IPAC2019 - List of Keywords (operation)

Paper	Title	Other Keywords	Page
MOYPLM1	Challenges to Higher Beam Power in J-PARC: Achieved Performance and Future Prospects	resonance, extraction, experiment, proton	6
	S. Igarashi KEK, Ibaraki, Japan
	J-PARC is a world leading intensity frontier accelerator facility, consisting of a 400-MeV H⁻ linac, a 3-GeV Rapid Cycling Synchrotron (RCS) and a 30-GeV slow cycling Main Ring synchrotron (MR). The RCS delivered a 500 kW beam (4.2·10¹³ particles per pulse (ppp)) to the Material and Life science experimental Facility (MLF) in April of 2018, The design power of 1 MW will be delivered in the next few years. Construction of a second target station (2TS) of the MLF with beam power upgraded to 1.5 MW is now under discussion. The MR delivers proton beam to a long-baseline neutrino oscillation experiment, T2K, by fast extraction (FX) and to the hadron experimental facility by slow extraction (SX). For the FX, the maximum beam power is 475 kW and 2.5·10¹⁴ ppp, the world highest ppp in synchrotrons, and for the SX 51 kW and 5.5·10¹³ ppp with an extremely high extraction efficiency of 99.5 %. To achieve 1.3 MW beam power for the neutrino experiment, upgrades to allow operation with a higher repetition rate are planned. The talk will review recent progress of J-PARC facility by highlighting technical challenges toward higher beam power together with future prospects.
	Slides MOYPLM1 [9.193 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOYPLM1
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOYPLM2	SRF Operation at XFEL: Lessons Learned After More Than One Year	FEL, cavity, linac, SRF	12
	D. Kostin, V. Ayvazyan, J. Branlard, W. Decking, L. Lilje, M. Omet, T. Schnautz, E. Vogel, N. Walker DESY, Hamburg, Germany
	The European XFEL is the largest high-field SRF installation in the world and has now been in operation more than a year. It serves as a "prototype" for other facilities being constructed or in the planning stages. Performance of the operation of the SRF system over this period of time and the lessons learned will be discussed.
	Slides MOYPLM2 [4.351 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOYPLM2
About •	paper received ※ 10 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOYPLM3	Progress with the High Luminosity LHC Project at CERN	luminosity, cavity, quadrupole, collider	17
	L. Rossi, O.S. Brüning CERN, Geneva, Switzerland
	The High Luminosity LHC (HL-LHC) project aims at upgrading the LHC by increasing the peak luminosity by a factor five, to allow to collect 3000 fb-1 for ATLAS and CMS experiments, each, which is ten times more than what is foreseen in the LHC. The upgrade is based on multiple factors. One factor is doubling the beam current, also thanks to the injector upgrade (LIU) project, and another one is operation in levelling mode. The most critical upgrade is the deploying of a stronger inner quadrupole triplet in the low-beta insertions with more than twice-larger aperture w.r.t. present LHC triplet, thanks to the use of Nb₃Sn superconductor, a world first for accelerators, with almost 12 T peak field in the coils. The novel concept of ATS optics allows to utilise the increased aperture efficiently by generating β^* values 3 to 4 times below the nominal values of the LHC. We will make use of compact crab cavities for hadrons (also a novelty in accelerators) to allow almost head-on collisions despite the larger crossing angle. We are developing new collimator insertions in the dispersion suppressor region to handle the losses in the cold part of the machine (the beam halo stores 30 MJ) thanks to the use of a few 11 T dipoles based on Nb₃Sn technology. We also aim at reducing drastically the impedance contribution of collimators by utilizing new materials and coating techniques. Many other technologies are developed for HL-LHC like new SC links of 100 kA: HL-LHC is critical as a technology turning point for HEP colliders as it is for Physics reach. The technologies developed for HL-LHC, namely (but not only) the high field superconducting magnets, are critical for the post-LHC hadron collider, like a High Energy LHC or the 100 km Future Circular Collider
	Slides MOYPLM3 [21.679 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOYPLM3
About •	paper received ※ 19 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOZPLS2	Ion Collider Precision Measurements With Different Species	target, electron, experiment, collider	28
	G.J. Marr, E.N. Beebe, I. Blackler, W. Christie, K.A. Drees, P.S. Dyer, A.V. Fedotov, W. Fischer, C.J. Gardner, H. Huang, T. Kanesue, N.A. Kling, V. Litvinenko, C. Liu, Y. Luo, D. Maffei, B. Martin, A. Marusic, K. Mernick, M.G. Minty, C. Naylor, M. Okamura, I. Pinayev, G. Robert-Demolaize, T. Roser, P. Sampson, V. Schoefer, T.C. Shrey, D. Steski, P. Thieberger, J.E. Tuozzolo, K. Zeno, I.Y. Zhang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC, under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Precedent to electron cooling commissioning and collisions of Gold at various energies at RHIC in 2018, the STAR experiment desired an exploration of the chiral magnetic effect in the quark gluon plasma (QGP) with an isobar run, utilizing Ruthenium and Zirconium. Colliding Zr-96 with Zr-96 and Ru-96 with Ru-96 create the same QGP but in a different magnetic field due to the different charges of the Zr (Z=40) and Ru (Z=44) ions. Since the charge difference is only 10%, the experimental program requires exacting store conditions for both ions. These systematic error concerns presented new challenges for the Collider, including frequent reconfiguration of the Collider for the different ion species, and maintaining level amounts of instantaneous and integrated luminosity between two species. Moreover, making beams of Zr-96 and Ru-96 is challenging since the natural abundances of these isotopes are low. Creating viable enriched source material for Zr-96 required assistance processing from RIKEN, while Ru-96 was provided by a new enrichment facility under commissioning at Oak Ridge National Laboratory.
	Slides MOZPLS2 [4.758 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOZPLS2
About •	paper received ※ 11 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW010	First Application of Online Particle Swarm Optimization at SOLEIL	injection, storage-ring, controls, vacuum	82
	A. Bence, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France J. Li HZB, Berlin, Germany
	First attempts of online optimisation of SOLEIL using Particle Swarm Optimisation (PSO) is reported with two major applications. This technique proves to be particularly suitable in a control room and could become a standard operation tool for tuning the accelerators in complement of other techniques. The first optimisation of the injection in the storage ring will be presented using the injection septa and the vertical correctors of the booster to storage ring transfer line. The second work will summarise the results obtained from the optimisation of the transverse on- and off-momentum dynamics in presence of insertion devices. Main results, the implementation and improvements will be presented and discussed thoroughly.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW010
About •	paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW025	Beam Breakup Simulations for the Mainz Energy Recovering Superconducting Accelerator MESA	cavity, HOM, cryomodule, simulation	135
	C.P. Stoll, F. Hug KPH, Mainz, Germany
	Funding: This work is supported by DFG through PRISMA+ cluster of excellence EXC 2118/2019, RTG 2128 and by the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871. MESA is a two pass energy recovery linac (ERL) currently under construction at the Johannes Gutenberg-University in Mainz. MESA uses four 1.3 GHz TESLA type cavities with 12.5 MV/m of accelerating gradient in two modified ELBE type cryomodule with improved thermal connection of the HOM antennas and cw operation. In the first stage of MESA operation 1mA of beam current is foreseen, which will later be upgraded to 10mA. One potential limit to maximum beam current in ERLs is the transverse beam breakup (BBU) instability induced by dipole Higher Order Modes (HOMs). These modes can be excited by bunches passing through the cavities off axis. Following bunches are then deflected by the HOMs, which results in even larger offsets for recirculated bunches. This feedback can even lead to beam loss. Simulation results for HOM spectra of a single TESLA cavity are available for example in . It was possible to measure the HOM spectra in the cold, not tuned cavities at DESY and in the cold string tuned to the 1.3 GHz fundamental mode at Mainz. Results for the maximum beam current for MESA, limited by BBU, for the various HOM spectra are presented. "Eigenmode Calculations for the TESLA Cavity Considering Wave-Propagation Losses through Fundamental and Higher-Order Mode Couplers", W. Ackermann, H. De Gersem, C. Liu, and T. Weiland
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW025
About •	paper received ※ 16 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW026	Transfer Line Optics Design Using Machine Learning Techniques	target, simulation, quadrupole, optics	139
	D.M. Vilsmeier IAP, Frankfurt am Main, Germany M. Bai, M. Sapinski GSI, Darmstadt, Germany
	Optimization of transfer line optics is essential for delivering high quality beams to the experimental areas. This type of optimization is usually done by hand and relies on the experience of operators. The nature of this task is repetitive though highly complex. Besides optimizing the beam quality at the experiments this task is often accompanied by secondary objectives or requirements such as keeping the beam losses below an acceptable threshold. In the past years Deep Learning algorithms have experienced a rapid development and gave rise to various advanced software implementations which allow for straightforward usage of corresponding techniques, such as automatic differentiation and gradient backpropagation. We investigate the applicability and performance of these techniques in the field of transfer line optics optimization, specifically for the HADES beamline at GSI, in form of gradient-based differentiable simulators. We test our setup on results obtained from MADX simulations and compare our findings to different gradient-free optimization methods. Successfully employing such methods relieves operators from the tedious optimization tasks.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW026
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW036	Studies on Coherent Multi-Bunch Tune Shifts with Different Bunch Spacing at the J-PARC Main Ring	space-charge, proton, impedance, injection	167
	A. Kobayashi, S. Igarashi, Y. Sato, T. Shimogawa, Y. Sugiyama, T. Toyama, M. Yoshii KEK, Tokai, Ibaraki, Japan
	At a high-power proton synchrotron, betatron tune shifts induced by space charge effects cause beam loss which limits the beam intensity. To achieve further high beam intensity at the main ring of the Japan Proton Accelerator Research Complex, precise control of the tune shift is indispensable. When carrying out multi-bunch measurements, we observed that the dependence of the tune shift intensity on the number of bunches follow opposite slope trends for the horizontal and vertical directions. The influence of the bunch spacing was also observed. We report on a simplified tune shift model reconstruction for understanding the origin of these phenomena and present a correction of the tune shifts for reducing beam loss up to 30 %.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW036
About •	paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW038	Collimator’s Impact Into the Transverse Emittance Growth at KEK Compact ERL	wakefield, emittance, simulation, FEL	174
	O.A. Tanaka, T. Miyajima, N. Nakamura, T. Obina, M. Shimada, Y. Tanimoto KEK, Ibaraki, Japan
	In high-intensity particle accelerators, unwanted trans-verse and longitudinal wakefields arise when the high-charge particle beam passes through the narrow chambers or locations with small transverse apertures, such as collimator jaws. Transverse wakefields impose a transverse kicks to the beam, changing its shape, and leading to the growth of the transverse emittance. Longitudinal wakes cause the beam energy losses, heating of the narrow chambers etc. In the present study we investigated the collimator’s impact to the beam. Thus, we evaluated the collimator’s wakefields through the CST simulations. We estimated the corresponding transverse kicks and longitudinal wakes. In the summary simulation results were cross-checked with correspondent analytical expressions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW038
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW039	Investigation of Longitudinal Beam Dynamics With Harmonic Cavities by Using the Code Mbtrack	cavity, impedance, synchrotron, beam-loading	178
	N. Yamamoto KEK, Ibaraki, Japan A. Gamelin, R. Nagaoka SOLEIL, Gif-sur-Yvette, France
	In diffraction-limited light sources, the study of collective effects is essential. With harmonic cavities (HCs), the ’flat potential condition’ can be achieved, lengthening the bunch by a factor of ~5. However, the effective rf voltage seen by the beam becomes sensitive to both positions and distributions of all bunches, as the beam-induced voltage of both HCs and fundamental cavities (FCs) contribute. In addition, when there are empty buckets, the transient beam loading induces considerable variations of the rf voltage impacting the beam performance. Here the use of analytical approaches is difficult. Then we introduced the new functions to treat the high-Q resonators driven by either or both of the beams and external generators to the code mbtrack. Using these features, various operating conditions with arbitrary fill patterns can be studied; coupled bunch instability induced by HOMs of the cavity, Robinson instabilities and general beam dynamics with HCs. The growth rates of the instabilities described above are compared with analytical results. The ring performance with HCs in several fill patterns shall be also reported. N.Yamamoto, et al., PRAB, 21, 012001 (2018). **G. Skripka, et al., NIM A806, 221 (2016).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW039
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW072	Reconfiguration of SPS Landau Octupole Circuits to Minimise Second Order Chromaticity	octupole, optics, target, acceleration	262
	H. Bartosik, M. Carlà, K. Cornelis CERN, Meyrin, Switzerland
	In the SPS Q20 optics presently used for LHC beams, the Landau octupole families of the SPS (LOF and LOD circuits) generate large second order chromaticity due to the relatively high dispersion at their locations. Since the induced second order chromaticity results in enhanced losses due to the large incoherent tune spread, these octupoles cannot be used for mitigating transverse instabilities for LHC beams. A new cabling scheme was proposed, exploiting additional octupoles that were already installed in the machine but not used, which allows minimizing the induced second order chromaticity in both the Q20 optics used for LHC beams, as well as the original SPS optics used for fixed target beams. This paper summarises the optics calculations as well as the experimental verification of the reduced chromatic detuning of the new octupole scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW072
About •	paper received ※ 12 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW093	Optics Calibration for Routine Operations In Taiwan Photon Source	optics, lattice, quadrupole, coupling	335
	F.H. Tseng, C.H. Chen, P.J. Chou NSRRC, Hsinchu, Taiwan
	To ensure a stable performance of Taiwan Photon Source (TPS), we perform the calibration of accelerator optics using LOCO (Linear Optics from Closed Orbit) technique every month. After the optics and coupling corrections, the rms beta beatings in both planes are reduced to less than 1%. The emittance coupling ratio is also restored to within the design value.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW093
About •	paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW110	Study of the Beam Current Effects on the NSLS-II Storage Ring Optics Using Turn-by-Turn Data	lattice, optics, storage-ring, dipole	375
	J. Choi, Y. Hidaka BNL, Upton, Long Island, New York, USA
	These days, the techniques using the turn-by-turn data are well developed in analyzing the accelerator optics. We compared the data for the low and high beam currents and studied the beam current effects on the storage ring lattice optics. Also, by comparing the local transfer matrices, we analyzed the amounts of the impacts on the linear optics around the ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW110
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP019	High Luminosity LHC Optics and Layout HLLHCV1.4	optics, luminosity, experiment, cavity	468
	R. De Maria, R. Bruce, D. Gamba, M. Giovannozzi, F. Plassard CERN, Geneva, Switzerland
	The goal of the High Luminosity Project is the upgrade of the LHC to deliver an integrated luminosity of at least 250 \rm fb^-1 per year in each of the two high-luminosity, general-purpose detectors ATLAS and CMS. This article presents the latest layout design and the corresponding optics features, which comprise optimisation of the orbit corrector and crab cavity systems, and new estimates of the performance reach thanks to the new concept of fully remote alignment. In addition, the new optics version incorporates improvements required by beam instrumentation, dump system, and collimation system, as well as low-beta solutions for the LHCb experiment.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP019
About •	paper received ※ 17 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP020	Smooth and Beta-Beating-Free Optics Transitions for HL-LHC	optics, injection, quadrupole, insertion	472
	R. De Maria, M. Solfaroli CERN, Geneva, Switzerland
	In the CERN LHC, optics transitions are mainly required to control the beam size at the four experimental interaction points. The current method, based on linearly-interpolated optics functions over a small set of matched optics and parabolic time-domain segments, introduces non-zero beta-beating and it is not optimal in time. This contribution presents an alternative approach, based on continuously-matched optics solutions distributed in time domain by using a realistic model of the superconducting circuits, which optimises the overall process duration. This method requires a change in the paradigm used in the control system and it is proposed for the future High Luminosity LHC (HL-LHC) runs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP020
About •	paper received ※ 18 April 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP024	Prospects for Future Asymmetric Collisions in the LHC	proton, luminosity, experiment, hadron	484
	M.A. Jebramcik, J.M. Jowett CERN, Geneva, Switzerland
	The proton-lead runs of the LHC in 2012, 2013 and 2016 provided luminosity far beyond expectations in a diversity of operating conditions and led to important new results in high-density QCD. This has permitted the scope of the future physics programme to be expanded in a recent review. Besides further high-luminosity p-Pb collisions, lighter nuclei are also under consideration. A short proton-oxygen run, on the model of the 2012 p-Pb run, would be of interest for cosmic-ray physics. Other collision systems like proton-argon or collisions of protons with other noble gases are also discussed. We provide an overview of the operational strategies and potential performance of various asymmetric collision options. Potential performance limits from moving beam-beam encounters at injection and various beam-loss mechanisms are evaluated in the light of our understanding of the LHC to date.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP024
About •	paper received ※ 18 April 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP029	Analysis on Bunch-by-Bunch Beam Losses at 6.5 TeV in the Large Hadron Collider	luminosity, betatron, beam-losses, collider	500
	K. Paraschou, G. Iadarola, N. Karastathis, S. Kostoglou, Y. Papaphilippou, L. Sabato CERN, Geneva, Switzerland S. Kostoglou National Technical University of Athens, Zografou, Greece K. Paraschou AUTH, Thessaloniki, Greece
	In 2018, a large fraction of the physics data taking at the Large Hadron Collider has been performed with a beam energy of 6.5 TeV, the nominal bunch spacing of 25 ns and beta functions at the high luminosity interaction points of 30 cm. In order to maximize the integrated luminosity, the crossing angles are gradually reduced as the beam intensity reduces due to luminosity burn-off. In these conditions the beam lifetime is visibly affected by collective effects and in particular by beam-beam interaction and electron cloud effects. By analyzing the beam losses at a bunch-by-bunch level, it is possible to disentangle the contributions from different effects and to assess the impact on the losses of changes applied to the machine configuration.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP029
About •	paper received ※ 10 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP031	Operation and Performance of the Cern Large Hadron Collider During Proton Run 2	luminosity, proton, emittance, injection	504
	R. Steerenberg, M. Albert, R. Alemany-Fernández, T. Argyropoulos, E. Bravin, G.E. Crockford, J.-C. Dumont, K. Fuchsberger, R. Giachino, M. Giovannozzi, G.H. Hemelsoet, W. Höfle, D. Jacquet, M. Lamont, E. Métral, D. Nisbet, G. Papotti, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, M. Schaumann, M. Solfaroli, R. Suykerbuyk, G. Trad, J.A. Uythoven, S. Uznanski, D.J. Walsh, J. Wenninger, M. Zerlauth CERN, Geneva, Switzerland
	Run 2 of the CERN Large Hadron Collider (LHC) was successfully completed on 10th December 2018, achieving largely all goals set in terms of luminosity production. Following the first two-year long shutdown and the re-commissioning in 2015 at 6.5 TeV, the beam performance was increased to reach a peak luminosity of more than twice the design value and a colliding beam time ratio of 50%. This was accomplished thanks to the increased beam brightness from the injector chain, the high machine availability and the performance enhancements made in the LHC for which some methods and tools, foreseen for the High Luminosity LHC (HL-LHC) were tested and deployed operationally. This contribution provides an overview of the operational aspects, main limitations and achievements for the proton Run 2.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP031
About •	paper received ※ 13 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP036	Machine Protection Experience from Beam Tests with Crab Cavity Prototypes in the CERN SPS	cavity, machine-protect, beam-losses, betatron	520
	B. Lindstrom, H. Bartosik, T. Bohl, A.C. Butterworth, R. Calaga, L.R. Carver, V. Kain, T.E. Levens, G. Papotti, R. Secondo, J.A. Uythoven, M. Valette, G. Vandoni, J. Wenninger, D. Wollmann, M. Zerlauth CERN, Meyrin, Switzerland
	Funding: Work supported by the High Luminosity LHC project. Crab cavities (CCs) constitute a key component of the High Luminosity LHC (HL-LHC) project. In case of a failure, they can induce significant transverse beam offsets within tens of microseconds, necessitating a fast removal of the circulating beam to avoid damage to accelerator components due to losses from the displaced beam halo. In preparation for the final design to be employed in the LHC, a series of tests were conducted on prototype crab cavities installed in the Super Proton Synchrotron (SPS) at CERN. This paper summarizes the machine protection requirements and observations during the first tests of crab cavities with proton beams in the SPS. In addition, the machine protection implications for future SPS tests and for the use of such equipment in the HL-LHC are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP036
About •	paper received ※ 01 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP044	Improving the Luminosity for Beam Energy Scan II at RHIC	cavity, electron, space-charge, luminosity	540
	C. Liu, M. Blaskiewicz, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, H. Huang, D. Kayran, Y. Luo, G.J. Marr, A. Marusic, K. Mernick, M.G. Minty, C. Montag, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, T.C. Shrey, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang BNL, Upton, Long Island, 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 QCD (Quantum Chromodynamics) phase diagram has many uncharted territories, particularly the nature of the transformation from Quark-Gluon plasma (QGP) to the state of Hadronic gas. The Beam Energy Scan I (BES-I) at the Relativistic Heavy Ion Collider (RHIC) was completed but measurements had large statistical errors. To improve the statistical error and expand the search for first-order phase transition and location of the critical point, Beam Energy Scan II will commence in 2019 with a goal of improving the luminosity by a factor of 3-4. The beam lifetime at low energies was and will be limited by some physical effects of which the most significant are intrabeam scattering, space charge, beam-beam, persistent current effects. This article will review these potential limiting factors and introduce the countermeasures which will be in place to improve BES-II luminosity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP044
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP045	RHIC Heavy Ion Operation With Near-Integer Working Point	acceleration, controls, feedback, power-supply	544
	C. Liu, G.J. Marr, A. Marusic, M.G. Minty, V. Schoefer BNL, Upton, Long Island, 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 interplay of space charge and beam-beam effects limits the beam lifetime at low energies at the Relativistic Heavy Ion Collider (RHIC). To improve the beam lifetime, a near-integer working point (0.096/0.094) was tested at fixed energy and during acceleration. In the demonstration experiments, we observed the benefit of the near-integer working point on beam lifetime, however, did not achieve the desired level of orbit correction. This article will present the experimental results of operation with a near-integer working point, and analyze the causes of the orbit control problem.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP045
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP051	56 MHz SRF System for SPHENIX Experiments at RHIC	cavity, SRF, HOM, detector	562
	Q. Wu, M. Blaskiewicz, K. Mernick, S. Polizzo, F. Severino, K.S. Smith, T. Xin BNL, Upton, Long Island, New York, USA
	Funding: Work supported by by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy The sPHENIX experiment is a proposal for a new detector at the Relativistic Heavy Ion Collider (RHIC), that plans to expand on discoveries made by RHIC’s existing STAR and PHENIX research groups. To minimize the luminosity outside the 20 cm vertex detector and keeping the radiation to other detector components as low as possible, a 56 MHz SRF system is added to the existing RHIC RF systems to compress the bunches with less beam loss. The existing 56 MHz SRF cavity was commissioned in previous RHIC runs, and contributed to the luminosity at a voltage of 300kV with thermal limitations from the Higher Order Mode coupler at high field, and at 1MV while using its fundamental damper for HOM damping. In this paper, we will analyze and compare the effect of different RF systems at various scenarios, and discuss possible solutions to the Higher Order Mode (HOM) damping scheme to bring the cavity to 2 MV.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP051
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP053	Numerical Optimization of DC Wire Compensation in HL-LHC	collider, luminosity, hadron, simulation	570
	K. Skoufaris, S.D. Fartoukh, N. Karastathis, Y. Papaphilippou, D. Pellegrini, A. Poyet, A. Rossi, G. Sterbini CERN, Meyrin, Switzerland
	The electromagnetic field generated from a set of DC wires parallel to the beam opens the path to the compensation of the beam-beam long-range (BBLR) interactions for the future operation of large hadron colliders, in particular for the upcoming High Luminosity upgrade of the Large Hadron Collider (HL-LHC). The effectiveness and simplicity of a current carrying wire are critical for overcoming some technical constraints of the machine. In order to better understand the potential of this device for the HL-LHC, various simulation studies are presented. The different observables are the dynamic aperture and the frequency analysis.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP053
About •	paper received ※ 03 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB022	Current Status of the High-Power RF Systems During Phase2 Operation in SuperKEKB	klystron, cavity, GUI, status	619
	K. Watanabe, K. Marutsuka, Ma. Yoshida, S.I. Yoshimoto KEK, Ibaraki, Japan
	The SuperKEKB is an asymmetric-energy two-ring collider consisting of the high-energy ring (HER) for 7 GeV electrons and the low-energy ring (LER) for 4 GeV positrons at KEK. Both the electron and positron beams are injected from the Linac injector complex, which includes a newly constructed 1.1 GeV positron damping ring (DR) to supply a high-quality low emittance positron beam to the LER. The high power RF system has a role to drive the ARES cavities and the superconducting RF cavities for the SuperKEKB. The operating frequency of RF system is 508.9 MHz. The required RF power from the klystron at maximum storage beam current is ~850 kW (CW). The number of RF stations is total 31 for the main ring (MR) and DR. The status of each high power RF components, troubles of them and operation condition that occurred during phase 2 commissioning from Feb 2018 to July 2018 will be reported in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB022
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB031	Progress of Conceptual Study for the Accelerators of a 2-7GeV Super Tau Charm Facility at China	collider, luminosity, factory, electron	643
	Q. Luo, W. Li, D.R. Xu USTC/NSRL, Hefei, Anhui, People’s Republic of China W.W. Gao, J.Q. Lan Fujian University of Technology, Fuzhou, People’s Republic of China
	Funding: Supported by National Natural Science Foundation of China U1832169 and the Double Fist-Class University Project Foundation of USTC. This paper shows the progress of the conceptual study for the accelerators of a super tau charm facility in China. Since the BEPCII will finish its historical mission in 5~10 years and its upgrade plan will only achieve a small luminosity enhancement of 3~5 times, a new next generation tau-charm collider will play an irreplaceable role in future high energy physics study. The luminosity of this successor is about 5×10³⁴cm⁻²s⁻¹ pilot and 1×10³⁵cm⁻²s⁻¹ nominal, with the electron beam longitudinally polarized at the IP. The general scheme of the accelerators and the beam pa-rameters are shown. Several key technologies such as beam polarization and beam emittance diagnostics are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB031
About •	paper received ※ 14 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB045	Future High Power Proton Drivers for Neutrino Beams	linac, proton, neutron, factory	662
	D.C. Plostinar, M. Eshraqi, B. Gålnander ESS, Lund, Sweden V.A. Lebedev Fermilab, Batavia, Illinois, USA C.R. Prior STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom Y. Sato KEK, Ibaraki, Japan J.Y. Tang IHEP, Beijing, People’s Republic of China
	Funding: ESSnuSB has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 7774. Over the last two decades, significant efforts were made through several international studies to identify and develop technical solutions for potential Neutrino Factories and Superbeam Facilities. With many questions now settled, as well as clearer R&D needs, various proposals are being made for future facilities in China, Europe, Japan and North America. These include both developing and adapting existing machines as well as green-field solutions. In this paper, we review all the major accelerator programmes aimed at delivering high-power proton beams for neutrino physics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB045
About •	paper received ※ 22 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB055	First Partially Stripped Ions in the LHC (208Pb⁸¹⁺)	experiment, injection, collimation, factory	689
	M. Schaumann, R. Alemany-Fernández, H. Bartosik, T. Bohl, R. Bruce, G.H. Hemelsoet, S. Hirlaender, J.M. Jowett, V. Kain, M.W. Krasny, J. Molson, G. Papotti, M. Solfaroli Camillocci, H. Timko, J. Wenninger CERN, Geneva, Switzerland
	The Gamma Factory initiative proposes to use partially stripped ion (PSI) beams as drivers of a new type of high intensity photon source. As part of the ongoing Physics Beyond Collider studies, initial beam tests with PSI beams have been executed at CERN. On 25 July 2018 lead ions with one remaining electron (208Pb⁸¹⁺) were injected and accelerated in the LHC for the first time. After establishing the injection and circulation of a few 208Pb⁸¹⁺ bunches, beam lifetimes of about 50 hours could be established at 6.5 TeV proton equivalent energy. This paper describes the setup of the beam tests and observations made.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB055
About •	paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB058	Collimation of Partially Stripped Ion Beams in the LHC	collimation, simulation, collider, hadron	700
	A. Abramov, L.J. Nevay JAI, Egham, Surrey, United Kingdom R. Bruce, N. Fuster-Martínez, A.A. Gorzawski, M.W. Krasny, J. Molson, S. Redaelli, M. Schaumann CERN, Meyrin, Switzerland
	In the scope of the Physics Beyond Colliders studies, the Gamma Factory initiative proposes the use of partially stripped ions as a driver of a new type, high intensity photon source in CERN’s Large Hadron Collider (LHC). In 2018, the LHC accelerated and stored partially stripped 208-Pb-81+ ions for the first time. The collimation system efficiency recorded during this test was found to be prohibitively low. The worst losses were localised in the dispersion suppressor (DS) of the betatron-cleaning insertion. Analytic arguments and simulations show that the large losses are driven by the stripping of the remaining electron from the Pb nucleus by the primary collimators. The rising dispersion in the DS pushes the resulting off-rigidity, fully-stripped ions into the aperture of the superconducting magnets. In this study the measured loss maps are compared against results from simulations. Different mitigation strategies are outlined, including a dispersion suppressor (DS) collimator, crystal collimation or an orbit bump.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB058
About •	paper received ※ 10 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB072	eRHIC in Electron-Ion Operation	electron, collider, heavy-ion, hadron	738
	W. Fischer, E.C. Aschenauer, E.N. Beebe, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, C.J. Gardner, H. Huang, T. Kanesue, C. Liu, M. Mapes, G.T. McIntyre, M.G. Minty, C. Montag, S.K. Nayak, M. Okamura, V. Ptitsyn, D. Raparia, J. Sandberg, K.S. Smith, P. Thieberger, N. Tsoupas, J.E. Tuozzolo, F.J. Willeke, A. Zaltsman, A. Zelenski BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. The design effort for the electron-ion collider eRHIC has concentrated on electron-proton collisions at the highest luminosities over the widest possible energy range. The present design also provides for electron-nucleon peak luminosities of up to 4.7·10³³ cm^-2s⁻¹ with strong hadron cooling, and up to 1.7·10³³ cm^-2s⁻¹ with stochastic cooling. Here we discuss the performance limitations and design choices for electron-ion collisions that are different from the electron-proton collisions. These include the ion bunch preparation in the injector chain, acceleration and intrabeam scattering in the hadron ring, path length adjustment and synchronization with the electron ring, stochastic cooling upgrades, machine protection upgrades, and operation with polarized electron beams colliding with either unpolarized ion beams or polarized He-3.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB072
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB087	Proposal for a High Transformer Ratio CW Dielectric Accelerator	electron, SRF, experiment, wakefield	773
	V. Litvinenko Stony Brook University, Stony Brook, USA J.C. Brutus, Y.C. Jing, I. Pinayev, G. Wang BNL, Upton, Long Island, New York, USA M.E. Conde, C.-J. Jing, J.G. Power ANL, Argonne, Illinois, USA A. Kanareykin Euclid Beamlabs LLC, Bolingbrook, USA N. Vafaei-Najafabadi UCLA, Los Angeles, California, USA
	Advanced CW accelerators are one of high priority directions identified by Advanced Accelerator Concepts Research Roadmap Workshop Report . High transformer ratio of beam-driven accelerators is critically important for cost-effective FEL systems. We present a proposed experiment for demonstrating a high transformer ratio CW dielectric accelerator using operational SRF accelerator built for Coherent electron Cooling experiment. This accelerator operates with CW electron beam comprised of 78 kHz train of electron bunches. Electron bunches with controllable longitudinal and charge up to 10 nC per bunch are generated in 1.25 MV SRF photo-electron gun. This bunches are ballistically compressed to duration of 10-to-30 psec and accelerated to 15 MeV in SRF linac. Such bunches would be excellent drivers of high-transformer ratio DWA accelerators. In this paper we present expected performance of proposed CW DWA accelerator. Advanced Accelerator Concepts Research Roadmap Workshop Report, 2016, *V.N. Litvinenko et al., In proc.of FEL’17, Santa Fe, NM, USA, August 20-25, 2017, p. 132
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB087
About •	paper received ※ 19 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB109	Cavity Design for the Updated eRHIC Crabbing System	cavity, proton, electron, hadron	818
	S. Verdú-Andrés, Q. Wu BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates LLC under contract no. DE-SC0012704 with the U.S. Department of Energy. The electron-ion collider eRHIC proposed by Brookhaven National Laboratory includes a crabbing system to reestablish head-on collisions for a maximum geometric overlap of the colliding bunches. Since the last cavity design, the crossing angle has increased from 22 to 25 mrad to relax the field strength requirement in one of the IR magnets - increasing the deflecting kick required to collider the bunches head on - and one of the considered options is to have both proton and electron crab cavities work at 200 MHz. The present paper discusses the RF design of the 200 MHz crab cavities for the electron and hadron beams of eRHIC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB109
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS001	Operational Experience with a Sled and Multibunch Injection at the Australian Synchrotron	linac, klystron, injection, cavity	830
	M.P. Atkinson, G. LeBlanc AS - ANSTO, Clayton, Australia K. Zingre ASCo, Clayton, Victoria, Australia
	The Australian third generation 3 GeV Synchrotron Light Source was originally commissioned with a 100 MeV linear accelerator (LINAC) fed by two 37 MW S band pulsed klystrons. A pulse compressor in form of a SLED cavity was added later to enable single klystron operation for redundancy in case of a modulator failure. The SLED was successfully commissioned in May 2017 including remote selection of single klystron with SLED operation without degradation of beam energy. Two years on there have been some unexpected operational benefits including reduced phase sensitivity and drift allowing repeatable injection based solely on diagnostic phase read backs. Temperature stabilised power amplifiers based on S band GaN radar technology are being trialed in the meantime with a goal to set and inject with minimal operator adjustment. The results from the SLED cavity upgrade are shown and the latest S band radar technology designs are outlined.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS001
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS002	Linac Energy Jitter Measurements with SPARK BPMs at ALBA	linac, electron, electronics, klystron	833
	R. Muñoz Horta, D. Lanaia, E. Marín, A. Olmos, F. Pérez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	At ALBA four Beam Position Monitors (BPMs) measure the beam position along the Linac to Booster Transfer Line. The BPM electronics (Libera Spark type) have been recently upgraded in order to be sensitive to single-pass beam detection. As a result, the position resolution measured in LTB BPMs has been increased by a factor 10 with respect to the former electronics. The increased resolution enables us to resolve the energy jitter of the Linac beam, providing an on-line measurement of the Linac energy during regular operation. In this paper a study of the Linac energy jitter is presented as well as its correlation with the jitter sources.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS002
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS015	FoS Cavity of the Alvarez 2.0 DTL as FAIR Injector	DTL, cavity, quadrupole, linac	871
	M. Heilmann, X. Du, L. Groening, S. Mickat, C. Mühle, A. Rubin, V. Srinivasan GSI, Darmstadt, Germany
	The Alvarez 2.0 DTL will be the new post-stripper DTL of the UNILAC at GSI. The existing GSI with its LINAC and SIS18 comprise the main operation injector chain for the Facility for Antiproton and Ion Research FAIR. The new Alvarez-DTL has an operation frequency of 10⁸.4 MHz, an input energy of 1.358 MeV/u and the output energy is 11.4 MeV/u with a total length of 55 m. The presented FoS section will be part of the first cavity of the Alvarez 2.0 DTL. The FoS-cavity with 11 drift tubes (including quadrupole singlets) and a total length of 1.9 m will be copper plated in GSI for high power tests. The design of the quadrupole singlet magnet is finalized; a prototype of a fully functional magnet with drift tube and stems will be fabricated within a design study. Empty drift tubes and all components of the tank shall be delivered 2019 for first low level RF investigations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS015
About •	paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS017	Status of Operation With Negative Momentum Compaction at KARA	optics, injection, quadrupole, sextupole	878
	P. Schreiber, T. Boltz, M. Brosi, B. Härer, A. Mochihashi, A.-S. Müller, A.I. Papash, M. Schuh KIT, Karlsruhe, Germany
	Funding: We are supported by the DFG-funded ’Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology’ and European Union’s Horizon 2020 research and innovation programme (No 730871) For future synchrotron light source development novel operation modes are under investigation. At the Karlsruhe Research Accelerator (KARA) an optics with negative momentum compaction has been proposed, which is currently under commissioning. In this context, the collective effects expected in this regime are studied with an initial focus on the head-tail instability and the micro-bunching instability resulting from CSR self-interaction. In this contribution, we will present the proposed optics and the status of implementation for operation in the negative momentum compaction regime as well as a preliminary discussion of expected collective effects.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS017
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS022	Current Status of the MYRRHA Cavities	cavity, resonance, status, vacuum	892
	K. Kümpel, D. Bade, M. Busch, D. Koser, S. Lamprecht, N.F. Petry, H. Podlech, S. Zimmermann IAP, Frankfurt am Main, Germany
	The MYRRHA (Multi-purpose hYbrid Research Reac-tor for High-tech Applications) Project is a planned ac-celerator driven system (ADS) for the transmutation of long-living radioactive waste. In order test the reliability of the planned 17 MeV injector, a shortened injector with 5.9 MeV consisting of the ion source, a 4-Rod RFQ, 2 Quarter Wave Rebunchers (QWRs) and a total of 7 normal conducting CH structures is currently being installed in Louvein-la-Neuve (LLN, Belgium). Before the cavities can be tested with beam, they are subjected to so-called low power tests several times during the individual con-struction stages in order to be able to correct any devia-tions. This paper describes the status of the two Quarter Wave Rebunchers, which are currently in the process of copper plating and final acceptance, as well as the first two CH structures, the first of which is already being conditioned while CH 2 is still in preparation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS022
About •	paper received ※ 10 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS033	RF Measurements and Tuning of the 325 MHz Ladder-RFQ	rfq, linac, simulation, proton	925
	M. Schuett, U. Ratzinger, M. Syha IAP, Frankfurt am Main, Germany
	Funding: BMBF 05P15RFRBA Based on the positive results of the unmodulated 325 MHz Ladder-RFQ prototype from 2013 to 2016, we developed and designed a modulated 3.4 m Ladder-RFQ. The unmodulated Ladder-RFQ features a very constant voltage along the axis. It accepted 3 times the operating power of which is needed in operation. That level corresponds to a Kilpatrick factor of 3.1 with a pulse length of 200 µs. The 325 MHz RFQ is designed to accelerate protons from 95 keV to 3.0 MeV according to the design parameters of the proton linac within the FAIR project. This particular high frequency for a 4-ROD-RFQ creates difficulties, which triggered the development of a Ladder-RFQ with its high symmetry. The results of the unmodulated prototype have shown, that the Ladder-RFQ is very well suited for that frequency. The duty cycle is up to 5% for the applied cooling concept. Manufacturing has been completed in September 2018. We will show the finalization of assembly after manufacturing as well as low level RF measurements. The final machining step for both flatness and frequency tuning has been finished in April 2019. Journal of Physics: Conf. Series 874 (2017) 012048 **Proceedings of LINAC2016, East Lansing, TUPLR053
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS033
About •	paper received ※ 01 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS035	Recommissioning of SIS18 After FAIR Upgrades	MMI, controls, extraction, cavity	932
	D. Ondreka, C. Dimopoulou, H.C. Hüther, H. Liebermann, J. Stadlmann, R.J. Steinhagen GSI, Darmstadt, Germany
	The synchrotron SIS18 of the GSI facility has recently resumed beam operation after a long shutdown, during which major upgrades for the operation of SIS18 in the FAIR facility were realized. This signifies a major milestone for the mission of GSI and FAIR. On one hand, the scientific program of GSI depends strongly on beam from SIS18, including the very important developments of detectors for FAIR experiments. On the other hand, large parts of the existing GSI accelerator facility, including SIS18, are now operated with the FAIR control system, demonstrating its suitability for control of a large scale accelerator facility. Commissioning of the new control system started during the shutdown with a series of dry runs, which proved very useful to establish the basic functionalities. Recommissioning of SIS18 was further facilitated by the fact that the machine model of SIS18, implemented in the modeling framework LSA, had already been tested with beam several years before the shutdown. Thus, all operation modes of SIS18, including multi-turn injection, electron cooling, as well as fast and slow extraction could be successfully commissioned during the first weeks of operation. Other commissioning activities concerned the operation of new devices installed during the shutdown. These devices, mostly installed to prepare SIS18 for the operation with FAIR design parameters, open new possibilities in the standard operation of SIS18. A challenge for the operation of SIS18 is posed by ground motion due to ground water lowering for the nearby FAIR construction site. Surveys revealed that SIS18 subsided by several centimeters during one year. Even though the machine was realigned prior to recommissioning, the dynamics of the ground motion will continue to affect operation of SIS18.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS035
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS036	RFQ Electrodes Change and Upgrade Option at the UNILAC HSI Injector	rfq, simulation, cavity, MMI	936
	M. Vossberg, P. Gerhard, L. Groening, S. Mickat, H. Vormann, C. Xiao GSI, Darmstadt, Germany V. Bencini, J.M. Garland, J.-B. Lallement, A.M. Lombardi CERN, Geneva, Switzerland
	In order to meet the beam intensity and quality requirements imposed by FAIR, the HSI-RFQ beam dynamics originally dating from 2009 has been re-designed recently at CERN. Front-to-end simulations demonstrated that the new design meets the FAIR targets. Implementation of the new electrodes, initially planned for 2019, will require re-adaption of the RFQ cavity rf-parameters by re-shaping the stems that keep the electrodes. However, during the beam time 2018 the existing RFQ did not reach its nominal voltage most likely due to expired lifetime of the electrodes originating from 2009. In order to shorten the RFQ maintenance period and to minimize any risk for upcoming beam time 2019, it was decided to post-pone the implementation of the new design and rather just re-producing the 2009 design electrodes. This contribution is on the re-production process as short-term solution and on the full implementation of the new design as mid-term solution. CST simulations performed at GSI assure that the resonance frequency with the new electrode geometry is recuperated through corrections of the carrier rings. The status of the exchange of the electrodes and simulations for the adaptation of the new electrode design are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS036
About •	paper received ※ 13 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS042	Hardware Commissioning of the Renovated PIAVE Injector at INFN-LNL	rfq, SRF, MMI, ion-source	949
	G. Bisoffi, L. Bellan, J. Bermudez, E. Bissiato, D. Bortolato, F. Chiurlotto, M. Comunian, T. Contran, A. Facco, E. Fagotti, P. Francescon, A. Friso, A. Galatà, C.S. Gallo, M.G. Giacchini, M. Lollo, D. Martini, M.O. Miglioranza, P. Modanese, M. Montis, E. Munaron, G. Nigrelli, S. Pavinato, M. Pengo, A. Pisent, M. Poggi, L. Pranovi, M. Rossignoli, D. Scarpa INFN/LNL, Legnaro (PD), Italy V. Andreev ITEP, Moscow, Russia M.A. Bellato INFN- Sez. di Padova, Padova, Italy
	During 2018, the PIAVE superconducting linac injector at INFN-LNL, based on superconducting RFQs and two cryomodules with quarter wave resonators, underwent a renovation plan. This operation was strictly related to the one carried out on ALPI [1], which will become a post-accelerator for both stable and exotic beams in a near future. PIAVE Quarter Wave Resonator (QWR) cryomod-ules, in operation since 2006, were moved to ALPI to be used for the acceleration of both stable beams and future exotic beams delivered from the cyclotron target-ion-source station, after appropriate purification, charge breeding and pre-acceleration stages. In order to cope with the removal of the two QWR cryomodules in PIAVE, a newly designed 80 MHz room temperature buncher was designed, built and tested: the buncher is required so as to match the longitudinal phase space between PIAVE su-perconducting RFQs (SRFQ1 and SRFQ2) and ALPI. In the same period, substantial refurbishments on the ECR ion source platform were carried out, in particular on its infrastructure and safety equipment. A problem on an electronic component on SRFQ2, though quickly fixed, delayed beam commissioning of the PIAVE injector, which will start at the end of May 2019.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS042
About •	paper received ※ 30 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS046	Upgrade of the 3-MeV LINAC for Testing of Accelerator Components at J-PARC	rfq, linac, MMI, experiment	960
	Y. Kondo, K. Hirano, T. Ito, N. Kikuzawa, R. Kitamura, T. Morishita, H. Oguri, K. Ohkoshi, S. Shinozaki, K. Shinto JAEA/J-PARC, Tokai-mura, Japan Z. Fang, Y. Fukui, K. Futatsukawa, K. Ikegami, T. Miyao, K. Nanmo, M. Otani, T. Shibata KEK, Ibaraki, Japan T. Hori, Y. Nemoto, Y. Sato Nippon Advanced Technology Co., Ltd., Tokai, Japan T. Ishiyama, Y. Sawabe Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan Y. Ito Total Saport System Corp., Naka-gun, Ibaraki, Japan Y. Kato Total Support Systems Corporation, Tokai-mura, Naka-gun, Ibaraki, Japan F. Kobayashi ULVAC Human Relations, Ltd., Kanagawa, Japan D. Takahashi, R. Tasaki KIS, Ibaraki, Japan
	We are now upgrading a 3-MeV linac at J-PARC. The old 30-mA RFQ is replaced by a spare one of the J-PARC 50-mA RFQ. The ion source is same as the J-PARC linac’s, therefore, the peak beam current is upgraded from 30 mA to 50 mA. This 3-MeV linac will be used for development of various accelerator components, such as beam dyagnostics devices, laser charge exchange equipments, new MEBT buncher, and so on. In this paper, present status of this 3-MeV test linac is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS046
About •	paper received ※ 30 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS049	The First Replacement of the RF Window of the ACS Cavity	cavity, linac, vacuum, proton	971
	J. Tamura, Y. Kondo, T. Morishita JAEA/J-PARC, Tokai-mura, Japan F. Naito, M. Otani KEK, Tokai, Ibaraki, Japan Y. Nemoto Nippon Advanced Technology Co., Ltd., Tokai, Japan
	In 2013, the Annular-ring Coupled Structure (ACS) cavities were installed to the Japan Proton Accelerator Research Complex (J-PARC) linac. Since then, the ACS cavities have been stably running. Although any serious problem induced by the ACS RF window has not yet observed, we decided to replace the RF window of one ACS cavity, which is the eighteenth accelerating cavity in the order of beam energy (ACS18), by the newly manufactured one. The major motivations of the replacement are to check the surface condition of the RF window which have been under operation for nearly five years and to confirm the availability of the newly manufactured RF window. By making use of the summer maintenance period of 2018, we carried out the replacement. This was the first experience for us to replace the RF window installed to the ACS cavity in the linac accelerator tunnel. As for the removed RF window, there was no any abnormal warning found with the visual examination. At the starting up of the cavity’s operation after the maintenance period, we investigated how much time would be required for an RF conditioning. It took around fifty hours so that the peak RF power including the beam loading is stably input to the cavity through the new RF window. The ACS cavity with the new RF window is now stably operating.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS049
About •	paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS054	Status of the CLEAR Electron Beam User Facility at CERN	experiment, electron, radiation, plasma	983
	K.N. Sjobak, E. Adli, C.A. Lindstrøm University of Oslo, Oslo, Norway M. Bergamaschi, S. Burger, R. Corsini, A. Curcio, S. Curt, S. Döbert, W. Farabolini, D. Gamba, L. Garolfi, A. Gilardi, I. Gorgisyan, E. Granados, H. Guerin, R. Kieffer, M. Krupa, T. Lefèvre, S. Mazzoni, G. McMonagle, N. Nadenau, H. Panuganti, S. Pitman, V. Rude, A. Schlogelhofer, P.K. Skowroński, M. Wendt, A.P. Zemanek CERN, Geneva, Switzerland A. Lyapin UCL, London, United Kingdom
	The CERN Linear Electron Accelerator for Research (CLEAR) has now finished its second year of operation, providing a testbed for new accelerator technologies and a versatile radiation source. Hosting a varied experimental program, this beamline provides a flexible test facility for users both internal and external to CERN, as well as being an excellent accelerator physics training ground. The energy can be varied between 60 and 220 MeV, bunch length between 1 and 4 ps, bunch charge in the range 10 pC to 2 nC, and number of bunches in the range 1 to 200, at a repetition rate of 0.8 to 10 Hz. The status of the facility with an overview of the recent experimental results is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS054
About •	paper received ※ 12 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS056	Optimization of SC Cavity Type for CSNS Linac Upgrade	cavity, linac, neutron, acceleration	987
	Y. Wang, M.X. Fan, A.H. Li, B. Li, P.H. Qu IHEP CSNS, Guangdong Province, People’s Republic of China J.P. Dai, H.C. Liu, P. Sha IHEP, Beijing, People’s Republic of China X.L. Wu DNSC, Dongguan, People’s Republic of China
	In order to increase CSNS beam power from 100kW to 500kW, the Linac injection energy need to be increased from 80MeV to 300MeV. The combined layout of superconducting spoke cavities and elliptical cavities will be adopted to accelerate H⁻ beam to 300MeV. Two operation frequency of spoke cavities were compared with single and double spoke structure, a compact 648MHz βg=0.4 single spoke cavity was proposed, and the RF performance was presented, as well as the MP behavior.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS056
About •	paper received ※ 09 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS059	The Status of CiADS Superconducting LINAC	linac, cavity, proton, cryomodule	994
	Z.J. Wang, Y. He, G. Huang, S.H. Liu, T. Tan, Y.Q. Wan, F.F. Wang, W.M. Yue IMP/CAS, Lanzhou, People’s Republic of China
	CiADS (China initiative Accelerator Driven System) approved by Chinese government at 2016 aims to build the first ADS experimental facility to demonstrate the nuclear waste transmutation. The CiADS driving linac can accelerate 5 mA proton beam to 500 MeV at the beam power up to 2.5 MW with the state-of-the-art accelerator technologies. The challenging programs include beam loss control-oriented physics design, high performance CW operated superconducting cavities, SRF cryomod-ules, and highly efficient RF amplifier system. As the driving linac of the ADS system, the RAMI characters will serve as the design philosophy to guide the physics design and the choice of technical routes. The physics design and key technologies of the high-power machine are descried in the paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS059
About •	paper received ※ 14 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS075	Design and Experiment of a Window-Type CW Deuteron RFQ	rfq, cavity, experiment, Windows	1021
	K. Zhu, M.J. Easton, P.P. Gan, S.L. Gao, H.P. Li, S. Liu, Y.R. Lu, Q.Y. Tan, L. Tao, Z. Wang PKU, Beijing, People’s Republic of China W.P. Dou, Y. He, C. Wang, Q. Wu, H.W. Zhao IMP/CAS, Lanzhou, People’s Republic of China
	A deutron CW RFQ was designed and fabricated in Peking University. It will accelerate 50mA CW deutron beam from 50keV to 1MeV at 162.5MHz. The novel structure of four-vane with window was used to seperate the dipole mode from the working mode. The field tuning of this RFQ was different from conventional four vane RFQ because that the four quadrants of RFQ cavity were coupled. The discipline of field tuning was studied by simulation and experiment. The beam dynamics of the RFQ was designed by equipartation and matching method, limit current effect was considered at the same time. The final design result of the RFQ was: voltage between electrodes was 60kV, transport efficiency of RFQ is 98%, field unflatness is less than 2% after tuning, the deformation of RFQcavity is less than 80um. Only 47 hours was spent to increase CW power of cavity from 0 to 55kW in high power test and The RFQ can working stable at the design voltage. The preliminary H²⁺ beam exeperiment has been done and 1.78mA CW beam was obtained at exit of RFQ. This paper will introduce the detail of design and experiment of the RFQ.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS075
About •	paper received ※ 22 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS077	RCCS Operation and Characteristics in Resonance Frequency Control Mode at KOMAC	controls, resonance, DTL, radio-frequency	1025
	K.H. Kim, H.S. Jeong, H.S. Kim, S.G. Kim, H.-J. Kwon, Y.G. Song Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
	Funding: This work has been supported through KOMAC (Korea Multi-purpose Accelerator Complex) operation fund of KAERI by MSIT (Ministry of Science and ICT) A 100-MeV proton accelerator is under operation at Korea Multi-purpose Accelerator Complex (KOMAC). The resonance control cooling system (RCCS) has supplied the cooling water to drift tube linac (DTL). The DTL need to keep the resonant frequency of 350MHz during the operation. RCCS has a critical role in sustaining the acceptable resonant frequency error in DTL by adopting the resonance frequency control mode. Details on the RCCS operation in resonance frequency control mode will be given in this study.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS077
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS085	Commissioning of a New Digital Transverse Damper System at the PSB	feedback, proton, MMI, hardware	1050
	G.P. Di Giovanni, F. Antoniou, A. Blas, Y. Brischetto, A. Findlay, G. Kotzian, B. Mikulec, G. Sterbini CERN, Geneva, Switzerland
	At the CERN Proton Synchrotron Booster, PSB, an analog transverse damper system has been in operation since 1999, providing satisfactory operational results with the proton beam supplied by Linac2. As a consequence of the LHC Injectors Upgrade, the PSB will face new challenges imposed by higher intensity, injection and extraction energy. In this framework, the transverse feedback system is subject to an upgrade to adapt to the expected Linac4 beam and to the demands for new features including transverse blow-up, beam excitation for optics measurements and new remote control and monitoring capabilities. The replacement of the aging electronic hardware is also recommended to improve the system maintainability for future years. During 2018 a new digital transverse feedback electronics was installed in the PSB, in parallel with the current operational one, offering for the first time the occasion to demonstrate its performance with beam. Encouraging results were obtained such as the suppression of beam instabilities at all PSB energies and intensities. In this paper we describe the steps undertaken in 2018 in order to commission the system with the main goal to accelerate and extract the highest intensity beams produced at the PSB.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS085
About •	paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS087	Transverse Emittance Studies at Extraction of the CERN PS Booster	emittance, optics, booster, injection	1058
	F. Antoniou, S.C.P. Albright, F. Asvesta, H. Bartosik, G.P. Di Giovanni, V. Forte, M.A. Fraser, A. Garcia-Tabares, A. Huschauer, B. Mikulec, T. Prebibaj, A. Santamaría García, P.K. Skowroński CERN, Meyrin, Switzerland F. Asvesta NTUA, Athens, Greece T. Prebibaj National Technical University of Athens, Zografou, Greece
	Transverse emittance discrepancy in the beam transfer between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is observed in operational conditions for the LHC beams at CERN. The ongoing LHC Injectors Upgrade (LIU) project requires a tight budget for beam degradation along the injector chain and therefore the reason for this emittance discrepancy needs to be understood. Systematic measurements have been performed for various beam characteristics (beam intensity, transverse and longitudinal emittance). In this paper, a comparison between the emittance measurements using all available beam instrumentation with different emittance computation algorithms is presented. The results are compared to measurements at PS injection. Furthermore, the impact on the LIU project requirements for the emittance preservation along the LHC Injectors Complex is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS087
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS094	Dust Analysis from LHC Vacuum System to Identify the Source of Macro-Particle-Beam-Interactions	vacuum, beam-losses, proton, dipole	1082
	L.K. Grob, A. Apollonio, C. Charvet, E. Garcia-Tabares Valdivieso, H. Kos, R. Schmidt CERN, Geneva, Switzerland C. Neves Hochschule Furtwangen, Furtwangen, Germany
	Since in 2010 the first sub-millisecond beam losses were observed at varying locations all along the LHC, it is well known that dust can interact with high-intensity proton beams and cause significant beam losses. Initially the sudden localized losses were enigmatic and coined the phrase ’unidentified falling objects’ (UFOs), which is still widely used. These very fast beam losses have resulted in hundreds of premature beam dumps and even magnet quenches since the start of LHC. So far, the only mitigation strategy involved an optimization of dump thresholds and the beneficial conditioning effect which leads to a reduction of the UFO rate over time. To understand the physics involved in these events and to allow an active diminution, it is essential to know the chemical composition and the size of the dust particulates interacting with the protons. The exchange of a dipole magnet offered the unique opportunity to collect dust samples from inside the LHC vacuum system. They were extracted from the various components and analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy to reveal size distribution and abundant elements. The results of this investigation will optimize the existing UFO models and the improved understanding of the phenomenon may help to prevent future performance limitations. This is also of relevance for future projects, in particular for the Future Circular Collider (FCC) under study.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS094
About •	paper received ※ 15 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS104	A Toolkit for Tracing Electron Beam Envelope at Low Energy Section of TPS Linac	electron, simulation, linac, gun	1122
	H.H. Chen, H.C. Chen, K.-K. Lin, Y.K. Lin NSRRC, Hsinchu, Taiwan
	Based on calculated Bz of solenoids installed at the TPS linac low energy section, the electron beam envelope along beam centerline has been explored in this work using the initial and boundary conditions provided in the linac specifications. Concept of magnetic flux compression is adopt to analyze the beam size variation along linac centerline. The calculated result of selected checkpoints has been experimentally verified using screen monitors. In order to benefit tuning capability in routine operation, the display of beam size variation along centerline is integrated into the previously developed toolkit ’linac’. It is hope that it will provide an interactive approach for linac tune-up process and would be helpful to its routine operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS104
About •	paper received ※ 23 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS107	Beam Manipulations With Barrier Buckets in the CERN PS	extraction, synchrotron, proton, cavity	1132
	M. Vadai, A. Alomainy QMUL, London, United Kingdom H. Damerau, S.S. Gilardoni, M. Giovannozzi, A. Huschauer CERN, Geneva, Switzerland
	A barrier bucket scheme is being considered to reduce losses during the Multi-Turn Extraction from the CERN Proton Synchrotron to the Super Proton Synchrotron for the fixed-target physics programme. For effective loss reduction, the extraction kicker has to be triggered during the gap at the time of the longitudinal barrier. Initial beam studies at injection energy and with low intensity beams allowed to fully qualify an existing wide-band cavity to generate one or multiple beam synchronous pulses per turn. Bunch-length stretching and shortening have been exercised with barriers moving in azimuth with respect to the beam. The encouraging results obtained at injection energy guided the implementation of a de-bunching manipulation at higher energy to move all bunches into a single barrier bucket. Beam measurements at a momentum of 14GeV/c, varying intensity and the width of the barrier, demonstrate that a quasi-constant longitudinal line density and an almost fully depleted gap can be achieved at highest intensities. The contribution summarises the results of the beam studies at high energy together with some observations related to the Multi-Turn Extraction.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS107
About •	paper received ※ 18 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS118	3D Electromagnetic/PIC Simulations for a Novel RFQ/RFI Linac Design	rfq, linac, simulation, neutron	1158
	S.J. Smith, S. Biedron, A.M.N. Elfrgani, E. Schamiloglu, S.I. Sosa Guitron University of New Mexico, Albuquerque, USA P.G. Bethoney, M.S. Curtin, B. Hartman, T. Pressnall, D.A. Swenson Ion Linac Systems, Inc., Albuquerque, USA T.B. Bolin Element Aero, Chicago, USA J.R. Cary, D.M. Cheatham Tech-X, Boulder, Colorado, USA
	Funding: This work was supported by Ion Linac Systems, Albuquerque, NM. Using the commercial software VSim 9, a highly parallelized particle-in-cell/finite difference time-domain modeling code, the performance of an existing novel RFQ/RFI linac structure designed by Ion Linac Systems is evaluated. This effort is aimed towards having an up to date full 3D start-to-end simulation of the accelerator system, which does not exist currently. The structure used is an efficient 200-MHz, 2.5-MeV, CW-RFQ/RFI proton linac. The methods employed in VSim for modelling and parameter setup are presented, along with the simulation procedures for both the Electromagnetic and PIC solver. The important figures of merit for the structure are given including the Q-factor, field distributions, shunt impedance, and important beam properties. These are then contrasted with the initial design values and analytical calculations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS118
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS119	APS LINAC Interleaving Operation	linac, gun, storage-ring, booster	1161
	Y. Sun, K. Belcher, J.C. Dooling, A. Goel, A.L. Hillman, R.T. Keane, A.F. Pietryla, H. Shang, A. Zholents ANL, Argonne, 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. Three s-band RF guns are installed at the front end of the Advanced Photon Source (APS) linac: two thermionic cathode guns (RG2 and RG1), and one Photo-Cathode Gun (PCG). During normal operations, RG2 provides electron beams for the storage ring to generate x-rays for APS users. The PCG generates high brightness electron beams that can be accelerated through the APS linac and transported into the Linac Extension Area (LEA) for advanced accelerator technology and beam physics experiments. The alternating acceleration of the RG2 and PCG beam in the linac is possible, as most of the time, RG2 beam is only needed for ~20 seconds every two minutes. This mode of interleaving operation of RG2 and PCG beams through the APS linac requires some modifications/additions to several systems of the linac, including RF, magnets, controls and Access Control Interlock System etc. In this paper we report our interleaving design and present the commissioning results of the two beam interleaving operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS119
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUXXPLM2	SRF Cavity Fault Classification Using Machine Learning at CEBAF	cavity, cryomodule, SRF, GUI	1167
	A.D. Solopova, A. Carpenter, T. Powers, Y. Roblin, C. Tennant JLab, Newport News, Virginia, USA K.M. Iftekharuddin, L. Vidyaratne ODU, Norfolk, Virginia, USA
	The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab is the first large high power CW recirculating electron accelerator which makes use of SRF accelerating structures configured in two antiparallel linacs. Each linac consists of twenty C20/C50 cryomodules each containing eight 5-cell cavities and five C100 upgrade cryomodules each containing eight 7-cell cavities. Accurately classifying the source of cavity faults is critical for improving accelerator performance. In addition to archived signals sampled at 10 Hz, a cavity fault triggers a waveform acquisition process where 16 waveform records sampled at 5 kHz are recorded for each of the 8 cavities in the effected cryomodule. The waveform record length is sufficiently long for transient microphonic effects to be observable. Significant time is required by a subject matter expert to analyze and identify the intra-cavity signatures of imminent faults. This paper describes a path forward that utilizes machine learning for automatic fault classification. Post-training identification of the physical origins of faults are discussed, as are potential machine-trained model-free implementations of trip avoidance procedures. These methods should provide new insights into cavity fault mechanisms and facilitate intelligent optimization of cryomodule performance
	Slides TUXXPLM2 [4.404 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUXXPLM2
About •	paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP003	Development of Remote Handleable Axially Decoupled Radiation Resistant Vacuum Seal	vacuum, target, interface, electron	1233
	R.R. Nagimov, Y. Bylinskii, L. Egoriti, A. Gottberg, G.W. Hodgson, A.N. Koveshnikov, D. Yosifov TRIUMF, Vancouver, Canada
	Funding: ARIEL is funded by the Canada Foundation for Innovation (CFI), the Provinces of AB, BC, MA, ON, QC, and TRIUMF. TRIUMF receives federal funding via a contribution agreement with the NRC of Canada. Advanced Rare IsotopE Laboratory (ARIEL) facility is a major expansion of TRIUMF’s rare isotope research program. Aiming to triple the production of rare isotopes, ARIEL facility includes the new electron linac driver and two target stations for electron and proton beams. Particularities of ARIEL target stations design define the requirements for vacuum interfaces with both primary electron and proton beamlines and rare-isotope beamlines. None of the existing products fully met the requirements, driving the development of custom vacuum interfaces. The design of new vacuum seals is driven both by unique design specifications (limited amount of allowed axial forces, extreme radiation resistance, remote handleability and high repeatability) as well as limitations of the proposed design of beamline infrastructure in the target hall (limited available space and the choice of materials for certain components). This paper discusses preliminary results of the vacuum seal development and presents first results of prototype testing.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP003
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP006	Cryogenic Tests of the SPIRAL2 LINAC Systems	cavity, cryomodule, cryogenics, linac	1240
	A. Ghribi, P.-E. Bernaudin, R. Ferdinand, A.V. Vassal GANIL, Caen, France
	Two full cool-down of the SPIRAL2 superconducting LINAC have been performed in 2017 and 2018 respectively, followed by a total of around 5 months of tests at 4 K. Several cool-down strategies were tested, in order to minimize 100 K effect on the SC cavities. Helium bath regulations (level and pressure) have been tested and optimized. Effects of pressure instabilities and coupling with the cryogenic plant have also been observed. Cryogenic performances of each cryomodule have been measured. Low-level RF measurements were also performed on all cavities and showed unidentified modulations at frequencies around 5Hz. These turned out to be thermoacoustic oscillations (TAO) on the cryogenic lines, which generate important pressure instabilities. Several solutions to remove TAO and cure these instabilities have been tested and one has been successfully deployed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP006
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP011	Storageless Resonant Converter for Accelerator Magnets	resonance, controls, simulation, storage-ring	1248
	M. Cautero, T.N. Gucin Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	Elettra Sincrotrone Trieste, a specialized research centre generating high quality synchrotron radiation, has been in operation since 1993 and was revised in 2009. Recently, Elettra has been funded for a complete renewal of the storage ring. For the new machine, it is planned to employ state of the art converters, mostly of which will be designed in-house. For this purpose, it has been decided to evaluate the performance of a storage-less resonant converter, pro-posed by Dr. Slobodan Ćuk, which is a step down DC/DC converter consisting of four switches, one resonant capac-itor and two resonant inductors. For this purpose, the voltage conversion ratio of the converter has been de-rived. The topology was confirmed with simulation and a PCB layout has been designed, which is still to be tested.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP011
About •	paper received ※ 08 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP015	Magnet Power Supply Calibration with a Portable Current Measuring Unit at the J-PARC Main Ring	power-supply, feedback, timing, controls	1263
	K. Miura, Y. Kurimoto, Y. Morita, D. Naito, T. Oogoe, T. Shimogawa KEK, Ibaraki, Japan Y. Kuniyasu Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan K. Ooya SANKYU PLANT TECHNO CO., LTD., 6-5-3, Kachidoki, Japan R. Sagawa Universal Engineering, Ibaraki-ken, Japan
	In the J-PARC MR, 96 bending magnets (BMs) are used in total. They are divided into 6 groups of 16 BMs. The 16 BMs in each group are connected in series and driven by a single power supply. Since all 96 BMs are symmetrically located in the ring, the magnet currents regulated by the 6 power supplies need to be same. Each power supply performs output current feedback control using electronic circuits including analog amplifications and AD / DA conversions. Due to individual differences of the electronic circuits, output current is generally expected to be different for each power supply. Therefore, we developed a current measurement unit with the portable DCCT as an independent reference. Further, we measured the magnet currents regulated by the 6 BM power supplies using the unit. We report the details of the unit as well as the results of the current measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP015
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP016	New Power Supply of Main Magnets for J-Parc Main Ring Upgrade	controls, extraction, quadrupole, proton	1266
	T. Shimogawa, Y. Kurimoto, K. Miura, Y. Morita, D. Naito KEK, Ibaraki, Japan R. Sagawa Universal Engineering, Ibaraki-ken, Japan
	It is plans that the proton beam power provided to experimental facilities increase with shortening repetition period in J-PARC Main Ring (MR). As the shorten repetition period, the replacement of the power converters for main magnets in J-PARC MR is necessary to cope with issues such as power fluctuation of the main grid and increase of the output voltage. We have considered and developed the power converters with a 10 MW class which have the capacitor banks with the large capacitance. In the end of 2017, the first new power converter for a bending magnets family, which is the largest power converter in this upgrade plan, was installed in J-PARC site and the power test is ongoing using a dummy and a real load. In this report, the first new power converter for a bending magnets family in J-PARC MR is reported including the test results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP016
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP018	Feasibility Tests of a Vacuum System for SPring-8-II	vacuum, photon, hardware, multipole	1272
	K. Tamura, T. Bizen, M. Masaki, H. Ohkuma, M. Oishi, M. Shoji, S. Takahashi, Y. Taniuchi JASRI, Hyogo, Japan T. Bizen, M. Oishi, S. Takahashi RIKEN SPring-8 Center, Hyogo, Japan
	For SPring-8-II, the major upgrade of SPring-8, a test half-cell including permanent/electro magnets and a vacuum system was constructed, and hardware feasibility tests have been performed since 2017. Features of the SPring-8-II vacuum system are 1) introduction of the concept of a stainless steel 12 m-long integral chamber (LIC) with a welded structure, and 2) adoption of ex-situ baking of the chamber. The 12 m LIC with a narrow aperture, flangeless structure and a minimum number of bellows was designed so that the vacuum system could be installed without interference with the magnets of a narrow bore diameter aligned on girders with a severe packing factor. For replacement of the existing system with a new one in a short black-out period, the 12 m LIC is planned to be moved into the accelerator tunnel with keeping ultra-high vacuum (UHV) by closing thin gate valves at both ends, after evacuation to UHV by ex-situ baking and NEG activation. This presentation will overview the vacuum system, mainly the 12 m LIC, developed for the test half-cell, and describe the vacuum performance and the result of the assembly test conducted with the permanent/electro magnets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP018
About •	paper received ※ 15 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP024	Research on Module Design and Network Management of Accelerator Power Supply System	power-supply, controls, interface, network	1291
	Y. Li, S.Y. Chen, C. Han, P. Liu IHEP, Beijing, People’s Republic of China
	Accelerator power supply system is a very special system. Many factors such as high number of power supplies, uninterrupted operation and unreasonable design lead to high failure rate, long maintenance time and the discovery of the fault is not timely, which bring a lot of unnecessary troubles to the operator. In this paper, a networked control method for accelerator power supply is studied, and the power supply parallel connection technology is used to maximize the trouble-free time of the power supply and increase the redundancy performance of the power supply. With independent networked control, the accelerator power supply system becomes a whole, no longer relying solely on the control of the accelerator control system, but in a network system with self-diagnosis and self-healing. Through the monitoring and management of the upper computer, the power supply system will be work stable, and the function of remote operation and remote repair of the power supply is realized finally. This is a research direction for the operation of large accelerator power supply systems in the future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP024
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP042	The Beam Cleaning Analysis for the TPS Vacuum System	vacuum, MMI, radiation, ECR	1344
	Y.C. Yang, C.K. Chan, C.-C. Chang, A.Y. Chen, J.-Y. Chuang, C.H. Huang NSRRC, Hsinchu, Taiwan
	Commissioning for the TPS, a low-emittance 3-GeV synchrotron ring, started in December 2014 and is now currently operating in top-up mode at 400mA for users. Until the last machine shut down in December 2018, a total beam dose of 4919 Ah was accumulated and the beam cleaning effect decreased the dynamic pressure to 1.5×10^-11 Pa/mA. During past years operation, several vacuum chambers were replaced to improve vacuum performance and avoid exposure to synchrotron radiation from insertion devices. In this paper, the beam cleaning evolution of new vacuum sections will be discussed and compared with experience in the rest of the storage ring. A particular cleaning evolution could be predicted and can be referenced for machine shutdown planning in the future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP042
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP045	The Protection Instrument for Cryogenic Phase Separator Pressure Relief Valve of TPS Beamline	controls, monitoring, software, cryogenics	1350
	C.C. Liang, C.Y. Chang, C.F. Chang, Y.H. Guo, M.H. Lee, C.Y.L. Liu, T.-C. Yu NSRRC, Hsinchu, Taiwan
	TPS (Taiwan Photon Source) beamlines have operated for three years after the successful commission in 2015. Recently, the electromagnetic activated pressure relief valve of cryogenic phase separator of beamline had malfunction due to the rust of its control circuits. After on site observation and temperature records, the water was found to be condensed around the outlet area due to fast temperature dropping near the valve as it was activated. Such situation would cause the rust of metal components due to humidity after a certain period of time. To avoid such event, fan is used to blow the condensed water and silicone heat belts are added to increase the local temperature with unique designed clamp for fixing the fan, sensors and safety circuit breaker. Via the temperature control system, the temperature monitoring, setting and the abnormal situation can be access on web page through Ethernet to make sure the proper operation of the protected devices. The instrument has been operated since Dec. 2018. After four months of operation, the moist situation has been improved and the relief valve is no longer frosted.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP045
About •	paper received ※ 30 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP047	Upgrade of the Cryogenic Control System for SRF Modules at the Taiwan Light Source	controls, cryogenics, SRF, interface	1356
	F.-T. Chung, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu NSRRC, Hsinchu, Taiwan
	An upgrade of the cryogenic control system for superconducting radio-frequency (SRF) modules of the Taiwan Light Source (TLS) has been completed. The biggest challenge was to recover all protection and operational functions, while minimizing the quantity of vented helium from SRF modules while replacing valve controllers. Gradually, this work was finished within several one- and ten-day scheduled machine shutdown periods for accelerator maintenance. No large helium vent nor pollution of the cryogenic system occurred during all component replacements and function verifications. Functions of the cryogenic electronics were improved, whereas the valve controllers are upgraded to new versions to increase reliability and availability. Communications with the data acquisition system was also secured by buffered signal processing module so that device shutdown of the data acquisition system will not interrupt the cryogenic valve operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP047
About •	paper received ※ 29 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP054	Investigations on Cryopanels in the Room Temperature Heavy Ion Synchrotron SIS18	vacuum, cryogenics, heavy-ion, synchrotron	1372
	L.H.J. Bozyk, S. Aumüller, P.J. Spiller GSI, Darmstadt, Germany
	The heavy ion synchrotron SIS18 at GSI will serve as injector ring for the FAIR-facility and provide high intensity heavy ion beams. The operation of such beams requires the usage of low charge states, which have high cross sections for ionization. To overcome this issue, many upgrade measure have been realized in the past decade, such as the installation of an ion catcher system with low desorption surfaces and coating 65% of the circumference of SIS18 with NEG to lower the static gas pressure. Since the vacuum dynamics during operation prevent the achievement of the intensity goals for FAIR, new concepts have to be developed, to increase the beam intensity. One idea is the installation of additional pumping speed in the form of cryogenic surfaces. Heavy residual gas components, which have the highest ionization cross sections can be cryopumped at moderate temperatures, i.e. already at 50-80 K. In fact, the only typical residual gas component which can not be pumped via cryosorption in this temperature regime is Hydrogen, which has a factor 50 lower ionization cross sections than Argon, the heaviest residual gas component. In this paper, we present a study of the integration of cryopanels into the vacuum chambers of SIS18.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP054
About •	paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP056	LANSCE Vacuum System Improvements in the Last ~10 Years	vacuum, neutron, linac, status	1375
	T. Tajima, J.E. Bernal, M.J. Borden, J.P. Chamberlin, F.A. Martinez, J.F. O’Hara, A. Poudel, K.A. Stephens LANL, Los Alamos, New Mexico, USA
	Funding: DOE/NNSA The Los Alamos Neutron Science Center (LANSCE) accelerator started its operation in 1972. To mitigate the vulnerability due to old equipment and to restore the 120 Hz operation capability we lost a while ago, we have gone through a refurbishment / risk mitigation project since 2007. This paper summarizes the improvements in the vacuum systems in the last ~10 years and shows some data on the downtimes caused by vacuum failures. The refurbished equipment is significantly more maintainable and will contribute to extend the life of this old accelerator, but it has been a challenge to reduce the downtime. Some examples that caused a long downtime will be described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP056
About •	paper received ※ 24 May 2019 paper accepted ※ 26 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW009	THE ESRF FROM 1988 TO 2018, 30 YEARS OF INNOVATION AND OPERATION	SRF, vacuum, injection, emittance	1400
	J.-L. Revol, L. Farvacque, L. Hardy, P. Raimondi ESRF, Grenoble, France
	In 1988, eleven European countries joined forces to build the European Synchrotron Facility in Grenoble [France]. The ESRF was the first third-generation light source worldwide. After 30 years of innovation and user operation, the present storage ring was shut down to leave room for a new and brighter source. This paper describes the evolution of the facility from its origin to the Ex-tremely Bright Source (EBS). Firstly, the operational aspects including reliability and beam modes are consid-ered. This is followed by the presentation of the progress of lattice and the implementation of top-up. Finally, the development of the radio frequency and vacuum systems are discussed. To conclude, the lessons learned from 30 years operation are summarized, especially in view of EBS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW009
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW014	Characterization and Implementation of the Cryogenic Permanent Magnet Undulator CPMU17 at Bessy II	undulator, vacuum, laser, feedback	1415
	J. Bahrdt, W. Frentrup, S. Gottschlich, S. Grimmer, M. Huck, C. Kuhn, A. Meseck, C. Rethfeldt, M. Scheer, B. Schulz HZB, Berlin, Germany E.C.M. Rial DLS, Oxfordshire, United Kingdom
	In fall 2018, the cryogenic undulator CPMU17 was installed in BESSY II. Before installation, the undulator was characterized with an in-vacuum Hallprobe bench and an in-vacuum moving wire. Both systems were developed at HZB. The commissioning of the device included the orbit and tune corrections, optimization of the injection, characterization of the heat dissipation, tuning the Landau cavities for a reduction of the heat dissipation in the taper sections (temperatures below 60°C) and testing of the machine protection system. The undulator is ready to deliver light for beamline commissioning. Spectral tuning on a high undulator harmonic (longitudinal taper and alignment of e-beam orbit and undulator axis) will be done as soon as the DCM is operational.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW014
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW015	Petra III Operation and Studies 2018	vacuum, impedance, undulator, radiation	1419
	M. Bieler, I.V. Agapov, Y.-C. Chae, J. Keil, G.K. Sahoo, R. Wanzenberg DESY, Hamburg, Germany
	At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. This paper describes the operational schedule, the operational statistics and the most important beam studies done at PETRA III in 2018.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW015
About •	paper received ※ 26 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW016	New Operation Regimes at the Storage Ring KARA at KIT	lattice, optics, injection, simulation	1422
	A.I. Papash, E. Blomley, T. Boltz, M. Brosi, E. Bründermann, S. Casalbuoni, J. Gethmann, E. Huttel, B. Kehrer, A. Mochihashi, A.-S. Müller, R. Ruprecht, M. Schuh, J.L. Steinmann KIT, Karlsruhe, Germany
	The storage ring Karlsruhe Research Accelerator (KARA) at KIT operates in a wide energy range from 0.5 to 2.5 GeV. Initially, the ring was designed to serve as a Light Source for synchrotron radiation facility ANKA. Since then different operation modes have been implemented at KARA: in particular, the double bend achromat (DBA) lattice with non-dispersive straight sections, the theoretical minimum emittance (TME) lattice with distributed dispersion, and 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 have been tested and implemented in a wide operational range of the ring and are now routinely used at 1.3 GeV for studies of CSR-induced beam dynamics and THz bursting in the micro-bunching instability. Different non-linear effects, in particular, residual high order components of magnetic fields generated in insertion devices have been studied and cured. A new operation mode at high vertical tune implemented at KARA essentially improves beam performance during user operation as well as at low alpha regimes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW016
About •	paper received ※ 23 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Paper

