About •	paper received ※ 21 May 2021       paper accepted ※ 08 June 2021       issue date ※ 20 August 2021
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MOPAB388	Status of the High Power Couplers for ESS Elliptical Cavities	1186
	C. Arcambal, P. Bosland, G. Devanz, T. Hamelin, C. Madec, C. Marchand, M. Oublaid, G. Perreu, C. Servouin, C. Simon CEA-IRFU, Gif-sur-Yvette, France M. Baudrier, C. Mayri, S. Regnaud, T.V. Vacher CEA-DRF-IRFU, France
	In the framework of the European Spallation Source (ESS), CEA Paris-Saclay is responsible for the delivery of 30 cryomodules (9 medium beta (β = 0.67) and 21 high beta (β = 0.86) ones). Each cryomodule contains 4 elliptical cavities equipped with a radio frequency power coupler. The ESS nominal pulse is 1.1 MW maximum peak power over a width of 3.6 ms at a repetition rate of 14 Hz. The design of the couplers for medium beta and for high beta cavities is the same, except a small difference of the antenna penetration to adjust the Qext. The mass production of the 120 couplers started and all the medium beta couplers have been conditioned at room temperature. The first cryomodules equipped with the power couplers were successfully tested at high RF power and with cavities at 2K reaching the ESS nominal pulse. The main issue at the start of the series production could be fixed and it was due to bad TiN coatings that caused abnormal dielectric losses in the window. Thus, this paper deals with the TiN coating defect, presents the conditioning procedure and gives a conditioning report of these 36 couplers.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB388
About •	paper received ※ 19 May 2021       paper accepted ※ 24 May 2021       issue date ※ 18 August 2021
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MOPAB390	Development of a 166.6 MHz Low-Level RF System by Direct Sampling for High Energy Photon Source	1189
	D.B. Li, H.Y. Lin, Q.Y. Wang, P. Zhang IHEP, Beijing, People’s Republic of China
	Funding: This work was supported by High Energy Photon Source, a major national science and technology infrastructure in China. A digital low-level radio frequency (LLRF) system by direct sampling has been proposed for 166.6 MHz superconducting cavities at High Energy Photon Source (HEPS). The RF field inside the cavities has to be controlled better than ±0.1% (peak to peak) in amplitude and ±0.1 deg (peak to peak) in phase. Considering that the RF frequency is 166.6 MHz, which is well within the analog bandwidth of modern high-speed ADCs and DACs, direct RF sampling and direct digital modulation can be achieved. A digital LLRF system utilizing direct sampling has therefore been developed with embedded experimental physics and industrial control system (EPICS) in the field programmable gate array (FPGA). The performance in the lab has been characterized in a self-closed loop with a residual peak-to-peak noise of ±0.05% in amplitude and ±0.03 deg in phase, which is well below the HEPS specifications. Further tests on a warm 166.6 MHz cavity in the lab are also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB390
About •	paper received ※ 17 May 2021       paper accepted ※ 09 June 2021       issue date ※ 30 August 2021
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MOPAB391	Conduction Cooling Methods for Nb₃Sn SRF Cavities and Cryomodules	1192
	N.A. Stilin, A.T. Holic, M. Liepe, R.D. Porter, J. Sears, Z. Sun Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Rapid progress in the performance of Nb3Sn SRF cavities during the last few years has made Nb3Sn an energy efficient alternative to traditional Nb cavities, thereby initiating a fundamental shift in SRF technology. These Nb3Sn cavities can operate at significantly higher temperatures than Nb cavities while simultaneously requiring less cooling power. This critical property enables the use of new, robust, turn-key style cryogenic cooling schemes based on conduction cooling with commercial cryocoolers. Cornell University has developed and tested a 2.6 GHz Nb3Sn cavity assembly which utilizes such cooling methods. These tests have demonstrated stable RF operation at 10 MV/m and the measured thermal dynamics match what is found in numerical simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB391
About •	paper received ※ 20 May 2021       paper accepted ※ 10 June 2021       issue date ※ 17 August 2021