Title

Other Keywords

Page

MOYPLM1

Challenges to Higher Beam Power in J-PARC: Achieved Performance and Future Prospects

resonance, extraction, experiment, proton

6

S. Igarashi
KEK, Ibaraki, Japan

J-PARC is a world leading intensity frontier accelerator facility, consisting of a 400-MeV H⁻ linac, a 3-GeV Rapid Cycling Synchrotron (RCS) and a 30-GeV slow cycling Main Ring synchrotron (MR). The RCS delivered a 500 kW beam (4.2·10¹³ particles per pulse (ppp)) to the Material and Life science experimental Facility (MLF) in April of 2018, The design power of 1 MW will be delivered in the next few years. Construction of a second target station (2TS) of the MLF with beam power upgraded to 1.5 MW is now under discussion. The MR delivers proton beam to a long-baseline neutrino oscillation experiment, T2K, by fast extraction (FX) and to the hadron experimental facility by slow extraction (SX). For the FX, the maximum beam power is 475 kW and 2.5·10¹⁴ ppp, the world highest ppp in synchrotrons, and for the SX 51 kW and 5.5·10¹³ ppp with an extremely high extraction efficiency of 99.5 %. To achieve 1.3 MW beam power for the neutrino experiment, upgrades to allow operation with a higher repetition rate are planned. The talk will review recent progress of J-PARC facility by highlighting technical challenges toward higher beam power together with future prospects.

Slides MOYPLM1 [9.193 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOYPLM1

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOYPLM2

SRF Operation at XFEL: Lessons Learned After More Than One Year

FEL, cavity, linac, SRF

12

D. Kostin, V. Ayvazyan, J. Branlard, W. Decking, L. Lilje, M. Omet, T. Schnautz, E. Vogel, N. Walker
DESY, Hamburg, Germany

The European XFEL is the largest high-field SRF installation in the world and has now been in operation more than a year. It serves as a "prototype" for other facilities being constructed or in the planning stages. Performance of the operation of the SRF system over this period of time and the lessons learned will be discussed.

Slides MOYPLM2 [4.351 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOYPLM2

About •

paper received ※ 10 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOYPLM3

Progress with the High Luminosity LHC Project at CERN

luminosity, cavity, quadrupole, collider

17

L. Rossi, O.S. Brüning
CERN, Geneva, Switzerland

The High Luminosity LHC (HL-LHC) project aims at upgrading the LHC by increasing the peak luminosity by a factor five, to allow to collect 3000 fb-1 for ATLAS and CMS experiments, each, which is ten times more than what is foreseen in the LHC. The upgrade is based on multiple factors. One factor is doubling the beam current, also thanks to the injector upgrade (LIU) project, and another one is operation in levelling mode. The most critical upgrade is the deploying of a stronger inner quadrupole triplet in the low-beta insertions with more than twice-larger aperture w.r.t. present LHC triplet, thanks to the use of Nb₃Sn superconductor, a world first for accelerators, with almost 12 T peak field in the coils. The novel concept of ATS optics allows to utilise the increased aperture efficiently by generating β^* values 3 to 4 times below the nominal values of the LHC. We will make use of compact crab cavities for hadrons (also a novelty in accelerators) to allow almost head-on collisions despite the larger crossing angle. We are developing new collimator insertions in the dispersion suppressor region to handle the losses in the cold part of the machine (the beam halo stores 30 MJ) thanks to the use of a few 11 T dipoles based on Nb₃Sn technology. We also aim at reducing drastically the impedance contribution of collimators by utilizing new materials and coating techniques. Many other technologies are developed for HL-LHC like new SC links of 100 kA: HL-LHC is critical as a technology turning point for HEP colliders as it is for Physics reach. The technologies developed for HL-LHC, namely (but not only) the high field superconducting magnets, are critical for the post-LHC hadron collider, like a High Energy LHC or the 100 km Future Circular Collider

Slides MOYPLM3 [21.679 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOYPLM3

About •

paper received ※ 19 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOZPLS2

Ion Collider Precision Measurements With Different Species

target, electron, experiment, collider

28

G.J. Marr, E.N. Beebe, I. Blackler, W. Christie, K.A. Drees, P.S. Dyer, A.V. Fedotov, W. Fischer, C.J. Gardner, H. Huang, T. Kanesue, N.A. Kling, V. Litvinenko, C. Liu, Y. Luo, D. Maffei, B. Martin, A. Marusic, K. Mernick, M.G. Minty, C. Naylor, M. Okamura, I. Pinayev, G. Robert-Demolaize, T. Roser, P. Sampson, V. Schoefer, T.C. Shrey, D. Steski, P. Thieberger, J.E. Tuozzolo, K. Zeno, I.Y. Zhang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC, under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Precedent to electron cooling commissioning and collisions of Gold at various energies at RHIC in 2018, the STAR experiment desired an exploration of the chiral magnetic effect in the quark gluon plasma (QGP) with an isobar run, utilizing Ruthenium and Zirconium. Colliding Zr-96 with Zr-96 and Ru-96 with Ru-96 create the same QGP but in a different magnetic field due to the different charges of the Zr (Z=40) and Ru (Z=44) ions. Since the charge difference is only 10%, the experimental program requires exacting store conditions for both ions. These systematic error concerns presented new challenges for the Collider, including frequent reconfiguration of the Collider for the different ion species, and maintaining level amounts of instantaneous and integrated luminosity between two species. Moreover, making beams of Zr-96 and Ru-96 is challenging since the natural abundances of these isotopes are low. Creating viable enriched source material for Zr-96 required assistance processing from RIKEN, while Ru-96 was provided by a new enrichment facility under commissioning at Oak Ridge National Laboratory.

Slides MOZPLS2 [4.758 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOZPLS2

About •

paper received ※ 11 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW010

First Application of Online Particle Swarm Optimization at SOLEIL

injection, storage-ring, controls, vacuum

82

A. Bence, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France
J. Li
HZB, Berlin, Germany

First attempts of online optimisation of SOLEIL using Particle Swarm Optimisation (PSO) is reported with two major applications. This technique proves to be particularly suitable in a control room and could become a standard operation tool for tuning the accelerators in complement of other techniques. The first optimisation of the injection in the storage ring will be presented using the injection septa and the vertical correctors of the booster to storage ring transfer line. The second work will summarise the results obtained from the optimisation of the transverse on- and off-momentum dynamics in presence of insertion devices. Main results, the implementation and improvements will be presented and discussed thoroughly.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW010

About •

paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW025

Beam Breakup Simulations for the Mainz Energy Recovering Superconducting Accelerator MESA

cavity, HOM, cryomodule, simulation

135

C.P. Stoll, F. Hug
KPH, Mainz, Germany

Funding: This work is supported by DFG through PRISMA+ cluster of excellence EXC 2118/2019, RTG 2128 and by the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871.
MESA is a two pass energy recovery linac (ERL) currently under construction at the Johannes Gutenberg-University in Mainz. MESA uses four 1.3 GHz TESLA type cavities with 12.5 MV/m of accelerating gradient in two modified ELBE type cryomodule with improved thermal connection of the HOM antennas and cw operation. In the first stage of MESA operation 1mA of beam current is foreseen, which will later be upgraded to 10mA. One potential limit to maximum beam current in ERLs is the transverse beam breakup (BBU) instability induced by dipole Higher Order Modes (HOMs). These modes can be excited by bunches passing through the cavities off axis. Following bunches are then deflected by the HOMs, which results in even larger offsets for recirculated bunches. This feedback can even lead to beam loss. Simulation results for HOM spectra of a single TESLA cavity are available for example in *. It was possible to measure the HOM spectra in the cold, not tuned cavities at DESY and in the cold string tuned to the 1.3 GHz fundamental mode at Mainz. Results for the maximum beam current for MESA, limited by BBU, for the various HOM spectra are presented.
* "Eigenmode Calculations for the TESLA Cavity Considering Wave-Propagation Losses through Fundamental and Higher-Order Mode Couplers", W. Ackermann, H. De Gersem, C. Liu, and T. Weiland

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW025

About •

paper received ※ 16 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW026

Transfer Line Optics Design Using Machine Learning Techniques

target, simulation, quadrupole, optics

139

D.M. Vilsmeier
IAP, Frankfurt am Main, Germany
M. Bai, M. Sapinski
GSI, Darmstadt, Germany

Optimization of transfer line optics is essential for delivering high quality beams to the experimental areas. This type of optimization is usually done by hand and relies on the experience of operators. The nature of this task is repetitive though highly complex. Besides optimizing the beam quality at the experiments this task is often accompanied by secondary objectives or requirements such as keeping the beam losses below an acceptable threshold. In the past years Deep Learning algorithms have experienced a rapid development and gave rise to various advanced software implementations which allow for straightforward usage of corresponding techniques, such as automatic differentiation and gradient backpropagation. We investigate the applicability and performance of these techniques in the field of transfer line optics optimization, specifically for the HADES beamline at GSI, in form of gradient-based differentiable simulators. We test our setup on results obtained from MADX simulations and compare our findings to different gradient-free optimization methods. Successfully employing such methods relieves operators from the tedious optimization tasks.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW026

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW036

Studies on Coherent Multi-Bunch Tune Shifts with Different Bunch Spacing at the J-PARC Main Ring

space-charge, proton, impedance, injection

167

A. Kobayashi, S. Igarashi, Y. Sato, T. Shimogawa, Y. Sugiyama, T. Toyama, M. Yoshii
KEK, Tokai, Ibaraki, Japan

At a high-power proton synchrotron, betatron tune shifts induced by space charge effects cause beam loss which limits the beam intensity. To achieve further high beam intensity at the main ring of the Japan Proton Accelerator Research Complex, precise control of the tune shift is indispensable. When carrying out multi-bunch measurements, we observed that the dependence of the tune shift intensity on the number of bunches follow opposite slope trends for the horizontal and vertical directions. The influence of the bunch spacing was also observed. We report on a simplified tune shift model reconstruction for understanding the origin of these phenomena and present a correction of the tune shifts for reducing beam loss up to 30 %.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW036

About •

paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW038

Collimator’s Impact Into the Transverse Emittance Growth at KEK Compact ERL

wakefield, emittance, simulation, FEL

174

O.A. Tanaka, T. Miyajima, N. Nakamura, T. Obina, M. Shimada, Y. Tanimoto
KEK, Ibaraki, Japan

In high-intensity particle accelerators, unwanted trans-verse and longitudinal wakefields arise when the high-charge particle beam passes through the narrow chambers or locations with small transverse apertures, such as collimator jaws. Transverse wakefields impose a transverse kicks to the beam, changing its shape, and leading to the growth of the transverse emittance. Longitudinal wakes cause the beam energy losses, heating of the narrow chambers etc. In the present study we investigated the collimator’s impact to the beam. Thus, we evaluated the collimator’s wakefields through the CST simulations. We estimated the corresponding transverse kicks and longitudinal wakes. In the summary simulation results were cross-checked with correspondent analytical expressions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW038

About •

paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW039

Investigation of Longitudinal Beam Dynamics With Harmonic Cavities by Using the Code Mbtrack

cavity, impedance, synchrotron, beam-loading

178

N. Yamamoto
KEK, Ibaraki, Japan
A. Gamelin, R. Nagaoka
SOLEIL, Gif-sur-Yvette, France

In diffraction-limited light sources, the study of collective effects is essential. With harmonic cavities (HCs), the ’flat potential condition’ can be achieved, lengthening the bunch by a factor of ~5. However, the effective rf voltage seen by the beam becomes sensitive to both positions and distributions of all bunches, as the beam-induced voltage of both HCs and fundamental cavities (FCs) contribute. In addition, when there are empty buckets, the transient beam loading induces considerable variations of the rf voltage impacting the beam performance*. Here the use of analytical approaches is difficult. Then we introduced the new functions to treat the high-Q resonators driven by either or both of the beams and external generators to the code mbtrack**. Using these features, various operating conditions with arbitrary fill patterns can be studied; coupled bunch instability induced by HOMs of the cavity, Robinson instabilities and general beam dynamics with HCs. The growth rates of the instabilities described above are compared with analytical results. The ring performance with HCs in several fill patterns shall be also reported.
* N.Yamamoto, et al., PRAB, 21, 012001 (2018).
**G. Skripka, et al., NIM A806, 221 (2016).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW039

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW072

Reconfiguration of SPS Landau Octupole Circuits to Minimise Second Order Chromaticity

octupole, optics, target, acceleration

262

H. Bartosik, M. Carlà, K. Cornelis
CERN, Meyrin, Switzerland

In the SPS Q20 optics presently used for LHC beams, the Landau octupole families of the SPS (LOF and LOD circuits) generate large second order chromaticity due to the relatively high dispersion at their locations. Since the induced second order chromaticity results in enhanced losses due to the large incoherent tune spread, these octupoles cannot be used for mitigating transverse instabilities for LHC beams. A new cabling scheme was proposed, exploiting additional octupoles that were already installed in the machine but not used, which allows minimizing the induced second order chromaticity in both the Q20 optics used for LHC beams, as well as the original SPS optics used for fixed target beams. This paper summarises the optics calculations as well as the experimental verification of the reduced chromatic detuning of the new octupole scheme.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW072

About •

paper received ※ 12 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW093

Optics Calibration for Routine Operations In Taiwan Photon Source

optics, lattice, quadrupole, coupling

335

F.H. Tseng, C.H. Chen, P.J. Chou
NSRRC, Hsinchu, Taiwan

To ensure a stable performance of Taiwan Photon Source (TPS), we perform the calibration of accelerator optics using LOCO (Linear Optics from Closed Orbit) technique every month. After the optics and coupling corrections, the rms beta beatings in both planes are reduced to less than 1%. The emittance coupling ratio is also restored to within the design value.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW093

About •

paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW110

Study of the Beam Current Effects on the NSLS-II Storage Ring Optics Using Turn-by-Turn Data

lattice, optics, storage-ring, dipole

375

J. Choi, Y. Hidaka
BNL, Upton, Long Island, New York, USA

These days, the techniques using the turn-by-turn data are well developed in analyzing the accelerator optics. We compared the data for the low and high beam currents and studied the beam current effects on the storage ring lattice optics. Also, by comparing the local transfer matrices, we analyzed the amounts of the impacts on the linear optics around the ring.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW110

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP019

High Luminosity LHC Optics and Layout HLLHCV1.4

optics, luminosity, experiment, cavity

468

R. De Maria, R. Bruce, D. Gamba, M. Giovannozzi, F. Plassard
CERN, Geneva, Switzerland

The goal of the High Luminosity Project is the upgrade of the LHC to deliver an integrated luminosity of at least 250 \rm fb^-1 per year in each of the two high-luminosity, general-purpose detectors ATLAS and CMS. This article presents the latest layout design and the corresponding optics features, which comprise optimisation of the orbit corrector and crab cavity systems, and new estimates of the performance reach thanks to the new concept of fully remote alignment. In addition, the new optics version incorporates improvements required by beam instrumentation, dump system, and collimation system, as well as low-beta solutions for the LHCb experiment.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP019

About •

paper received ※ 17 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP020

Smooth and Beta-Beating-Free Optics Transitions for HL-LHC

optics, injection, quadrupole, insertion

472

R. De Maria, M. Solfaroli
CERN, Geneva, Switzerland

In the CERN LHC, optics transitions are mainly required to control the beam size at the four experimental interaction points. The current method, based on linearly-interpolated optics functions over a small set of matched optics and parabolic time-domain segments, introduces non-zero beta-beating and it is not optimal in time. This contribution presents an alternative approach, based on continuously-matched optics solutions distributed in time domain by using a realistic model of the superconducting circuits, which optimises the overall process duration. This method requires a change in the paradigm used in the control system and it is proposed for the future High Luminosity LHC (HL-LHC) runs.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP020

About •

paper received ※ 18 April 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP024

Prospects for Future Asymmetric Collisions in the LHC

proton, luminosity, experiment, hadron

484

M.A. Jebramcik, J.M. Jowett
CERN, Geneva, Switzerland

The proton-lead runs of the LHC in 2012, 2013 and 2016 provided luminosity far beyond expectations in a diversity of operating conditions and led to important new results in high-density QCD. This has permitted the scope of the future physics programme to be expanded in a recent review. Besides further high-luminosity p-Pb collisions, lighter nuclei are also under consideration. A short proton-oxygen run, on the model of the 2012 p-Pb run, would be of interest for cosmic-ray physics. Other collision systems like proton-argon or collisions of protons with other noble gases are also discussed. We provide an overview of the operational strategies and potential performance of various asymmetric collision options. Potential performance limits from moving beam-beam encounters at injection and various beam-loss mechanisms are evaluated in the light of our understanding of the LHC to date.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP024

About •

paper received ※ 18 April 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP029

Analysis on Bunch-by-Bunch Beam Losses at 6.5 TeV in the Large Hadron Collider

luminosity, betatron, beam-losses, collider

500

K. Paraschou, G. Iadarola, N. Karastathis, S. Kostoglou, Y. Papaphilippou, L. Sabato
CERN, Geneva, Switzerland
S. Kostoglou
National Technical University of Athens, Zografou, Greece
K. Paraschou
AUTH, Thessaloniki, Greece

In 2018, a large fraction of the physics data taking at the Large Hadron Collider has been performed with a beam energy of 6.5 TeV, the nominal bunch spacing of 25 ns and beta functions at the high luminosity interaction points of 30 cm. In order to maximize the integrated luminosity, the crossing angles are gradually reduced as the beam intensity reduces due to luminosity burn-off. In these conditions the beam lifetime is visibly affected by collective effects and in particular by beam-beam interaction and electron cloud effects. By analyzing the beam losses at a bunch-by-bunch level, it is possible to disentangle the contributions from different effects and to assess the impact on the losses of changes applied to the machine configuration.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP029

About •

paper received ※ 10 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP031

Operation and Performance of the Cern Large Hadron Collider During Proton Run 2

luminosity, proton, emittance, injection

504

R. Steerenberg, M. Albert, R. Alemany-Fernández, T. Argyropoulos, E. Bravin, G.E. Crockford, J.-C. Dumont, K. Fuchsberger, R. Giachino, M. Giovannozzi, G.H. Hemelsoet, W. Höfle, D. Jacquet, M. Lamont, E. Métral, D. Nisbet, G. Papotti, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, M. Schaumann, M. Solfaroli, R. Suykerbuyk, G. Trad, J.A. Uythoven, S. Uznanski, D.J. Walsh, J. Wenninger, M. Zerlauth
CERN, Geneva, Switzerland

Run 2 of the CERN Large Hadron Collider (LHC) was successfully completed on 10th December 2018, achieving largely all goals set in terms of luminosity production. Following the first two-year long shutdown and the re-commissioning in 2015 at 6.5 TeV, the beam performance was increased to reach a peak luminosity of more than twice the design value and a colliding beam time ratio of 50%. This was accomplished thanks to the increased beam brightness from the injector chain, the high machine availability and the performance enhancements made in the LHC for which some methods and tools, foreseen for the High Luminosity LHC (HL-LHC) were tested and deployed operationally. This contribution provides an overview of the operational aspects, main limitations and achievements for the proton Run 2.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP031

About •

paper received ※ 13 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP036

Machine Protection Experience from Beam Tests with Crab Cavity Prototypes in the CERN SPS

cavity, machine-protect, beam-losses, betatron

520

B. Lindstrom, H. Bartosik, T. Bohl, A.C. Butterworth, R. Calaga, L.R. Carver, V. Kain, T.E. Levens, G. Papotti, R. Secondo, J.A. Uythoven, M. Valette, G. Vandoni, J. Wenninger, D. Wollmann, M. Zerlauth
CERN, Meyrin, Switzerland

Funding: Work supported by the High Luminosity LHC project.
Crab cavities (CCs) constitute a key component of the High Luminosity LHC (HL-LHC) project. In case of a failure, they can induce significant transverse beam offsets within tens of microseconds, necessitating a fast removal of the circulating beam to avoid damage to accelerator components due to losses from the displaced beam halo. In preparation for the final design to be employed in the LHC, a series of tests were conducted on prototype crab cavities installed in the Super Proton Synchrotron (SPS) at CERN. This paper summarizes the machine protection requirements and observations during the first tests of crab cavities with proton beams in the SPS. In addition, the machine protection implications for future SPS tests and for the use of such equipment in the HL-LHC are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP036

About •

paper received ※ 01 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP044

Improving the Luminosity for Beam Energy Scan II at RHIC

cavity, electron, space-charge, luminosity

540

C. Liu, M. Blaskiewicz, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, H. Huang, D. Kayran, Y. Luo, G.J. Marr, A. Marusic, K. Mernick, M.G. Minty, C. Montag, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, T.C. Shrey, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang
BNL, Upton, Long Island, 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 QCD (Quantum Chromodynamics) phase diagram has many uncharted territories, particularly the nature of the transformation from Quark-Gluon plasma (QGP) to the state of Hadronic gas. The Beam Energy Scan I (BES-I) at the Relativistic Heavy Ion Collider (RHIC) was completed but measurements had large statistical errors. To improve the statistical error and expand the search for first-order phase transition and location of the critical point, Beam Energy Scan II will commence in 2019 with a goal of improving the luminosity by a factor of 3-4. The beam lifetime at low energies was and will be limited by some physical effects of which the most significant are intrabeam scattering, space charge, beam-beam, persistent current effects. This article will review these potential limiting factors and introduce the countermeasures which will be in place to improve BES-II luminosity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP044

About •

paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP045

RHIC Heavy Ion Operation With Near-Integer Working Point

acceleration, controls, feedback, power-supply

544

C. Liu, G.J. Marr, A. Marusic, M.G. Minty, V. Schoefer
BNL, Upton, Long Island, 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 interplay of space charge and beam-beam effects limits the beam lifetime at low energies at the Relativistic Heavy Ion Collider (RHIC). To improve the beam lifetime, a near-integer working point (0.096/0.094) was tested at fixed energy and during acceleration. In the demonstration experiments, we observed the benefit of the near-integer working point on beam lifetime, however, did not achieve the desired level of orbit correction. This article will present the experimental results of operation with a near-integer working point, and analyze the causes of the orbit control problem.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP045

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP051

56 MHz SRF System for SPHENIX Experiments at RHIC

cavity, SRF, HOM, detector

562

Q. Wu, M. Blaskiewicz, K. Mernick, S. Polizzo, F. Severino, K.S. Smith, T. Xin
BNL, Upton, Long Island, New York, USA

Funding: Work supported by by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The sPHENIX experiment is a proposal for a new detector at the Relativistic Heavy Ion Collider (RHIC), that plans to expand on discoveries made by RHIC’s existing STAR and PHENIX research groups. To minimize the luminosity outside the 20 cm vertex detector and keeping the radiation to other detector components as low as possible, a 56 MHz SRF system is added to the existing RHIC RF systems to compress the bunches with less beam loss. The existing 56 MHz SRF cavity was commissioned in previous RHIC runs, and contributed to the luminosity at a voltage of 300kV with thermal limitations from the Higher Order Mode coupler at high field, and at 1MV while using its fundamental damper for HOM damping. In this paper, we will analyze and compare the effect of different RF systems at various scenarios, and discuss possible solutions to the Higher Order Mode (HOM) damping scheme to bring the cavity to 2 MV.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP051

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP053

Numerical Optimization of DC Wire Compensation in HL-LHC

collider, luminosity, hadron, simulation

570

K. Skoufaris, S.D. Fartoukh, N. Karastathis, Y. Papaphilippou, D. Pellegrini, A. Poyet, A. Rossi, G. Sterbini
CERN, Meyrin, Switzerland

The electromagnetic field generated from a set of DC wires parallel to the beam opens the path to the compensation of the beam-beam long-range (BBLR) interactions for the future operation of large hadron colliders, in particular for the upcoming High Luminosity upgrade of the Large Hadron Collider (HL-LHC). The effectiveness and simplicity of a current carrying wire are critical for overcoming some technical constraints of the machine. In order to better understand the potential of this device for the HL-LHC, various simulation studies are presented. The different observables are the dynamic aperture and the frequency analysis.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP053

About •

paper received ※ 03 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB022

Current Status of the High-Power RF Systems During Phase2 Operation in SuperKEKB

klystron, cavity, GUI, status

619

K. Watanabe, K. Marutsuka, Ma. Yoshida, S.I. Yoshimoto
KEK, Ibaraki, Japan

The SuperKEKB is an asymmetric-energy two-ring collider consisting of the high-energy ring (HER) for 7 GeV electrons and the low-energy ring (LER) for 4 GeV positrons at KEK. Both the electron and positron beams are injected from the Linac injector complex, which includes a newly constructed 1.1 GeV positron damping ring (DR) to supply a high-quality low emittance positron beam to the LER. The high power RF system has a role to drive the ARES cavities and the superconducting RF cavities for the SuperKEKB. The operating frequency of RF system is 508.9 MHz. The required RF power from the klystron at maximum storage beam current is ~850 kW (CW). The number of RF stations is total 31 for the main ring (MR) and DR. The status of each high power RF components, troubles of them and operation condition that occurred during phase 2 commissioning from Feb 2018 to July 2018 will be reported in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB022

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB031

Progress of Conceptual Study for the Accelerators of a 2-7GeV Super Tau Charm Facility at China

collider, luminosity, factory, electron

643

Q. Luo, W. Li, D.R. Xu
USTC/NSRL, Hefei, Anhui, People’s Republic of China
W.W. Gao, J.Q. Lan
Fujian University of Technology, Fuzhou, People’s Republic of China

Funding: Supported by National Natural Science Foundation of China U1832169 and the Double Fist-Class University Project Foundation of USTC.
This paper shows the progress of the conceptual study for the accelerators of a super tau charm facility in China. Since the BEPCII will finish its historical mission in 5~10 years and its upgrade plan will only achieve a small luminosity enhancement of 3~5 times, a new next generation tau-charm collider will play an irreplaceable role in future high energy physics study. The luminosity of this successor is about 5×10³⁴cm⁻²s⁻¹ pilot and 1×10³⁵cm⁻²s⁻¹ nominal, with the electron beam longitudinally polarized at the IP. The general scheme of the accelerators and the beam pa-rameters are shown. Several key technologies such as beam polarization and beam emittance diagnostics are also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB031

About •

paper received ※ 14 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB045

Future High Power Proton Drivers for Neutrino Beams

linac, proton, neutron, factory

662

D.C. Plostinar, M. Eshraqi, B. Gålnander
ESS, Lund, Sweden
V.A. Lebedev
Fermilab, Batavia, Illinois, USA
C.R. Prior
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
Y. Sato
KEK, Ibaraki, Japan
J.Y. Tang
IHEP, Beijing, People’s Republic of China

Funding: ESSnuSB has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 7774.
Over the last two decades, significant efforts were made through several international studies to identify and develop technical solutions for potential Neutrino Factories and Superbeam Facilities. With many questions now settled, as well as clearer R&D needs, various proposals are being made for future facilities in China, Europe, Japan and North America. These include both developing and adapting existing machines as well as green-field solutions. In this paper, we review all the major accelerator programmes aimed at delivering high-power proton beams for neutrino physics.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB045

About •

paper received ※ 22 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB055

First Partially Stripped Ions in the LHC (208Pb⁸¹⁺)

experiment, injection, collimation, factory

689

M. Schaumann, R. Alemany-Fernández, H. Bartosik, T. Bohl, R. Bruce, G.H. Hemelsoet, S. Hirlaender, J.M. Jowett, V. Kain, M.W. Krasny, J. Molson, G. Papotti, M. Solfaroli Camillocci, H. Timko, J. Wenninger
CERN, Geneva, Switzerland

The Gamma Factory initiative proposes to use partially stripped ion (PSI) beams as drivers of a new type of high intensity photon source. As part of the ongoing Physics Beyond Collider studies, initial beam tests with PSI beams have been executed at CERN. On 25 July 2018 lead ions with one remaining electron (208Pb⁸¹⁺) were injected and accelerated in the LHC for the first time. After establishing the injection and circulation of a few 208Pb⁸¹⁺ bunches, beam lifetimes of about 50 hours could be established at 6.5 TeV proton equivalent energy. This paper describes the setup of the beam tests and observations made.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB055

About •

paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB058

Collimation of Partially Stripped Ion Beams in the LHC

collimation, simulation, collider, hadron

700

A. Abramov, L.J. Nevay
JAI, Egham, Surrey, United Kingdom
R. Bruce, N. Fuster-Martínez, A.A. Gorzawski, M.W. Krasny, J. Molson, S. Redaelli, M. Schaumann
CERN, Meyrin, Switzerland

In the scope of the Physics Beyond Colliders studies, the Gamma Factory initiative proposes the use of partially stripped ions as a driver of a new type, high intensity photon source in CERN’s Large Hadron Collider (LHC). In 2018, the LHC accelerated and stored partially stripped 208-Pb-81+ ions for the first time. The collimation system efficiency recorded during this test was found to be prohibitively low. The worst losses were localised in the dispersion suppressor (DS) of the betatron-cleaning insertion. Analytic arguments and simulations show that the large losses are driven by the stripping of the remaining electron from the Pb nucleus by the primary collimators. The rising dispersion in the DS pushes the resulting off-rigidity, fully-stripped ions into the aperture of the superconducting magnets. In this study the measured loss maps are compared against results from simulations. Different mitigation strategies are outlined, including a dispersion suppressor (DS) collimator, crystal collimation or an orbit bump.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB058

About •

paper received ※ 10 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB072

eRHIC in Electron-Ion Operation

electron, collider, heavy-ion, hadron

738

W. Fischer, E.C. Aschenauer, E.N. Beebe, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, C.J. Gardner, H. Huang, T. Kanesue, C. Liu, M. Mapes, G.T. McIntyre, M.G. Minty, C. Montag, S.K. Nayak, M. Okamura, V. Ptitsyn, D. Raparia, J. Sandberg, K.S. Smith, P. Thieberger, N. Tsoupas, J.E. Tuozzolo, F.J. Willeke, A. Zaltsman, A. Zelenski
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
The design effort for the electron-ion collider eRHIC has concentrated on electron-proton collisions at the highest luminosities over the widest possible energy range. The present design also provides for electron-nucleon peak luminosities of up to 4.7·10³³ cm^-2s⁻¹ with strong hadron cooling, and up to 1.7·10³³ cm^-2s⁻¹ with stochastic cooling. Here we discuss the performance limitations and design choices for electron-ion collisions that are different from the electron-proton collisions. These include the ion bunch preparation in the injector chain, acceleration and intrabeam scattering in the hadron ring, path length adjustment and synchronization with the electron ring, stochastic cooling upgrades, machine protection upgrades, and operation with polarized electron beams colliding with either unpolarized ion beams or polarized He-3.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB072

About •

paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB087

Proposal for a High Transformer Ratio CW Dielectric Accelerator

electron, SRF, experiment, wakefield

773

V. Litvinenko
Stony Brook University, Stony Brook, USA
J.C. Brutus, Y.C. Jing, I. Pinayev, G. Wang
BNL, Upton, Long Island, New York, USA
M.E. Conde, C.-J. Jing, J.G. Power
ANL, Argonne, Illinois, USA
A. Kanareykin
Euclid Beamlabs LLC, Bolingbrook, USA
N. Vafaei-Najafabadi
UCLA, Los Angeles, California, USA

Advanced CW accelerators are one of high priority directions identified by Advanced Accelerator Concepts Research Roadmap Workshop Report *. High transformer ratio of beam-driven accelerators is critically important for cost-effective FEL systems. We present a proposed experiment for demonstrating a high transformer ratio CW dielectric accelerator using operational SRF accelerator built for Coherent electron Cooling experiment. This accelerator operates with CW electron beam comprised of 78 kHz train of electron bunches. Electron bunches with controllable longitudinal and charge up to 10 nC per bunch are generated in 1.25 MV SRF photo-electron gun. This bunches are ballistically compressed to duration of 10-to-30 psec and accelerated to 15 MeV in SRF linac**. Such bunches would be excellent drivers of high-transformer ratio DWA accelerators. In this paper we present expected performance of proposed CW DWA accelerator.
*Advanced Accelerator Concepts Research Roadmap Workshop Report, 2016,
*V.N. Litvinenko et al., In proc.of FEL’17, Santa Fe, NM, USA, August 20-25, 2017, p. 132

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB087

About •

paper received ※ 19 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB109

Cavity Design for the Updated eRHIC Crabbing System

cavity, proton, electron, hadron

818

S. Verdú-Andrés, Q. Wu
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates LLC under contract no. DE-SC0012704 with the U.S. Department of Energy.
The electron-ion collider eRHIC proposed by Brookhaven National Laboratory includes a crabbing system to reestablish head-on collisions for a maximum geometric overlap of the colliding bunches. Since the last cavity design, the crossing angle has increased from 22 to 25 mrad to relax the field strength requirement in one of the IR magnets - increasing the deflecting kick required to collider the bunches head on - and one of the considered options is to have both proton and electron crab cavities work at 200 MHz. The present paper discusses the RF design of the 200 MHz crab cavities for the electron and hadron beams of eRHIC.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB109

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS001

Operational Experience with a Sled and Multibunch Injection at the Australian Synchrotron

linac, klystron, injection, cavity

830

M.P. Atkinson, G. LeBlanc
AS - ANSTO, Clayton, Australia
K. Zingre
ASCo, Clayton, Victoria, Australia

The Australian third generation 3 GeV Synchrotron Light Source was originally commissioned with a 100 MeV linear accelerator (LINAC) fed by two 37 MW S band pulsed klystrons. A pulse compressor in form of a SLED cavity was added later to enable single klystron operation for redundancy in case of a modulator failure. The SLED was successfully commissioned in May 2017 including remote selection of single klystron with SLED operation without degradation of beam energy. Two years on there have been some unexpected operational benefits including reduced phase sensitivity and drift allowing repeatable injection based solely on diagnostic phase read backs. Temperature stabilised power amplifiers based on S band GaN radar technology are being trialed in the meantime with a goal to set and inject with minimal operator adjustment. The results from the SLED cavity upgrade are shown and the latest S band radar technology designs are outlined.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS001

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS002

Linac Energy Jitter Measurements with SPARK BPMs at ALBA

linac, electron, electronics, klystron

833

R. Muñoz Horta, D. Lanaia, E. Marín, A. Olmos, F. Pérez
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

At ALBA four Beam Position Monitors (BPMs) measure the beam position along the Linac to Booster Transfer Line. The BPM electronics (Libera Spark type) have been recently upgraded in order to be sensitive to single-pass beam detection. As a result, the position resolution measured in LTB BPMs has been increased by a factor 10 with respect to the former electronics. The increased resolution enables us to resolve the energy jitter of the Linac beam, providing an on-line measurement of the Linac energy during regular operation. In this paper a study of the Linac energy jitter is presented as well as its correlation with the jitter sources.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS002

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS015

FoS Cavity of the Alvarez 2.0 DTL as FAIR Injector

DTL, cavity, quadrupole, linac

871

M. Heilmann, X. Du, L. Groening, S. Mickat, C. Mühle, A. Rubin, V. Srinivasan
GSI, Darmstadt, Germany

The Alvarez 2.0 DTL will be the new post-stripper DTL of the UNILAC at GSI. The existing GSI with its LINAC and SIS18 comprise the main operation injector chain for the Facility for Antiproton and Ion Research FAIR. The new Alvarez-DTL has an operation frequency of 10⁸.4 MHz, an input energy of 1.358 MeV/u and the output energy is 11.4 MeV/u with a total length of 55 m. The presented FoS section will be part of the first cavity of the Alvarez 2.0 DTL. The FoS-cavity with 11 drift tubes (including quadrupole singlets) and a total length of 1.9 m will be copper plated in GSI for high power tests. The design of the quadrupole singlet magnet is finalized; a prototype of a fully functional magnet with drift tube and stems will be fabricated within a design study. Empty drift tubes and all components of the tank shall be delivered 2019 for first low level RF investigations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS015

About •

paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS017

Status of Operation With Negative Momentum Compaction at KARA

optics, injection, quadrupole, sextupole

878

P. Schreiber, T. Boltz, M. Brosi, B. Härer, A. Mochihashi, A.-S. Müller, A.I. Papash, M. Schuh
KIT, Karlsruhe, Germany

Funding: We are supported by the DFG-funded ’Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology’ and European Union’s Horizon 2020 research and innovation programme (No 730871)
For future synchrotron light source development novel operation modes are under investigation. At the Karlsruhe Research Accelerator (KARA) an optics with negative momentum compaction has been proposed, which is currently under commissioning. In this context, the collective effects expected in this regime are studied with an initial focus on the head-tail instability and the micro-bunching instability resulting from CSR self-interaction. In this contribution, we will present the proposed optics and the status of implementation for operation in the negative momentum compaction regime as well as a preliminary discussion of expected collective effects.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS017

About •

paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS022

Current Status of the MYRRHA Cavities

cavity, resonance, status, vacuum

892

K. Kümpel, D. Bade, M. Busch, D. Koser, S. Lamprecht, N.F. Petry, H. Podlech, S. Zimmermann
IAP, Frankfurt am Main, Germany

The MYRRHA (Multi-purpose hYbrid Research Reac-tor for High-tech Applications) Project is a planned ac-celerator driven system (ADS) for the transmutation of long-living radioactive waste. In order test the reliability of the planned 17 MeV injector, a shortened injector with 5.9 MeV consisting of the ion source, a 4-Rod RFQ, 2 Quarter Wave Rebunchers (QWRs) and a total of 7 normal conducting CH structures is currently being installed in Louvein-la-Neuve (LLN, Belgium). Before the cavities can be tested with beam, they are subjected to so-called low power tests several times during the individual con-struction stages in order to be able to correct any devia-tions. This paper describes the status of the two Quarter Wave Rebunchers, which are currently in the process of copper plating and final acceptance, as well as the first two CH structures, the first of which is already being conditioned while CH 2 is still in preparation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS022

About •

paper received ※ 10 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS033

RF Measurements and Tuning of the 325 MHz Ladder-RFQ

rfq, linac, simulation, proton

925

M. Schuett, U. Ratzinger, M. Syha
IAP, Frankfurt am Main, Germany

Funding: BMBF 05P15RFRBA
Based on the positive results of the unmodulated 325 MHz Ladder-RFQ prototype from 2013 to 2016, we developed and designed a modulated 3.4 m Ladder-RFQ*. The unmodulated Ladder-RFQ features a very constant voltage along the axis. It accepted 3 times the operating power of which is needed in operation**. That level corresponds to a Kilpatrick factor of 3.1 with a pulse length of 200 µs. The 325 MHz RFQ is designed to accelerate protons from 95 keV to 3.0 MeV according to the design parameters of the proton linac within the FAIR project. This particular high frequency for a 4-ROD-RFQ creates difficulties, which triggered the development of a Ladder-RFQ with its high symmetry. The results of the unmodulated prototype have shown, that the Ladder-RFQ is very well suited for that frequency. The duty cycle is up to 5% for the applied cooling concept. Manufacturing has been completed in September 2018. We will show the finalization of assembly after manufacturing as well as low level RF measurements. The final machining step for both flatness and frequency tuning has been finished in April 2019.
*Journal of Physics: Conf. Series 874 (2017) 012048
**Proceedings of LINAC2016, East Lansing, TUPLR053

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS033

About •

paper received ※ 01 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS035

Recommissioning of SIS18 After FAIR Upgrades

MMI, controls, extraction, cavity

932

D. Ondreka, C. Dimopoulou, H.C. Hüther, H. Liebermann, J. Stadlmann, R.J. Steinhagen
GSI, Darmstadt, Germany

The synchrotron SIS18 of the GSI facility has recently resumed beam operation after a long shutdown, during which major upgrades for the operation of SIS18 in the FAIR facility were realized. This signifies a major milestone for the mission of GSI and FAIR. On one hand, the scientific program of GSI depends strongly on beam from SIS18, including the very important developments of detectors for FAIR experiments. On the other hand, large parts of the existing GSI accelerator facility, including SIS18, are now operated with the FAIR control system, demonstrating its suitability for control of a large scale accelerator facility. Commissioning of the new control system started during the shutdown with a series of dry runs, which proved very useful to establish the basic functionalities. Recommissioning of SIS18 was further facilitated by the fact that the machine model of SIS18, implemented in the modeling framework LSA, had already been tested with beam several years before the shutdown. Thus, all operation modes of SIS18, including multi-turn injection, electron cooling, as well as fast and slow extraction could be successfully commissioned during the first weeks of operation. Other commissioning activities concerned the operation of new devices installed during the shutdown. These devices, mostly installed to prepare SIS18 for the operation with FAIR design parameters, open new possibilities in the standard operation of SIS18. A challenge for the operation of SIS18 is posed by ground motion due to ground water lowering for the nearby FAIR construction site. Surveys revealed that SIS18 subsided by several centimeters during one year. Even though the machine was realigned prior to recommissioning, the dynamics of the ground motion will continue to affect operation of SIS18.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS035

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS036

RFQ Electrodes Change and Upgrade Option at the UNILAC HSI Injector

rfq, simulation, cavity, MMI

936

M. Vossberg, P. Gerhard, L. Groening, S. Mickat, H. Vormann, C. Xiao
GSI, Darmstadt, Germany
V. Bencini, J.M. Garland, J.-B. Lallement, A.M. Lombardi
CERN, Geneva, Switzerland

In order to meet the beam intensity and quality requirements imposed by FAIR, the HSI-RFQ beam dynamics originally dating from 2009 has been re-designed recently at CERN. Front-to-end simulations demonstrated that the new design meets the FAIR targets. Implementation of the new electrodes, initially planned for 2019, will require re-adaption of the RFQ cavity rf-parameters by re-shaping the stems that keep the electrodes. However, during the beam time 2018 the existing RFQ did not reach its nominal voltage most likely due to expired lifetime of the electrodes originating from 2009. In order to shorten the RFQ maintenance period and to minimize any risk for upcoming beam time 2019, it was decided to post-pone the implementation of the new design and rather just re-producing the 2009 design electrodes. This contribution is on the re-production process as short-term solution and on the full implementation of the new design as mid-term solution. CST simulations performed at GSI assure that the resonance frequency with the new electrode geometry is recuperated through corrections of the carrier rings. The status of the exchange of the electrodes and simulations for the adaptation of the new electrode design are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS036

About •

paper received ※ 13 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS042

Hardware Commissioning of the Renovated PIAVE Injector at INFN-LNL

rfq, SRF, MMI, ion-source

949

G. Bisoffi, L. Bellan, J. Bermudez, E. Bissiato, D. Bortolato, F. Chiurlotto, M. Comunian, T. Contran, A. Facco, E. Fagotti, P. Francescon, A. Friso, A. Galatà, C.S. Gallo, M.G. Giacchini, M. Lollo, D. Martini, M.O. Miglioranza, P. Modanese, M. Montis, E. Munaron, G. Nigrelli, S. Pavinato, M. Pengo, A. Pisent, M. Poggi, L. Pranovi, M. Rossignoli, D. Scarpa
INFN/LNL, Legnaro (PD), Italy
V. Andreev
ITEP, Moscow, Russia
M.A. Bellato
INFN- Sez. di Padova, Padova, Italy

During 2018, the PIAVE superconducting linac injector at INFN-LNL, based on superconducting RFQs and two cryomodules with quarter wave resonators, underwent a renovation plan. This operation was strictly related to the one carried out on ALPI [1], which will become a post-accelerator for both stable and exotic beams in a near future. PIAVE Quarter Wave Resonator (QWR) cryomod-ules, in operation since 2006, were moved to ALPI to be used for the acceleration of both stable beams and future exotic beams delivered from the cyclotron target-ion-source station, after appropriate purification, charge breeding and pre-acceleration stages. In order to cope with the removal of the two QWR cryomodules in PIAVE, a newly designed 80 MHz room temperature buncher was designed, built and tested: the buncher is required so as to match the longitudinal phase space between PIAVE su-perconducting RFQs (SRFQ1 and SRFQ2) and ALPI. In the same period, substantial refurbishments on the ECR ion source platform were carried out, in particular on its infrastructure and safety equipment. A problem on an electronic component on SRFQ2, though quickly fixed, delayed beam commissioning of the PIAVE injector, which will start at the end of May 2019.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS042

About •

paper received ※ 30 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS046

Upgrade of the 3-MeV LINAC for Testing of Accelerator Components at J-PARC

rfq, linac, MMI, experiment

960

Y. Kondo, K. Hirano, T. Ito, N. Kikuzawa, R. Kitamura, T. Morishita, H. Oguri, K. Ohkoshi, S. Shinozaki, K. Shinto
JAEA/J-PARC, Tokai-mura, Japan
Z. Fang, Y. Fukui, K. Futatsukawa, K. Ikegami, T. Miyao, K. Nanmo, M. Otani, T. Shibata
KEK, Ibaraki, Japan
T. Hori, Y. Nemoto, Y. Sato
Nippon Advanced Technology Co., Ltd., Tokai, Japan
T. Ishiyama, Y. Sawabe
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
Y. Ito
Total Saport System Corp., Naka-gun, Ibaraki, Japan
Y. Kato
Total Support Systems Corporation, Tokai-mura, Naka-gun, Ibaraki, Japan
F. Kobayashi
ULVAC Human Relations, Ltd., Kanagawa, Japan
D. Takahashi, R. Tasaki
KIS, Ibaraki, Japan

We are now upgrading a 3-MeV linac at J-PARC. The old 30-mA RFQ is replaced by a spare one of the J-PARC 50-mA RFQ. The ion source is same as the J-PARC linac’s, therefore, the peak beam current is upgraded from 30 mA to 50 mA. This 3-MeV linac will be used for development of various accelerator components, such as beam dyagnostics devices, laser charge exchange equipments, new MEBT buncher, and so on. In this paper, present status of this 3-MeV test linac is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS046

About •

paper received ※ 30 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS049

The First Replacement of the RF Window of the ACS Cavity

cavity, linac, vacuum, proton

971

J. Tamura, Y. Kondo, T. Morishita
JAEA/J-PARC, Tokai-mura, Japan
F. Naito, M. Otani
KEK, Tokai, Ibaraki, Japan
Y. Nemoto
Nippon Advanced Technology Co., Ltd., Tokai, Japan

In 2013, the Annular-ring Coupled Structure (ACS) cavities were installed to the Japan Proton Accelerator Research Complex (J-PARC) linac. Since then, the ACS cavities have been stably running. Although any serious problem induced by the ACS RF window has not yet observed, we decided to replace the RF window of one ACS cavity, which is the eighteenth accelerating cavity in the order of beam energy (ACS18), by the newly manufactured one. The major motivations of the replacement are to check the surface condition of the RF window which have been under operation for nearly five years and to confirm the availability of the newly manufactured RF window. By making use of the summer maintenance period of 2018, we carried out the replacement. This was the first experience for us to replace the RF window installed to the ACS cavity in the linac accelerator tunnel. As for the removed RF window, there was no any abnormal warning found with the visual examination. At the starting up of the cavity’s operation after the maintenance period, we investigated how much time would be required for an RF conditioning. It took around fifty hours so that the peak RF power including the beam loading is stably input to the cavity through the new RF window. The ACS cavity with the new RF window is now stably operating.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS049