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MOPAB392	Alternative RF Tuning Methods Performed on Spoke Cavities for ESS and MYRRHA Projects	1196
	P. Duchesne, S. Blivet, G. Olivier, G. Olry, T. Pépin-Donat Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
	In order to obtain the target frequency in operation, the resonant frequency of superconducting radiofrequency cavities is controlled and adjusted from the manufacturing to the end of preparation phase. Reaching this right frequency can be challenging due to the narrow frequency range defined by the tuning sensitivity of the cavity and the capability of the tuner. Mechanical deformation until plasticity is attained is of great interest to tune SRF cavities when large frequency shift is needed. But once a cavity is dressed with its helium tank, the only accessible part is its beam pipe, reducing the mechanical action to a push/pull action. This limited possibility has hence to be skilfully associated with chemical etching. An original mechanical tuning of Spoke dressed cavities consists in increasing the pressure inside the helium tank to induce a permanent deformation of the cavity walls. The frequency shift induced by nonlinear deformation is numerically evaluated in order to determine the pressure increments. Both methods were successfully performed on the cavities of the ESS accelerator and of the Myrrha project.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB392
About •	paper received ※ 20 May 2021       paper accepted ※ 25 June 2021       issue date ※ 17 August 2021
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MOPAB393	Design of an RF-Dipole Crabbing Cavity System for the Electron-Ion Collider	1200
	S.U. De Silva, J.R. Delayen ODU, Norfolk, Virginia, USA J. Henry, F. Marhauser, H. Park, R.A. Rimmer JLab, Newport News, Virginia, USA
	The Electron-Ion Collider requires several crabbing systems to facilitate head-on collisions between electron and proton beams in increasing the luminosity at the interaction point. One of the critical rf systems is the 197 MHz crabbing system that will be used in crabbing the proton beam. Many factors such as the low operating frequency, large transverse voltage requirement, tight longitudinal and transverse impedance thresholds, and limited beam line space makes the crabbing cavity design challenging. The rf-dipole cavity design is considered as one of the crabbing cavity options for the 197 MHz crabbing system. The cavity is designed including the HOM couplers, FPC and other ancillaries. This paper presents the detailed electromagnetic design, mechanical analysis, and conceptual cryomodule design of the crabbing system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB393
About •	paper received ※ 26 May 2021       paper accepted ※ 02 June 2021       issue date ※ 26 August 2021
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MOPAB394	Preliminary BCP Flow Field Investigation by CFD Simulations and PIV in a Transparent Model of a SRF Elliptical Low Beta Cavity	1204
	A. D’Ambros, M. Bertucci, A. Bosotti, A.T. Grimaldi, P. Michelato, L. Monaco, R. Paparella, D. Sertore INFN/LASA, Segrate (MI), Italy F. Cozzi, G. Pianello Politecnico di Milano, Milano, Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	Standard vertical Buffered Chemical Polishing (BCP) is one of the main surface treatment for Superconducting Radiofrequency (SRF) cavities. A finite element Computational Fluid Dynamic (CFD) model has been developed. Uncertainties in the solution of fluid simulations are not negligible due to the complex geometry of a SRF cavity; thus without an experimental validation, results from this type of simulations cannot be confidently used to improve the process. To this aim, an experimental study was started to investigate the fluid dynamics of the BCP process by means of Particle Image Velocimetry (PIV) technique. Similitude on Reynolds number and Refractive Index Matching (RIM) technique were also implemented to replace the dangerous BCP mixture with a glycerine-water mixture. The paper describes the preliminary results from simulations and experiment.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB394
About •	paper received ※ 19 May 2021       paper accepted ※ 24 June 2021       issue date ※ 13 August 2021