About •

paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS054

Status of the CLEAR Electron Beam User Facility at CERN

experiment, electron, radiation, plasma

983

K.N. Sjobak, E. Adli, C.A. Lindstrøm
University of Oslo, Oslo, Norway
M. Bergamaschi, S. Burger, R. Corsini, A. Curcio, S. Curt, S. Döbert, W. Farabolini, D. Gamba, L. Garolfi, A. Gilardi, I. Gorgisyan, E. Granados, H. Guerin, R. Kieffer, M. Krupa, T. Lefèvre, S. Mazzoni, G. McMonagle, N. Nadenau, H. Panuganti, S. Pitman, V. Rude, A. Schlogelhofer, P.K. Skowroński, M. Wendt, A.P. Zemanek
CERN, Geneva, Switzerland
A. Lyapin
UCL, London, United Kingdom

The CERN Linear Electron Accelerator for Research (CLEAR) has now finished its second year of operation, providing a testbed for new accelerator technologies and a versatile radiation source. Hosting a varied experimental program, this beamline provides a flexible test facility for users both internal and external to CERN, as well as being an excellent accelerator physics training ground. The energy can be varied between 60 and 220 MeV, bunch length between 1 and 4 ps, bunch charge in the range 10 pC to 2 nC, and number of bunches in the range 1 to 200, at a repetition rate of 0.8 to 10 Hz. The status of the facility with an overview of the recent experimental results is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS054

About •

paper received ※ 12 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS056

Optimization of SC Cavity Type for CSNS Linac Upgrade

cavity, linac, neutron, acceleration

987

Y. Wang, M.X. Fan, A.H. Li, B. Li, P.H. Qu
IHEP CSNS, Guangdong Province, People’s Republic of China
J.P. Dai, H.C. Liu, P. Sha
IHEP, Beijing, People’s Republic of China
X.L. Wu
DNSC, Dongguan, People’s Republic of China

In order to increase CSNS beam power from 100kW to 500kW, the Linac injection energy need to be increased from 80MeV to 300MeV. The combined layout of superconducting spoke cavities and elliptical cavities will be adopted to accelerate H⁻ beam to 300MeV. Two operation frequency of spoke cavities were compared with single and double spoke structure, a compact 648MHz βg=0.4 single spoke cavity was proposed, and the RF performance was presented, as well as the MP behavior.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS056

About •

paper received ※ 09 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS059

The Status of CiADS Superconducting LINAC

linac, cavity, proton, cryomodule

994

Z.J. Wang, Y. He, G. Huang, S.H. Liu, T. Tan, Y.Q. Wan, F.F. Wang, W.M. Yue
IMP/CAS, Lanzhou, People’s Republic of China

CiADS (China initiative Accelerator Driven System) approved by Chinese government at 2016 aims to build the first ADS experimental facility to demonstrate the nuclear waste transmutation. The CiADS driving linac can accelerate 5 mA proton beam to 500 MeV at the beam power up to 2.5 MW with the state-of-the-art accelerator technologies. The challenging programs include beam loss control-oriented physics design, high performance CW operated superconducting cavities, SRF cryomod-ules, and highly efficient RF amplifier system. As the driving linac of the ADS system, the RAMI characters will serve as the design philosophy to guide the physics design and the choice of technical routes. The physics design and key technologies of the high-power machine are descried in the paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS059

About •

paper received ※ 14 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS075

Design and Experiment of a Window-Type CW Deuteron RFQ

rfq, cavity, experiment, Windows

1021

K. Zhu, M.J. Easton, P.P. Gan, S.L. Gao, H.P. Li, S. Liu, Y.R. Lu, Q.Y. Tan, L. Tao, Z. Wang
PKU, Beijing, People’s Republic of China
W.P. Dou, Y. He, C. Wang, Q. Wu, H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China

A deutron CW RFQ was designed and fabricated in Peking University. It will accelerate 50mA CW deutron beam from 50keV to 1MeV at 162.5MHz. The novel structure of four-vane with window was used to seperate the dipole mode from the working mode. The field tuning of this RFQ was different from conventional four vane RFQ because that the four quadrants of RFQ cavity were coupled. The discipline of field tuning was studied by simulation and experiment. The beam dynamics of the RFQ was designed by equipartation and matching method, limit current effect was considered at the same time. The final design result of the RFQ was: voltage between electrodes was 60kV, transport efficiency of RFQ is 98%, field unflatness is less than 2% after tuning, the deformation of RFQcavity is less than 80um. Only 47 hours was spent to increase CW power of cavity from 0 to 55kW in high power test and The RFQ can working stable at the design voltage. The preliminary H²⁺ beam exeperiment has been done and 1.78mA CW beam was obtained at exit of RFQ. This paper will introduce the detail of design and experiment of the RFQ.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS075

About •

paper received ※ 22 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS077

RCCS Operation and Characteristics in Resonance Frequency Control Mode at KOMAC

controls, resonance, DTL, radio-frequency

1025

K.H. Kim, H.S. Jeong, H.S. Kim, S.G. Kim, H.-J. Kwon, Y.G. Song
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea

Funding: This work has been supported through KOMAC (Korea Multi-purpose Accelerator Complex) operation fund of KAERI by MSIT (Ministry of Science and ICT)
A 100-MeV proton accelerator is under operation at Korea Multi-purpose Accelerator Complex (KOMAC). The resonance control cooling system (RCCS) has supplied the cooling water to drift tube linac (DTL). The DTL need to keep the resonant frequency of 350MHz during the operation. RCCS has a critical role in sustaining the acceptable resonant frequency error in DTL by adopting the resonance frequency control mode. Details on the RCCS operation in resonance frequency control mode will be given in this study.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS077

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS085

Commissioning of a New Digital Transverse Damper System at the PSB

feedback, proton, MMI, hardware

1050

G.P. Di Giovanni, F. Antoniou, A. Blas, Y. Brischetto, A. Findlay, G. Kotzian, B. Mikulec, G. Sterbini
CERN, Geneva, Switzerland

At the CERN Proton Synchrotron Booster, PSB, an analog transverse damper system has been in operation since 1999, providing satisfactory operational results with the proton beam supplied by Linac2. As a consequence of the LHC Injectors Upgrade, the PSB will face new challenges imposed by higher intensity, injection and extraction energy. In this framework, the transverse feedback system is subject to an upgrade to adapt to the expected Linac4 beam and to the demands for new features including transverse blow-up, beam excitation for optics measurements and new remote control and monitoring capabilities. The replacement of the aging electronic hardware is also recommended to improve the system maintainability for future years. During 2018 a new digital transverse feedback electronics was installed in the PSB, in parallel with the current operational one, offering for the first time the occasion to demonstrate its performance with beam. Encouraging results were obtained such as the suppression of beam instabilities at all PSB energies and intensities. In this paper we describe the steps undertaken in 2018 in order to commission the system with the main goal to accelerate and extract the highest intensity beams produced at the PSB.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS085

About •

paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS087

Transverse Emittance Studies at Extraction of the CERN PS Booster

emittance, optics, booster, injection

1058

F. Antoniou, S.C.P. Albright, F. Asvesta, H. Bartosik, G.P. Di Giovanni, V. Forte, M.A. Fraser, A. Garcia-Tabares, A. Huschauer, B. Mikulec, T. Prebibaj, A. Santamaría García, P.K. Skowroński
CERN, Meyrin, Switzerland
F. Asvesta
NTUA, Athens, Greece
T. Prebibaj
National Technical University of Athens, Zografou, Greece

Transverse emittance discrepancy in the beam transfer between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is observed in operational conditions for the LHC beams at CERN. The ongoing LHC Injectors Upgrade (LIU) project requires a tight budget for beam degradation along the injector chain and therefore the reason for this emittance discrepancy needs to be understood. Systematic measurements have been performed for various beam characteristics (beam intensity, transverse and longitudinal emittance). In this paper, a comparison between the emittance measurements using all available beam instrumentation with different emittance computation algorithms is presented. The results are compared to measurements at PS injection. Furthermore, the impact on the LIU project requirements for the emittance preservation along the LHC Injectors Complex is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS087

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS094

Dust Analysis from LHC Vacuum System to Identify the Source of Macro-Particle-Beam-Interactions

vacuum, beam-losses, proton, dipole

1082

L.K. Grob, A. Apollonio, C. Charvet, E. Garcia-Tabares Valdivieso, H. Kos, R. Schmidt
CERN, Geneva, Switzerland
C. Neves
Hochschule Furtwangen, Furtwangen, Germany

Since in 2010 the first sub-millisecond beam losses were observed at varying locations all along the LHC, it is well known that dust can interact with high-intensity proton beams and cause significant beam losses. Initially the sudden localized losses were enigmatic and coined the phrase ’unidentified falling objects’ (UFOs), which is still widely used. These very fast beam losses have resulted in hundreds of premature beam dumps and even magnet quenches since the start of LHC. So far, the only mitigation strategy involved an optimization of dump thresholds and the beneficial conditioning effect which leads to a reduction of the UFO rate over time. To understand the physics involved in these events and to allow an active diminution, it is essential to know the chemical composition and the size of the dust particulates interacting with the protons. The exchange of a dipole magnet offered the unique opportunity to collect dust samples from inside the LHC vacuum system. They were extracted from the various components and analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy to reveal size distribution and abundant elements. The results of this investigation will optimize the existing UFO models and the improved understanding of the phenomenon may help to prevent future performance limitations. This is also of relevance for future projects, in particular for the Future Circular Collider (FCC) under study.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS094

About •

paper received ※ 15 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS104

A Toolkit for Tracing Electron Beam Envelope at Low Energy Section of TPS Linac

electron, simulation, linac, gun

1122

H.H. Chen, H.C. Chen, K.-K. Lin, Y.K. Lin
NSRRC, Hsinchu, Taiwan

Based on calculated Bz of solenoids installed at the TPS linac low energy section, the electron beam envelope along beam centerline has been explored in this work using the initial and boundary conditions provided in the linac specifications. Concept of magnetic flux compression is adopt to analyze the beam size variation along linac centerline. The calculated result of selected checkpoints has been experimentally verified using screen monitors. In order to benefit tuning capability in routine operation, the display of beam size variation along centerline is integrated into the previously developed toolkit ’linac’. It is hope that it will provide an interactive approach for linac tune-up process and would be helpful to its routine operation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS104

About •

paper received ※ 23 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS107

Beam Manipulations With Barrier Buckets in the CERN PS

extraction, synchrotron, proton, cavity

1132

M. Vadai, A. Alomainy
QMUL, London, United Kingdom
H. Damerau, S.S. Gilardoni, M. Giovannozzi, A. Huschauer
CERN, Geneva, Switzerland

A barrier bucket scheme is being considered to reduce losses during the Multi-Turn Extraction from the CERN Proton Synchrotron to the Super Proton Synchrotron for the fixed-target physics programme. For effective loss reduction, the extraction kicker has to be triggered during the gap at the time of the longitudinal barrier. Initial beam studies at injection energy and with low intensity beams allowed to fully qualify an existing wide-band cavity to generate one or multiple beam synchronous pulses per turn. Bunch-length stretching and shortening have been exercised with barriers moving in azimuth with respect to the beam. The encouraging results obtained at injection energy guided the implementation of a de-bunching manipulation at higher energy to move all bunches into a single barrier bucket. Beam measurements at a momentum of 14GeV/c, varying intensity and the width of the barrier, demonstrate that a quasi-constant longitudinal line density and an almost fully depleted gap can be achieved at highest intensities. The contribution summarises the results of the beam studies at high energy together with some observations related to the Multi-Turn Extraction.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS107

About •

paper received ※ 18 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS118

3D Electromagnetic/PIC Simulations for a Novel RFQ/RFI Linac Design

rfq, linac, simulation, neutron

1158

S.J. Smith, S. Biedron, A.M.N. Elfrgani, E. Schamiloglu, S.I. Sosa Guitron
University of New Mexico, Albuquerque, USA
P.G. Bethoney, M.S. Curtin, B. Hartman, T. Pressnall, D.A. Swenson
Ion Linac Systems, Inc., Albuquerque, USA
T.B. Bolin
Element Aero, Chicago, USA
J.R. Cary, D.M. Cheatham
Tech-X, Boulder, Colorado, USA

Funding: This work was supported by Ion Linac Systems, Albuquerque, NM.
Using the commercial software VSim 9, a highly parallelized particle-in-cell/finite difference time-domain modeling code, the performance of an existing novel RFQ/RFI linac structure designed by Ion Linac Systems is evaluated. This effort is aimed towards having an up to date full 3D start-to-end simulation of the accelerator system, which does not exist currently. The structure used is an efficient 200-MHz, 2.5-MeV, CW-RFQ/RFI proton linac. The methods employed in VSim for modelling and parameter setup are presented, along with the simulation procedures for both the Electromagnetic and PIC solver. The important figures of merit for the structure are given including the Q-factor, field distributions, shunt impedance, and important beam properties. These are then contrasted with the initial design values and analytical calculations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS118

About •

paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS119

APS LINAC Interleaving Operation

linac, gun, storage-ring, booster

1161

Y. Sun, K. Belcher, J.C. Dooling, A. Goel, A.L. Hillman, R.T. Keane, A.F. Pietryla, H. Shang, A. Zholents
ANL, Argonne, 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.
Three s-band RF guns are installed at the front end of the Advanced Photon Source (APS) linac: two thermionic cathode guns (RG2 and RG1), and one Photo-Cathode Gun (PCG). During normal operations, RG2 provides electron beams for the storage ring to generate x-rays for APS users. The PCG generates high brightness electron beams that can be accelerated through the APS linac and transported into the Linac Extension Area (LEA) for advanced accelerator technology and beam physics experiments. The alternating acceleration of the RG2 and PCG beam in the linac is possible, as most of the time, RG2 beam is only needed for ~20 seconds every two minutes. This mode of interleaving operation of RG2 and PCG beams through the APS linac requires some modifications/additions to several systems of the linac, including RF, magnets, controls and Access Control Interlock System etc. In this paper we report our interleaving design and present the commissioning results of the two beam interleaving operation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS119

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUXXPLM2

SRF Cavity Fault Classification Using Machine Learning at CEBAF

cavity, cryomodule, SRF, GUI

1167

A.D. Solopova, A. Carpenter, T. Powers, Y. Roblin, C. Tennant
JLab, Newport News, Virginia, USA
K.M. Iftekharuddin, L. Vidyaratne
ODU, Norfolk, Virginia, USA

The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab is the first large high power CW recirculating electron accelerator which makes use of SRF accelerating structures configured in two antiparallel linacs. Each linac consists of twenty C20/C50 cryomodules each containing eight 5-cell cavities and five C100 upgrade cryomodules each containing eight 7-cell cavities. Accurately classifying the source of cavity faults is critical for improving accelerator performance. In addition to archived signals sampled at 10 Hz, a cavity fault triggers a waveform acquisition process where 16 waveform records sampled at 5 kHz are recorded for each of the 8 cavities in the effected cryomodule. The waveform record length is sufficiently long for transient microphonic effects to be observable. Significant time is required by a subject matter expert to analyze and identify the intra-cavity signatures of imminent faults. This paper describes a path forward that utilizes machine learning for automatic fault classification. Post-training identification of the physical origins of faults are discussed, as are potential machine-trained model-free implementations of trip avoidance procedures. These methods should provide new insights into cavity fault mechanisms and facilitate intelligent optimization of cryomodule performance

Slides TUXXPLM2 [4.404 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUXXPLM2

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP003

Development of Remote Handleable Axially Decoupled Radiation Resistant Vacuum Seal

vacuum, target, interface, electron

1233

R.R. Nagimov, Y. Bylinskii, L. Egoriti, A. Gottberg, G.W. Hodgson, A.N. Koveshnikov, D. Yosifov
TRIUMF, Vancouver, Canada

Funding: ARIEL is funded by the Canada Foundation for Innovation (CFI), the Provinces of AB, BC, MA, ON, QC, and TRIUMF. TRIUMF receives federal funding via a contribution agreement with the NRC of Canada.
Advanced Rare IsotopE Laboratory (ARIEL) facility is a major expansion of TRIUMF’s rare isotope research program. Aiming to triple the production of rare isotopes, ARIEL facility includes the new electron linac driver and two target stations for electron and proton beams. Particularities of ARIEL target stations design define the requirements for vacuum interfaces with both primary electron and proton beamlines and rare-isotope beamlines. None of the existing products fully met the requirements, driving the development of custom vacuum interfaces. The design of new vacuum seals is driven both by unique design specifications (limited amount of allowed axial forces, extreme radiation resistance, remote handleability and high repeatability) as well as limitations of the proposed design of beamline infrastructure in the target hall (limited available space and the choice of materials for certain components). This paper discusses preliminary results of the vacuum seal development and presents first results of prototype testing.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP003

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP006

Cryogenic Tests of the SPIRAL2 LINAC Systems

cavity, cryomodule, cryogenics, linac

1240

A. Ghribi, P.-E. Bernaudin, R. Ferdinand, A.V. Vassal
GANIL, Caen, France

Two full cool-down of the SPIRAL2 superconducting LINAC have been performed in 2017 and 2018 respectively, followed by a total of around 5 months of tests at 4 K. Several cool-down strategies were tested, in order to minimize 100 K effect on the SC cavities. Helium bath regulations (level and pressure) have been tested and optimized. Effects of pressure instabilities and coupling with the cryogenic plant have also been observed. Cryogenic performances of each cryomodule have been measured. Low-level RF measurements were also performed on all cavities and showed unidentified modulations at frequencies around 5Hz. These turned out to be thermoacoustic oscillations (TAO) on the cryogenic lines, which generate important pressure instabilities. Several solutions to remove TAO and cure these instabilities have been tested and one has been successfully deployed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP006

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP011

Storageless Resonant Converter for Accelerator Magnets

resonance, controls, simulation, storage-ring

1248

M. Cautero, T.N. Gucin
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Elettra Sincrotrone Trieste, a specialized research centre generating high quality synchrotron radiation, has been in operation since 1993 and was revised in 2009. Recently, Elettra has been funded for a complete renewal of the storage ring. For the new machine, it is planned to employ state of the art converters, mostly of which will be designed in-house. For this purpose, it has been decided to evaluate the performance of a storage-less resonant converter, pro-posed by Dr. Slobodan Ćuk, which is a step down DC/DC converter consisting of four switches, one resonant capac-itor and two resonant inductors. For this purpose, the voltage conversion ratio of the converter has been de-rived. The topology was confirmed with simulation and a PCB layout has been designed, which is still to be tested.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP011

About •

paper received ※ 08 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP015

Magnet Power Supply Calibration with a Portable Current Measuring Unit at the J-PARC Main Ring

power-supply, feedback, timing, controls

1263

K. Miura, Y. Kurimoto, Y. Morita, D. Naito, T. Oogoe, T. Shimogawa
KEK, Ibaraki, Japan
Y. Kuniyasu
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
K. Ooya
SANKYU PLANT TECHNO CO., LTD., 6-5-3, Kachidoki, Japan
R. Sagawa
Universal Engineering, Ibaraki-ken, Japan

In the J-PARC MR, 96 bending magnets (BMs) are used in total. They are divided into 6 groups of 16 BMs. The 16 BMs in each group are connected in series and driven by a single power supply. Since all 96 BMs are symmetrically located in the ring, the magnet currents regulated by the 6 power supplies need to be same. Each power supply performs output current feedback control using electronic circuits including analog amplifications and AD / DA conversions. Due to individual differences of the electronic circuits, output current is generally expected to be different for each power supply. Therefore, we developed a current measurement unit with the portable DCCT as an independent reference. Further, we measured the magnet currents regulated by the 6 BM power supplies using the unit. We report the details of the unit as well as the results of the current measurements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP015

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP016

New Power Supply of Main Magnets for J-Parc Main Ring Upgrade

controls, extraction, quadrupole, proton

1266

T. Shimogawa, Y. Kurimoto, K. Miura, Y. Morita, D. Naito
KEK, Ibaraki, Japan
R. Sagawa
Universal Engineering, Ibaraki-ken, Japan

It is plans that the proton beam power provided to experimental facilities increase with shortening repetition period in J-PARC Main Ring (MR). As the shorten repetition period, the replacement of the power converters for main magnets in J-PARC MR is necessary to cope with issues such as power fluctuation of the main grid and increase of the output voltage. We have considered and developed the power converters with a 10 MW class which have the capacitor banks with the large capacitance. In the end of 2017, the first new power converter for a bending magnets family, which is the largest power converter in this upgrade plan, was installed in J-PARC site and the power test is ongoing using a dummy and a real load. In this report, the first new power converter for a bending magnets family in J-PARC MR is reported including the test results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP016

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP018

Feasibility Tests of a Vacuum System for SPring-8-II

vacuum, photon, hardware, multipole

1272

K. Tamura, T. Bizen, M. Masaki, H. Ohkuma, M. Oishi, M. Shoji, S. Takahashi, Y. Taniuchi
JASRI, Hyogo, Japan
T. Bizen, M. Oishi, S. Takahashi
RIKEN SPring-8 Center, Hyogo, Japan

For SPring-8-II, the major upgrade of SPring-8, a test half-cell including permanent/electro magnets and a vacuum system was constructed, and hardware feasibility tests have been performed since 2017. Features of the SPring-8-II vacuum system are 1) introduction of the concept of a stainless steel 12 m-long integral chamber (LIC) with a welded structure, and 2) adoption of ex-situ baking of the chamber. The 12 m LIC with a narrow aperture, flangeless structure and a minimum number of bellows was designed so that the vacuum system could be installed without interference with the magnets of a narrow bore diameter aligned on girders with a severe packing factor. For replacement of the existing system with a new one in a short black-out period, the 12 m LIC is planned to be moved into the accelerator tunnel with keeping ultra-high vacuum (UHV) by closing thin gate valves at both ends, after evacuation to UHV by ex-situ baking and NEG activation. This presentation will overview the vacuum system, mainly the 12 m LIC, developed for the test half-cell, and describe the vacuum performance and the result of the assembly test conducted with the permanent/electro magnets.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP018

About •

paper received ※ 15 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP024

Research on Module Design and Network Management of Accelerator Power Supply System

power-supply, controls, interface, network

1291

Y. Li, S.Y. Chen, C. Han, P. Liu
IHEP, Beijing, People’s Republic of China

Accelerator power supply system is a very special system. Many factors such as high number of power supplies, uninterrupted operation and unreasonable design lead to high failure rate, long maintenance time and the discovery of the fault is not timely, which bring a lot of unnecessary troubles to the operator. In this paper, a networked control method for accelerator power supply is studied, and the power supply parallel connection technology is used to maximize the trouble-free time of the power supply and increase the redundancy performance of the power supply. With independent networked control, the accelerator power supply system becomes a whole, no longer relying solely on the control of the accelerator control system, but in a network system with self-diagnosis and self-healing. Through the monitoring and management of the upper computer, the power supply system will be work stable, and the function of remote operation and remote repair of the power supply is realized finally. This is a research direction for the operation of large accelerator power supply systems in the future.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP024

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP042

The Beam Cleaning Analysis for the TPS Vacuum System

vacuum, MMI, radiation, ECR

1344

Y.C. Yang, C.K. Chan, C.-C. Chang, A.Y. Chen, J.-Y. Chuang, C.H. Huang
NSRRC, Hsinchu, Taiwan

Commissioning for the TPS, a low-emittance 3-GeV synchrotron ring, started in December 2014 and is now currently operating in top-up mode at 400mA for users. Until the last machine shut down in December 2018, a total beam dose of 4919 Ah was accumulated and the beam cleaning effect decreased the dynamic pressure to 1.5×10^-11 Pa/mA. During past years operation, several vacuum chambers were replaced to improve vacuum performance and avoid exposure to synchrotron radiation from insertion devices. In this paper, the beam cleaning evolution of new vacuum sections will be discussed and compared with experience in the rest of the storage ring. A particular cleaning evolution could be predicted and can be referenced for machine shutdown planning in the future.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP042

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP045

The Protection Instrument for Cryogenic Phase Separator Pressure Relief Valve of TPS Beamline

controls, monitoring, software, cryogenics

1350

C.C. Liang, C.Y. Chang, C.F. Chang, Y.H. Guo, M.H. Lee, C.Y.L. Liu, T.-C. Yu
NSRRC, Hsinchu, Taiwan

TPS (Taiwan Photon Source) beamlines have operated for three years after the successful commission in 2015. Recently, the electromagnetic activated pressure relief valve of cryogenic phase separator of beamline had malfunction due to the rust of its control circuits. After on site observation and temperature records, the water was found to be condensed around the outlet area due to fast temperature dropping near the valve as it was activated. Such situation would cause the rust of metal components due to humidity after a certain period of time. To avoid such event, fan is used to blow the condensed water and silicone heat belts are added to increase the local temperature with unique designed clamp for fixing the fan, sensors and safety circuit breaker. Via the temperature control system, the temperature monitoring, setting and the abnormal situation can be access on web page through Ethernet to make sure the proper operation of the protected devices. The instrument has been operated since Dec. 2018. After four months of operation, the moist situation has been improved and the relief valve is no longer frosted.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP045

About •

paper received ※ 30 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP047

Upgrade of the Cryogenic Control System for SRF Modules at the Taiwan Light Source

controls, cryogenics, SRF, interface

1356

F.-T. Chung, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

An upgrade of the cryogenic control system for superconducting radio-frequency (SRF) modules of the Taiwan Light Source (TLS) has been completed. The biggest challenge was to recover all protection and operational functions, while minimizing the quantity of vented helium from SRF modules while replacing valve controllers. Gradually, this work was finished within several one- and ten-day scheduled machine shutdown periods for accelerator maintenance. No large helium vent nor pollution of the cryogenic system occurred during all component replacements and function verifications. Functions of the cryogenic electronics were improved, whereas the valve controllers are upgraded to new versions to increase reliability and availability. Communications with the data acquisition system was also secured by buffered signal processing module so that device shutdown of the data acquisition system will not interrupt the cryogenic valve operation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP047

About •

paper received ※ 29 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP054

Investigations on Cryopanels in the Room Temperature Heavy Ion Synchrotron SIS18

vacuum, cryogenics, heavy-ion, synchrotron

1372

L.H.J. Bozyk, S. Aumüller, P.J. Spiller
GSI, Darmstadt, Germany

The heavy ion synchrotron SIS18 at GSI will serve as injector ring for the FAIR-facility and provide high intensity heavy ion beams. The operation of such beams requires the usage of low charge states, which have high cross sections for ionization. To overcome this issue, many upgrade measure have been realized in the past decade, such as the installation of an ion catcher system with low desorption surfaces and coating 65% of the circumference of SIS18 with NEG to lower the static gas pressure. Since the vacuum dynamics during operation prevent the achievement of the intensity goals for FAIR, new concepts have to be developed, to increase the beam intensity. One idea is the installation of additional pumping speed in the form of cryogenic surfaces. Heavy residual gas components, which have the highest ionization cross sections can be cryopumped at moderate temperatures, i.e. already at 50-80 K. In fact, the only typical residual gas component which can not be pumped via cryosorption in this temperature regime is Hydrogen, which has a factor 50 lower ionization cross sections than Argon, the heaviest residual gas component. In this paper, we present a study of the integration of cryopanels into the vacuum chambers of SIS18.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP054

About •

paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMP056

LANSCE Vacuum System Improvements in the Last ~10 Years

vacuum, neutron, linac, status

1375

T. Tajima, J.E. Bernal, M.J. Borden, J.P. Chamberlin, F.A. Martinez, J.F. O’Hara, A. Poudel, K.A. Stephens
LANL, Los Alamos, New Mexico, USA

Funding: DOE/NNSA
The Los Alamos Neutron Science Center (LANSCE) accelerator started its operation in 1972. To mitigate the vulnerability due to old equipment and to restore the 120 Hz operation capability we lost a while ago, we have gone through a refurbishment / risk mitigation project since 2007. This paper summarizes the improvements in the vacuum systems in the last ~10 years and shows some data on the downtimes caused by vacuum failures. The refurbished equipment is significantly more maintainable and will contribute to extend the life of this old accelerator, but it has been a challenge to reduce the downtime. Some examples that caused a long downtime will be described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP056

About •

paper received ※ 24 May 2019 paper accepted ※ 26 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW009

THE ESRF FROM 1988 TO 2018, 30 YEARS OF INNOVATION AND OPERATION

SRF, vacuum, injection, emittance

1400

J.-L. Revol, L. Farvacque, L. Hardy, P. Raimondi
ESRF, Grenoble, France

In 1988, eleven European countries joined forces to build the European Synchrotron Facility in Grenoble [France]. The ESRF was the first third-generation light source worldwide. After 30 years of innovation and user operation, the present storage ring was shut down to leave room for a new and brighter source. This paper describes the evolution of the facility from its origin to the Ex-tremely Bright Source (EBS). Firstly, the operational aspects including reliability and beam modes are consid-ered. This is followed by the presentation of the progress of lattice and the implementation of top-up. Finally, the development of the radio frequency and vacuum systems are discussed. To conclude, the lessons learned from 30 years operation are summarized, especially in view of EBS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW009

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW014

Characterization and Implementation of the Cryogenic Permanent Magnet Undulator CPMU17 at Bessy II

undulator, vacuum, laser, feedback

1415

J. Bahrdt, W. Frentrup, S. Gottschlich, S. Grimmer, M. Huck, C. Kuhn, A. Meseck, C. Rethfeldt, M. Scheer, B. Schulz
HZB, Berlin, Germany
E.C.M. Rial
DLS, Oxfordshire, United Kingdom

In fall 2018, the cryogenic undulator CPMU17 was installed in BESSY II. Before installation, the undulator was characterized with an in-vacuum Hallprobe bench and an in-vacuum moving wire. Both systems were developed at HZB. The commissioning of the device included the orbit and tune corrections, optimization of the injection, characterization of the heat dissipation, tuning the Landau cavities for a reduction of the heat dissipation in the taper sections (temperatures below 60°C) and testing of the machine protection system. The undulator is ready to deliver light for beamline commissioning. Spectral tuning on a high undulator harmonic (longitudinal taper and alignment of e-beam orbit and undulator axis) will be done as soon as the DCM is operational.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW014

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW015

Petra III Operation and Studies 2018

vacuum, impedance, undulator, radiation

1419

M. Bieler, I.V. Agapov, Y.-C. Chae, J. Keil, G.K. Sahoo, R. Wanzenberg
DESY, Hamburg, Germany

At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. This paper describes the operational schedule, the operational statistics and the most important beam studies done at PETRA III in 2018.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW015

About •

paper received ※ 26 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW016

New Operation Regimes at the Storage Ring KARA at KIT

lattice, optics, injection, simulation

1422

A.I. Papash, E. Blomley, T. Boltz, M. Brosi, E. Bründermann, S. Casalbuoni, J. Gethmann, E. Huttel, B. Kehrer, A. Mochihashi, A.-S. Müller, R. Ruprecht, M. Schuh, J.L. Steinmann
KIT, Karlsruhe, Germany

The storage ring Karlsruhe Research Accelerator (KARA) at KIT operates in a wide energy range from 0.5 to 2.5 GeV. Initially, the ring was designed to serve as a Light Source for synchrotron radiation facility ANKA. Since then different operation modes have been implemented at KARA: in particular, the double bend achromat (DBA) lattice with non-dispersive straight sections, the theoretical minimum emittance (TME) lattice with distributed dispersion, and 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 have been tested and implemented in a wide operational range of the ring and are now routinely used at 1.3 GeV for studies of CSR-induced beam dynamics and THz bursting in the micro-bunching instability. Different non-linear effects, in particular, residual high order components of magnetic fields generated in insertion devices have been studied and cured. A new operation mode at high vertical tune implemented at KARA essentially improves beam performance during user operation as well as at low alpha regimes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW016

About •

paper received ※ 23 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW017

Superconducting Undulator Coils with Period Length Doubling

undulator, vacuum, FEM, storage-ring

1426

S. Casalbuoni, N. Glamann, A.W. Grau, T. Holubek, D. Saez de Jauregui
KIT, Eggenstein-Leopoldshafen, Germany

Funding: Work supported by the German government in the BMBF-project Superconducting ’Insertion Device Technologies for Ultra-Low-Emittance Light Sources’ (05K12CK1)
Only since few years it has been demonstrated experimentally that NbTi based superconducting undulators (SCUs) have a higher peak field on axis for the same gap and period length in operation with electron beam with respect to permanent magnet undulators (even the ones in vacuum and cooled to cryogenic temperatures). Another advantage of NbTi based SCUs with respect to permanent magnet devices is radiation hardness, widely demonstrated for NbTi magnets, which is and will become an increasingly important issue with the small gaps in the newest machines as round beam storage rings and FELs. Moreover, SCU technology allows switching of the period length by changing the current direction in one of separately powered subset of winding packages of the superconducting coils. This feature further broadens the energy range of the emitted photons, required by the different beamlines. To this end 0.5 m long superconducting undulator coils with switchable period length between 17 mm and 34 mm have been developed. In this contribution we describe the design and report on the quench tests, as well as on the magnetic field measurements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW017

About •

paper received ※ 25 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW023

Incorporation of a MESA Linac Modules into BERLinPro

linac, optics, HOM, cavity

1449

B.C. Kuske, W. Anders, A. Jankowiak, A. Neumann
HZB, Berlin, Germany
K. Aulenbacher
IKP, Mainz, Germany
K. Aulenbacher
HIM, Mainz, Germany
F. Hug, T. Stengler, C.P. Stoll
KPH, Mainz, Germany

Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin, grants of the Helmholtz Association and grants of Helmholtz Association and the DFG within GRK 2128
BERLinPro is an Energy Recovery Linac (ERL) project, currently being set up at the Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. BERLinPro is designed as - and for - experiments in accelerator physics and as a test bed for novel ERL components. MESA is an ERL project under construction at the Johannes Gutenberg-Universität, Mainz, Germany. MESA is designed as a user facility to perform experiments in dark matter physics and precision measurements of natural constants. Despite the diverse goals, the main linac, providing the larger part of the particles energy, is fairly compatible. It is planned to test and run the MESA linac module in BERLinPro, prior to its usage in MESA. The goals and benefits of this unique cooperation for both projects are outlined in this paper. The necessary adaptions in BERLinPro, including hardware aspects, the new optics, and the scope of performance are described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW023

About •

paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW031

Elettra, Present and Future

dipole, emittance, coupling, insertion-device

1468

E. Karantzoulis, A. Carniel, S. Krecic
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

The operational status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with the final version of the upcoming upgrade, the diffraction limited light source Elettra 2.0.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW031

About •

paper received ※ 16 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW036

1 mA Stable Energy Recovery Beam Operation with Small Beam Emittance

emittance, cavity, linac, gun

1482

T. Obina, D.A. Arakawa, M. Egi, T. Furuya, K. Haga, K. Harada, T. Honda, Y. Honda, T. Honma, E. Kako, R. Kato, H. Kawata, Y. Kobayashi, Y. Kojima, T. Konomi, H. Matsumura, T. Miura, T. Miyajima, S. Nagahashi, H. Nakai, N. Nakamura, K. Nakanishi, K.N. Nigorikawa, T. Nogami, F. Qiu, H. Sagehashi, H. Sakai, S. Sakanaka, M. Shimada, M. Tadano, T. Takahashi, R. Takai, O.A. Tanaka, Y. Tanimoto, T. Uchiyama, K. Umemori, M. Yamamoto
KEK, Ibaraki, Japan
R. Hajima, R. Nagai, M. Sawamura
QST, Tokai, Japan
N. Nishimori
National Institutes for Quantum and Radiological Science and Technology (QST), Sayo-cho, Japan

A compact energy-recovery linac (cERL) have been operating since 2013 at KEK to develop critical components for ERL facility. Details of design, construction and the result of initial commissioning are already reported*. This paper will describe the details of further improvements and researches to achieve higher averaged beam current of 1 mA with continuous-wave (CW) beam pattern. At first, to keep the small beam emittance produced by 500 kV DC-photocathode gun, tuning of low-energy beam transport is essential. Also, we found some components degrades the beam quality, i.e., a non-metallic mirror which disturbed the beam orbit. Other important aspects are the measurement and mitigation of the beam losses. Combination of beam collimator and tuning of the beam optics can improve the beam halo enough to operate with 1 mA stably. The cERL has been operated with beam energy at 20 MeV or 17.5 MeV and with beam rep-rate of 1300 MHz or 162.5 MHz depending on the purpose of experiments. In each operation, the efficiency of the energy recovery was confirmed to be better than 99.9 %.
* S. Sakanaka, et.al., Nucl. Instr. and Meth. A 877 (2017)197, https://doi.org/10.1016/j.nima.2017.08.051

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW036

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW063

Studying the Dynamic Influence on the Stored Beam From a Coating in a Multipole Injection Kicker

injection, emittance, kicker, simulation

1547

J. Kallestrup, Å. Andersson, J. Breunlin, D.K. Olsson, P.F. Tavares
MAX IV Laboratory, Lund University, Lund, Sweden
P. Alexandre, R. Ben El Fekih
SOLEIL, Gif-sur-Yvette, France

The MAX IV 3 GeV ring is the first synchrotron light source utilizing the Multi-Bend Achromat scheme to achieve a low horizontal bare-lattice emittance of 328 pm rad providing high brilliance x-rays for users. A novel Multipole Injection Kicker (MIK) designed and constructed by SOLEIL is used to allow top-up operation with only minor disturbances to the stored beam, i.e., the users. We investigate the stored beam perturbations due to quadrupole fields arising during the MIK pulse, originating from its inner coating. Maximum bunch emittance growth of §I{21}{πco\meter\radian} was found in simulations. Measurements of the stored beam impact are performed and found to be in good agreement with simulations. We conclude that the MIK at MAX IV 3 GeV has the potential to deliver quasi-transparent injections with good capture efficiency.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW063

About •

paper received ※ 06 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW066

Exploring the Potential of the Swiss Light Source

emittance, storage-ring, damping, cavity

1554

M. Aiba, M. Böge, A. Citterio, M.M. Dehler, A. Lüdeke, C. Ozkan Loch, L. Stingelin, A. Streun
PSI, Villigen PSI, Switzerland

Swiss Light Source (SLS) has been on-line since 2001. Although its performance meets the specifications, it still has a potential to achieve better storage ring beam parameters. We explore two possible improvements. The first one is for the beam lifetime. There are 480 rf buckets while normally 390 bunches are stored. The gap in filing pattern (90 empty buckets) is held to suppress ion instability. After many years of operation, however, the vacuum condition is much better than that of the time when the SLS was turned on. Hence it is possible to shorten the gap. The beam lifetime can then be prolonged due to less bunch current while keeping the net beam current. The study may be also useful to predict possible filling patter in SLS2, which is the SLS upgrade planned. The second one is for the beam emittance. The nominal energy closed orbit coincides with the axes of quadrupole magnets. An off-momentum closed orbit is therefore off-centered through quadrupoles, resulting in a damping partition shift. The beam emittance can be decreased at the expense of a larger energy spread. This was successfully achieved in the ESRF booster. We study whether it is applicable to the SLS storage ring.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW066

About •

paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW077

Impact of the DIAD Wiggler and ’Missing-sextupole’ Optics on the Diamond Storage Ring

wiggler, sextupole, storage-ring, optics

1581

I.P.S. Martin, R. Bartolini, B. Singh
DLS, Oxfordshire, United Kingdom

In order to generate space for a short, out-of-vacuum multipole wiggler for the DIAD beamline, a single sextupole was removed from one of the DBA arcs in the Diamond Storage Ring during June 2018. The removal of this sextupole presented a number of challenges to the operation of the storage ring, requiring a re-optimisation of the remaining sextupole strengths*, a change in tune-point and modification of the orbit and coupling correction schemes. In this paper we describe the implementation of these changes, and provide an assessment of the impact that the installed wiggler has made on the storage ring parameters.
* B. Singh et al. ’Studies to Install a Multipole Wiggler by Removing a Chromatic Sextupole in Diamond Storage Ring’, Proc. IPAC 2016, Busan, Korea, paper THPMR050, (2016)

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW077

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW094

First Attempts at Applying Machine Learning to ALS Storage Ring Stabilization

experiment, quadrupole, storage-ring, emittance

1631

S.C. Leemann, Ph. Amstutz, M.P. Ehrlichman, T. Hellert, A. Hexemer, S. Liu, M. Marcus, C.N. Melton, H. Nishimura, G. Penn, F. Sannibale, D.A. Shapiro, C. Sun, D. Ushizima, M. Venturini
LBNL, Berkeley, USA

Funding: This research is funded by 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 ALS storage ring operates multiple feedbacks and feed-forwards during user operations to ensure that various source properties such as beam position, beam angle, and beam size are maintained constant. Without these active corrections, strong perturbations of the electron beam would result from constantly varying ID gaps and phases. An important part of the ID gap/phase compensation requires recording feed-forward tables. While recording such tables takes a lot of time during dedicated machine shifts, the resulting compensation data is imperfect due to machine drift both during and after recording of the table. Since it is impractical to repeat recording feed-forward tables on a more frequent basis, we have decided to employ Machine Learning techniques to improve ID compensation in order to stabilize electron beam properties at the source points.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW094

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW102

CBETA - Novel Superconducting ERL

electron, linac, MMI, cryomodule

1651

R.J. Michnoff, J.S. Berg, S.J. Brooks, J. Cintorino, Y. Hao, C. Liu, G.J. Mahler, F. Méot, S. Peggs, V. Ptitsyn, T. Roser, P. Thieberger, S. Trabocchi, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, F.J. Willeke, H. Witte
BNL, Upton, Long Island, New York, USA
N. Banerjee, J. Barley, A.C. Bartnik, I.V. Bazarov, D.C. Burke, J.A. Crittenden, L. Cultrera, J. Dobbins, S.J. Full, F. Furuta, R.E. Gallagher, M. Ge, C.M. Gulliford, B.K. Heltsley, G.H. Hoffstaetter, D. Jusic, R.P.K. Kaplan, V.O. Kostroun, Y. Li, M. Liepe, W. Lou, J.R. Patterson, P. Quigley, D.M. Sabol, D. Sagan, J. Sears, C.H. Shore, E.N. Smith, K.W. Smolenski, V. Veshcherevich, D. Widger
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
D. Douglas
Douglas Consulting, York, Virginia, USA
M. Dunham, C.E. Mayes
SLAC, Menlo Park, California, USA

Funding: New York State Research&Development Authority - NYSERDA agreement number 102192
We are successfully commissioning a unique Cornell University and Brookhaven National Laboratory Electron Recovery Linac (ERL) Test Accelerator ’CBETA’ [1]. The ERL has four accelerating passes through the supercon-ducting linac with a single Fixed Field Alternating Linear Gradient (FFA-LG) return beam line built of the Halbach type permanent magnets. CBETA ERL accelerates elec-trons from 42 MeV to 150 MeV, with the 6 MeV injec-tor. The novelties are that four electron beams, with ener-gies of 42, 78, 114, and 150 MeV, are merged by spreader beam lines into a single arc FFA-LG beam line. The elec-tron beams from the Main Linac Cryomodule (MLC) pass through the FFA-LG arc and are adiabatically merged into a single straight line. From the straight section the beams are brought back to the MLC the same way. This is the first 4 pass superconducting ERL and the first single permanent magnet return line.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW102

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW106

Present Status of the PF-ring and PF-AR Operations

injection, photon, undulator, ECR

1654

R. Takai, T. Honda, Y. Kobayashi, S. Nagahashi
KEK, Ibaraki, Japan

The Photon Factory at KEK has been managing two synchrotron radiation sources, the PF-ring and PF-AR, for over 30 years. Although their operation time has been decreasing in recent years for budget reasons, continuous efforts to improve their performance have been made. In this paper, the operational status of these light sources for FY2018 is described. At the PF-ring, a first-generation undulator was renewed with the beamline components. A vacuum chamber for the new undulator was applied the NEG coating on the inner surface. This is the first attempt in Japanese light sources that the NEG-coated chamber is used for undulators. At the PF-AR, the top-up injection using the direct beam transport line was introduced to the user operation for the first time. Since modification of the beam injector LINAC for enabling simultaneous injection to the four different rings (the PF-ring, PF-AR, SuperKEKB HER and LER) was completed, this top-up operation no longer disturbs the operation of the other three rings. A low-energy operation of the PF-AR was also tested to secure more operation time within the limited budget.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW106

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW107

Overview of Collective Effects in SLS 2.0

cavity, impedance, simulation, damping

1658

M.M. Dehler, M. Aiba, A. Citterio, L. Stingelin
PSI, Villigen PSI, Switzerland

At the end of 2017, the conceptual design for an upgrade of the Swiss Light Source was finished, promising a 40 fold smaller emittance and a corresponding increase of the spectral brightness from the current value. From the point of view of collective effects, the main changes in the new design are a reduced chamber size, fully coated with NEG, and operation at small and negative momentum compaction with low synchrotron frequency. We give an overview of the latest results for the ring. Most critical is the threshold for the longitudinal single bunch instability. Taking into account the combined effect of wake impedances and CSR, we have to rely on bunch stretching by a higher harmonic system to achieve stable operation at nominal current.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW107

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPGW110

Improvement of Touschek Lifetime by Higher Harmonic RF Cavity in the SPS Storage Ring

cavity, storage-ring, synchrotron, scattering

1669

T. Phimsen, N. Juntong, P. Sudmuang
SLRI, Nakhon Ratchasima, Thailand
B.C. Jiang
Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China
Z.T. Zhao
SSRF, Shanghai, People’s Republic of China

Siam Photon Source (SPS), located at Nakhon Ratchasima, Thailand, is a synchrotron light source with the beam energy of 1.2 GeV. User operation is performed in beam decay mode with the maximum current of 150 mA. Beam lifetime is about 12 hours at the beam current of 100 mA. Beam injection is carried out twice a day, and even with full energy, it takes roughly 30 minutes. Beam lifetime in the SPS storage ring is limited by Touschek scattering and strongly depends on operation conditions. Higher harmonic RF cavity is a proven method to increase the beam lifetime and suppressing coupled bunch instabilities through Landau damping effect. If the beam lifetime is increased for examples, to be double, only one injection per day would be needed. In this study, an improvement of Touschek lifetime by passive harmonic RF cavity is investigated.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW110

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB005

Photon Polarisation Modelling of APPLE-II EPUs

polarization, photon, undulator, simulation

1687

M.J. Sigrist, C.K. Baribeau, T.M. Pedersen
CLS, Saskatoon, Saskatchewan, Canada

The CLS is currently commissioning two APPLE-II in-sertion devices (IDs), see [1], and constructing two more that allow for operation in ’universal mode’, i.e. selecting arbitrary photon polarisation parameters. Two of these devices will operate in the soft x-ray range where there is expected to be a significant change to polarisation at the sample due to transmission effects of the beam line op-tics. Arbitrary polarisation selection of the ID will counter transmission effects and enable circular polarisation at the sample position. A polarisation model of the device is derived which allows for the calculation of both the Stokes parameters and photon energy for any set point of ID gap and phase. Numerical solutions of these equa-tions allow the calculation of gap and phase set points for any desired photon energy or polarisation. The results of the polarisation model are compared with numerical simulations of the synchrotron radiation calculated using measured magnetic fields at various polarisation modes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB005

About •

paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB019

Collimator Performance Study at the European XFEL

FEL, alignment, gun, collimation

1717

S. Liu, F. Brinker, W. Decking, L. Fröhlich, N. Golubeva, T. Wamsat, J. Wilgen
DESY, Hamburg, Germany

Beam halo collimation is of great importance for the high repetition rate operation at the European XFEL and for the future CW machines. At the European XFEL several different types of collimators are installed at different locations of the beam line, which include the gun collimators, the bunch compressor collimators, and the main and supplementary collimators in the collimation section. Beam halo measurements have been performed using the wire scanners downstream of the main linac, which show that large part of beam halo is collimated by the gun collimator. Remaining losses in the collimation section are mainly due to misalignment. Alignment using orbit bumps in the collimation section is performed and presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB019

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB020

Status of the European XFEL

FEL, electron, photon, MMI

1721

W. Decking, F. Brinker, L. Fröhlich, R. Kammering, T. Limberg, S. Liu, D. Nölle, M. Omet, M. Scholz, T. Wamsat
DESY, Hamburg, Germany

The European XFEL is a Hard X-ray Free Electron Laser based on superconducting accelerator technology. In operation since 2017, it now serves 3 FEL beamlines simultaneously for user experiments. We will report on the present operation of the linear accelerator, the beam distribution to the various beamlines and the performance of the FEL radiators.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB020

About •

paper received ※ 15 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB022

Triple Period Undulator

undulator, radiation, vacuum, photon

1728

A. Meseck, J. Bahrdt, W. Frentrup, M. Huck, C. Kuhn, C. Rethfeldt, M. Scheer
HZB, Berlin, Germany
E.C.M. Rial
DLS, Oxfordshire, United Kingdom

Insertion devices are one of the key components of modern synchrotron radiation facilities. They allow for generation of radiation with superior properties enabling experiments in a variety of disciplines, such as chemistry, biology, crystallography and physics to name a few. For future cutting edge experiments in soft and tender x-rays users require high flux and variable Polarization over a wide photon energy range independent of other desired properties like variable pulse length, variable timing or Fourier transform limited pulses. In this paper, we propose a novel ID-structure, called Triple Period Undulator (TPU), which allow us to deliver a wide energy range from a few ten eV to a few keV at the same beamline with high flux and variable Polarization. The TPU are particularly interesting in context of BESSY III, the successor facility of BESSY II.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB022

About •

paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB023

Considerations for the Ultrahard X-ray Undulator Line of the European XFEL

undulator, FEL, photon, electron

1732

E. Schneidmiller, V. Balandin, W. Decking, M. Dohlus, N. Golubeva, D. Nölle, M.V. Yurkov, I. Zagorodnov
DESY, Hamburg, Germany
G. Geloni, Y. Li, S. Molodtsov, J. Pflüger, S. Serkez, H. Sinn, T. Tanikawa, S. Tomin
EuXFEL, Schenefeld, Germany

The European XFEL is a multi-user X-ray FEL facility based on superconducting linear accelerator. Presently, three undulators (SASE1, SASE2, SASE3) routinely deliver high-brightness soft- and hard- X-ray beams for users. There are two empty undulator tunnels that were originally designed to operate with spontaneous radiators in the range 20-90 keV. We consider, instead a possible installation of two FEL undulators. One of them (SASE4) is proposed for operation in a standard (7-25 keV) range as well as in ultrahard (25-100 keV) regime. We discuss a possible location and length of SASE4, modifications of electron beam transport, beam dynamics, choice of undulator technology, different operation modes (SASE and advanced lasing concepts) etc.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB023

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB024

A Concept for Upgrade of FLASH2 Undulator Line

undulator, FEL, polarization, electron

1736

E. Schneidmiller, B. Faatz, I. Hartl, S. Schreiber, M. Tischer, M. Vogt, M.V. Yurkov, J. Zemella
DESY, Hamburg, Germany
W. Wurth
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany

FLASH is the first soft X-ray FEL user facility, routinely providing brilliant photon beams for users since 2005. There are plans to upgrade both existing undulator lines of this facility, FLASH1 and FLASH2. FLASH1 will mainly operate in XUV range in seeding and SASE modes, while FLASH2 will use the standard SASE regime as well as new lasing concepts aiming at production of brilliant photon beams on the fundamental and harmonics down to 1nm. In this paper we present a concept for FLASH2 upgrade, and discuss different advanced options.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB024

About •

paper received ※ 30 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB025

Harmonic Lasing of the European XFEL in the Angstrom Regime

FEL, undulator, photon, experiment

1740

E. Schneidmiller, F. Brinker, W. Decking, D. Nölle, M.V. Yurkov, I. Zagorodnov
DESY, Hamburg, Germany
N. Gerasimova, J. Grünert, N.G. Kujala, J. Laksman, Y. Li, J. Liu, Th. Maltezopoulos, I. Petrov, L. Samoylova, S. Serkez, H. Sinn, F. Wolff-Fabris
EuXFEL, Hamburg, Germany

Harmonic lasing in XFELs is an opportunity to extend the photon energy range of existing and planned X-ray FEL user facilities. Contrary to nonlinear harmonic generation, harmonic lasing can provide much more intense, stable, and narrow-band FEL beam. Another interesting application is Harmonic Lasing Self-Seeding (HLSS) that allows to improve longitudinal coherence and spectral power of a Self-Amplified Spontaneous Emission (SASE) FEL. This concept was successfully tested at FLASH2 in the range of 4.5 - 15 nm and at PAL XFEL at 1 nm. In this contribution we present recent results from the European XFEL where we successfully demonstrated operation of HLSS FEL at 5.9 A, thus pushing harmonic lasing for the first time into the Angstrom regime.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB025

About •

paper received ※ 09 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB027

Upgrade Plans for FLASH for the Years After 2020

laser, electron, FEL, undulator

1748

M. Vogt, K. Honkavaara, J. Rönsch-Schulenburg, S. Schreiber, J. Zemella
DESY, Hamburg, Germany

FLASH is a unique superconducting soft X-ray FEL capable of producing up to 8000 photon pulses per second. A substantial upgrade is planned to keep FLASH attractive and competitive. Several upgrade scenarios are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB027

About •

paper received ※ 14 May 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB033

Fixed-gap Undulators for Elettra and FERMI

undulator, polarization, electron, FEL

1760

B. Diviacco, R. Bracco, D. Millo
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

In the context of an R&D program on alternative undulator schemes, two fixed-gap, linearly polarised, adjustable-phase undulators (APUs) were built and successfully tested, the first on the FERMI free electron laser, the second on the Elettra storage ring. The latter is now in regular operation for the ALOISA surface science beam line. As a further elaboration on the fixed-gap concept, two elliptically polarised undulators (EPUs) are now being developed for FERMI and for Elettra. We have also started the construction of a double period APU providing an extended tuning range to the TwinMic soft X-Ray microscopy beam line. We present here the main design and construction aspects of the new undulators under development.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB033

About •

paper received ※ 09 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB069

Study of FEL Operation Using Collimator without X-band Linearizer in HX Line at PAL-XFEL

FEL, electron, linac, simulation

1824

H. Yang, C.-K. Min, I.H. Nam
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: This work is supported by MSIP, Korea.
A Hard X-ray (HX) line in PAL-XFEL consists of an e-gun, a Laser Heater (LH), S-band accelerators, an X-band LINearizer (XLIN), three Bunch Compressors (BC), a dog-leg, and an undulator line. It generates 2.5 - 15-keV FEL with over than 1-mJ pulse energy. The XLIN before BC1 is used for linearizing the energy chirp in the longitudinal phase space and provides the flexibility for FEL optimization and operation. However, it causes the instability of FEL by large jitters and drift because of higher frequency. We study the FEL operation without XLIN. The collimator in the center of BC1 is used removing the slices to cause nonlinear compression. We optimize the FEL by short electron bunch with under 30 fs. In this paper, we present details of the optimizing sequence and performance for the FEL operation without XLIN.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB069

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB084

High Level Software Development Framework and Activities on VELA/CLARA

controls, hardware, interface, simulation

1855

D.J. Scott, A.D. Brynes, M.P. King
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
A.D. Brynes, D.J. Scott
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The success of modern particle accelerators depends on good high level software. Over the past few years an integrated framework has been developed to better connect machine physicists to VELA/CLARA at the STFC’s Daresbury laboratory. This framework is comprised of a number of tools, including, a c++/Python API to interface to the EPICS control system with which all High Level Software can be developed. The API is encapsulated, extensible and designed to grow as further Phases of CLARA are installed. The API is seamlessly integrated with the VELA/CLARA virtual accelerator and other activities by the simulations group. As well as presenting the design choices and methodology we will give an overview of the first control room applications built using our tools and how they will form the basis for a new programme of machine learning and optimisation on CLARA.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB084

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB095

Superconducting Undulators for the Advanced Photon Source Upgrade

undulator, vacuum, photon, electron

1884

M. Kasa, E.R. Anliker, J.D. Fuerst, Q.B. Hasse, Y. Ivanyushenkov, I. Kesgin, Y. Shiroyanagi, E. Trakhtenberg
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The magnetic devices group at the Advanced Photon Source (APS) is in the process of designing and developing superconducting undulators (SCUs) for the APS upgrade. While similar in some aspects to previous SCU systems currently in operation at the existing APS, the new SCU systems will include two undulators installed in one cryostat which occupies an entire straight section of the storage ring. Straight sections containing planar undulators will either be configured as ’in-line’, where the two undulators behave as one source, or canted, where the two undulators are operated independently. Also under development is a superconducting arbitrary polarizing emitter (SCAPE) which can produce planar, elliptical, and helical undulator fields.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB095

About •

paper received ※ 14 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB103

The FHI FEL Upgrade Design

FEL, undulator, cavity, dipole

1903

A.M.M. Todd
AMMTodd Consulting, Princeton Junction, New Jersey, USA
W.B. Colson
NPS, Monterey, California, USA
M. De Pas, S. Gewinner, H. Junkes, G. Meijer, W. Schöllkopf, G. von Helden
FHI, Berlin, Germany
S.C. Gottschalk
STI Magnetics LLC, Woodinville, USA
J. Rathke, T. Schultheiss
AES, Medford, New York, USA
L.M. Young
LMY Technology, Lincolnton, Georgia, USA

Since coming on-line in November 2013, the Fritz-Haber-Institut (FHI) der Max-Planck-Gesellschaft (MPG) Free-Electron Laser (FEL) has provided intense, tunable infrared radiation to FHI user groups. It has enabled experiments in diverse fields ranging from bio-molecular spectroscopy to studies of clusters and nanoparticles, nonlinear solid-state spectroscopy, and surface science, resulting in 50 peer-reviewed publications so far. The MPG has now funded a significant upgrade to the original FHI FEL. A second short Rayleigh range undulator FEL beamline is being added that will permit lasing from < 5 microns to > 160 microns. Additionally, a 500 MHz kicker cavity will permit simultaneous two-color operation of the FEL from both FEL beamlines over an optical range of 5 to 50 microns by deflecting alternate 1 GHz pulses into each of the two undulators. We will describe the upgraded FHI FEL physics and engineering design and present the plans for two-color FEL operations in November 2020.
A.M.M. Todd, L.M. Young, J.W Rathke, W.B. Colson, T.J Schultheiss and S. Gottschalk are Consultants to the Fritz-Haber-Institut

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB103

About •

paper received ※ 02 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB106

Status of the Superconducting Soft X-Ray Free-Electron Laser User Facility Flash at DESY

experiment, laser, electron, undulator

1909

J. Rönsch-Schulenburg, K. Honkavaara, M. Kuhlmann, S. Schreiber, R. Treusch, M. Vogt
DESY, Hamburg, Germany

FLASH, the free electron laser user facility at DESY (Hamburg, Germany), delivers high brilliance XUV and soft x-ray FEL radiation to photon experiments with different parameters at two undulator beamlines simultaneously. FLASH’s superconducting linac can produce bunch trains of up to 800 bunches within a 0.8 ms RF flat top at a repetition rate of 10 Hz. In standard operation during 2018, FLASH supplied up to 500 bunches in two bunch trains with independent fill patterns and compression schemes to each of the two beamlines. In 2018 first successful plasma accelerating experiments could be reported by the FLASHForward plasma wakefield acceleration experiment situated in a third beamline. We report on the highlights of FLASH operation in 2018/2019.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB106

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB117

Disk and Washer Coupled Cavity Linac Design and Cold-Model for Muon Linac

cavity, linac, acceleration, emittance

1924

M. Otani, N. Saito
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
K. Futatsukawa, T. Mibe, F. Naito
KEK, Ibaraki, Japan
K. Hasegawa, T. Ito, Y. Kondo, T. Morishita
JAEA/J-PARC, Tokai-mura, Japan
H. Iinuma, Y. Nakazawa
Ibaraki University, Ibaraki, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
R. Kitamura
University of Tokyo, Tokyo, Japan

Funding: This work was supported by JSPS KAKENHI Grant Numbers JP15H03666, JP 16H03987, JP18H03707.
A disk and washer (DAW) coupled cavity linac (CCL) has been developed for a middle velocity part in a muon linac at the J-PARC E34 experiment. It will accelerate muons from v/c = 0.3 to 0.7 at an operational frequency of 1296 MHz. In this poster, the cavity designs, beam dynamics designs, and the cold-model measurements will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB117

About •

paper received ※ 30 April 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS001

Improvements in Rf Multi Cusp Negative Ion Source

plasma, ion-source, simulation, coupling

1928

A.M. George, M.P. Dehnel, S.V. Melanson, D.E. Potkins, T.M. Stewart
D-Pace, Nelson, British Columbia, Canada
N. Broderick
University of Auckland, Auckland, New Zealand
Y. Shimabukuro
Doshisha University, Graduate School of Engineering, Kyoto, Japan

D-Pace’s 13.56 MHz Radio Frequency (RF) multi cusp negative ion source uses an Aluminium Nitride (AlN) dielectric window for coupling RF power from an external antenna to the plasma chamber. Ion source operation was limited to low RF power (< 3500 W) due to failures (cracks) occurring on the window during experiments. Such events can cause damages to the vacuum system and plasma chamber. The current work deals with simulations performed on the ion source to study the factors leading to the failure of the window. Based on results from the simulations, a new design was introduced. The improved design yielded positive results in terms of source performance and stability of the AlN window.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS001

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS021

Basic Design of the RF Power System for IRANCYC-10 Accelerator

cyclotron, simulation, ISOL, vacuum

1972

M. Dehghan, F. Abbasi
Shahid Beheshti University, Tehran, Iran
H. Azizi
ILSF, Tehran, Iran
F. Ghasemi
NSTRI, Tehran, Iran
A. Taghibi Khotbeh-Sara
KNTU, Tehran, Iran

In this paper the basic design of an RF system to produce the required power of IRANCYC-10 cyclotron accelerator is reported. The designed system can generate 15 kW power at the operating frequency of 71 MHz CW. The authors provide a step-by-step ex-planation of the process of the design. It is carried out in three sections; (1) RF design features of the acceler-ator is investigated and power value is calculated in accordance with the requirements of the cyclotron, (2) the choice of solid state amplifiers as the RF power source is presented with its available power and struc-ture, (3) design of insertion instruments is reported to transfer and combine the RF power. The purpose of the paper is to achieve the best performance of the RF system, as well as decreasing overall size by using modular devices.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS021

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS025

Arc and Convertor Current Transient Studies for Multi-cusp Cesiated Surface Conversion H⁻ Source at Lansce

ion-source, plasma, extraction, electron

1983

D. Kleinjan
LANL, Los Alamos, New Mexico, USA

The Multi-cusp Cesiated Surface Conversion H⁻ Ion Source at the Los Alamos Neutron Science Center (LANSCE) has provided beam at ~14 mA, 120 Hz, and 10% D.F. for many years of neutron science research. Recently, random high current transients were discovered in the arc current used to ionize hydrogen in the LANSCE H⁻ ion source, and in the convertor current used to convert protons to H⁻ ions. Most have no effect, but more severe transients can cripple beam output. Hypothesized causes are related to cesiation effects, plasma potential changes, tungsten filament vaporation/sputtering, or from the pulsed power system. A dedicated study was recently done on the LANSCE H⁻ Ion source test stand to determine the cause of these transients. Current understanding indicates that the more severe transients come from a combination of cesiation effects and plasma potential changes. The status of these current transient studies on the LANSCE H⁻ ion source will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS025

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS027

Progress of J-PARC LINAC Commissioning

linac, lattice, rfq, DTL

1990

Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
Z. Fang, K. Futatsukawa, T. Miyao, M. Otani, T. Shibata
KEK, Ibaraki, Japan
T. Ito, A. Miura, T. Morishita, K. Moriya, K. Okabe, J. Tamura
JAEA/J-PARC, Tokai-mura, Japan

After energy and intensity upgrade to 400MeV and 50mA respectively, J-PARC linac were ready for 1 MW beam power from RCS. J-PARC is now successfully operated at 50mA/400MeV for 500kW at neutron target, and on the way to 1MW. The next milestones 1.2 and 1.5MW from RCS are relying on feasibility and property of increase of peak current to 60 mA and the pulse width to 600us in linac. Beam studies were carried out at linac to study the initial beam parameters from ion source/RFQ, to find the optimized lattice and matching, to clarify beam loss source and to mitigate the loss/residue dose for the power upgrade.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS027

About •

paper received ※ 17 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS029

The New Eddy Current type Septum Magnets for Upgrading of Fast Extraction in Main Ring of J-PARC

septum, extraction, experiment, feedback

1997

T. Shibata, K. Ishii, H. Matsumoto, T. Sugimoto
KEK, Ibaraki, Japan
K. Fan
HUST, Wuhan, People’s Republic of China
K. Hamano
Nichicon (Kusatsu) Corporation, Shiga, Japan

The J-PARC Main Ring (MR) is working on imporved beam to 750 kW by shorting the repetition period from 2.48 s to 1.3 s which we call 1Hz operation. The septum magnets for fast extraction in MR will be improved to the new septum magnets which can operate 1Hz. The new magnets will be installed to MR in 2021. In this poster we will report about the new low field septum magnet for the fast extraction. The present septum magnets are conventional type. Therefore, we have problem in durability of thin septum coil by its magnetic vibration, and large leakage field at the exit of the circulating beam duct. The new septum magnets are eddy current type. The eddy current type does not have septum coil, but has a thin septum plate. We can expect that there is no problem in durability of septum coil, and leakage field can be reduced. The output of the present power supply are pattern current which of flat top is 10 ms width, the new one is short pulse which of one is 10 us. The short pulse consists of fundamental and 3rd harmonic sin-wave pulse. We can expect that the flatness and reproducibility of flat top current can be improved. We confirmed that 1Hz operation and high accuracy of its output current and magnetic field with the new septum magnet system. We had some problem in unexpected instability of output current. In this report we also summarize the measure against the instabillity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS029

About •

paper received ※ 26 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS030

The New High Field Septum Magnets for Upgrading of Fast Extraction in Main Ring of J-PARC

extraction, septum, flattop, power-supply

2001

T. Shibata, K. Ishii, H. Matsumoto, T. Sugimoto
KEK, Ibaraki, Japan
K. Fan
HUST, Wuhan, People’s Republic of China

The J-PARC Main Ring (MR) is working on imporved beam to 750 kW by shorting the repetition period from 2.48 s to 1.3 s which we call 1Hz operation. There are fout high field septum magnet along the fast extraction line in the MR, and these will be improved to the new magnets which can operate 1Hz frequency. The new high field septa will be installed in 2021. In this poster we will report about the performance of these new septum magnets. These high field septum magnets are called Septum 30(SM30), 31(SM31), 32(SM32), 33(SM33). We will replace SM30, SM31, and SM32. One reasons of cethe replacement is installation of a large-size quadrupole magnet to upsteam postion of the septa. We need to change the longitudinal length of the septa. Second is large aperture of the beam duct for reduction of beam loss by the collision of the halo of the proton beam to the duct. The new high field SM30, SM31 and SM32 have large aperture. and the material of the beam ducts for extraction line are ceramics for reduction of amount of heat generation by eddy current on the surface of the duct. The maetial of the circulating duct are titanium for reduction of radioactivation. On the other hand, the power supply will not be replaced, then the current power supplies will be used for these new septa. The new SM30, SM31, and SM32 were produced in 2015. The first test operation of SM31 were conduced with 2.48 s repein 2015, and we have meaured the magnetic field without problem. In 2018, we conduced the first 1Hz operation with SM30. The minimum repetition period of the operation was 1.16 s without any problem. We measuered magnetic fields in the gap of the pole and in the circulating beam duct. In this report we will report the detail of the results of the operation and field measurement.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS030

About •

paper received ※ 26 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS033

J-PARC RCS: High-Order Field Components Inherent in the Injection Bump Magnets and Their Effects on the Circulating Beam During Multi-Turn Injection

injection, resonance, simulation, sextupole

2009

H. Hotchi, H. Harada, T. Takayanagi
JAEA/J-PARC, Tokai-mura, Japan

The J-PARC RCS utilizes four sets of pulsed dipole magnets for the formation of injection orbit bump. The injection bump magnets have a large aspect ratio (gap length/core length), so there are other high-order field components inherent in their magnetic fields in addition to the main dipole component. The high-order field components, which locally exist in the injection section not following the lattice super-periodicity, have a significant influence on the circulating beam during multi-turn injection via the excitation of high-order random betatron resonances. This paper discusses the detailed mechanism of emittance growth and beam loss caused by the high-order field components of the injection bump magnets including its correction scenario on the basis of numerical simulation and experimental results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS033

About •

paper received ※ 18 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS034

Development of Low Inductance Circuit for Radially Symmetric Circuit

experiment, impedance, kicker, high-voltage

2013

T. Takayanagi, K. Horino, T. Ueno
JAEA/J-PARC, Tokai-mura, Japan

Radiation symmetric type circuits using semiconductors of SIC-MOSFETs, one of next generation semiconductors, are composed of circuits in which many semiconductor switches are multiplexed in series and in parallel. Since the lengths of all parallel circuits are equal, the output waveform will not be distorted due to timing jitter or level change. This circuit is useful for outputting the waveform of ultrafast short pulse. Therefore, we have developed a circuit that achieves further low inductance by making the power transmission circuit into a double circular ring structure equal to the coaxial shape. Compare the inductance value obtained from the structure and the output waveform. In addition, we compare the calculation and the actual measurement in the actual test and present the verification result of the developed circular ring structure.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS034

About •

paper received ※ 01 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS035

Vacuum Tube Operation Analysis for 1.2 MW Beam Acceleration in J-PARC RCS

acceleration, cavity, vacuum, power-supply

2017

M. Yamamoto, M. Nomura, T. Shimada, F. Tamura
JAEA/J-PARC, Tokai-mura, Japan
M. Furusawa, K. Hara, K. Hasegawa, C. Ohmori, Y. Sugiyama, M. Yoshii
KEK, Tokai, Ibaraki, Japan

The J-PARC RCS has successfully accelerated 1 MW proton beam, matching the designed beam power. Therefore, we have considered acceleration beyond the designed beam power, with the next target being 1.2 MW. An issue for 1.2 MW beam acceleration is the rf system. The present anode power supply is limited by its output current, and the vacuum tube amplifier suffers from an unbalance of the anode voltage swing, arising from the combination of multi-harmonic rf driving and push-pull operation. We have investigated the mitigation of the maximum anode currents and unbalanced tubes by choosing appropriate circuit parameters of the rf cavity with the tube amplifier. We describe the analysis results of the vacuum tube operation for 1.2 MW beam acceleration in the RCS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS035

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS036

Operation Status of J-PARC Rapid Cycling Synchrotron

proton, vacuum, status, synchrotron

2020

J. Kamiya, K. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

The 3 GeV rapid cycling synchrotron (RCS) at the Japan Proton Accelerator Research Complex (J-PARC) provides more than 500 kW beams to the Material and Life Science Facility (MLF) and Main Ring (MR). In such a high-intensity hadron accelerator, even losing less than 0.1% of the beam can cause many problems. Such lost protons can cause serious radio-activation and accelerator component malfunctions. Therefore, we have conducted a beam study to achieve high-power operation. In addition, we have also maintained the accelerator components to enable stable operation. This paper reports the status of the J-PARC RCS over the last year.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS036

About •

paper received ※ 10 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS038

The Operation Status of CSNS Front End

rfq, ion-source, emittance, LEBT

2024

Y.W. An, Y.J. Lv, H.F. Ouyang, Y.C. Xiao
IHEP, Beijing, People’s Republic of China
X. Cao, W. Chen, T. Huang, H. Li, S. Liu, K. Xue
IHEP CSNS, Guangdong Province, People’s Republic of China

Funding: Work supported by National Natural Science Foundation of China(11875271)
China spallation neutron source (CSNS), as the China’s first 100kW beam power pulsed neutron source, its operation target beam power is now larger than 50kW. During the beam power upgrading process of CSNS to 50kW from 2018 to 2019, many improvements have been made for the front end of CSNS. In this paper, the commissioning and improvement of front end as well as the laboratory construction are introduced. The improvements mainly focus on solving the stability of ion source and the spark of Radio Frequncy quadrupole (RFQ) caused by the pre-chopped beam into RFQ.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS038

About •

paper received ※ 08 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS051

Recent Beam Commissioning of LEAF at IMP

rfq, MMI, acceleration, LEBT

2043

Y. Yang, Y.H. Guo, L. Lu, L.B. Shi, L.T. Sun, L.P. Sun, X.B. Xu, Y.H. Zhai, H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China

LEAF (Low Energy intense-highly-charged ion Accelerator Facility) has been successfully commissioned with several beams in CW regime, covering the M/Q from 2 to 7, such as H²⁺, He²⁺, C⁴⁺, O⁴⁺, He⁺, Kr¹³⁺, N²⁺ et al. This paper presents recent beam commissioning results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS051

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS065

RF Conditioning of the CLARA 400 Hz Photoinjector

cavity, GUI, controls, vacuum

2067

L.S. Cowie, D.J. Scott
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Automated conditioning of the 400 Hz photoinjector for CLARA was begun and the conditioning program refined. The conditioning was performed at 100 Hz. Masks were used to detect breakdowns in the reflected power and phase, and the breakdown rate was limited to 5x106 breakdowns per pulse. The cavity gradient and breakdown rate evolution over the conditioning time is presented. Post-pulse multipactor and other evidence of electron effects were detected. Possible mechanisms for this are discussed. The conditioning was interrupted by breakdown in the waveguide after reaching 2.5 MW, and will be resumed after the planned 6 month shutdown of CLARA.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS065

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS066

Re-optimisation of the ALICE Gun Upgrade Design for the 500-pC Bunch Charge Requirements of PERLE

cathode, gun, electron, laser

2071

B. Hounsell, M. Klein, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
B. Hounsell, B.L. Militsyn, T.C.Q. Noakes, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
B. Hounsell, W. Kaabi
LAL, Orsay, France
B.L. Militsyn, T.C.Q. Noakes
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The injector for PERLE, a planned ERL test facility, must be capable of delivering 500 pC bunches at a repetition rate of 40.1 MHz to provide a beam with 20 mA average current with a projected rms emittance of less than 6 mm mrad. This must be achieved at two different operational voltages 350 kV and 220 kV for unpolarised and polarised operation respectively. The PERLE injector will be based on an upgrade of a DC photocathode electron gun operated previously at ALICE ERL at Daresbury. The upgrade will add a load lock system for photocathode interchange. This paper presents the results of a re-optimisation of the electrode system as ALICE operated with a bunch charge of around 80 pC while PERLE needs a bunch charge of 500 pC. This re-optimisation was done using the many-objective genetic algorithm NSGAIII to minimise both the slice emittance and transverse beam size for both required operational voltages.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS066

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS106

First Commissioning of LCLS-II CW Injector Source

gun, cavity, electron, vacuum

2171

F. Zhou, C. Adolphsen, A.L. Benwell, G.W. Brown, W.S. Colocho, Y. Ding, M.P. Dunning, K. Grouev, B.T. Jacobson, X. Liu, T.J. Maxwell, J.F. Schmerge, T.J. Smith, T. Vecchione, F.Y. Wang, C.M. Zimmer
SLAC, Menlo Park, California, USA
G. Huang, F. Sannibale
LBNL, Berkeley, California, USA

Funding: The work is supported by DOE under grant No. DE-AC02-76SF00515
The LCLS-II injector source includes a 186MHz CW rf-gun, a 1.3 GHz CW rf-buncher, a loadlock system for photocathode change, two main solenoids, and a few essential diagnostics. The electron beam is designed to operate at a high repetition rate, up to 1-MHz. Since summer of 2018 we started LCLS-II injector source commissioning immediately after the major installation was completed. Initial commissioning showed the rf-gun was severely contaminated with hydrocarbons and very limited power <600W could be fed into the gun cavity. After a few significant processes, we eventually removed the hydrocarbons and successfully delivered desired rf power of 80 kW to the gun. This paper reports first com-missioning results including gun bakeout and vacuum processing, CW RF-gun and buncher operation with nom-inal power, and measurements of rf stability and dark current.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS106

About •

paper received ※ 10 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS112

Stand-alone Accelerator System Based on SRF Quarter-wave Resonators

cryomodule, SRF, cavity, vacuum

2185

S.V. Kutsaev, R.B. Agustsson, R.D. Berry, D. Chao
RadiaBeam, Santa Monica, California, USA
Z.A. Conway
ANL, Argonne, Illinois, USA

Funding: This material is based upon work supported by the U.S. Department of Energy under contracts DE-SC0017101 and DE-AC02-06CH11357. This research used resources of DOE ANL’s ATLAS facility.
Superconducting accelerators are large and complex systems requiring a central refrigerator and distributed transfer systems to supply 2-4 K liquid helium. Stand-alone, cryocooler-based systems are of interest both to scientific facilities and industrial applications, as they do not require large cryogenic infrastructure and trained specialists for operation. Here we present our approach to the challenge of using low-power commercially available cryocoolers to operate niobium superconducting resonators at 4.4 K with high accelerating voltages and several watts of heating. Engineering and design results from RadiaBeam Systems, collaborating with Argonne National Laboratory, for a stand-alone liquid-cooled cryomodule with 10 Watts of 4.4 K cooling capacity housing a 72.75 MHz quarter-wave resonator operating at 2 MV for synchronous ions travelling at 7.7% of speed of light will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS112

About •

paper received ※ 30 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS116

Adjustment and Improvement of 100 MeV/100 kW Electron Linear Accelerator Parameters for the NSC KIPT SCA Neutron Source

electron, neutron, gun, MMI

2200

P. Gladkikh, V.P. Androsov, O. Bezditko, O.V. Bykhun, V.V. Gevtsev, A.N. Gordienko, A. Gvozd, V.E. Ivashchenko, D.A. Kapliy, I.I. Karhaukhov, I.M. Karnaukhov, V.P. Lyashchenko, M. Moisieienko, A. Mytsykov, A.V. Reuzayev, A.B. Shevtsov, D.V. Tarasov, V.I. Trotsenko, A.Y. Zelinsky
NSC/KIPT, Kharkov, Ukraine

The NSC KIPT SCA Neutron Source uses 100 MeV/ 100 kW electron linear accelerator as a driver for the generation of the initial neutrons. The electron linear accelerator was designed and manufactured by the Institute of High Energy Physics (IHEP) of China. At present, the accelerator was assembled at NSC KIPT, all the components were tested, and the first beam commissioning results are obtained. The pilot operation of the accelerator was started in 2018. The progress in the accelerator system operations and electron beam performance improvement are described in the paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS116

About •

paper received ※ 10 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTS117

Photocathode Activities at INFN LASA

cathode, electron, laser, gun

2203

D. Sertore, G. Guerini Rocco, P. Michelato, L. Monaco
INFN/LASA, Segrate (MI), Italy
S.K. Mohanty
DESY Zeuthen, Zeuthen, Germany
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

We present the activity on alkali antimonide photocathodes at INFN LASA. The long term goal is to transfer to these photocathodes the know-how acquired in the successful development of cesium telluride photocathodes, nowadays used in many leading FEL facilities and accelerator complex. In this paper we present and discuss the results so far obtained on alkali antimonide films grown in our R&D system and the status of the new preparation system specifically designed for these sensitive materials.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS117

About •

paper received ※ 16 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYYPLM1

Status of Early SuperKEKB Phase-3 Commissioning

MMI, optics, detector, luminosity

2255

A. Morita
KEK, Ibaraki, Japan

SuperKEKB is an asymmetric energy electron-positron collider for B-meson physics experiment. The beam collision with 3mm vertical beta function at the interaction point is confirmed during prior beam commissioning until July 2018. The next beam commissioning with the inner silicon vertex detectors so called "phase-3 commissioning" will start in March 2019. In the early part of next phase-3 commissioning, we plan to try the collision operation with over 1A stored beam current in order to exceed 1 x 10³⁴ cm^-2 s^-1 luminosity. We will report the preliminary results of the early stage of the SuperKEKB phase-3 commissioning.

Slides WEYYPLM1 [2.570 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLM1

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYYPLM3

First Results of the Compensation of the Beam-Beam Effect with DC Wires in the LHC

experiment, beam-beam-effects, collider, simulation

2262

G. Sterbini, D. Amorim, H. Bartosik, A. Bertarelli, R. Bruce, X. Buffat, F. Carra, L.R. Carver, G. Cattenoz, E. Effinger, S.D. Fartoukh, N. Fuster-Martínez, M. Gąsior, M. Gonzalez-Berges, A.A. Gorzawski, G.H. Hemelsoet, M. Hostettler, G. Iadarola, O.R. Jones, N. Karastathis, S. Kostoglou, I. Lamas Garcia, T.E. Levens, L.E. Medina Medrano, D. Mirarchi, J. Olexa, S. Papadopoulou, Y. Papaphilippou, D. Pellegrini, M. Pojer, L. Ponce, A. Poyet, S. Redaelli, A. Rossi, B. Salvachua, H. Schmickler, F. Schmidt, K. Skoufaris, M. Solfaroli, R. Tomás, G. Trad, D. Valuch, C. Xu, C. Zamantzas, P. Zisopoulos
CERN, Geneva, Switzerland
D. Amorim
Grenoble-INP Phelma, Grenoble, France
M. Fitterer, A. Valishev
Fermilab, Batavia, Illinois, USA
D. Kaltchev
TRIUMF, Vancouver, Canada
S. Kostoglou
National Technical University of Athens, Zografou, Greece
A.E. Levichev
BINP SB RAS, Novosibirsk, Russia
A. Poyet
Université Grenoble Alpes, Grenoble, France

The compensation of the long-range beam-beam interactions using DC wires is presently under study as an option for enhancing the machine performance in the frame of the High-Luminosity LHC project (HL-LHC). The original idea dates back more than 15 years. After the installation of four wire prototypes in the LHC in 2018, a successful experimental campaign was performed during the last months. The experimental setup and the main results are reported in this paper.

Slides WEYYPLM3 [6.371 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLM3

About •

paper received ※ 06 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEZPLM1

The LATINO Project - An Italian Perspective on Connecting SMEs with Research Infrastructures

vacuum, laser, instrumentation, radio-frequency

2277

L. Sabbatini, D. Alesini, A. Falone, A. Gallo
INFN/LNF, Frascati, Italy
V. Pettinacci
INFN-Roma, Roma, Italy

Funding: The LATINO project is co-funded by the Regione Lazio within POR-FESR 2014-2020 European activities (public call ’Open Research Infrastructures’).
The National Laboratories of Frascati (LNF) are the first Italian research facility for the study of nuclear and subnuclear physics with accelerators and are the largest laboratories of the Italian National Institute for Nuclear Physics (INFN), the public body whose mission is theoretical, experimental and technological research in subnuclear, nuclear and astroparticle physics. LNF have an extensive experience in designing, installation, testing and operation of particle accelerators and the related technologies. The competences range over almost all the technologies related to particle accelerators, including radio frequency, vacuum, magnets and mechanics. LNF have always had a close relationship with the regional and national industries, stimulating the development and growth of the industrial background by means of close collaboration with partners. The LATINO (a Laboratory in Advanced Technologies for INnOvation) project is an initiative that fits into this path and aims to strengthen this relationship, allowing access to the technologies, instruments and competences not otherwise available to the enterprises. A modern vision of advanced economies recommends the Technology Transfer from the research world to the productive activities through the creation of research infrastructures as the most efficient system for generating innovation and economic development [1-3]. The Regione Lazio, despite hosting centres of excellence, has a delay in the establishment of this kind of infrastructures.