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MOPAB396	Measurements of Magnetic Field Penetration in Superconducting Materials for SRF Cavities	1208
	I.H. Senevirathne, J.R. Delayen, A.V. Gurevich ODU, Norfolk, Virginia, USA J.R. Delayen, A-M. Valente-Feliciano JLab, Newport News, Virginia, USA
	Funding: This work is supported by NSF Grants PHY-1734075 and PHY-1416051, and DOE Award DE-SC0010081 and DE-SC0019399 Superconducting radiofrequency (SRF) cavities used in particle accelerators operate in the Meissner state. To achieve high accelerating gradients, the cavity material should stay in the Meissner state under high RF magnetic field without penetration of vortices through the cavity wall. The field onset of flux penetration into a superconductor is an important parameter of merit of alternative superconducting materials other than Nb which can enhance the performance of SRF cavities. There is a need for a simple and efficient technique to measure the onset of field penetration into a superconductor directly. We have developed a Hall probe experimental setup for the measurement of the flux penetration field through a superconducting sample placed under a small superconducting solenoid magnet which can generate magnetic fields up to 500 mT. The system has been calibrated and used to measure different bulk and thin film superconducting materials. This system can also be used to study SIS multilayer coatings that have been proposed to enhance the vortex penetration field in Nb cavities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB396
About •	paper received ※ 19 May 2021       paper accepted ※ 23 June 2021       issue date ※ 30 August 2021
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MOPAB400	Development of Helium Vessel Welding Process for SNS PPU Cavities	1212
	P. Dhakal, E. Daly, G.K. Davis, J.F. Fischer, N.A. Huque, K. Macha, P.D. Owen, K.M. Wilson, M. Wiseman JLab, Newport News, Virginia, USA
	Funding: This manuscript has been authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The Spallation Neutron Source Proton Power Upgrade cavities are produced by Research Instrument with all the cavity processing done at vendor sites with final chemistry applied to the cavity to be electropolishing. Cavities are delivered to Jefferson Lab, ready to be tested. One of the tasks to be completed before the arrival of production-ready PPU cavities is to develop a robust helium vessel welding protocol. We have successfully developed the process and applied it to three six-cell high beta cavities. Here, we present the summary of RF results, welding process development, and post helium vessel RF results.
	Poster MOPAB400 [1.313 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB400
About •	paper received ※ 18 May 2021       paper accepted ※ 26 May 2021       issue date ※ 01 September 2021
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MOPAB401	In-Situ EXAFS Investigations of Nb-Treatments in N₂, O₂ and N₂-O₂ Mixtures at Elevated Temperatures	1214
	P. Rothweiler, B. Bornmann, J. Klaes, D. Lützenkirchen-Hecht, R. Wagner University of Wuppertal, Wuppertal, Germany
	Funding: We gratefully acknowledge financial support by the German Federal Ministry of Education and Research (BMBF) under project No. 05H18PXRB1. Smooth polycrystalline Nb metal foils were treated in dilute gas atmospheres using a temperature of 900 °C. Transmission mode X-ray absorption spectroscopy (EX-AFS) at the Nb K-edge was used to investigate changes in the atomic short-range order structure of the bulk Nb-material in-situ. The experiments were performed in a dedicated high-vacuum cell that allows treatments in a dilute gas atmosphere and temperatures of up to 1200 °C. Typical treatments include (i) pre-heating at 900 °C under high-vacuum, (ii) gas exposure at the desired pressure and temperature, and (iii) cooldown to room temperature under vacuum. EXAFS data were collected during the entire procedure with a time resolution of 1 s. For the treatments in N2 at T = 900°C, the data show subtle changes in the Nb-EXAFS, that are compatible with N-doping of the bulk Nb, and the results suggest Nb uptake on octahedral interstitial sites. However, even a small O2-partial pressure leads to distinct oxidation of the Nb. The results will be discussed in more detail in the presentation.
	Poster MOPAB401 [2.032 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB401
About •	paper received ※ 19 May 2021       paper accepted ※ 26 May 2021       issue date ※ 27 August 2021
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MOPAB404	A Low Emittance Compact Proton Injector for a Proton Therapy Facility	1218
	S.X. Peng, J.E. Chen, B.J. Cui, Z.Y. Guo, Y.X. Jiang, K. Li, T.H. Ma, J. Sun, W.B. Wu, A.L. Zhang, J.F. Zhang PKU, Beijing, People’s Republic of China Y.H. Pu Shanghai APACTRON Particle Equipment Company Limited, Shanghai, People’s Republic of China
	To meet the requirements of a Proton Therapy Facility funded by the National Key Research and Development Program of China, a new compact ion source-LEBT integrated proton injector was developed at Peking University (PKU). It consists of a typical PKU permanent magnet compact 2.45 GHz ECR ion source (PMECRIS) and an electrostatic LEBT with an electrostatic lens, a beam chopper, a set of beam steers, an ACCT, a bellow, an e-trap, and a valve. A 1000 L/s molecular pump is adopted to maintain the vacuum for this integrated injector. The length from RF matching plane to RFQ front flange is about 450 mm. Chopper is used to shorten the pulse length from ms to µs with sharp edges. Test results of this PMECR source prove that it has the ability to deliver a proton beam with a current from 10 mA to 90 mA with a duty factor of 3%(100Hz/0.3ms) and its RMS emittance less than 0.1 mm·mrad at 30 keV. The acceptance tests of this integrated injector have been performed with a 30 keV hydrogen beam. A required proton current of 18 mA with ripple wave less than 0.1 mA successfully passed through a 20 mm aperture diaphragm at RFQ entrance flange. Its rms emittance is about 0.06 mm·mrad.
	Poster MOPAB404 [1.946 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB404
About •	paper received ※ 19 May 2021       paper accepted ※ 17 August 2021       issue date ※ 18 August 2021
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MOPAB405	Study of Targets to Produce Molybdenum-99 Using 30 MeV Electron Linear Accelerator	1222
	T.S. Dixit, A.P. Deshpande, R. Krishnan, A. Shaikh SAMEER, Mumbai, India
	Funding: Ministry of Electronics and Information Technology, Government of India (MeitY) Two approaches to produce 99Mo are studied using GEANT4 are reported in this paper. First, in converter target approach, bremsstrahlung photons are generated in a high Z target. The emitted photons then hit 100Mo secondary target, producing 99Mo through (gamma, n) reaction. Second, in direct target approach, high energy electron beam hits 100Mo target, where both (e, gamma) and (gamma, n) reactions take place simultaneously. A 30 MeV, 5-10 kW beam power electron linac is under development at SAMEER. The acceleration gradient required to achieve 30 MeV energy will be provided by two linacs operated in series configuration and the high average beam power will be achieved by running the system at high duty operation. Main aim of this study is to optimize experimental parameters to maximize specific activity of 99Mo. Since, 100Mo is very expensive material therefore judicious use of the material is very important. Hence, optimization of electron beam energy and target dimensions are studied in detail in both the approaches. It is found that the direct target approach gives higher specific activity compared to the converter target approach.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB405
About •	paper received ※ 19 May 2021       paper accepted ※ 06 June 2021       issue date ※ 14 August 2021
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MOPAB409	FLUKA Simulations of ²²⁵Ac Production Using Electron Accelerators: Validation Through Comparison with Published Experiments	1226
	T.V. Szabo, I.C. Moraes CNPEM, Campinas, SP, Brazil F.A. Bacchim Neto LNLS, Campinas, Brazil P.V. Guillaumon USP/LAL, Sao Paulo, Brazil H.B. de Oliveira IPEN, São Paulo, Brazil
	Targeted Alpha Therapy (TAT) is an active area of study worldwide. This technique has shown a potential in nuclear medicine to treat metastatic disease by alpha particles that deposit energy in small regions nearby cancer cells. Ac-225 is an important alpha-emitting that can be used for cancer TAT. This radioisotope shows good potential for medical applications, therefore is important to study ways of increase its production and availability. One possible path for the Ac-225 product is to radiate a radium target (Ra-226) on a linear electron accelerator (LINAC). Isotope production studies could be implemented using computational tools. In this work, Monte Carlo simulations with FLUKA code were performed and compared to experimental results *. We studied Ac-225 production by photonuclear reactions using a 24 MeV electron beam LINAC hitting a tungsten electron-photon converter. Different energies and geometries were also simulated to obtain optimal production conditions. The specific activity values obtained with simulations had a good agreement with published experimental results. * MASLOV, O., et. al. Preparation of 225Ac by 226Ra(g, n) photonuclear reaction on an mt25 microtron. Radiochemistry