Slides WEZPLM1 [4.103 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEZPLM1

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP007

Current Status of Slow Extraction from J-PARC Main Ring

extraction, proton, experiment, radiation

2311

R. Muto, Y. Arakaki, T. Kimura, S. Murasugi, M. Okada, K. Okamura, T. Shimogawa, Y. Shirakabe, M. Tomizawa, T. Toyama, E. Yanaoka
KEK, Ibaraki, Japan
A. Matsumura
Nihon Advanced Technology Co., Ltd, Ibaraki, Nakagun, Tokaimura, Japan

A 30 GeV proton beam accelerated in the J-PARC Main Ring (MR) is slowly extracted by the third integer resonant extraction and delivered to the hadron experimental hall. The slow extraction (SX) from the MR has unique characteristics that can be used to obtain a low beam loss rate. A dynamic bump scheme under achromatic condition drastically reduces beam hit rate on the septa devices. We have attained 50 kW SX operation at 5.2s cycle in current physics run. Slow extraction efficiency has been achieved to be very high, 99.5%. A beam instability during debunching with beam loss can be suppressed by a unique RF phase offset technique at MR injection. A spill duty factor indicating a uniformity for time structure of the extracted beam is typically 50%, which can be obtained by a feedback system using fast response quadrupoles, applying transverse RF field and so on. Future plans to improve present SX performances will be introduced.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP007

About •

paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP008

A Consideration on the Transfer Function Between RQ Field and Slow Extraction Spill in the Main Ring of J-Parc

extraction, feedback, experiment, controls

2315

K. Okamura, Y. Arakaki, S. Murasugi, R. Muto, Y. Shirakabe, M. Tomizawa, E. Yanaoka
KEK, Ibaraki, Japan
T. Kimura
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

A 30 GeV proton beam accelerated in the J-PARC Main Ring (MR) is slowly extracted by the third integer reso-nant extraction and delivered to the hadron experimental facility. Increasing the duty of beam spill is one of the important issues in the slow extraction system. In the MR, the spill feedback system utilizing a digital signal processor (DSP) combined with EQ and RQ magnet is used to smooth the spill, where EQ defines a rough out-line of the slow extraction shape and RQ is used for the ripple cancelling. In this study, frequency domain charac-teristics between the current of RQ magnet and the beam spill was investigated by driving the RQ magnet with sinusoidal current, so that the transfer function from the current of RQ magnet to the spill signal is delivered.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP008

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP011

Residual Orbits Estimation of the Injection Painting Bumps for CSNS

injection, MMI, neutron, dipole

2326

M.Y. Huang, S. Wang, S.Y. Xu
IHEP, Beijing, People’s Republic of China

Funding: Work supported by National Natural Science Foundation of China (Project No. U1832210)
There are three bumps (one chicane bump and two painting bumps) in the injection system of the China Spallation Neutron Source (CSNS). They are the core parts of the injection system and the important guarantee that the Linac beam injecting into the rapid cycling synchrotron (RCS). During the beam commissioning, to check the effect of the residual orbits of the three bumps in the injection region was an important problem. In this paper, the residual orbits of BH and BV painting bumps were studied and estimated in the beam commissioning. The data analysis results showed that the residual orbits of BH and BV painting bumps were very small and they didn’t need to be corrected.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP011

About •

paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP012

Beam Loss and the Stripping Efficiency Measurement for CSNS Injection System

injection, MMI, neutron, proton

2329

M.Y. Huang, S. Wang, S.Y. Xu
IHEP, Beijing, People’s Republic of China

Funding: Work supported by National Natural Science Foundation of China (Project No. U1832210)
The injection beam loss is the main beam loss of the rapid cycling synchrotron (RCS) for the China Spallation Neutron Source (CSNS). After the optimization of injection system during the beam commissioning, the current injection beam loss for CSNS/RCS is approximately 1%. There are several sources of injection beam loss. In order to distinguish these different sources, the stripping efficiency of the main stripping foil should be studied and measured accurately. In this paper, a scheme for the accurate measurement of the stripping efficiency for CSNS will be proposed and studied. It can not only reduce the injection beam loss, but also be used to estimate the operation state and lifespan of the main stripping foil accurately. This method will be applied in future beam commissioning.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP012

About •

paper received ※ 30 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP021

Frequency Modulated Capture of Cooled Coasting Ion Beams

emittance, low-level-rf, injection, simulation

2356

S.C.P. Albright, M.E. Angoletta
CERN, Geneva, Switzerland

Transverse space charge effects in the Low Energy Ion Ring (LEIR) at CERN have been shown to be a major source of particle losses, which can be mitigated with a larger RMS longitudinal emittance. However, due to electron cooling during the injection plateau, the longitudinal density is very high prior to RF capture. In addition there is an uncontrolled cycle to cycle variation in the revolution frequency of the coasting beam on the flat bottom, which degrades the beam quality at capture. In this paper we show that applying an RF frequency modulation during the capture process allows both a controlled blow-up of the longitudinal emittance and a very good reproducibility in the longitudinal distribution, which in turn improves beam transmission through the machine.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP021

About •

paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP025

Matching Studies Between CERN PSB and PS Through Multi-Turn Beam Profile Acquisitions

emittance, injection, optics, betatron

2367

M.A. Fraser, Y. Dutheil, V. Forte, A. Guerrero, A. Huschauer, A. Oeftiger, S. Ogur, F. Roncarolo, E. Senes, F. Tecker
CERN, Geneva, Switzerland

In the framework of the LHC Injectors Upgrade (LIU) project, the investigation and quantification of the optics mismatch between the CERN Proton Synchrotron Booster (PSB) and PS is a crucial step in understanding the source of horizontal emittance growth between the two machines. Extensive studies were carried out to estimate the mismatch from single-pass measurements in the transfer line and to rematch the transfer line to reduce the dispersive mismatch at PS injection while keeping the betatron matching unaltered. This paper presents the results of the data analysis of more recent multi-turn measurements, which profited from a new turn-by-turn beam profile monitor in the PS ring, to assess the achieved level of matching and corresponding emittance growth. The results confirm the improved matching and demonstrate the feasibility of the multi-turn technique as a fundamental tool that will be important for the recommissioning of the renovated transfer line after Long Shutdown 2.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP025

About •

paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP026

Emittance Dilution from the CERN Proton Synchrotron Booster’s Extraction Kickers

kicker, emittance, extraction, proton

2371

M.A. Fraser, S.C.P. Albright, F. Antoniou, G.P. Di Giovanni, Y. Dutheil, V. Forte, A. Huschauer, F. Roncarolo
CERN, Meyrin, Switzerland

Understanding the different sources of emittance dilution along the LHC injector chain is an important part of providing the high brightness proton beams demanded by the LHC Injectors Upgrade (LIU) project. In this context, the first beam-based measurements of the magnetic waveforms of the Proton Synchrotron Booster’s (PSB) extraction kickers were carried out and used to quantify the transverse emittance blow-up during extraction and transfer to the Proton Synchrotron (PS). In this contribution, the waveform measurement technique will be briefly outlined before the results and their implications for the LIU project and beam performance reach are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP026

About •

paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP030

LHC Injection Losses and Trajectories During Run 1 and 2 and Outlook to Injection of HL-LHC Beams

injection, extraction, kicker, emittance

2387

W. Bartmann, C. Bracco, B. Goddard, F.M. Velotti, J. Wenninger
CERN, Geneva, Switzerland

The LHC turn-around time is impacted by the control of injection losses and trajectories. While shot-to-shot trajectory variations dominated the injection efficiency during LHC Run 1, several improvements of hardware and operational settings allowed for a high rate of successful injections during Run 2. Injection losses and trajectories are analysed and presented for the high intensity proton runs, as well as for different beam types used from the injectors. Based on this analysis, an outlook is shown for the HL-LHC era, where double the bunch intensity will have to be injected.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP030

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP031

SPS Slow Extraction Losses and Activation: Update on Recent Improvements

extraction, octupole, proton, alignment

2391

M.A. Fraser, B. Balhan, H. Bartosik, J. Bernhard, C. Bertone, D. Björkman, J.C.C.M. Borburgh, M. Brugger, N. Charitonidis, N. Conan, K. Cornelis, Y. Dutheil, L.S. Esposito, R. Garcia Alia, L. Gatignon, C.M. Genton, B. Goddard, C. Heßler, Y. Kadi, V. Kain, A. Mereghetti, M. Pari, M. Patecki, J. Prieto, S. Redaelli, F. Roncarolo, R. Rossi, W. Scandale, N. Solieri, J. Spanggaard, O. Stein, L.S. Stoel, F.M. Velotti, H. Vincke
CERN, Meyrin, Switzerland
D. Barna, K. Brunner
Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary

Annual high intensity requests of over 10¹⁹ protons on target (POT) from the CERN Super Proton Synchrotron (SPS) Fixed Target (FT) physics program continue, with the prospect of requests for even higher, unprecedented levels in the coming decade. A concerted and multifaceted R&D effort has been launched to understand and reduce the slow extraction induced radioactivation of the SPS and to anticipate future experimental proposals, such as SHiP* at the SPS Beam Dump Facility (BDF)**, which will request an additional 4·10¹⁹ POT per year. In this contribution, we report on operational improvements and recent advances that have been made to significantly reduce the slow extraction losses, by up to a factor of 3, with the deployment of new extraction concepts, including passive and active (thin, bent crystal) diffusers and extraction on the third-integer resonance with octupoles. In light of the successful tests of the prototype extraction loss reduction schemes, an outlook and implications for future SPS FT operation will be presented.
* A. Golutvin et al., Rep. CERN-SPSC-2015-016 (SPSC-P-350), CERN, Geneva, Switzerland, Apr. 2015.
** M. Lamont et al., Rep. CERN-PBC-REPORT-2018-001, CERN, Geneva, Switzerland, 11 Dec 2018.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP031

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP035

Model and Measurements of CERN-SPS Slow Extraction Spill Re-Shaping - the Burst Mode Slow Extraction

extraction, experiment, sextupole, simulation

2406

M. Pari, M.A. Fraser, B. Goddard, V. Kain, L.S. Stoel, F.M. Velotti
CERN, Geneva, Switzerland

The ENUBET ("Enhanced NeUtrino BEams from kaon Tagging") Project aims at reaching a new level of precision of the short-baseline neutrino cross section measurement by using an instrumented decay tunnel. The North Area (NA) experimental facility of the Super Proton Synchrotron (SPS) offers the required infrastructure for the experiment. A new slow extraction type, consisting of bursts of many consecutive millisecond spills within one macro spill, has been modeled and tested for the ENUBET Project. The burst-mode slow extraction has been tested for the first time at CERN-SPS, and MADX simulations of the process have been developed. In this paper the experimental results obtained during the test campaign are presented along with the results of the quality of the produced spill and comparing it with predictions from simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP035

About •

paper received ※ 12 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP040

Machine Protection Aspects of High-Voltage Flashovers of the LHC Beam Dump Dilution Kickers

kicker, simulation, vacuum, high-voltage

2418

C. Wiesner, W. Bartmann, C. Bracco, M. Calviani, E. Carlier, L. Ducimetière, M.I. Frankl, M.A. Fraser, S.S. Gilardoni, B. Goddard, V. Gomes Namora, T. Kramer, A. Lechner, N. Magnin, M. Meddahi, A. Perillo-Marcone, T. Polzin, L.C. Richtmann, V. Rizzoglio, V. Senaj, J.A.F. Somoza, D. Wollmann
CERN, Geneva, Switzerland

The LHC Beam Dump System is required to safely dispose of the energy of the stored beam. In order to reduce the energy density deposited in the beam dump, a dedicated dilution system is installed. On July 14, 2018, during a regular beam dump at 6.5 TeV beam energy, a high-voltage flashover of two vertical dilution kickers was observed, leading to a voltage breakdown and reduced dilution in the vertical plane. It was the first incident of this type since the start of LHC beam operation. In this paper, the flashover event is described and the implications analysed. Circuit simulations of the current in the magnet coil as well as simulations of the resulting beam sweep pattern are presented and compared with the measurements. The criticality of the event is assessed and implications for future failure scenarios are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP040

About •

paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP053

Operational Results of Simultaneous Four-Beam Delivery at Jefferson Lab

laser, experiment, cavity, gun

2454

R. Kazimi, A. Freyberger, J.M. Grames, J. Hansknecht, A.S. Hofler, T.E. Plawski, M. Poelker, M.F. Spata, Y.W. Wang
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
A concept for simultaneous beam delivery to all four CEBAF experimental halls from a single injector and a single main accelerator for the 12 GeV era was proposed in 2012. The original 12 GeV beam delivery plan was for a maximum of three experimental halls at a time as in the 6 GeV era. Therefore, the new concept increases the po-tential beam time for the experiments up to 33%. This change, although a major improvement in operational capabilities, required only limited modifications to the existing machine. The modifications were mainly timing and pattern changes to the beams in the injector, adding a fourth laser to the photo-cathode gun, and the addition of new RF separators to the highest pass of CEBAF. These changes are now complete and, for the first time, the full system is operating, producing four simultaneous beams through the accelerator to four different destinations. In this paper, in addition to presenting the results of the full system commissioning, we will discuss important details about the new configuration plus some of our operational challenges.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP053

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW006

Development of a Beam Loss Monitor and Transverse Beam Dynamics Studies at ARRONAX C70XP Cyclotron

cyclotron, experiment, radiation, quadrupole

2470

A. Sengar, X. Goiziou, F. Gomez Serito, C. Koumeir, F. Poirier
Cyclotron ARRONAX, Saint-Herblain, France
F. Haddad
SUBATECH, Nantes, France

Funding: "Investissements d’Avenir", Equipex Arronax-Plus, Institute of Nuclear and Particle Physics from the National Scientific Research center (CNRS) and the Regional Council of Pays de la Loire, France.
The ARRONAX Interest Public Group uses a multi-particle, high energy and high intensity industrial accelerator which has several beamlines used for various purposes. For improvement of operations, ARRONAX has foster and installed robust air-based Beam Loss Monitors (BLMs) outside the beam pipes. BLMs consist of four active detecting plates and are integrated within the experimental physics and industrial control system (EPICS) monitoring and data acquisition system. Each BLM has been tested for the pre-commissioning phase with beams at low intensity (600pA to 6nA on target). Comparative studies and selection of the BLMs has led to their installation at high intensity beam lines. BLMs are now used in beam dynamics studies to investigate transverse characteristics while in regular operation. They support present and future operations extension foreseen at ARRONAX. The results from experimental studies on BLMs at low beam intensity and status of beam dynamics studies at high intensity (A) are presented here. Keywords: BLM, beam dynamics, EPICS, Gas ionization detector, cyclotron, proton.
*F. Poirier, S. Girault, STUDIES AND UPGRADES ON THE C70 CYCLOTRON ARRONAX, Proceedings of Cyclotrons 2016, Zurich, Switzerland

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW006

About •

paper received ※ 30 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW007

Progress of the Machine Control Upgrade at COSY/JüLICH

controls, EPICS, experiment, quadrupole

2473

V. Kamerdzhiev, I. Bekman, C. Böhme, R. Gebel, B. Lorentz, P. Niedermayer, M. Simon, M. Thelen
FZJ, Jülich, Germany
R. Modic, ’. Oven
Cosylab, Ljubljana, Slovenia

The Cooler Synchrotron COSY operated at the Research Center Jülich is undergoing staged machine control upgrades driven by the requirements of the JEDI (Jülich Electric Dipole moment Investigations) collaboration. The upgrades aim towards better beam control e.g. beam orbit, tune, and chromaticity control improvements. A better orbit control was achieved through the upgrade of BPM electronics and migration from initial Tcl/Tk based control system to Control System Studio (CSS) utilizing EPICS. Currently, a design for improved beam tune control is in development. The main part of work is the transition towards a faster and less restrictive magnet control. It further includes improved tune measurement tools as well as the migration of control for quadrupole magnets to EPICS. Ultimately the control of all systems should be centralized around EPICS to enable ease of operation, automation, setup of services, etc. The decision path, technical details of the upgrade and performance of the upgraded sub-systems are presented. We also showcase how the COSY team’s physics and research goals are complemented by Cosylab’s technical design and implementation to form a synergetic collaboration.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW007

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW021

Generic Digitization of Analog Signals at FAIR – First Prototype Results at GSI

controls, interface, software, hardware

2514

R.J. Steinhagen, R. Bär, A. Franke, A. Krimm, K. Lüghausen, D. Ondreka, A. Schwinn, M. Thieme
GSI, Darmstadt, Germany

FAIR operation and notably the new FAIR Control Centre will be based on a ’fully-digital’ control paradigm for which about 300 generic digitizers covering analog bandwidths and sampling frequencies from a few MHz to a GHz will be deployed. The aim is to acquire all pertinent accelerator system and beam parameters to facilitate a multi-mission of continuous performance tracking, (semi-)automated feedbacks and setup tools, early detection and isolation of hardware failures or near-misses, and to provide a dependable generic platform for equipment experts that enable post-mortem analyses or remote diagnostics. The goal of the controls integration was to provide a generic abstraction of the vendor-specific electro-mechanical form-factor and software interfaces based on modern software-defined-radio (SDR) principles. In addition to a ns-level-syncronised time- and frequency-domain based acquisitions, the interface provides a wide range of generic user-configurable signal post-processing routines common for SDRs and also found in many modern benchtop oscilloscopes, spectrum- or vector-network analysers. The acquired raw and derived signals are exported to the FAIR control system using a standardised front-end software architecture (FESA) and a common middle-ware (CMW). Further integration goals were to simplify possible future extensions, compactness, readability, reusability, testability, and long-term maintainability of the code-based which led to the re-use of established open-source signal processing and data fitting frameworks such as GNU-Radio and ROOT. While explicitly kept open for new or other specific digitizer or SDRs, the initial integration, prototyping, and testing have been done for the PS3000-, PS4000-, and PS600-series of digitizers from Pico Technology.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW021

About •

paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW027

Evaluation and Reduction of Influence of Filling Pattern on X-Ray Beam Position Monitors for SPring-8

space-charge, storage-ring, electron, undulator

2526

H. Aoyagi, Y. Furukawa, S. Takahashi
JASRI/SPring-8, Hyogo, Japan

SPring-8 constantly provides various several-bunch mode operations, which combine single bunches and train bunches. Recently, influence of filling pattern on the accuracy of the XBPMs became apparent, so that we started a systematic evaluation. It was found that the influence was caused by suppression of current signal due to space charge effect, which could be quantified by observing a behaviour of the current signal while changing the voltage of photoelectron collecting electrodes. In order to mitigate the space charge effect, we examined some methods, such as, changing operation parameters of the XBPMs and the undulators. As a result, we successfully reduced the influence of filling pattern.
* H. Aoyagi et al., Proc. of PASJ2018 WEOL06
http://www.pasj.jp/web_publish/pasj2018/proceedings/PDF/WEOL/WEOL06.pdf
http://www.pasj.jp/web_publish/pasj2018/proceedings/PDF/WEOL/WEOL06_oral.pdf

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW027

About •

paper received ※ 10 May 2019 paper accepted ※ 17 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW029

The Design of the Control System for the SACLA/SPring-8 Accelerator Complex to Use the LINAC of SACLA for a Full-Energy Injector of SPring-8

controls, database, storage-ring, injection

2529

T. Fukui
RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan
T. Hara, N. Hosoda, T. Inagaki, H. Maesaka, T. Ohshima, H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Hasegawa, O. Morimoto, Y. Tajiri, S. Tanaka, M. Yoshioka
SES, Hyogo-pref., Japan
S. Matsubara, K. Okada
JASRI, Hyogo, Japan
M. Yamaga
JASRI/SPring-8, Hyogo-ken, Japan

At the SPring-8 site, the X-ray free electron laser facili-ty, SACLA, and the third-generation light source, SPring-8 storage ring, have been operated. On the SPring-8 up-grade project we have a plan to use the linac of SACLA as a full-energy injector of the storage ring. To achieve the SACLA’s user operation and the beam injection to the storage ring in parallel, it is necessary to control the beam energy and the peak current on a pulse by pulse. The demand for an injection occurs anytime during the top-up operation of the storage ring. For this purpose, two accel-erators should be controlled seamlessly and the SACLA has to provide the low emittance electron beam to gener-ate X-ray laser and to be an injector of the storage ring simultaneously. Because SACLA has to control the beam energy and peak current on a pulse by pulse, we are de-signing a system to meet these requirements. A master controller stores a pattern of parameters required for the low-level RF controllers. Each pattern consists of 60 rows which correspond to the parameters for one second with a beam repetition rate of the SACLA, 60Hz. The master sends the parameters to the controllers with reflective memory. We can select the pattern every second on de-mand and it is flexible enough for the top-up operation of the storage ring. Also the data of low-level RF and beam position monitor are stored into the database with a beam repetition rate. In this paper, we report the design of con-trol system for SACLA/SPring-8 to control the beam energy and the peak current on a pulse by pulse.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW029

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW033

Development of the Bunch Shape Monitor Using the Carbon-Nano Tube Wire

electron, high-voltage, vacuum, DTL

2543

R. Kitamura, N. Hayashi, K. Hirano, Y. Kondo, K. Moriya, H. Oguri
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
K. Futatsukawa, T. Miyao, M. Otani
KEK, Ibaraki, Japan
S. Kosaka, Y. Nemoto
Nippon Advanced Technology Co., Ltd., Tokai, Japan

A bunch shape monitor (BSM) is one of the important instruments to measure the longitudinal phase space distribution. The information of the bunch length measured by the BSM is useful to tune phases of the accelerating cavities in the linear accelerator. For example, in the J-PARC linac, three BSM’s using the tungsten wire are installed and tested at the ACS section to measure the bunch shapes between the accelerating cavities. However, this conventional BSM is hard to measure the bunch shape of H⁻ beam with 3 MeV at the beam transport between the RFQ and DTL sections, because the wire is broken around the center region of the beam. The new BSM using the carbon-nano-tube (CNT) wire is being developed to be able to measure the bunch shape of the H⁻ beam with 3 MeV. One challenge to introduce the CNT wire for the BSM is the measure to the discharge. The careful attention should be paid to apply the high voltage of 10 kV to the CNT wire. The several measures are taken to suppress the discharge from the wire and operate the CNT-BSM. This presentation reports the current status of the development and future prospective for the CNT-BSM.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW033

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW036

Archive System of Beam Injection Information at SuperKEKB

injection, background, kicker, linac

2550

H. Kaji, T. Obina
KEK, Ibaraki, Japan
M. Hirose
KIS, Ibaraki, Japan
Y. Iitsuka
EJIT, Hitachi, Ibaraki, Japan

The archive system is one of the most important tools for the modern accelerators. It records the machine parameters during the operation so that we can retrieve and review the status of machine anytime later. SuperKEKB develops the injection archiver system. This system records the injection related parameters, pulse-by-pulse*. The information related with beam injections is fully recorded and it can be utilize to understand the condition of injection operation. Besides, the recorded data can be utilized also for the understanding of beam background related with injections.
* "Archive System for Injection Current at SuperKEKB", in Proc. of 15th Annual Meeting of PASJ, Nagaoka, Japan.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW036

About •

paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW043

Quality Assurance for CSNS Operation

database, interface, MMI, controls

2575

L. Wang, M.T. Kang, X. Wu
IHEP CSNS, Guangdong Province, People’s Republic of China
C.P. Chu, F.Q. Guo, Y.C. He, D.P. Jin, Y.L. Zhang, P. Zhu
IHEP, Beijing, People’s Republic of China

Because CSNS (China Spallation Neutron Source) is now in early operation, the focus has been shifted from beam commissioning to reliable operation, therefore, a suite of QA tools are under development. These tools include Elog system and operation issue tracking system which can record events and track issue status in the process of operation. This paper will describe the application of QA tools in CSNS and the development progress of them.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW043

About •

paper received ※ 10 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW046

Key Technologies for Remote Detection of CSNS Radiation Environment

vacuum, controls, radiation, target

2584

L. Kang, R.H. Liu, X.J. Nie, A.X. Wang, G.Y. Wang, D.H. Zhu
IHEP, Beijing, People’s Republic of China
J.X. Chen, H.Y. He, L. Liu, C.J. Ning, J.B. Yu, Y.J. Yu, J.S. Zhang
IHEP CSNS, Guangdong Province, People’s Republic of China

Funding: Work supported by National Nature Science Foundation of China (11375217)
China Spallation Neutron Source (CSNS) has been continuously operating in September 2018. As the operating time increases the radiation dose will also increase, some equipment maintenance and testing must take special tools and equipment. This article mainly introduced the studies on radiation environment of several detection technologies, such as: remote vacuum leak detection methods and equipment, strong magnetic field environment vibration measuring technology, using Qr code tracing machine walking vehicle inspection system and remote image vision measurement technology, etc., these advanced technology also has a guiding significance to other related fields.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW046

About •

paper received ※ 23 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW061

Bunch Length Measurement Using Multi-Frequency Harmonic Analysis Method at SSRF

SRF, experiment, storage-ring, framework

2616

Y.M. Zhou, B. Gao, Y.B. Leng, N. Zhang
SSRF, Shanghai, People’s Republic of China

Harmonics method in the frequency domain is an effective and inexpensive bunch length measurement method, which was implemented at the Shanghai Synchrotron Radiation Facility (SSRF). A multi-frequency bunch-bybunch length measurement system using an integrated RF conditioning module will be established to reduce the system noise and signal reflection, and to improve the bunch length measurement accuracy as well. The module consists of power splitters, band-pass filters, mixers and so on. The main function of the integrated RF conditioning module is to extract the beam signals at 500MHz, 1.5GHz, 2GHz, and 3GHz operating frequency. Raw data are acquired by a high-precision digitizer and analyzed by MATLAB code. The absolute bunch length can be obtained with a streak camera, which was used to calibrate the response coefficients of the system. Bunch-by-bunch length can be measured by the multi-frequency harmonic analysis method from the button BPM

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW061

About •

paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW063

Fiber-based Cherenkov Beam Loss and Beam Profile Monitor at BEPC II

linac, electron, instrumentation, beam-losses

2622

L. Yu, Y.F. Sui, L. Wang, D.C. Zhu
IHEP, Beijing, People’s Republic of China

A fiber-based Cherenkov beam loss monitor (CBLM) consisting of large core (400μm), long (50 m) multimode fibers, has been developed as an long-range detection tool for the BEPCII: primarily designed for radiation safety in order to limit the dose outside the shielding of the machine, this monitor also serves as an tool to measure beam profile with the wire sccaner. In this paper, principal of operation, instrumentation and programming of these CBLMs are discussed. Some results of beam loss and beam profile measurement with these CBLMs are also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW063

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW085

Development of Operating Alarm System at TPS

controls, vacuum, storage-ring, EPICS

2684

C.S. Huang, B.Y. Chen, C.K. Kuan, C.H. Kuo, T.Y. Lee, W.Y. Lin, S.Y. Perng, T.C. Tseng, H.S. Wang
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) has many subsystems which includes magnet, power supply, vacuum, RF system, insertion device, control system, etc. Therefore, the operational and system check procedures are complex. In this paper, we summarize the routine operational procedures and propose an integrated operational alarm system that gathers machine information and sets high/low warning and fault limits for various signals which can help operators to quickly identify abnormal subsystems, thereby reducing machinery down time. The alarm system also has a wide range of applications, such as the event recording that helps the analysis after event. This new alarm system interface clearly indicates the machine status and improves operational efficiency.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW085

About •

paper received ※ 15 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW087

Control System Studio to Monitor Front End and Beamlines Status as well as Light Source Stability

electron, status, controls, photon

2687

W.Y. Lin, B.Y. Chen, C.S. Huang, C.H. Kuo, T.Y. Lee
NSRRC, Hsinchu, Taiwan

The primary task during a shift change at the Taiwan Photon Source Accelerator Operations team is to know the exact status of the machine, so that problems can be discovered immediately and solved when the machine behaves abnormal. To provide a stable beam during top-up operation, it is necessary to monitor closely the stability of the light source, of front end areas and beamlines. Should any abnormality occur, the operator would initiate initial troubleshooting and adjustments, inform users and sub-system staff members and perform subsequent first anal-yses and system optimizations. In this article, we describe how to sort through the nec-essary information with the Control System Studio (CSS) design page. There are currently seven beamlines in operation at the Taiwan Photon Source (05, 09, 21, 23, 25, 41, 45) and more new beamlines will be added in the future. Com-pared with other tools, CSS is intuitive and easy to revise. No matter weather adding new parameters or changing settings, the operation team can quickly get familiar with the machine status and perform an interface upgrade.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW087

About •

paper received ※ 27 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW091

Beam Loss Control with Scintillating Monitors at ISIS

dipole, synchrotron, monitoring, neutron

2701

B. Jones, S.A. Fisher, A. Pertica
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS Facility at the Rutherford Appleton Laboratory produces intense neutron and muon beams for condensed matter research. Since 1984 its 50 Hz, rapid cycling synchrotron has accelerated protons from 70 to 800 MeV and now typically delivers 0.2 MW of beam to two target stations supplying thirty-four instruments. Control and minimisation of beam loss is vital to the success of high-power proton accelerators. Coverage and sensitivity of beam loss monitoring at ISIS has recently been improved by the installation of scintillating monitors inside the synchrotron’s main dipoles. In addition to their primary goal of preventing damage to dipole RF screens, these monitors have also provided a highly sensitive tool for empirical accelerator optimisation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW091

About •

paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW102

Investigation on Mysterious Long-Term Orbit Drift at NSLS-II

accumulation, storage-ring, power-supply, quadrupole

2728

Y. Hidaka, W.X. Cheng, L. Doom, R.P. Fliller, G. Ganetis, J. Gosman, C. Hetzel, R.A. Hubbard, D. Padrazo Jr, B. Podobedov, J. Rose, T.V. Shaftan, S.K. Sharma, V.V. Smaluk, T. Tanabe, Y. Tian, G.M. Wang, C.H. Yu
BNL, Upton, Long Island, New York, USA

Funding: The study is supported by U.S. DOE under Contract No. DE-SC0012704.
Over a few months in 2018, we observed occasional episodes of relatively quick accumulation of correction strengths for the fast correctors (used by the fast orbit feedback) near Cell 4 (C04) region at NSLS-II Storage Ring. We immediately started investigating the problem, but the cause remained unclear. However, after coming back from the Fall shutdown, we experienced even faster drifts, at a rate of as much as 10 urad per day in terms of orbit kick angle accumulation. The risk of damage on the ring vacuum chambers by the continuing orbit drift without explanation eventually forced us to take emergency study shifts and temporarily lock out the C04 IVU beamline. After extensive investigation by many subsystem experts in Accelerator Division, ruling out many suspicious sources one by one, we were finally able to conclude the cause to be the localized ground motion induced by large temperature jumps of the utility tunnel right underneath the C04 straight section. We report the details of this incident.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW102

About •

paper received ※ 19 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW109

Double Quarter Wave Deflector Cavity Design & Simulation

cavity, coupling, simulation, diagnostics

2749

M.S. Stefani
ODU, Norfolk, Virginia, USA
G.-T. Park
JLab, Newport News, Virginia, USA

Funding: This manuscript has been authored by Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 with the U.S. Department of Energy.
A Double Quarter Wave (DQW) Cavity has been designed, tested and installed for use in longitudinal measurements as part of a diagnostic beamline. This report will describe the design and testing used to characterize this cavity before its use in the study of a magnetized electron beam.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW109

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB009

Validation of the Series Power Couplers of the LIPAc SRF Linac

SRF, cryomodule, vacuum, linac

2811

H. Jenhani, N. Bazin, C. Boulch, S. Chel, G. Devanz, G. Disset, C. Servouin
CEA-IRFU, Gif-sur-Yvette, France
I. Kirpitchev, J. Mollá, P. Méndez, D. Regidor, C. de la Morena
CIEMAT, Madrid, Spain

In the framework of the IFMIF/EVEDA project, the cryomodule of the Linear IFMIF Prototype Accelerator (LIPAc) will be assembled then tested at Rokkasho in 2019. Eight Series Power Couplers (PC) operating at 175 MHz were manufactured under a CEA contract, in order to equip this Cryomodule. They were all successfully RF conditioned up to 100 kW CW in TW and SW configurations. All the high RF power tests were performed under CIEMAT responsibility in BTESA Company premises, according to the CEA requirements. In order to fix difficulties encountered during the fab process, manufacturing and quality control have been analyzed in depth. Thanks to the corrective actions implemented, every PC reached the performances targeted for qualification. This paper will give details about this manufacturing phase and provide an overview of the obtained RF test results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB009

About •

paper received ※ 09 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB014

Further RF Measurements on the Superconducting 217 MHz CH Demonstrator Cavity for a CW Linac at GSI

cavity, linac, heavy-ion, MMI

2826

F.D. Dziuba, K. Aulenbacher, W.A. Barth, C. Burandt, V. Gettmann, T. Kürzeder, S. Lauber, J. List, M. Miski-Oglu
HIM, Mainz, Germany
K. Aulenbacher
IKP, Mainz, Germany
K. Aulenbacher, W.A. Barth, C. Burandt, V. Gettmann, M. Heilmann, T. Kürzeder, S. Lauber, J. List, M. Miski-Oglu, J. Salvatore, A. Schnase, S. Yaramyshev
GSI, Darmstadt, Germany
M. Basten, M. Busch, T. Conrad, H. Podlech, M. Schwarz
IAP, Frankfurt am Main, Germany
S. Lauber, J. List
KPH, Mainz, Germany

Funding: Work supported by GSI, HIM, BMBF Contr. No. 05P18UMRB2
Recently, the first section of the superconducting (sc) continuous wave (cw) Linac has been extensively tested with heavy ion beam from the GSI High Charge State Injector (HLI). During this testing phase, the reliable operability of 217 MHz multi gap crossbar-H-mode (CH) cavities has been successfully demonstrated. The sc 217 MHz CH cavity (CH⁰) of the demonstrator setup accelerated heavy ions up to the design beam energy and even beyond at high beam intensities and full transmission. This worldwide first beam test with a sc CH cavity is a major milestone on the way realizing the entire sc cw Linac project. In this contribution further RF measurements on the cavity are presented providing full characterization of the RF structure.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB014

About •

paper received ※ 26 April 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB015

Cleanroom Installations for SRF Cavities at the Helmholtz-Institut Mainz

cavity, vacuum, heavy-ion, SRF

2830

T. Kürzeder, K. Aulenbacher, W.A. Barth, C. Burandt, F.D. Dziuba, V. Gettmann, R.G. Heine, S. Lauber, J. List, M. Miski-Oglu
HIM, Mainz, Germany
K. Aulenbacher, F.D. Dziuba
IKP, Mainz, Germany
W.A. Barth, C. Burandt, V. Gettmann, M. Miski-Oglu, S. Yaramyshev
GSI, Darmstadt, Germany
J. Conrad
TU Darmstadt, Darmstadt, Germany
R.G. Heine, F. Hug, T. Stengler
KPH, Mainz, Germany

At the Helmholtz-Institut Mainz (HIM) a cleanroom has been equipped with new tools and installations for the planned treatment of different superconducting RF-cavities. At first TESLA/XFEL type 9-cell cavities for the Mainz Energy-Recovering Superconducting Accelerator (MESA) project or 217 MHz multigap Crossbar H-mode cavities for the HElmholtz LInear ACcelerator (HELIAC) under development by HIM and GSI will be treated. The cleanroom installations, including the greyroom, cover an area of about 155 sqm. In its ISO-class 6 area a large ultrasonic and a conductance rinsing bath has been installed recently. A high pressure rinsing cabinet (HPR) has been implemented between the ISO-class 6 and 4 cleanroom. A RF-cavity can be loaded and unloaded from both sides. HPR treatments are possible for cavities of up to 1.4 m length and about 0.7 m diameter. For drying the ISO-class 4 clean room is equipped with a 160 C vacuum oven. New cleanroom lifters allow the handling of up to 200 kg heavy objects. A rail system in the cleanroom floor is installed to move out the entire cold string of the cleanroom after assembly and leak testing. First operational experiences with this facility will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB015

About •

paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB020

Compact Ultra High-Gradient Ka-Band Accelerating Structure for Research, Medical and Industrial Applications

linac, electron, accelerating-gradient, gun

2842

L. Faillace
INFN-Milano, Milano, Italy
M. Behtouei
Sapienza University of Rome, Rome, Italy
V.A. Dolgashev
SLAC, Menlo Park, California, USA
B. Spataro, A. Variola
INFN/LNF, Frascati, Italy
G. Torrisi
INFN/LNS, Catania, Italy

Technological advancements are strongly required to fulfil demands for new accelerators devices from the compact or portable devices for radiotherapy to mo-bile cargo inspections and security, biology, energy and environmental applications, and ultimately for the next generation of colliders. In the frame of the collab-oration with INFN-LNF, SLAC (USA) we are working closely on design studies, fabrication and high-power operation of Ka-band accelerating structures. In par-ticular, new manufacturing techniques for hard-copper structures are being investigated in order to determine the maximum sustainable gradients above 150 MV/m and extremely low probability of RF breakdown. In this paper, the preliminary RF and mechanical design as well as beam dynamics estimations for a Ka-Band accelerating structure at 35 GHz are presented together with discussions on practical accelerating gradients and maximum average beam current throughput.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB020

About •

paper received ※ 08 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB025

High Density Mapping for Superconducting Cavities

cavity, cryogenics, radiation, status

2860

Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
Y. Fuwa
Kyoto University, Research Reactor Institute, Osaka, Japan
R.L. Geng
JLab, Newport News, Virginia, USA
H. Hayano
KEK, Ibaraki, Japan

High density mapping system for superconducting cavities are under development. Testing on the stiffener X-ray mapping system at JLAB showed consistent results in comparison with simultaneously taken GM tube or ion chamber output signals. The system provides better visi-bility as shown by data briefly reported here. In addition to the temperature and the X-ray mapping, a sensitive magnetic field mapping system with high spatial density is also under development. The magnetic field sensor is AF755B, whose operations at cryogenic temperatures are already reported by other group. Our development status using the magnetic field sensor will be reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB025

About •

paper received ※ 19 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB031

SRF Trip Caused by the Tuner in BEPCII

SRF, cavity, electron, collider

2880

J.P. Dai, Z.H. Mi, P. Sha, Y. Sun, Q.Y. Wang, L.G. Xiao
IHEP, Beijing, People’s Republic of China

Funding: Work support by Natural Science Foundation of China (11575216)
The stability and reliability of the Superconducting RF system (SRF) is generally a key issue in a large scale accelerator such as Beijing Electron Positron Collider II (BEPCII). In the past several years, SRF is one of the main factors limiting the availability of BEPCII, and many efforts have been made to fix the SCRF troubles. This paper focuses on the details of the SCRF trip caused by the tuner, which is one of the most persistent troubles and figured out till the summer of 2018.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB031

About •

paper received ※ 08 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB032

Superconducting Elliptical Cavities Developed in IMP for the CiADS

cavity, HOM, multipactoring, simulation

2883

Y.L. Huang, Y. He, R. Huang, T.C. Jiang, L.B. Liu, S.H. Liu, T. Tan, R.X. Wang, Z.J. Wang, S.H. Zhang, S.X. Zhang
IMP/CAS, Lanzhou, People’s Republic of China

Multicell superconducting radio frequency (SRF) ellip-tical cavities are proposed for efficient acceleration of proton beam in the Chinese initiative Accelerator Driven Subcritical System (CiADS). Two families of such cavities will be used in the driver SRF Linac, the first family corresponding to βopt=0.62 cavities that will be used to accelerate the H⁺ beam from 175 MeV to 377 MeV and the second family corresponding to βopt=0.82 cavities that will accelerate the H⁺ beam from 377 MeV to 500 MeV, with the possibility to upgrade to 1 GeV and higher. The electromagnetic optimization of the cavities with the HOM, wakefield and multipacting analysis will be dis-cussed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB032

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB052

Design of Two Types of X-Band High Power Directional Coupler

GUI, coupling, simulation, scattering

2928

G. Wang, X. Lin, Y.G. Tang, C.-F. Wu
USTC/NSRL, Hefei, Anhui, People’s Republic of China

The directional coupler is one of the most widely used components in many microwave systems, which is used to distribute the power of the input microwave signal according to a desired ratio. Directional coupler may be a three-port component or a four-port component with certain specification such as frequencies, bandwidth and structure. To meet the requirements of stable coupling degree and high directivity, we designed two types of directional coupler working at 11.424 GHz with high power handling capacity. One consists of two parallel rectangular waveguides with four holes drilled along the central line of the narrow-wall for coupling the electromagnetic power from the main-waveguide to the sub-waveguide which is called H-plane directional coupler. Simulations show that the coupling degree of H-face directional coupler is 49.9 dB and the directivity is 54.5 dB .The peak electric field is about 29MV/m while operating at 200 MW peak power. The other consists of a circular main-waveguide transmitting TM01 mode and a rectangular sub-waveguide transmitting TE10 mode, called circular-rectangle waveguide directional coupler. These two waveguide are connected by six holes drilled on the side of the circular main-waveguide and along the central line of the wide-wall of the sub-waveguide. The coupling degree of this directional coupler is 50.14 dB and the directivity is 37.93 dB due to the simulation. The bandwidth is about 800MHz. The peak electric field is 404.5V/m while operating at 200 MW peak power. Comparing with the H-plane directional coupler, peak electric field of this directional coupler is lower. Low peak electric field can reduce the risk of RF breakdown and the Multipactor effect, which ensures the stable high power operation of the directional coupler.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB052

About •

paper received ※ 27 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB059

Dark Current Analysis at CERN’s X-band Facility

radiation, electron, ECR, linac

2944

D. Banon-Caballero, M. Boronat, V. Sánchez Sebastián, A. Vnuchenko
IFIC, Valencia, Spain
N. Catalán Lasheras, S. Pitman, M. Widorski, W. Wuensch, V. del Pozo Romano
CERN, Meyrin, Switzerland
A. Faus-Golfe
LAL, Orsay, France
B. Gimeno
UVEG, Burjasot (Valencia), Spain
T.G. Lucas, M. Volpi
The University of Melbourne, Melbourne, Victoria, Australia
W.L. Millar
Lancaster University, Lancaster, United Kingdom
J. Paszkiewicz
University of Oxford, Oxford, United Kingdom

Dark current is particularly relevant during operation in high-gradient linear accelerators. Resulting from the capture of field emitted electrons, dark current produces additional radiation that needs to be accounted for in experiments. In this paper, an analysis of dark current is presented for four accelerating structures that were tested and conditioned in CERN’s X-band test facility for CLIC. The dependence on power, and therefore on accelerating gradient, of the dark current signals is presented. The Fowler-Nordheim equation for field emission seems to be in accordance with the experimental data. Moreover, the analysis shows that the current intensity decreases as a function of time due to conditioning, but discrete jumps in the dark current signals are present, probably caused by breakdown events that change the emitters’ location and intensity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB059