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB409
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 30 August 2021
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MOPAB410	Preliminary Studies of a Compact VHEE Linear Accelerator System for FLASH Radiotherapy	1229
	L. Giuliano, F. Bosco, M. Carillo, D. De Arcangelis, L. Faillace, L. Ficcadenti, M. Migliorati, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy D. Alesini, M. Behtouei, B. Spataro INFN/LNF, Frascati, Italy G. Cuttone, G. Torrisi INFN/LNS, Catania, Italy V. Favaudon, S. Heinrich, A. Patriarca Institut Curie - Centre de Protonthérapie d’Orsay, Orsay, France
	Funding: The work is supported by La Sapienza University, research grant "grandi progetti di ricerca 2020". The Flash Radio Therapy is a revolutionary new technique in the cancer cure: it spares healthy tissue from the damage of the ionizing radiation maintaining the tumor control as efficient as in conventional radiotherapy. To allow the implementation of the FLASH Therapy concept into actual clinical use, it is necessary to have a linear accelerator able to deliver the very high dose and very high dose rate (>106 Gy/s) in a very short irradiation time (beam on time < 100ms). Low energy S-band Linacs (up to 7 MeV) are being used in Radiobiology and pre-clinic applications but in order to treat deep tumors, the energy of the electrons should achieve the range of 60-100 MeV. In this paper, we address the main issues in the design of a compact C band (5.712 GHz) electron linac-VHEE for FLASH Radio Therapy. We present preliminary studies on C-band structures at La Sapienza and at INFN-LNS, aiming to reach a high accelerating gradient and high current necessary to deliver a dose >1 Gy/pulse, with very short electron pulse.
	Poster MOPAB410 [0.650 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB410
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 21 August 2021
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MOPAB411	Quantifying DNA Damage in Comet Assay Images Using Neural Networks	1233
	S.J.K. Dhinsey, T. Greenshaw, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom J.L. Parsons Cancer Research Centre, University of Liverpool, Liverpool, United Kingdom C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. Proton therapy for cancer treatment is a rapidly growing field and increasing evidence suggests it induces more complex DNA damage than photon therapy. Accurate comparison between the two treatments requires quantification of the DNA damage the cause, which can be assessed using the Comet Assay. The program outlined here is based on neural network architecture and aims to speed up analysis of Comet Assay images and provide accurate, quantifiable assessment of the DNA damage levels apparent in individual cells. The Comet Assay is an established technique in which DNA fragments are spread out under the influence of an electric field, producing a comet-like object. The elongation and intensity of the comet tail (consisting of DNA fragments) indicate the level of damage incurred. Many methods to measure this damage exist, using a variety of algorithms. However, these can be time consuming, so often only a small fraction of the comets available in an image are analysed. The automatic analysis presented in this contribution aims to improve this. To supplement the training and testing of the network, a Monte Carlo model will also be presented to create simulated comet assay images.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB411
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 16 August 2021
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MOPAB412	Accelerator Production of Mo-99 Using Mo-100	1237
	J.L. McCarter, M.J. Brennan, S.M. Burns, J.T. Harvey, S.W. Kelley, T.A. Montenegro, Q. Schiller NorthStar Medical Technologies, LLC, Beloit, USA
	Funding: DE-NA0001878 Tc-99m is an essential radionuclide for nearly 40,000 diagnostic nuclear medicine tests in the U.S. each day. Its daily production depends on Mo-99, which must be replenished weekly due to Mo-99’s 2.75 day half-life. Mo-99, in the past, was supplied from uranium fission production, depending on overseas nuclear reactors that average 50 years old. Their age in combination with shipment uncertainties make the availability of Mo-99 fragile and subject to severe shortages. The U.S. now has one domestic, FDA-approved supplier that produces Mo-99, NorthStar Medical Radioisotopes. Currently, NorthStar produces Mo-99 via the irradiation of Mo-98 in a nuclear reactor. In the future, NorthStar will also irradiate Mo-100 with accelerator created x-rays to produce Mo-99. This process will use 2 distinct, 40 MeV, 125 kW average electron accelerators, Rhodotrons produced by IBA. Accelerator produced Mo-99 has several advantages over that produced by reactors, including a dual supply and an ability to adjust irradiation timing to meet radiopharmacy demands, such as Sunday delivery. NorthStar is currently installing and commissioning this accelerator based system, entering production in late-2022.
	Poster MOPAB412 [2.150 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB412
About •	paper received ※ 24 May 2021       paper accepted ※ 07 June 2021       issue date ※ 19 August 2021
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MOPAB413	The Next Ion Medical Machine Study at CERN: Towards a Next Generation Cancer Research and Therapy Facility with Ion Beams	1240
	M. Vretenar, V. Bencini, E. Benedetto, M.R. Khalvati, A.M. Lombardi, M. Sapinski, D. Tommasini CERN, Meyrin, Switzerland E. Benedetto, M. Sapinski TERA, Novara, Italy P. Foka GSI, Darmstadt, Germany
	Cancer therapy with ions has several advantages over X-ray and proton therapy, but its diffusion remains limited primarily because of the size and cost of the accelerator. To develop technologies that might improve performance and reduce accelerator cost with respect to present facilities, CERN has recently launched the Next Ion Medical Machine Study (NIMMS), leveraging CERN expertise in accelerator fields to disseminate technologies developed for basic science. A perspective user and key partner of NIMMS is the SEEIIST (South East European International Institute for Sustainable Technologies), established to build in the region an innovative facility for combined cancer therapy and biomedical research with ion beams. For SEEIIST and other potential users, three options are being considered. Conceptual designs of a warm-magnet synchrotron at high beam intensity, of a compact superconducting synchrotron, and of a high-frequency linear accelerator have been compared in terms of cost, risk and development time. The development of curved superconducting magnets, of compact synchrotrons and ion gantries, and of linacs is being pursued within EU-funded projects or specific collaborations
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB413
About •	paper received ※ 18 May 2021       paper accepted ※ 20 July 2021       issue date ※ 13 August 2021
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MOPAB414	A Novel Facility for Cancer Therapy and Biomedical Research with Heavy Ions for the South East European International Institute for Sustainable Technologies	1244
	S. Damjanovic, P. Grübling, H. Schopper SEEIIST, Geneva, Switzerland U. Amaldi, E. Benedetto, M. Sapinski TERA, Novara, Italy E. Benedetto, G. Bisoffi, M. Dosanjh, M. Sapinski, M. Vretenar CERN, Meyrin, Switzerland G. Bisoffi INFN/LNL, Legnaro (PD), Italy S. Damjanovic, M. Durante, P. Foka, C. Graeff GSI, Darmstadt, Germany Th. Haberer HIT, Heidelberg, Germany S. Rossi CNAO Foundation, Milan, Italy H.J. Specht Universität Heidelberg, Heidelberg, Germany
	The South East European International Institute for Sustainable Technologies (SEEIIST) proposes the construction of a major joint Research Infrastructure in the region, to rebuild cooperation after the recent wars and overcome lasting consequences like technology deficits and brain drain, having at its core a facility for cancer therapy and biomedical research with heavy ions. Beams of ions like Carbon are an advanced way to irradiate tumours but more research is needed, while the higher investment costs than for other radiation treatments have so far limited the European facilities to only four. This initiative aims at being strongly innovative, beyond the existing European designs. While the initial baseline relies on a conservative warm-magnet synchrotron, superconducting magnets for an advanced version of the synchrotron and for the gantry are being developed, with a potential for reductions in size, cost, and power consumption. Both warm and superconducting designs feature high beam intensity for faster treatment, and flexible extraction for novel treatment methods. A novel injector linac has the potential for producing radioisotopes in parallel with synchrotron injection.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB414