About •

paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB064

High Power Conditioning of X-Band Variable Power Splitter and Phase Shifter

simulation, klystron, GUI, ISOL

2964

V. del Pozo Romano, H. Bursali, N. Catalán Lasheras, A. Grudiev, S. Pitman, I. Syratchev
CERN, Meyrin, Switzerland
C. Serpico
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
M. Volpi
The University of Melbourne, Melbourne, Victoria, Australia

The three X-band test facilities currently at CERN aim at qualifying CLIC structures prototypes but are also exten- sively used to qualify X-band components operation at high power. In order to upgrade one of the facilities from a single test line to a double test line facility, a high power variable splitter and variable phase shifter have been designed and manufactured at CERN. They have been power tested, ﬁrst in a dedicated test and also in their ﬁnal conﬁguration, to en- sure stable power operation before installing them together with an accelerating structure. In this paper, we broadly describe the RF and mechanical design, manufacturing and low power measurements agreement with simulations. We report the high power qualiﬁcation of both components and their suitability to be used in existing and planned X-band facilities.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB064

About •

paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB073

CW Room Temperature Accelerating Structures

impedance, electron, radiation, SRF

2990

S.P. Antipov, P.V. Avrakhov, E. Gomez, S.V. Kuzikov
Euclid TechLabs, LLC, Solon, Ohio, USA
A.A. Vikharev
IAP/RAS, Nizhny Novgorod, Russia

To this day CW linear electron accelerators were based only on expensive and bulky (embedded in a cryostat) superconducting accelerating structures. CW regime can in principle be realized with normal conducting structures provided the shunt impedance is high. Such structures can be designed using dielectrics (ultra-pure ceramics in C-band and diamond in mm-waves) with ultra-low loss tangent (~10-6). The use of dielectrics allows to concentrate the electromagnetic energy density in the dielectric region and thus minimize fields and ohmic loss on metallic walls. The thermal loss in dielectric can be relatively low given the loss tangent is small. We report here the design of structures with shunt impedance on the order of 10⁴ MOhm/m, which is several orders of magnitude higher than shut impedance in copper structures in GHz and THz range. High shunt impedance makes it possible to accelerate electrons to 1 MeV using kW-level CW RF sources like magnetrons in C-band and gyrotrons in THz range. Such CW accelerators will find applications in sterilization, food irradiation, industrial radiography and cargo inspection.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB073

About •

paper received ※ 21 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB075

Optimizing Room Temperature RF Structures for Accelerator Driven System Operations

vacuum, cavity, RF-structure, DTL

2993

D.L. Brown, M.T. Crofford
ORNL, Oak Ridge, Tennessee, USA
C.C. Peters
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.
Minimizing beam trip rates is one of the key operational goals at the Spallation Neutron Source (SNS). Trip rates are closely monitored, and real-time statistics are kept during beam operations for immediate analysis. Beam trips are automatically binned by the length of the trip along with the cause for each trip. The shortest beam trips occur with the highest frequency and those trip rates are dominated by the room temperature RF structures. There can be many causes for the RF structure malfunctions, but one area that has had a major impact on trip rates is improvement in how RF processing is done on structures after extended maintenance periods. Details about the improvement in RF conditioning will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB075

About •

paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB078

RF Commissioning and Performance in the CBETA ERL

cavity, controls, linac, LLRF

3003

N. Banerjee, K.E. Deitrick, J. Dobbins, G.H. Hoffstaetter, R.P.K. Kaplan, M. Liepe, C.W. Miller, P. Quigley, E.N. Smith, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: This work was supported by the New York State Energy Research and Development Authority, Contract No. DE-SC0012704 with the U.S. Department of Energy and NSF award DMR-0807731.
The Cornell-BNL ERL Test Accelerator (CBETA) is a new multi-turn energy recovery linac currently being commissioned at Cornell University. It uses a superconducting main linac to accelerate electrons by 36 MeV and recover their energy. The energy recovery process is sensitive to fluctuations in the accelerating field of all cavities. In this paper, we outline our semi-automated RF commissioning procedure, which starts from automatic coarse tuning of the cavity all the way to adjusting the field control loops. We show some results of using these tools and describe the recent performance of the RF system during our ongoing commissioning phase.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB078

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB097

Understanding and Mitigation of Field Emission in CEBAF SRF Linacs

cavity, cryomodule, linac, vacuum

3039

R.L. Geng, A. Freyberger, R.A. Rimmer
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We will present current understanding of field emission in two 1.1 GeV CW SRF linacs at CEBAF and its mitigation for improved CEBAF energy reach and operation reliability. This contribution will provide a review of CEBAF gradient evolution since 2014, the impact of field emission, the effort in understanding the root cause of field emission in operational SRF cavities including the recently installed C100 cavities. We will evaluate the effect of initial mitigations implemented since 2016, aimed at reducing generation and transportation of new field emitting particulates. Effects of cavity thermal cycling aimed at abating activation of settled field emitting particulates will be evaluated as well. Remaining issues toward predictable control of field emission in operational SRF cavities will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB097

About •

paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB098

Cryogenic RF Performance of Double-Quarter Wave Cavities Equipped with HOM Filters

cavity, HOM, cryogenics, SRF

3043

S. Verdú-Andrés, I. Ben-Zvi, Q. Wu, B.P. Xiao
BNL, Upton, Long Island, New York, USA
I. Ben-Zvi
Stony Brook University, Stony Brook, USA
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
G. Burt, J.A. Mitchell
Lancaster University, Lancaster, United Kingdom
R. Calaga, O. Capatina
CERN, Geneva, Switzerland
N.A. Huque, E.A. McEwen, H. Park, T. Powers
JLab, Newport News, Virginia, USA
Z. Li, A. Ratti
SLAC, Menlo Park, California, USA

Funding: Work supported by US DOE through BSA LLC under contracts No. DE-AC02-98CH10886, No. DE-SC0012704, and the US LHC Accelerator Research Program (LARP) and by the EU HL-LHC Project.
Crab cavities are one of the several components included in the luminosity upgrade of the Large Hadron Collider (HL-LHC). The cavities have to provide a nominal deflecting kick of 3.4 MV per cavity while the cryogenic load per cavity stays below 5 W. Cold RF tests confirmed the required performances in bare cavities, with several cavities exceeding the required voltage by more than 50%. However, the first tests of a Double-Quarter Wave (DQW) cavity with one out of three HOM filters did not reach the required voltage. The present paper describes the studies and tests conducted on a DQW cavity with HOM filter to understand the limiting factor. The recipe to meet the performance specification and exceed the voltage requirement by more than 35% is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB098

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTS020

Development of 6D Particle Tracking Code for Particle Therapy System

synchrotron, acceleration, multipole, emittance

3138

Y. Nakashima, K. Miyata
Hitachi Ltd., Ibaraki-ken, Japan

For achieving required specifications of a particle therapy system such as beam profile and beam current, it is important to tune system operation parameters to appropriate values before commissioning. We are developing 6d particle tracking code to analyze whole the through beam motion in a synchrotron from multiturn injection to the RF-knock out extraction for the precise tuning. The code includes effects of multipole magnetic fields and space charge effect. We report on the implementation of the code and discuss about the simulation results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS020

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTS039

Momentum Slip-Stacking in CERN SPS for the Ion Beams

simulation, cavity, optics, emittance

3184

T. Argyropoulos, T. Bohl, A. Lasheen, G. Papotti, D. Quartullo, E.N. Shaposhnikova
CERN, Geneva, Switzerland

The LHC Injectors Upgrade (LIU) project at CERN aims at doubling the total intensity of the lead ion beam for the High-Luminosity (HL) LHC. Achieving this goal requires using momentum slip-stacking in the SPS, the LHC injector. Slip-stacking will be applied on an intermediate energy plateau to interleave two batches, reducing the bunch spacing from 100 ns to 50 ns and thus increasing the total number of bunches injected into the LHC. Realistic macro-particle simulations, with the present SPS impedance model are used to study and design this complicated beam manipulation. Slip-stacking can be tested experimentally only after the upgrade of the SPS 200 MHz RF system, in 2021. Preliminary, slip-stacking related beam measurements were performed at the end of 2018. In this paper both macro-particle simulations and beam measurements are reported with emphasis given on optimisation of the process, crucial to achieve the required HL-LHC parameters (bunch lengths, beam losses).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS039

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTS040

Energy Dependence of the Reproducibility and Injection Efficiency of the LINAC3-LEIR Complex

linac, cavity, injection, bunching

3188

S. Hirlaender
ATI, Vienna, Austria
H. Bartosik, G. Bellodi, N. Biancacci, V. Kain, A. Saá Hernández, R. Scrivens
CERN, Geneva, Switzerland

High intensities in the CERN Low Energy Ion Ring (LEIR) are achieved by stacking several multi-turn injections from the pre-accelerator LINAC3. Up to seven consecutive 200 μs long, 200 ms spaced pulses are injected from LINAC3 into LEIR. An inclined septum magnet combined with a collapsing horizontal orbit bump allows a 6-D phase space painting via a linearly ramped mean momentum along with the LINAC3 pulse and injection at high dispersion. The injected energy distribution measured by the LEIR longitudinal Schottky is correlated with the obtained injection efficiency in this paper. Studies in 2018 revealed that the achievable accumulated intensity of LEIR strongly depends on the longitudinal distribution from LINAC3, which does not stay constant. This paper summarises the experimental results and means to further improve reproducibility and high injection efficiency.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS040

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTS046

Monitoring and Modelling of the LHC Emittance and Luminosity Evolution in 2018

emittance, luminosity, experiment, proton

3212

S. Papadopoulou, F. Antoniou, I. Efthymiopoulos, M. Hostettler, G. Iadarola, N. Karastathis, S. Kostoglou, Y. Papaphilippou, G. Trad
CERN, Geneva, Switzerland

Operating at 6.5 TeV, the LHC surpassed the expectations and delivered an average of 66 fb−1 integrated luminosity to the two high luminosity experiments ATLAS and CMS by the end of 2018. In order to provide a continuous feedback to the machine coordination for further optimizing the performance, an automated tool for monitoring the main beam parameters and machine configurations, has been devised and extensively used. New features like the coupling between the two planes and effects of noise, were added to the numerical model used since 2016 to calculate the machine luminosity. Estimates, based both on simulations and on observed beam parameters, were reported fill-by-fill as well as in overall trends during the year. Highlights of the observations including the observed additional emittance blow up (on top of IBS, SR and elastic scattering) as well as additional losses (on top of the expected proton burn off) are presented for the 2018 data. Finally, cumulated integrated luminosity projections from the model for the entire 2018 data based on different degradation mechanisms are compared also with respect to the achieved luminosity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS046

About •

paper received ※ 17 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTS050

Multi-Species Electron-Ion Simulations and their Application to the LHC

electron, simulation, beam-losses, space-charge

3228

L. Mether, G. Iadarola, K.L. Poland, G. Rumolo, G. Skripka
CERN, Meyrin, Switzerland

During operation in 2017 and 2018, the LHC suffered from recurrent beam aborts associated with beam losses in one of its arc cells in correlation with quickly developing transverse coherent oscillations. The events are thought to have been caused by a localised high gas density resulting from the phase transition of a macro-particle that has entered the beam. In order to model the observed coherent effects through the interaction of the beam with the induced pressure bump, novel modelling capabilities have been implemented that allow for the simulation of multiple clouds of different particle species and their interaction with the beam. In this contribution the simulation model and its application are described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS050

About •

paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTS051

Comparison of Electron Cloud Build-Up Simulations Against Heat Load Measurements for the LHC Arcs With Different Beam Configurations

electron, simulation, synchrotron-radiation, radiation

3232

G. Skripka, G. Iadarola, L. Mether, G. Rumolo, E.G.T. Wulff
CERN, Meyrin, Switzerland
P. Dijkstal
PSI, Villigen PSI, Switzerland

Electron cloud effects are among the main performance limitations for the operation of the Large Hadron Collider (LHC) with 25 ns bunch spacing. A large number of electrons impacting on the beam screens of the cold magnets induces significant heat load, reaching values close to the full cooling capacity available from the cryogenic system. Interestingly, it is observed that parts of the machine that are by design identical show very different heat loads. We used numerical simulations to investigate the possibility that these differences are induced by different surface properties, in particular maximum Secondary Electron Yield (SEY) for the different cryomagnets. Using the PyECLOUD code, the electron cloud build-up was simulated assuming different values of SEY in the LHC cold magnets. Comparing the measured heat loads to the simulation results for the 25 ns beams at 450 GeV we have identified the SEY values that match the observations in these conditions. These SEY values were found to be in good agreement with the heat loads measured with different beam configurations (changing the bunch pattern, the bunch intensity and the beam energy).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS051

About •

paper received ※ 13 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTS052

Electron Cloud Build-Up Simulations in the Two-Beam Common Chamber of the HL-LHC TDIS With Nonuniform Surface Properties

electron, simulation, injection, vacuum

3236

G. Skripka, C. Bracco, G. Iadarola, A. Perillo-Marcone
CERN, Meyrin, Switzerland

The segmented injection protection absorber (TDIS) foreseen for the High-Luminosity Large Hadron Collider (HL-LHC) project is designed to protect the machine in case of injection kicker malfunctioning. Since the current LHC injection protection absorber has suffered from vacuum issues possibly induced by electron multipacting, numerical studies were done to estimate the electron flux expected on the internal surfaces of the TDIS. This device will consist of three pairs of movable absorbing blocks above and below one beam and a beam screen surrounding the second circulating beam. The build-up of electron cloud in the TDIS was simulated accounting for the presence of two counter-rotating beams, for the configuration of the jaws and for the different materials used for the different surfaces in the device. The simulation studies have also investigated the possibility of coating the most critical surfaces with amorphous carbon in order to mitigate the multipacting.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS052

About •

paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTS053

Frequency Map Measurements at the TPS

resonance, dynamic-aperture, MMI, storage-ring

3240

C.H. Chen, B.Y. Chen, J.Y. Chen, M.-S. Chiu, P.J. Chou, T.W. Hsu, B.Y. Huang, C.-C. Kuo, W.Y. Lin, Y.-C. Liu, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) has been operated for several years since it’s first light in December 2014. TPS has achieved reliable routine operation at 500 mA with more than 10 hrs beam lifetime. The dynamic aperture measurements and associated Frequency Map Analyses (FMA) at TPS reveal the beam dynamics behavior with and without insertion devices. A preliminary measurement study by using the turn-by-turn BPMs and comparison with the model simulation results will be presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS053

About •

paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THXPLM1

LHC Injectors Upgrade Project: Towards New Territory Beam Parameters

target, proton, injection, extraction

3385

M. Meddahi, R. Alemany-Fernández, H. Bartosik, G. Bellodi, J. Coupard, H. Damerau, G.P. Di Giovanni, F.B. Dos Santos Pedrosa, A. Funken, B. Goddard, K. Hanke, A. Huschauer, V. Kain, A.M. Lombardi, B. Mikulec, S. Prodon, G. Rumolo, R. Scrivens, E.N. Shaposhnikova
CERN, Meyrin, Switzerland

The LHC injectors Upgrade (LIU) project aims at increasing the intensity and brightness in the LHC injectors in order to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring high availability and reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2035). This requires extensive hardware modifications and new beam dynamics solutions in the entire LHC proton and ion injection chains: the new Linac4, the Proton Synchrotron Booster, the Proton Synchrotron the Super Proton Synchrotron together with the ion PS injectors (the Linac3 and the Low Energy Ion Ring). All hardware modifications will be implemented during the 2019-2020 CERN accelerators shutdown. This talk would analyze the various project phases, share the lessons learned, and conclude on the expected beam parameter reach, together with the related risks.

Slides THXPLM1 [20.029 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THXPLM1

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THXPLS1

Review of Ion Therapy Machine and Future Perspective

radiation, synchrotron, controls, proton

3391

K. Noda
NIRS, Chiba-shi, Japan

Cancer therapy with ion beams presents several advantages as compared to proton therapy or conventional radiation therapy but its diffusion is limited by the size and cost of the accelerator facility. The ion therapy facilities are presently in operation have generated important developments in particular to the gantry, beam delivery technique, and beam scanning system, while new treatment facilities being planned in United States, Europe, and Asia. This talk will present the current status of this field, as well as the future perspective.

Slides THXPLS1 [26.303 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THXPLS1

About •

paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THXXPLM2

Demonstration of Loss Reduction Using a Thin Bent Crystal to Shadow an Electrostatic Septum During Resonant Slow Extraction

extraction, septum, optics, experiment

3399

F.M. Velotti, P. Bestmann, M.E.J. Butcher, M. Calviani, M. Di Castro, M. Donzé, L.S. Esposito, M.A. Fraser, M. Garattini, S.S. Gilardoni, B. Goddard, V. Kain, J. Lendaro, A. Masi, D. Mirarchi, M. Pari, J. Prieto, S. Redaelli, R. Rossi, W. Scandale, R. Seidenbinder, P. Serrano Galvez, L.S. Stoel, C. Zamantzas, V. Zhovkovska
CERN, Meyrin, Switzerland
F.M. Addesa, F. Iacoangeli
INFN-Roma, Roma, Italy
A.G. Afonin, Y.A. Chesnokov, A.A. Durum, V.A. Maisheev, Yu.E. Sandomirskiy, A.A. Yanovich
IHEP, Moscow Region, Russia
J.E. Borg, M. Garattini, G. Hall, T. James, M. Pesaresi
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
A.S. Denisov, Y. Gavrikov, Yu.M. Ivanov, M.A. Koznov, L.G. Malyarenko, V. Skorobogatov
PNPI, Gatchina, Leningrad District, Russia
F. Galluccio
INFN-Napoli, Napoli, Italy
F. Murtas
INFN/LNF, Frascati, Italy

A proof-of-principle experiment demonstrating the feasibility of using a thin, bent crystal aligned upstream of an extraction septum (ES) to increase the efficiency of the third-integer resonant slow extraction process has been carried out at the CERN Super Proton Synchrotron (SPS). With the primary aim of reducing the beam loss and induced radio-activation of the SPS, the crystal was aligned to both the beam and the septum to reduce by up to 40% the beam intensity impinging the ES and increase the intensity entering the external transfer line. In this contribution, we introduce the concept and the prototype system that was installed in 2018 before reporting in detail on the dedicated program of machine development studies carried out to characterise its performance and demonstrate operational feasibility. The performance reach and compatibility with other loss reduction techniques proposed to further increase the extraction efficiency, such as phase space folding with octupoles, is discussed in view of future high intensity operation.

Slides THXXPLM2 [1.397 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THXXPLM2

About •

paper received ※ 15 May 2019 paper accepted ※ 28 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THYPLM1

Development of the Vertically Polarizing Hard X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project

undulator, photon, free-electron-laser, electron

3408

M. Leitner, D. Arbelaez, J.N. Corlett, A.J. DeMello, L. Garcia Fajardo, D. Leitner, S. Marks, K.A. McCombs, T. Miller, D.V. Munson, J. Niu, K.L. Ray, D.A. Sadlier, D. Schlueter, E.J. Wallén
LBNL, Berkeley, California, USA
H. Bassan, D.E. Bruch, D.S. Martinez-Galarce, H.-D. Nuhn, M. Rowen, Z.R. Wolf
SLAC, Menlo Park, California, USA
C.W. Chen
NSRRC, Hsinchu, Taiwan

Funding: Work supported by the Director, Oﬃce of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Linear Coherent Light Source II (LCLS-II) is a free electron laser facility currently in its final construction stage at Stanford Linear Accelerator Center. The project includes two variable-gap, hybrid-permanent-magnet undulator lines: A soft x-ray undulator line with 21 undulator segments optimized for a photon energy range from 0.2 keV to 1.3 keV and a hard x-ray undulator line with 32 undulator segments designed for a photon energy range from 1.0 keV to 25.0 keV. This paper focuses on the design, development, and performance of the hard x-ray undulator line which utilizes uniquely-developed, vertically-polarizing undulators. To fully compensate the magnetic force throughout the entire gap range these devices incorporate non-linear spring systems which permit the construction of relatively compact undulators. However, significant magnetic field repeatability challenges have been encountered during prototyping of this novel design. The paper describes the innovative design improvements that were implemented which lead to reaching the LCLS-II required performance. These final design solutions can also be advantageous improving the operation of any future undulator design.

Slides THYPLM1 [28.498 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THYPLM1

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THYYPLM2

Two Orbit Operation at Bessy II - During a User Test Week

injection, resonance, electron, experiment

3419

P. Goslawski, F. Andreas, F. Armborst, T. Atkinson, J. Feikes, A. Jankowiak, J. Li, T. Mertens, M. Ries, A. Schälicke, G. Schiwietz, G. Wüstefeld
HZB, Berlin, Germany

Operating a storage ring close to a horizontal resonance and manipulating the transverse non-linear beam dynamics can generate stable Transverse Resonance Island Buckets (TRIBs), which give a 2nd stable orbit in the ring. Both orbits can be populated with different electron bunch filling patterns and provide two different radiation sources to the user community. Such a machine setting has been established at BESSY II and was tested under realistic user conditions in a first ’TRIBs/Two Orbit User Test Week’ in February 2018. Results and user feedback will be discussed in this contribution.

Slides THYYPLM2 [64.754 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THYYPLM2

About •

paper received ※ 14 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THYYPLS2

Different Versions of Cryogenic Current Comparators with Magnetic Core for Beam Current Measurements

cryogenics, shielding, pick-up, proton

3431

J. Golm, F. Schmidl, P. Seidel
FSU Jena, Jena, Germany
H. De Gersem, N. Marsic, W.F.O. Müller
TEMF, TU Darmstadt, Darmstadt, Germany
M.F. Fernandes, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M.F. Fernandes, J. Tan, C.P. Welsch
CERN, Geneva, Switzerland
M.F. Fernandes, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
D.M. Haider, F. Kurian, M. Schwickert, T. Sieber, T. Stöhlker
GSI, Darmstadt, Germany
R. Neubert
Thuringia Observatory Tautenburg, Tautenburg, Germany
M. Schmelz, R. Stolz, V. Zakosarenko
IPHT, Jena, Germany
T. Stöhlker
IOQ, Jena, Germany
T. Stöhlker, V. Tympel
HIJ, Jena, Germany
V. Zakosarenko
Supracon AG, Jena, Germany

For more than 20 years Cryogenic Current Comparators (CCC) are used to measure the current of charged particle beams with low intensity (nA-range). The device was first established at GSI in Darmstadt and was improved over the past two decades by the cooperation of institutes in Jena, GSI and CERN. The improved versions differ in material parameters and electronics to increase the resolution and in dimensions in order to meet the requirements of the respective application. The device allows non-destructive measurements of the charged particle beam current. The azimuthal magnetic field which is generated by the beam current is detected by low temperature Superconducting Quantum Interference Device (SQUID) current sensors. A complex shaped superconductor cooled down to 4.2 K is used as magnetic shielding and a high permeability core serves as flux concentrator. Three versions of the CCC shall be presented in this work: (1) GSI-Pb-CCC which was running at GSI Darmstadt in a transfer line, (2) CERN-Nb-CCC currently installed in the Antiproton Decelerator at CERN and (3) GSI-Nb-CCC-XD which will be operating in the CRYRING at GSI 2019. Noise, signal and drift measurements were performed in the Cryo-Detector Lab at the University of Jena.

Slides THYYPLS2 [4.344 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THYYPLS2

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THYYPLS3

A Remote-Controlled Robot-Car in the TPS Tunnel

photon, controls, radiation, laser

3435

T.Y. Lee, B.Y. Chen, T.W. Hsu, B.Y. Huang, C.H. Kuo, W.Y. Lin
NSRRC, Hsinchu, Taiwan

A remote-controlled robot-car named ’PhotonBot’ was put into the TPS accelerator tunnel and is equipped with a 360 degrees LiDAR for SLAM and navigation, two cameras for perception and first-person view, and a thermal imaging system. The robot can be remotely controlled and can send data to a remote PC through Wi-Fi. With SLAM, it can go more freely without being restricted to a designated path. In order to ensure it can work continuously, there is a wireless charging station in case of a low battery.

Slides THYYPLS3 [18.013 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THYYPLS3

About •

paper received ※ 09 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAPLM3

2019 Nishikawa Tetsuji Prize Talk

electron, collider, proton, experiment

3439

V.D. Shiltsev
Fermilab, Batavia, Illinois, USA

For his original work on electron lenses in synchrotron colliders, his outstanding contribution to the construction and operation of high-energy, high-luminosity hadron colliders and for his tireless leadership in the accelerator community.

Slides THAPLM3 [17.631 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THAPLM3

About •

paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMP007

MICROTCA TECHNOLOGY LAB AT DESY: CURRENT CASES IN TECHNOLOGY TRANSFER

controls, LLRF, hardware, electron

3459

T. Walter, I. Mahns, H. Schlarb
DESY, Hamburg, Germany

Funding: The MicroTCA Technology Lab (A Helmholtz Innovation Lab) is supported by the Helmholtz Association under grant HIL-002.
MicroTCA-based LLRF systems for beam control and beam diagnostics are gaining traction in many facilities around the world. Over the past decade, a comprehensive portfolio of hardware solutions (boards, crates, backplanes) has become available to cater for demanding signal processing applications in state-of-the-art facilities like the European XFEL. Gradually, industrial applications of MicroTCA also have become more common. In response various requests, DESY has opened the MicroTCA Technology Lab (A Helmholtz Innovation Lab) in April 2018 as a service unit for research and industry with a focus on: - Customer-specific developments in MicroTCA (hardware, firmware, software), - High-end test and measurement services, - Consulting and system integration. We report on intermediate results and emerging projects after one year of operation, with transfer examples from the industrial automation and medical technology sectors as well as overlapping developments for the physics research community.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP007

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMP009

LATINO: A Laboratory in Advanced Technologies for Innovation

vacuum, laser, controls, radio-frequency

3466

L. Sabbatini, D. Alesini, A. Falone, A. Gallo
INFN/LNF, Frascati (Roma), Italy
V. Pettinacci
INFN-Roma, Roma, Italy

Funding: The LATINO project is co-funded by the Regione Lazio within POR-FESR 2014-2020 European activities (public call ’Open Research Infrastructures’).
LATINO (a Laboratory in Advanced Technologies for INnOvation) is an open Research Infrastructure that will be hosted at the Frascati National Laboratories (LNF) of the Italian National Institute for Nuclear Physics (INFN). LATINO will allow the scientific community and the SMEs to get access to the technologies and competences developed for particle accelerators. The Infrastructure will be organized in four Laboratories: Radio Frequency, Vacuum and Thermal Treatments, Magnetic Measurements, Mechanical Integration. The list of the available instruments will include, besides others, a high power X-Band station to test cavities up to 50 Hz repetition rate and 200 MW input power, a network analyser to characterize microwave devices up to 100 GHz, a ultra high vacuum oven for thermal treatments and brazing, an outgassing measurement system to characterize vacuum materials, a stretched wire bench and a rotating coil for the magnetic field measurements of multipoles, environment and laser scanners. The regional and national industrial background comprises a remarkable number of highly qualified small and medium enterprises that could take advantage of the technologies offered by LATINO infrastructure to develop novel products within the Key Enabling Technologies and to get the access to new market segments. The Infrastructure will be fully operational at the beginning of 2020. For further information please visit www.latino.lnf.infn.it.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP009

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMP021

X-ray Dose Rate of 6/4 MeV European S-band Linac Structure for Industrial Application at RTX

target, electron, linac, simulation

3494

P. Buaphad, I.G. Jeong, Y. Joo, H.R. Lee
University of Science and Technology of Korea (UST), Daejeon, Republic of Korea
I.G. Jeong, J.Y. Lee
Korea Atomic Energy Research Institute (KAERI), Daejeon, Republic of Korea
Y. Joo, Y. Kim, H.R. Lee
KAERI, Daejon, Republic of Korea
H.D. Park, S. Song
RTX, Daejeon, Republic of Korea

Recently, RTX has been developing a 6/4 MeV European S-band (= 2998 MHz) industrial linac by using a magnetron with a low RF power of about 3 MW for container inspection system (CIS). Its accelerating structure is designed to operate in π/2 mode by coupling 6 accelerating cells together through 5 side-coupled cells. In CIS, high dose rate X-rays from MeV-energy electron beam has been used to detect the possible presence of contrabands in cargoes or truck containers. To determine a dose rate output, the X-ray dose rate can be simulated by using FLUKA Monte Carlo simulation. The aim of this work was to study the effects of thickness of X-ray target on dose rate as well as X-ray dose map at 1.0 m away from the X-ray target. This study gives the thickness of target in which the dose rate can be highest and electron beam current can be lowest.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP021

About •

paper received ※ 24 May 2019 paper accepted ※ 24 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMP048

Mu*STAR: A Modular Accelerator-Driven Subcritical Reactor Design

site, neutron, target, SRF

3555

R.P. Johnson, R.J. Abrams, M.A. Cummings, J.D. Lobo, M. Popovic, T.J. Roberts
Muons, Inc, Illinois, USA

Mu*STAR is an accelerator-driven molten-salt sub-critical reactor based on recent superconducting RF technological breakthroughs that allow a highly efficient and powerful proton accelerator to drive a spallation target inside a graphite-moderated, thermal-spectrum reactor. The additional spallation neutrons can be used to overcome the absorption of neutrons by fission products to allow a deeper burn than is possible with critical reactor designs. Simulations have shown that as much as seven times the energy that was extracted from used fuel from light water reactors can be produced by this method before the accelerator demands significant power from the reactor. Once the fuel rods have been converted from oxide ceramics to fluoride salts, in a process that is proliferation resistant (not chemical reprocessing), the fuel can be burned for centuries without increasing its volume while reducing its radio-toxicity. Our 2017 GAIN voucher grant supported studies by ORNL, SRNL, and INL to design and cost a Fuel Processing Plant to convert used nuclear fuel into the molten-salt fuel for Mu*STAR. Based on those studies, it seems possible to build Mu*STAR systems on existing sites where used fuel is stored, convert it to fluoride salts, and use it to provide affordable carbon-free electricity for centuries.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP048

About •

paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMP051

Development of 211-Astatine Production in the Crocker Nuclear Laboratory Cyclotron

target, cyclotron, proton, extraction

3564

E. Prebys
Fermilab, Batavia, Illinois, USA
R.J. Abergel
UCB, Berkeley, California, USA
W.H. Casey
University of California at Davis (UC Davis), Davis, California, USA
D.A. Cebra
UCD, Davis, California, USA

There is a great deal of interest in the medical community in the use of the alpha-emitter 211-At as a therapeutic isotope. Among other things, its 7.2 hour half life is long enough to allow for recovery and labeling, but short enough to avoid long term activity in patients. Unfortunately, the only practical technique for its production is to bombard a 209-Bi target with a ~29 MeV alpha beam, so it is not accessible to commercial isotope production facilities, which all use fixed energy proton beams. The US Department of Energy is therefore supporting the development of a "University Isotope Network" (UIN) to satisfy this need. Our prposoal is to retrofit the variable-energy, multi-species cyclotron at the Crocker Nuclear Laboratory at the University of California Davis with an internal Bi-209 target, such that we can put at least 100 uA of 29 MeV alpha particles on target without concerns about extraction efficiency. Using very conservative assumptions, we are confident we will be able to produce 60 mCi of 211-At in solution in an eight hour shift, which includes setup, exposure, and chemical recovery. This poster will cover the design of the target, as well as the required chemical processing and reliability upgrades.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP051

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPGW005

Recent Developments of the 520 MeV Cyclotron’s High-Power RF System at TRIUMF

cyclotron, simulation, rf-amplifier, coupling

3591

N.V. Avreline, Y. Bylinskii, D. Gregoire, B. Jakovljevic, R.E. Laxdal, X. Wang, B.S. Waraich, V. Zvyagintsev
TRIUMF, Vancouver, Canada

520 MeV Cyclotron’s High-Power RF System has been in the state of continuous operation for over 50 years since its commissioning. This paper describes the recent upgrades of the RF System, the main goal of which was to improve reliability. Specially, we discuss the upgrades done to the RF Transmission Line (TL), the RF Power Amplifier (PA) components and their diagnostics tools. We upgraded the structure of Intermediate Power Amplifier (IPA), installed Solid State (SS) driver and are in the process of replacing tubes with a SS option for IPA and PA.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW005

About •

paper received ※ 08 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPGW011

Commissioning-Stages and Radio-Protection Concept for the THz-Linac Based Accelerator "AXSIS" at DESY

electron, MMI, laser, linac

3598

F. Burkart, R.W. Aßmann, U. Dorda, B. Marchetti
DESY, Hamburg, Germany
F.X. Kärtner, N.H. Matlis, T. Rohwer
CFEL, Hamburg, Germany

The dedicated accelerator R&D facility SINBAD at DESY hosts the AXSIS accelerator. This project is funded by the European Research Council to develop a compact source for attosecond serial X-ray crystallography and spectroscopy. For that purpose, in one of the arcs of the SINBAD facility and the neighboring laser labs, an accelerator research site is being constructed where a fully THz-driven accelerator (electron gun and linac, < 30MeV) will be installed. The current status of the hardware installation of the electron beam accelerator is presented. Furthermore, the required radio-protection measures and maximum beam parameters are presented. In this contribution the commissioning plans and the staging of the beam operation for the accelerator complex will be shown and discussed in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW011

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPGW031

Hardware Commissioning of the Refurbished Alpi LINAC at INFN-LNL to Serve as Spes Exotic Beam Accelerator

linac, MMI, rfq, alignment

3650

G. Bisoffi, L. Bellan, D. Bortolato, O. Carletto, F. Chiurlotto, M. Comunian, A. Conte, T. Contran, M. De Lazzari, E. Fagotti, A. Friso, M.G. Giacchini, M. Lollo, D. Marcato, M.O. Miglioranza, P. Modanese, M.F. Moisio, M. Montis, E. Munaron, G. Nigrelli, S. Pavinato, M. Pengo, A. Pisent, M. Poggi, L. Pranovi, C.R. Roncolato, M. Rossignoli, D. Scarpa
INFN/LNL, Legnaro (PD), Italy
M.A. Bellato
INFN- Sez. di Padova, Padova, Italy

The ALPI linac at INFN-LNL was substantially refur-bished in 2018, especially in view of its use as secondary accelerator for exotic species in the framework of the SPES project. In particular: 10 magnetic triplets were replaced with higher gradient ones; two cryomodules with quarter wave resonator were moved from the PIAVE injector to ALPI, so as to make them available both for exotic and stable beams; the cryogenic plant was renovat-ed; the whole linac, its injector and its beam lines were eventually realigned via LASER tracking (LT). The ex-pected outcome of the refurbishment project is a larger beam transmission (crucial for the efficient transport of the unavoidably low current exotic beams) and improved overall reliability so as to further extend the lifetime of an already 25 years old machine. The hardware commission-ing of this new configuration will be reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW031

About •

paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPGW057

HL-LHC Full Remote Alignment Study

alignment, vacuum, MMI, luminosity

3716

A. Herty, R. De Maria, P. Fessia, D. Gamba, M. Giovannozzi, J. Hansen, I. Lamas Garcia, H. Mainaud Durand, S. Redaelli
CERN, Meyrin, Switzerland

Funding: Research supported by the HL-LHC project.
This study explores the benefits of extending the monitoring and remote alignment concept, proposed in the HL-LHC baseline, to additional components of the matching sections of the HL-LHC. The objective was to evaluate the benefits in terms of equipment performance and new opportunities for system simplification. In collaboration with the HL-LHC Working Group on Alignment, critical input parameters such as ground motion, manufacturing, assembly, and alignment tolerances, have been quantified. Solutions for the selected, manually aligned compo-nents have been investigated with the particular focus on vacuum design, mechanical design and the new alignment concept compatible with reliability and maintainability requirements. In this context, collimators and masks are key elements to be included in the extended alignment system. Their supporting systems will integrate the concept of on-line monitoring sensors and an actuator based, remote alignment platform. The full remote alignment of components will provide a positive impact to the machine operation reducing the need of human intervention in the tunnel and providing enhanced flexibility to perform the required alignment adjustment as part of an operational tool for the HL-LHC.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW057

About •

paper received ※ 09 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPGW058

Design and Study of a 6 Degree-Of-Freedom Universal Adjustment Platform for HL-LHC Components

alignment, radiation, ECR, target

3720

M. Sosin, T. Blaszczyk, A. Herty, J. Jaros, H. Mainaud Durand
CERN, Meyrin, Switzerland

In the accelerator domain, the safe and easy alignment of components located in radioactive areas, is a main concern. The position of devices, such as magnets and collimators, has to be adjusted in a fast and ergonomic way to decrease the ionizing dose received by the personnel. Each equipment type has its own unique set of requirements such as the weight, or the desired position accuracy. The two opposite approaches are, on one hand, a simple and time-consuming manual adjustment, using regulating screws and shims, and, on the other hand, the use of precise and expensive automatic positioning stages and platforms. In the frame of the High Luminosity LHC project, in order to fulfill the safety and technical requirements of alignment for lightweight components, a standardized system is under development. It will provide easy, low-cost and fast adjustment capability for several types of components that could be embarked on it. This paper describes the design, the study and the test results of such a universal adjustment solution. The engineering approach, the lessons learned, the issues and the mechanical components behavior are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW058

About •

paper received ※ 10 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPGW096

CERN Accelerator Operation’s Planning Manager and Dashboard

interface, framework, controls, distributed

3792

E. Matli, T. Hesselberg, J.N. Nielsen
CERN, Geneva, Switzerland
T. Hesselberg
NTNU, Trondheim, Norway

Running CERN complex of accelerators and infrastructure requires the seamless collaboration of many people, such as operators, experts and people-on-call to name only a few. Distributed in teams from different groups, it is important to centralise schedule planning and operational information and make this information readily available. In BE/OP these tasks are handled by two applications to manage shift work as well as piquet and expert services. At the beginning of 2018, a project was started to replace the ageing web piquet application. While collecting requirements we realised a more flexible application was needed to suit a broader set of customers, and to offer a more generic, people- oriented tool. The new planning tool consists of two separate applications: The Planning Manager, which is used to organise work schedules of a teams members, and to keep each group’s planning up-to-date, coherently, and visible to all involved. The Planning Dashboard, which allows any user to create a customised view of the available services they use.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW096

About •

paper received ※ 02 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB003

Automatic Classification of Post Mortem Data for Reduced Beam Down Time

synchrotron, power-supply, real-time, dipole

3799

M.C. Chalmers, Y.E. Tan
AS - ANSTO, Clayton, Australia

Time spent recovering from faults that result in a rapid loss of stored current (a total beam loss event) can be costly to the Australian Synchrotron facility and its researchers. The identification of a fault leading to total beam loss is assisted by a large variety of investigative tools for specific tasks, but they do not often give a thorough overview of all systems required to store beam. Post mortem data uniquely provides insight into how the beam was behaving at the specific time the dump occurred. With machine learning, we find that we can automatically and rapidly identify many types of total beam loss events by learning about the unique characteristics in the post mortem files.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB003

About •

paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB005

Orbit Feedback and Beam Stability at the Australian Synchrotron

feedback, FPGA, controls, EPICS

3805

A.C. Starritt, A. Pozar, Y.E. Tan
AS - ANSTO, Clayton, Australia

The Australian Synchrotron (AS) is a 3rd generation light source which has been in operation since 2006. Measurement of the storage ring’s beam position is provided by 98 beam position monitors, and corrections can be applied using 42 horizontal and 56 vertical slow corrector magnets, and 42 horizontal and 42 vertical fast corrector magnets. This paper provides a background describing the feedback strategies adopted at the AS leading to the current integrated orbit feedback system, together with a description of the beam position analyse techniques currently in use. It will also highlight some of the issues encountered with the system and how they were overcome. The paper also describes planned improvements, including the enhanced orbit diagnostics functionality we are intending to introduce in the next 12 months.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB005

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB021

Automatic Loop for Carrier Suppression in Attosecond RF Receivers

controls, electron, FPGA, electronics

3847

U. Mavrič, M. Hoffmann, F. Ludwig, H. Schlarb, L. Springer
DESY, Hamburg, Germany

The carrier suppression interferometer method can be used as a radio receiver architecture which allows for detection of RF signals in the attosecond range. The carrier suppression scheme requires an automatic carrier suppression circuit which provides stable operation of the RF receiver in the best operating point. In the poster we investigate the requirements for such an algorithm, evaluate the achievable closed loop bandwidth and the side effects on the overall-performance. In addition we apply the carrier tracking to simplify and automate the characterization of various electronic phase shifters and attenuators in the as-range

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB021

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB025

New MicroTCA Piezo Driver (PZT4)

cavity, high-voltage, controls, power-supply

3860

K.P. Przygoda, L. Butkowski, M. Fenner, M. Hierholzer, R. Rybaniec, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany
R. Rybaniec
PSI, Villigen PSI, Switzerland

In the paper we would like to present a new Micro Telecommunication Computing Architecture (MicroTCA) piezo driver (PZT4). The piezo driver module is capable of driving of 4 piezo actuators with high voltages up to 160 Vpp. It is also possible to measure cavity mechanical vibrations using 4 analog to digital converters (ADC) ported to the driver electronics. The new piezo driver can be supplied using internal 12 V payload power provided by the MicroTCA standard. For the applications that need more than 30 W of the input power, the external power supply module can be provided. In order to protect the piezo driver electronics against output short condition a dedicated supervision circuit is designed. The piezo driver module has been setup at Cryo Module Test Bench (CMTB) facility in Deutsches-Elektronen Synchrotron (DESY) as a part of the single cavity low-level radio frequency (LLRF) controls. The LLRF control system has been used to demonstrate the radio frequency (RF) field stabilization and cavity tuning capabilities for continuous (CW) and pulse modes of operation of 1.3 GHz superconducting resonant RF (SCRF) cavity. The preliminary results are demonstrated and briefly discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB025

About •

paper received ※ 08 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB030

Novel FPGA-based Instrumentation for Personnel Safety Systems in Particle Accelerator Facility