About •	paper received ※ 17 May 2021       paper accepted ※ 06 July 2021       issue date ※ 22 August 2021
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MOPAB415	Failure Rates and Downtimes of Multi-Leaf Collimators in Indonesia	1248
	G.S. Peiris, S.L. Sheehy The University of Melbourne, Melbourne, Victoria, Australia M.F. Kasim, S.A. Pawiro University of Indonesia, Depok, Jawa Barat, Indonesia
	One of the greatest barriers to cancer treatment in Low and Middle-Income Countries (LMICs) is the access to Radiotherapy Linear Accelerators (LINACs). Not only are the LINACs complex, the harsh environment of LMICs cause frequent breakdowns resulting in downtimes ranging from days to months. Recent research has identified a disparity between LMICs and High Income Countries (HICs) and determined the Multi-Leaf Collimator (MLC) as a component needing re-evaluation. The MLC causes over 30% of the problems in RT LINACs, but the modes of failure and quantify the extent of the damage done are yet to be quantified. Using data from across Indonesia, we show the pathways to failure of RT Machines and frequency of breakdowns over time. A component of the MLC needs to be replaced every 9.98 faults per 1000 patients treated and the MLC itself breaks down on average every 36±1.8 days. When comparing the downtime by leaf width, the data shows 5mm leaves contribute 18.27±6.5% to all breakdowns while 10mm makes up 15.87±4.3%. These results outline the need to reassess the current generation of RT LINACs and ultimately work towards guiding future designs to be robust enough for all environments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB415
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 16 August 2021
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MOPAB416	BDSIM Developments for Hadron Therapy Centre Applications	1252
	E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde ULB, Bruxelles, Belgium S.T. Boogert, L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom C. Hernalsteens CERN, Geneva, Switzerland W. Shields JAI, Egham, Surrey, United Kingdom
	Hadron therapy centres are evolving towards reduced-footprint layouts, often featuring a single treatment room. The evaluation of beam properties, radiation protection quantities, and concrete shielding activation via numerical simulations poses new challenges that can be tackled using the numerical beam transport and Monte-Carlo code Beam Delivery Simulation (BDSIM), allowing a seamless simulation of the dynamics as a whole. Specific developments have been carried out in BDSIM to advance its efficiency toward such applications, and a detailed 4D Monte-Carlo scoring mechanism has been implemented. It produces tallies such as the spatial-energy differential fluence in arbitrary scoring meshes. The feature makes use of the generic boost::histogram library and allows an event-by-event serialisation and storage in the ROOT data format. The pyg4ometry library is extended to improve the visualisation of critical features such as the complex geometries of BDSIM models, the beam tracks, and the scored quantities. Data are converted from Geant4 and ROOT to a 3D visualisation using the VTK framework. These features are applied to a complete IBA Proteus One model.
	Poster MOPAB416 [1.575 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB416
About •	paper received ※ 19 May 2021       paper accepted ※ 12 July 2021       issue date ※ 15 August 2021
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MOPAB417	Preliminary Study of a Large Energy Acceptance FFA Beam Delivery System for Particle Therapy	1256
	J.S.L. Yap, E.R. Higgins, S.L. Sheehy The University of Melbourne, Melbourne, Victoria, Australia
	The availability and use of ion beams for radiotherapy has grown significantly, led by technological developments to exploit the dosimetric advantages offered by charged particles. The benefits of particle therapy (PT) are well identified however its utilisation is still limited by high facility costs and technological challenges. A possibility to address both of these can be considered by improvements to the beam delivery system (BDS). Existing beamlines and gantries transport beams with a momentum range of ±1% and consequently, adjustments in depth or beam energy require all the magnetic fields to be changed. The speed to switch energies is a limiting constraint of the BDS and a determinant of the overall treatment time. A novel concept using fixed field alternating gradient (FFA) optics enables a large energy acceptance (LEA) as beams of varying energies can traverse the beamline at multiple physical positions given the same magnetic field. This presents the potential to provide faster, higher quality treatments at lower costs, with the capability to deliver advanced PT techniques such as multi-ion therapy. We explore the applicability and benefits of a LEA BDS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB417
About •	paper received ※ 18 May 2021       paper accepted ※ 27 July 2021       issue date ※ 15 August 2021
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MOPAB418	Tracking and LET Measurements with the MiniPIX-TimePIX Detector for 60 MeV Clinical Protons	1260
	J.S.L. Yap, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom N.J.S. Bal NIKHEF, Amsterdam, The Netherlands M.D. Brooke University of Oxford, Oxford, United Kingdom C. Granja, C. Oancea ADVACAM s.r.o, Prague, Czech Republic A. Kacperek The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom C.P. Welsch, J.S.L. Yap The University of Liverpool, Liverpool, United Kingdom
	Funding: EU FP7 grant agreement 215080, H2020 Marie Sklodowska-Curie grant agreement No 675265, OMA - Optimization of Medical Accelerators and the Cockcroft Institute core grant STGA00076-01. Recent advancements in accelerator technology have led the rapid emergence of particle therapy facilities worldwide, affirming the need for enhanced characterisation methods of radiation fields and radiobiological effects. The Clatterbridge Cancer Centre, UK operates a 60 MeV proton beam to treat ocular cancers and facilitates studies into proton induced radiobiological responses. Accordingly, an indicator of radiation quality is the linear energy transfer (LET), a challenging physical quantity to measure. The MiniPIX-Timepix is a miniaturised, hybrid semiconductor pixel detector with a Timepix ASIC, enabling wide-range measurements of the deposited energy, position and direction of individual charged particles. High resolution spectrometric tracking and simultaneous energy measurements of single particles enable the beam profile, time, spatial dose mapping and LET (0.1 to >100 keV/µm) to be resolved. Measurements were performed to determine the LET spectra in silicon, at different positions along the Bragg Peak (BP). We discuss the experimental setup, preliminary results and applicability of the MiniPIX for clinical environments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB418
About •	paper received ※ 18 May 2021       paper accepted ※ 23 July 2021       issue date ※ 25 August 2021
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MOPAB419	Acceleration and Measurement of Alpha Particles and Hydrogen Molecular Ions with the HZB Cyclotron	1264
	G. Kourkafas, J. Bundesmann, A. Denker, T. Fanselow, J. Röhrich HZB, Berlin, Germany J. Heufelder, A. Weber Charite, Berlin, Germany
	The HZB cyclotron has treated more than 4000 patients with eye tumors using protons. The accelerator can also provide heavier ions which could be suitable for ocular radiation therapy. Helium ions exhibit less lateral spread, increased relative biological effectiveness and a sharper Bragg-Peak compared to protons of the same range, while minimizing nuclear fragmentation and thus excessive dose downstream the irradiated volume compared to more heavy ions. When accelerating fully stripped helium ions (alpha particles), hydrogen molecular ions can also be accelerated to the same energy with a small tuning of the machine due to having almost the same mass-to-charge ratio, yielding a proton beam of double current after the beam exits the vacuum window towards the target. The acceleration and characterization of these two ion species are described in this paper, suggesting the feasibility of a corresponding clinical cyclotron for ocular or even deep-seated tumors.
	Poster MOPAB419 [0.806 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB419
About •	paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 13 August 2021
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