FPGA, controls, radiation, monitoring

3872

S. Pioli, M. Belli, M.M. Beretta, B. Buonomo, P. Ciambrone, D.G.C. Di Giulio, O. Frasciello, A. Variola
INFN/LNF, Frascati, Italy
P. Valente
INFN-Roma, Roma, Italy

Personnel safety system for particle accelerator facility involves different devices to monitor gates, shielding doors, dosimetry stations, search and emergency buttons. In order to achieve the proper reliability, fail-safe and fail-proof capabilities, these systems are developed compliant with safety standards (like the IEC-61508 on ’Functional Safety’, ANSI N43.1 ’Radiation Safety for the design and operation of Particle Accelerator’ and NCRP report 88) involving stable technologies like electro-mechnaical relays and, recently, PLC. As part of the Singularity project at Frascati National Laboratories of INFN, this work will report benchmark of a new FPGA-based system from the design to the validation phase of the prototype currently operating as personnel safety system at the Beam Test Facility (BTF) of Dafne facility. This novel instrument is capable of: devices monitoring in real-time at 1 kHz, dual modular redundancy, fail-safe and fail-proof, multi-node distributed solution on optical link, radiation damage resistance and compliant with IEC-61508, ANSI N43.1 and NCRP report 88. The aim of this FPGA-based system is to illustrate the feasibility of FPGA technology in the field of personnel safety for particle accelerator in order to take advantage of a fully digital system integrated with facility control system, evaluate the related reliability and availability and realize a standard, scalable and flexible hardware solution also for other fields with similar requirements like machine protection systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB030

About •

paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB031

Operational Performance of the Machine Protection Systems of the Large Hadron Collider During Run 2 and Lessons Learnt for the LIU/HL-LHC Era

machine-protect, injection, optics, experiment

3875

M. Zerlauth, A. Antoine, W. Bartmann, C. Bracco, E. Carlier, Z. Charifoulline, R. Denz, B. Goddard, A. Lechner, N. Magnin, C. Martin, R. Mompo, S. Redaelli, I. Romera, B. Salvachua, R. Schmidt, J.A. Uythoven, A.P. Verweij, J. Wenninger, C. Wiesner, D. Wollmann, C. Zamantzas
CERN, Geneva, Switzerland

The Large Hadron Collider (LHC) has successfully completed its second operational run of four years length in December 2018. Operation will be stopped during two years for maintenance and upgrades. To allow for the successful completion of the diverse physics program at 6.5 TeV, the LHC has been routinely operating with stored beam energies close to 300 MJ per beam during high intensity proton runs as well as being frequently reconfigured to allow for special physic runs and important machine developments. No significant damage has incurred to the protected accelerator equipment throughout the run thanks to the excellent performance of the various machine protection systems, however a number of important observations and new failure scenarios have been identified, which were studied experimentally as well as through detailed simulations. In this contribution, we provide an overview of the performance of the machine protection systems throughout Run 2 as well as the important lessons learnt that will impact consolidation actions and the upgrade of the machine protection systems for the LIU/HL-LHC era.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB031

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB035

Development of Beam Window Protection System for J-PARC Linac

linac, PLC, vacuum, site

3886

H. Takahashi, S. Hatakeyama, Y. Sawabe
JAEA/J-PARC, Tokai-mura, Japan
T. Ishiyama, T. Suzuki
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
T. Miyao
KEK, Ibaraki, Japan

In J-PARC Linac, beam study (including beam conditioning) is mainly performed using beam dump. A beam window is installed in the beam line to each beam dump. It is considered that the parameters of acceptable beam　to able to be injected the beam window are the 50 mA current, the 100 micro-sec width and the 2.5 Hz repetition. On the other hand, at beam study of Linac, the beam with higher power than these parameters are not used. Therefore, the beam study was started and performed only after the operator checked that the beam parameters are within the acceptable values. However, at the beam study of 2018, a beam windows of 0-degree dump was cracked because the beam that exceeds acceptable parameters was injected due to human error. Then, beam study using 0-degree dump was impossible at all. And, in order not to cause such accident again, we began to develop the beam window protection system. Moreover, as soon as possible, implementation of the system was required. Therefore, we designed and developed this system by improving it based on the particle management system which can measure all 25 Hz beam. We have developed a beam window protection system that monitors the beam current for each shot and accumulated beam current for a prescribed time and inhibits the beam by MPS when either value exceeds the threshold. Moreover, we succeeded in developing and implementing this system in a short time. This paper is described about development and function test of beam window protection system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB035

About •

paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB053

Upgrade of the Historical Data Query and Analysis System for HLS-II

radiation, database, status, real-time

3928

Z.Y. Xie, C. Li, G. Liu, Z.X. Shao, Y. Song, J.G. Wang, K. Xuan
USTC/NSRL, Hefei, Anhui, People’s Republic of China

The current historical data query and analysis system for the Hefei Light Source II (HLS-II) was developed with Apache Struts2. However, Apache Struts2 need to be fixed from time to time to avoid being attacked. Therefore, a new system based on Spring Boot and Vue.js is developed. Meanwhile, the performance of the system is optimized, and the radiation monitor module is added. This paper will detail the system architecture and software implementation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB053

About •

paper received ※ 24 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB067

Time Varying RF Phase Noise for Longitudinal Emittance Blow-Up

synchrotron, emittance, proton, extraction

3954

S.C.P. Albright
CERN, Geneva, Switzerland
D. Quartullo
Sapienza University of Rome, Rome, Italy

RF phase noise was shown to be effective for controlled longitudinal emittance blow-up in the Proton Synchrotron Booster (PSB) at CERN during beam tests in 2017, with further developments in 2018. At CERN, RF phase noise is used operationally in the Super Proton Synchrotron (SPS) and Large Hadron Collider (LHC). In this paper we show that it is suitable for operation with a variety of beam types in the PSB. In the PSB the synchrotron frequency changes by approximately a factor 4 during the 500 ms acceleration ramp, requiring large changes in the frequency band of the noise. During 2018, a new method of calculating the noise parameters has been demonstrated, which gives upper and lower bounds to the noise frequency band that are smoothly varying through the ramp. The new calculation method has been applied to operational beams accelerated in both single and double RF harmonics, the final results are presented here.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB067

About •

paper received ※ 29 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB068

Upgrade of CERN’s PSB Digital Low-Level RF System

HLRF, LLRF, controls, proton

3958

M.E. Angoletta, S.C.P. Albright, A. Findlay, M. Jaussi, J.C. Molendijk, N. Pittet
CERN, Geneva, Switzerland

The CERN PS Booster (PSB) is the first circular accelerator in the LHC proton injector chain. The upgrade of this four-ring machine is underway within the framework of the LHC Injectors Upgrade project. The existing digital Low-Level RF (LLRF) system will also be upgraded. This paper outlines the LLRF capabilities required, their implementation and the challenges involved. Results of tests carried out to prepare for the LLRF upgrade are given.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB068

About •

paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB069

The New Digital Low-Level RF System for CERN’s Extra Low Energy Antiproton Machine

LLRF, proton, extraction, antiproton

3962

M.E. Angoletta, M. Jaussi, J.C. Molendijk
CERN, Geneva, Switzerland

CERN’s new Extra Low ENergy Antiproton accelerator/decelerator (ELENA) completed its initial commissioning in 2018. This machine is equipped with a new digital Low-Level RF (LLRF) system that implements beam and cavity loops as well as longitudinal diagnostics. ELENA’s LLRF was instrumental for machine commissioning by decelerating some 1 E7 antiprotons from 5.3 MeV to 100 keV. Commissioning with H⁻ ions took also place. Challenges faced included coping with low beam intensity and the wide frequency swing. This paper gives an overview of the LLRF system capabilities and operation. Beam results achieved with both H⁻ ions and antiprotons are also shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB069

About •

paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB070

A New Digital Low-Level RF and Longitudinal Diagnostic System for CERN’s AD

LLRF, proton, diagnostics, antiproton

3966

M.E. Angoletta, S.C.P. Albright, A. Findlay, M. Jaussi, J.C. Molendijk, V.R. Myklebust
CERN, Geneva, Switzerland

The Antiproton Decelerator (AD) has been routinely providing 3 E7 antiprotons since July 2000 at 100 MeV/c from 3.5 GeV/c. It will be refurbished during the Long Shutdown 2 (LS2) to provide reliable operation for the new Extra Low ENergy Antiproton (ELENA) ring. AD will be equipped with a new digital Low-Level RF (LLRF) system before its restart in 2021. Diagnostics to measure beam intensity, Δp/p and Schottky spectra will also be developed. This paper is an overview of the planned capabilities and implementations, as well as of the challenges to overcome.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB070

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB072

Operational Experience of a Prototype LHC Injection Kicker Magnet with a Low SEY Coating and Redistributed Power Deposition

kicker, injection, vacuum, electron

3974

M.J. Barnes, C. Bracco, G. Bregliozzi, A. Chmielinska, L. Ducimetière, B. Goddard, G. Iadarola, T. Kramer, V. Vlachodimitropoulos, W.J.M. Weterings
CERN, Geneva, Switzerland
A. Chmielinska
EPFL, Lausanne, Switzerland
L. Vega Cid
ETSII UPM, Madrid, Spain

Funding: This research was supported by the HL-LHC project
In the event that it is necessary to exchange an LHC injection kicker magnet (MKI), the newly installed kicker magnet would limit HL-LHC operation for a few hundred hours due to dynamic vacuum activity. A surface coating with a low secondary electron yield, applied to the inner surface of an alumina tube to reduce dynamic vacuum activity without increasing the probability of UFOs, and which is compatible with the high voltage environment, was included in a prototype MKI installed in the LHC during the 2017-18 Year End Technical Stop. In addition, this MKI included an upgrade to relocate a significant portion of beam induced power from the yoke to a ’damping element’: this element is not at pulsed high voltage. The effectiveness of the upgrades has been demonstrated during LHC operation, hence a future version will include water cooling of this ’damping element’. This paper reviews dynamic vacuum around the MKIs and summarizes operational experience of the upgraded MKI.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB072

About •

paper received ※ 08 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB074

Studies Towards the New Beam Screen System of the LHC Injection Kicker Magnet for HL-LHC Operation

kicker, injection, vacuum, simulation

3982

V. Vlachodimitropoulos, M.J. Barnes, A. Chmielinska, L. Ducimetière, L. Vega Cid, W.J.M. Weterings
CERN, Geneva, Switzerland
A. Chmielinska
EPFL, Lausanne, Switzerland
L. Vega Cid
ETSII UPM, Madrid, Spain

Although no heating issues were observed in the Large Hadron Collider’s (LHC) injection kicker magnets (MKIs) during Run 2, simulations suggest that for operation with the high intensity beams of the High Luminosity LHC (HL-LHC) project, the magnet’s ferrite yokes will reach their Curie temperature, thus leading to long turnaround times before a new beam can be safely injected into the machine. To safely enter the HL-LHC era, a campaign to redesign the kicker’s beam screen was launched. An improved beam-screen has already been implemented in an upgraded MKI, that was installed in the LHC tunnel in the Year End Technical Stop (YETS) 17/18, and has been successfully tested during 2018 operation. However, the improved design alone is not expected to be enough for HL-LHC operation, and further modifications are required. In this work, the approach to the design from an electromagnetic point of view is presented and different considered options are reported, emphasising the final design of the new beam screen system that is currently being implemented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB074

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB078

Performance Validation of the Existing and Upgraded PS Injection Kicker

kicker, injection, flattop, simulation

3994

A. Ferrero Colomo, N. Ayala, A. Chmielinska, V. Forte, M.A. Fraser, T. Kramer, L. Sermeus
CERN, Geneva, Switzerland

The CERN PS injection kicker KFA45 will be upgraded in the framework of the LHC Injector Upgrade (LIU) project to allow for injection of 2 GeV proton beams. This paper summarizes the recent efforts to validate beam based waveform measurements, Pspice simulations and current waveform measurements by direct magnetic field measurements in the aperture of the existing system. The magnetic probe, associated measurement hardware design and measurements results are discussed. The paper concludes with a performance comparison and an outlook to future waveform tuning possibilities.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB078

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB079

DC Testing and Phase Resolved Partial Discharge Measurements of the New Trigger Transformers for the LHC Beam Dump Kickers

high-voltage, kicker, GUI, power-supply

3998

T. Stadlbauer, A. Chmielinska, L. Ducimetière, D. Kontelis, T. Kramer, V. Senaj
CERN, Geneva, Switzerland

During LS2 the LHC beam dump kicker pulse generators will be subject to a substantial consolidation program. One major part is the replacement of the existing GTO stack trigger transformer by a new more performant one. The transformer is assembled, moulded and tested in-house. Part of the validation procedure are standard DC tests and subsequent discharge monitoring as well as newly introduced phase resolved partial discharge measurements. This paper briefly highlights the trigger transformer parameters and construction and outlines in detail the testing and partial discharge measurements. It concludes with a comparison and analysis of the results of the different measurement techniques.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB079

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB080

Automatisation of the SPS ElectroStatic Septa Alignment

alignment, simulation, extraction, septum

4001

S. Hirlaender
ATI, Vienna, Austria
M.A. Fraser, B. Goddard, V. Kain, J. Prieto, L.S. Stoel, F.M. Velotti
CERN, Geneva, Switzerland
M. Szakaly
Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary

An electrostatic septum composed of 5 separate tanks is used to slow-extract the 400 GeV proton beam resonantly on the third integer resonance from the CERN SPS. The septa are all mounted on a single support structure that can move the ensemble coherently and, in addition, the internal anode and cathode of each tank can be moved independently. The septum is aligned to the beam by measuring and minimising the induced beam loss signals in the extraction region following an alignment procedure that is usually carried out manually at the beginning of each year. The large number of positional degrees of freedom complicates the procedure and until recently each tank was aligned one after the other semi-manually, typically requiring 8 hours. It is not uncommon that the septum has to be re-aligned later in the run taking time away from physics programme. To tackle this issue, a simplified beam dynamics and scattering simulation routine was developed to permit error studies with a large number of seeds to be carried out in a reasonable computation time. In this contribution, the simulation model will be described before the results of its exploitation to understand the efficacy of alignment procedures based on different optimization algorithms are discussed and compared to the present operational procedure. The effort culminated with the implementation of an automated alignment procedure based on a Powell optimisation algorithm that reduced the time needed to align the septum by over an order of magnitude.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB080

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB083

Detailed Analysis Of The Baseline Dose Levels And Localized Radiation Spikes In The Arc Sections Of The Large Hadron Collider During Run 2

radiation, experiment, ECR, monitoring

4009

K. Bilko, M. Brugger, R. Garcia Alia, F.J. Harden, Y. Kadi, O. Stein
CERN, Geneva, Switzerland

The Large Hadron Collider (LHC) has eight insertion regions (IRs) which house the large experiments or accelerator equipment. These IRs are interconnected with the arc sections consisting of a periodic magnet structure. During the operation of the LHC small amounts of the beam particles are lost, creating prompt radiation fields in the accelerator tunnels and the adjacent caverns. One of the main loss mechanisms in the LHC arc sections is the interaction of the beam particles with the residual gas molecules. The analysis of the dose levels based on the beam loss measurement data shows that the majority of the measurements have similar levels, which allow to define baseline values for each arc section. The baseline levels decreased during the years 2015, 2016 and stabilised in 2017 and 2018 at annual dose levels below 50 mGy, which can be correlated with the residual gas densities in the LHC arcs. In some location of the arcs radiation spikes exceed the base line by more than two orders of magnitude. In addition to the analysis of these dose levels, a novel approach of identifying local dose maxima and the main driving mechanisms creating these radiation spikes will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB083

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB084

Run 2 Prompt Dose Distribution and Evolution at the Large Hadron Collider and Implications for Future Accelerator Operation

radiation, collimation, proton, luminosity

4013

O. Stein, K. Bilko, M. Brugger, R. Garcia Alia, F.J. Harden, Y. Kadi, A. Lechner, G. Lerner
CERN, Geneva, Switzerland

During the operation of the Large Hadron Collider (LHC) small fractions of beam particles are lost, creating prompt radiation fields in the accelerator tunnels. Exposed electronics and accelerator components show lifetime degradation and stochastic Single Event Effects (SEEs) which can lead to faults and downtime of the LHC. Close to the experiments the radiation levels scale nicely with the integrated luminosity since the luminosity debris is the major contributor for creating the radiation fields in this area of the LHC. In the collimation regions it was expected that the radiation fields scale with the integrated beam intensities since the beams are continuously cleaned from particles which exceed the accelerator’s acceptance. The analysis of radiation data shows that the dose measurements in the collimation regions normalised with the integrated beam intensities for 2016 and 2017 are comparable. Against expectations, the intensity normalised radiation datasets of 2018 in these regions differ significantly from the previous years. Especially in the betatron collimation region the radiation levels are up to a factor 3 higher. The radiation levels in the collimation regions correlate with the levelling of beta-star and the crossing angle in the high luminosity experiments ATLAS and CMS. These increased normalised doses have direct implications on the expected dose levels during future LHC operation, including the High-Luminosity LHC (HL-LHC) upgrade.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB084

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB086

Design & Optimization of the Alignment Supports for the New Laminated Magnets for the CERN East Area Consolidation Project

alignment, radiation, GUI, secondary-beams

4020

R. Vanhoutte, D. Brethoux, A. Ebn Rahmoun, S. Evrard, F.J. Harden, E. Harrouch, M. Lazzaroni, M. Lino Diogo dos Santos, R. Lopez, D.E. Nogtikov, J. Renedo Anglada
CERN, Meyrin, Switzerland

The East Area is one of CERNs experimental area, running since its foundation in 1958. Extracting a 24GeV proton beam from the Proton Synchrotron accelerator, the primary beam is divided into different secondary beams, serving various experiments and user’s facilities such as CLOUD, CHARM, IRRAD. Due to improved optics and an energy saving scheme, the facility will go under a renovation between 2019 and 2020, including the replacement of the magnets with new laminated ones to allow a cycled powering scheme. Those magnets need improved supports, and in some cases even a new design, to optimize the alignment operations in those areas. This article will mainly address the different proposed solutions for plug-in supports as well as for conventional ones.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB086

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB087

Study of the Energy Savings Resulting from the East Area Renovation

ECR, experiment, power-supply, radiation

4023

B.LM. Lamaille, F. Dragoni, S. Evrard, F.J. Harden, E. Harrouch, M. Lazzaroni, R. Lopez, K.D. Papastergiou
CERN, Meyrin, Switzerland

CERN’s East Experimental Area, situated on the Swiss side of the Meyrin site, with its four beamlines, has served physics for more than 40 years. As the building and equipment are reaching their end of life, a thorough consolidation project has been initiated in order to pro-vide many more years of reliable operation. This article addresses the different proposed solutions to reduce significantly the energy consumption of the East Area. It outlines the methodology applied to estimate as precisely as possible the future attained energy savings, which will result in an estimated reduction of approximately 80% in electricity usage (from 11 GWh to 2 GWh per year) and of approximately 65% in gas usage for heating purpose (from 3 GWh to 1 GWh per year).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB087

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB091

APPLICATION PROGRAMS FOR TPS BEAM TRIP ANALYSIS

power-supply, kicker, electron, photon

4032

B.Y. Chen, T.W. Hsu, B.Y. Huang, C.S. Huang, C.H. Kuo, T.Y. Lee, W.Y. Lin
NSRRC, Hsinchu, Taiwan

For the Taiwan Photon Source (TPS), the orbit inter-lock system is one of the most important machine pro-tection systems. It is the fastest and the most preferred system to detect abnormalities to prevent possible dam-ages caused by magnet power supply failures or subsys-tems failures. In order to monitor electron orbit changes during a beam trip, we developed the ’orbit monitoring and recording tool’, the ’TBT BPM analysis tool’ and the ’magnet power supply recording and analysis tool’ to assist us in the failure analysis as will be discussed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB091

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB104

Improvements in Long-Term Orbit Stability at NSLS-II

feedback, photon, controls, storage-ring

4070

Y. Hidaka, A. Caracappa, Y. Hu, B. Podobedov, R.M. Smith, Y. Tian, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: The study is supported by U.S. DOE under Contract No. DE-SC0012704.
We report our latest efforts to further improve long-term orbit stability at NSLS-II, on top of what is already provided by fast orbit feedback (FOFB) system. A DC local bump generation program, only utilizing RF beam position monitors (BPM) and compatible with FOFB, was first implemented and deployed in operation successfully, allowing on-demand fine adjustments of beamline source positions and angles. Then we introduced a simple feedback version that performs these bump corrections automatically as needed to maintain the sources within in 1 um/urad for select beamlines. In addition, an RF frequency feedback was also implemented to improve stability for 3-pole wigglers and bending magnet users. As a parallel effort, X-ray BPMs were included in a local feedback system to stabilize photon beam motion for several ID beamlines. However, this feedback scheme is not transparent to FOFB, and suspected to be the source of occasional saturation of fast corrector strength. As an alternative solution, the local bump program and its feedback version has been recently upgraded to include bumps with X-ray BPMs and in operation since April 2019.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB104

About •

paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB108

LBNF Hadron Absorber: Updated Mechanical Design and Analysis for 2.4 MW Operation

hadron, site, simulation, shielding

4078

A. Deshpande, K. Anderson, K.E. Gollwitzer, B.D. Hartsell, J. Hylen, V.I. Sidorov, S. Tariq
Fermilab, Batavia, Illinois, USA

The Long-Baseline Neutrino Facility (LBNF) Hadron Absorber is located downstream of the decay pipe. It consists of actively cooled aluminum and steel blocks surrounded by steel and concrete shielding. Majority of the beam power is deposited in the absorber core which is water cooled. The surrounding steel and concrete shielding are air-cooled. The absorber provides radiation protection to personnel and keeps soil and ground activation levels to below allowable limits. It is designed for 2.4 MW beam operations. The total heat load deposited into the absorber is approximately 400 kW. The current design considers the longer 4-interaction length target of the optimized beam design. In addition, the ‘bafflette’ around the target reduces the energy deposited into the absorber. For this reason, the sculpting in the aluminum core blocks, which was in the previous design, was removed, making the design uniform and less complicated. In addition, the uniformity of the absorber makes it easier to understand the muon monitor data. Steady state thermal, structural, and Computational Fluid Dynamics (CFD) analysis of critical absorber aluminum and steel components during steady state operations is discussed herein. A similar analysis for a 120 GeV, 10 µs pulse, accident condition is also discussed. A preliminary design for the accident pulse prevention system that protects the absorber is also described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB108

About •

paper received ※ 30 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB115

MicroTCA Based LLRF Control Systems for TARLA and NICA

LLRF, cavity, controls, electron

4089

P. Nonn, C. Gümüş, C.K. Kampmeyer, H. Schlarb, Ch. Schmidt, T. Walter
DESY, Hamburg, Germany

The MicroTCA Technology Lab (A Helmholtz Innovation Lab) is preparing two turn-key Low Level RF control systems for facilities outside of DESY. The Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) is a 40 MeV electron accelerator with continuous wave (CW) RF operation. The MicroTCA based LLRF control system is responsible for two normal conducting and four superconducting cavities, controlling the RF as well as cavity tuning via motors and piezos. The Light Ion Linac (LILAC) is one of the injectors for the Nuclotron-based Ion Collider Facility (NICA) in Dubna, Russia. It will provide a 7 MeV/u pulsed, polarized proton or deuteron beam. The MicroTCA based LLRF control system will control five normal conducting cavities, consisting of one RFQ, one buncher, one debuncher and two IH-cavities. MicroTCA Technology Lab is cooperating with BEVATECH GmbH, Frankfurt, Germany, who designed the cavities. This paper gives a brief overview of the design of both LLRF systems as well as the status of their assembly.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB115

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB116

Effect of Ground Motion Introduced by HL-LHC CE Work on LHC Beam Operation

ground-motion, luminosity, civil-engineering, GUI

4092

M. Schaumann, D. Gamba, M. Guinchard, L. Scislo, J. Wenninger
CERN, Geneva, Switzerland

Funding: Research supported by the HL-LHC project
The official groundbreaking of the civil engineering (CE) work for the high luminosity upgrade of the LHC started on 15 June 2018 parallel to LHC beam operation. Compactor work and shaft excavation around the two low beta experiments, ATLAS and CMS, were expected to induce vibrations to the accelerator magnets and cause orbit disturbance, beam loss and potentially premature beam dumps. Ground motion sensors were installed on the surface and close to the triplets, where the CE works were expected to have the largest impact on the beams. This paper discusses the observations made on the LHC beams that could be correlated to CE work.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB116

About •

paper received ※ 13 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB117

Stability and Reliability Issues of PAL-XFEL Modulator

FEL, klystron, power-supply, electron

4096

S.H. Kim, H.-S. Kang, K.H. Kim, H.-S. Lee, C.-K. Min, S.S. Park, Y.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: This work is supported by Ministry of Science, ICT(Information/Communication Technology) and Future Planning.
The Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL) employs 51 units of the pulse modulator in order to obtain the 10 GeV electron beam, which drive one X-band to linearize and 50 S-band klystrons. The PAL-XFEL requires very tight control of the klystron RF phase jitter 0.03-degree for S-band RF, 0.1-degree for X-band RF and the beam voltage stability of below 50 ppm. The RF phase jitter is directly related to the amplitude stability of modulator output pulses. There are several factors to satisfy the stability and reliability for the PAL-XFEL modulator. The largest sources of pulse-to-pulse instability are a current charging power supply (CCPS) for PFN charging, a thyratron switch, and a klystron focusing magnet power supply (MPS). In this paper, the operation and debugging results of those devices are described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB117

About •

paper received ※ 16 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS006

Upgrade of the Canadian Light Source Booster RF System to Solid State

booster, controls, klystron, cavity

4112

J.M. Patel, D. Bertwistle, J. Stampe
CLS, Saskatoon, Saskatchewan, Canada
A. Bachtior, A. Borisov, N. Pupeter
CRE, Wuppertal, Germany
P. Hartmann
DELTA, Dortmund, Germany

Funding: CFI, NSERC, NRC, CIHR, the Province of Saskatchewan, WD, and the University of Saskatchewan
The Canadian Light Source synchrotron (CLS) had first light in 2004. For the last 14 years of operation we have exclusively used klystrons to provide RF power to our linac, booster, and storage ring. The klystrons represent a single point of failure for the operation of our booster and storage ring. This is especially poignant in the case of our booster ring klystron which is no longer manufactured. We have chosen to move to solid state amplifier (SSA) RF technology for its implicit high redundancy, modularity, ease of maintenance, and efficiency. Herein we review the performance parameters of our upgraded booster RF to a 100 kW 500 MHz transmitter built by Cryoelectra.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS006

About •

paper received ※ 08 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS010

Start of the Series Production for the Cryogenic Magnet Corrector Modules of FAIR

dipole, quadrupole, sextupole, superconducting-magnet

4124

E.S. Fischer, A. Bleile, V.I. Datskov, V. Marusov, J.P. Meier, P.J. Spiller
GSI, Darmstadt, Germany

The fast cycling superconducting synchrotron SIS100 has to deliver high intensity beams for the FAIR project at GSI, Darmstadt. The main dipoles will ramp with 4 T/s up to a maximum magnetic field of 1.9 T where the field gradient of the main quadrupole will reach 27.77 T/m. The integral magnetic field length of the horizontal/vertical steerer and of the chromaticity sextupole will provide 0.403/0.41 m and 0.383 m respectively. We present the status of the first magnets test results as well as the overall procedure of production and testing of the complete series of the cryomagnetic corrector modules.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS010

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS028

Recent Improvements and Future Upgrades of the J-PARC Main Ring Kicker Systems

kicker, power-supply, injection, extraction

4167

T. Sugimoto, K. Ishii, H. Matsumoto, T. Shibata
KEK, Ibaraki, Japan

J-PARC Main Ring provides 500kW proton beam to the long baseline neutrino oscillation experiment (T2K). In order to increase the beam intensity to improve the sensitivity of the CP violation study in neutrino sector, shorter repetition cycle and higher beam current are required. As part of the upgrade project, both injection and fast-extraction (Fx) kicker magnet systems have been improved. Air-cooled non-inductive ceramic resistors are used as the impedance-matching terminator for the injection kicker magnet. Power consumption and temperature rise of the termination resistor due to the beam induced current was simulated to optimize the number of parallel of the resistors. Efficiency of cooling fans was also simulated to improve the cooling ability. For the Fx kicker magnet, a fast charging power supply of the modulator was developed and deployed to shorten the charging period from 1.4 sec to 0.2 sec. This paper represents the simulation results, performance of the charging unit and future upgrade plans.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS028

About •

paper received ※ 21 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS043

PRELIMINARY MAGNETIC FIELD CALCULATION OF A 30-DEGREE DIPOLE MAGNET

dipole, simulation, proton, laser

4204

H. Liang, J. Huang, C. Jiang, T. Liu, B. Qin, K. Tang, J. Yang, J.Q. Ye
HUST, Wuhan, People’s Republic of China
Y. Xie, T. Yu
Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China

Preliminary design and field calculation of a 30-degree H-type dipole which can be applied to the beamline is introduced in this paper. According to the phys-ical requirements, 2D and 3D models are built and ana-lysed using OPERA. For achieving the magnetic field specifications, air slots are adopted, and trapezoidal shim on pole surface is used to improve the magnetic field error. Rogowski curve and harmonic shim at the pole end is used to reduce the integral magnetic field error and the higher order harmonic field error.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS043

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS045

Preparation of Titanum-Zirconium-Vanadium Films by Quantitative Deposition

vacuum, experiment, electron, ECR

4210

J.Q. Shao, C. Chen, X.Q. Ge, W. Li, S. Wang, Y. Wang, W. Wei, B. Zhang, Y.X. Zhang, B.L. Zhu
USTC/NSRL, Hefei, Anhui, People’s Republic of China

TiZrV has been used in vacuum technology and electric vacuum devices due to its high pumping speed and low activation temperature in recent years. At the same time, many preparation methods have been developed. Different from the current coating method of magnetron sputtering, this paper discusses the preparation of thin film coating from the viewpoint of vacuum sintering, which is flexible in design and more suitable for operation. Based on the analysis of the surface morphology of the sintered film, the feasibility and operability of the experimental method were explored from the surface compactness of the getter.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS045

About •

paper received ※ 25 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS053

Design of a Fast Cycled Low Loss 6 T Model Dipole Cooling at 1.9 K

dipole, synchrotron, experiment, superconducting-magnet

4221

A.D. Kovalenko, V.A.. Gromov, E.E. Perepelkin, G. Shirkov
JINR, Dubna, Moscow Region, Russia
B. Bordini, D. Tommasini
CERN, Geneva, Switzerland
A. Kolomiets
ITEP, Moscow, Russia
S. Kozub, L. Tkachenko
IHEP, Moscow Region, Russia

The option being considered for the FCC-hh high energy injector is a superconducting synchrotron replacing the CERN SPS. The new machine would operate in a cycled mode also to feed experimental areas, much like the SPS nowadays. Due to this specific cycled operation, innovative design and development approaches is required to cope with the AC losses in the superconducting cables and iron yoke. The research joins experience accumulated at CERN and JINR respectively in the design and operation of large systems operated at 1.9 K and, in fast ramped and cycled magnets. The specified parameters are the following: magnet aperture -80 mm; aperture field - 6 T; field ramp 0.2-0.5 T/s; coil conductor - NbTi; magnetic field homogeneity between 0.12 and 6 T of the order of 5·10^-4. The minimization of the cycling losses is particular important. Total thermal losses should be limited to tentatively < 2 W/m at 4.2 K. The magnet design, and the results of preliminary tests on a candidate NbTi-wire for building a model magnet are presented and discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS053

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS058

New 50 KW SSPA Transmitter for the ALBA Booster

booster, ISOL, synchrotron, cavity

4237

P. Solans, B. Bravo, J.R. Ocampo, F. Pérez, A. Salom
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
J.V. Balboa, I. Fernández, D. Iriarte, J. Lluch, A. Mellado, C. Rosa, F. Sierra, E. Ugarte
BTESA, Leganés, Spain

ALBA is a 3th generation 3 GeV synchrotron light source located in Barcelona and operating with users since May 2012. The IOT based transmitter for the booster cavity has been replaced by a Solid State Power Amplifier (SSPA) of 50 kW at 500 MHz in August 2018. The new transmitter is made of 96 active devices, which are divided in 12 modules of 8 transistors each one. The modules are combined in groups of four using the Gysel topology and two hybrid combiners are used for the final combining stage. The design allows the transmitter to provide enough power even when multiple transistor fails occur, in the same module or in different ones, and it also presents power supplies redundancy. These modules can be hot swapped, i.e., the module can be replaced by a spare at any time, even when the transmitter is providing power without affecting the operation. After two months of operation, the transmitter fulfills very well the design specifications regarding power, efficiency and gain; and although minor problems have arisen due to infant mortality in some components, the operation of the transmitter has never been affected due to the high redundancy.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS058

About •

paper received ※ 15 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS059

Development of a 1.5 GHz, 1 KW Solid State Power Amplifier for 3rd Harmonic System of the Alba Storage Ring

cavity, storage-ring, network, ISOL

4240

Z. Hazami, F. Pérez, A. Salom, P. Solans
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

ALBA is the Spanish third generation synchrotron light source, located near Barcelona, in operation since 2012. In order to improve the operation, a third harmonic system has been designed for the Storage Ring in order to stretch the bunch length, and so, improve the beam life time and increase the stability current thresholds. The design of the system consist of four Higher Order Mode (HOM) damped normal conductive active cavities at 1.5 GHz*, feed with 20 kW of RF power each cavity, in order to provide the voltage of 1 MV to the electron beam. The 20 kW RF power transmitter system is based on 250 W solid state power amplifier modules added in parallel by a tree combination technique. The selected combination tree divides the 20 kW overall power per cavity in twenty 1 kW crates. This paper presents the designs of the 250 W power amplifier modules, of the splitter and of the combiner, as well as the measurement results of a 1 kW prototype crate.
* HOM Damped Normal Conducting 1.5 GHz Cavity for the 3rd Harmonic System of the ALBA Storage Ring. IPAC 2019 proceedings

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS059

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS069

A Monitoring System for TPS Linac

linac, PLC, controls, injection

4272

C.L. Chen, H.-P. Chang, C.-S. Fann, K.L. Tsai
NSRRC, Hsinchu, Taiwan

Abstract Since 2014, TPS Linac system has been operating regularly. In order to keep a high stability during a long operating time, it is important to develop a monitoring system to monitor all sub-systems, parameters, including setting values, reading values, control inputs and outputs. This system is not only recording all above mentioned parameters, but also provides an efficient diagnosis in case of troubleshooting. Because the controlling system in TPS Linac is using Siemens S7-300 PLCs, Simatic WinCC is utilized to develop a historical archiving, operational analyses, and operator activities in operation. This paper attempts to show a complete solution for the integrated software structure and its resulting process analysis.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS069

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS090

Injection Locked 1497 MHz Magnetron

klystron, status, cathode, injection

4322

M.L. Neubauer, M.A. Cummings, A. Dudas, R.P. Johnson, S.A. Kahn, G.M. Kazakevich, M. Popovic
Muons, Inc, Illinois, USA
R.A. Rimmer, H. Wang
JLab, Newport News, Virginia, USA

Muons, In is building an amplitude modulated phase-locked magnetron to replace the klystrons in CEBAF. To do that requires changing the magnetic field at a rate that would induce eddy currents in the standard magnetron. We report on the status of the project to make a stainless steel anode with copper elements to minimize heating while the stainless steel reduces eddy current effects. The construction of the magnetron is two months from completion, while the test stand is ready for delivery of the magnetron

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS090

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS091

Phase and Frequency Locked 350 MHz Magnetron

cathode, injection, status, vacuum

4325

M.L. Neubauer, A. Dudas, R.P. Johnson, S.A. Kahn, G.M. Kazakevich, M. Popovic
Muons, Inc, Illinois, USA

The 120kW 350 MHz magnetron is being developed for a number of RF systems, chiefly among them, Niowave’s 10 MeV accelerator. Industri-al applications of the magnetron have also been explored. The CW magnetron can be operated in the pulse mode by a novel injection locking system. We report on the status of the program and progress to date

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS091

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS095

High Efficiency High Power Resonant Cavity Amplifier For PIP-II

cavity, coupling, impedance, network

4335

M.P.J. Gaudreau, D.B. Cope, E.G. Johnson, M.K. Kempkes, R.E. Simpson, N.A. Stuart
Diversified Technologies, Inc., Bedford, Massachusetts, USA

Funding: Work funded under US DOE Grant No. DE-SC0015780
Diversified Technologies, Inc. (DTI) is developing an integrated resonant-cavity combined solid-state amplifier for the Proton Improvement Plan-II (PIP-II) at Fermilab. The prototype has demonstrated multiple-transistor combining at 70% efficiency, at 675 watts per transistor at 650 MHz. The patent pending design simplifies solid-state transmitters to create straightforward scaling to 200 kW and higher high power levels. A crucial innovation is the reliable "soft-failure" mode of operation; a failure in one or more of the transistors has negligible performance impact. This design couples the transistor drains directly to the cavity without first transforming to 50 Ohms, avoiding the circulators, cables, and connectors that would normally be required. Under an ongoing SBIR grant from the US Department of Energy, DTI designed the system to accommodate over 96 transistors in each 50 kW cavity, with minimal RF, DC, and cooling connections. By the end of the SBIR, DTI will build and demonstrate a complete 100 kW-class (~200 kW) transmitter by combining four cavity modules to show the expandability of the design to very high power levels, comparable to large VEDs.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS095

About •

paper received ※ 19 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS099

Fermilab Superconducting Nb₃Sn High Field Magnet R&D Program

dipole, collider, status, proton

4338

G. Velev, G. Ambrosio, E.Z. Barzi, V.V. Kashikhin, S. Krave, V. Lombardo, I. Novitski, S. Stoynev, D. Turrioni, X. Xu, A.V. Zlobin
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.
Magnets based on the modern Nb₃Sn conductor are the main candidates for future high-energy hadron colliders. Fermilab as part of the U.S. MDP executes an extensive R&D program on these high-field magnets. This program includes basic conductor and material R&D, quench per-formance studies, and building a meter-long high-field demonstrator. This paper summarizes the current status of the program including its recent results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS099

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS102

Radio Frequency Power Stations for ESS LINAC Spoke Section

controls, power-supply, cavity, site

4346

C. Pasotti, M. Cautero, T.N. Gucin
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
C.A. Martins, R.A. Yogi
ESS, Lund, Sweden

26 equivalent 400 kW Radio Frequency Power Station (RFPS) units will be provided by Elettra as part of the Italian in kind contribution to ESS. They will be installed in the LINAC "Spoke Section". Each RFPS will power a single superconducting spoke cavity in pulsed operation at 352.21 MHz. The RFPS is a complete system that operates unmanned, based on a combination of solid state and tetrode amplification’s stages. The tender specification, the RFPS main features and requested performances are reported here.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS102

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTS103

First Results of the Analytical Method Used to Reduce Downtime Risk at an Accelerator Facility

target, linac, DTL, vacuum

4349

W.C. Barkley, M.J. Borden, R.W. Garnett, M.S. Gulley, E.L. Kerstiens, M. Pieck, D. Rees, F.E. Shelley, B.G. Smith
LANL, Los Alamos, New Mexico, USA

Funding: DOE
The Los Alamos Neutron Science Center (LANSCE), like many other accelerator facilities, was built decades ago and has been repurposed when new missions were adopted. With an ongoing beam availability expectation of at least 80% delivered to the Experimental Areas (EAs), a balance between cost of spare equipment and budget has always been a challenge. Beam availability data has been meticulously captured and binned over the years to completely characterize the Structures, Systems and Components (SSCs) and other factors that have caused or contributed to accelerator downtime. Over these years, a critical spares list prioritized the spare equipment purchases that were deemed most critical by the management team. In the span of the years 2013 ’ 2015, significant accelerator upgrades and equipment replacements were performed in a set of activities known as LANSCE-RM. Last year, a new risk-based approach was developed by the management team that included an analytical assessment and a quantitative evaluation of probability and consequence. The resulting risk register (risk-based equipment list) is being used to guide decisions on funding requests and provide justification to mitigate operational risks. A paper by the same authors was published at LINAC 2018 describing this risk-based approach that serves to reformulate the critical spares list. This paper, in the sections that follow, expands on the approach by detailing the specific results of the analyses that led to the first risk register. Additionally, it evaluates the historical beam downtime at LANSCE compared to the current funding allocation choices made to increase the reliability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS103

About •

paper received ※ 10 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRXXPLM3

Development of a Pulsed Power Supply Utilizing 13 kV Class SiC-MOSFET

pulsed-power, high-voltage, power-supply, electron

4364

K. Okamura, F. Naito, K. Takayama
KEK, Ibaraki, Japan
K. Fukuda, H. Kitai, K. Sakamoto
AIST, Tsukuba, Ibaraki, Japan
T. Kaito
Chiba Institute of Technology, Narashino, Chiba, Japan
D. Kumamoto
Nagaoka University of Technology, Nagaoka, Niigata, Japan
S. Lim, A. Tokuchi
Pulsed Power Japan Laboratory Ltd., Kusatsu-shi Shiga, Japan

Funding: A part of this work has been implemented under a joint research project of Tsukuba Power Electronics Constellation (TPEC).
To resolve the drawback of conventional thyratron switches, development of a semiconductor high voltage switch utilizing a 13 kV class SiC-MOSFET developed by Tsukuba Power Electronics Constellations (TPEC) is proceeding. At first, the device evaluation test was carried out with a resistive load circuit. With the conditions of drain voltage of 10 kV and load resistance of 1 kΩ, turn on loss Eon, turn off loss Eoff, rise time Tr and fall time Tf were 1.7 mJ, 1.1 mJ, 64 ns, and 75 ns, respectively. As to gate charge characteristics, required electric charge to increase gate source voltage from 0 V to 20 V was about 80 nC. Thereafter, the 2s-12p switch array was designed and assembled, where 12 MOSFETs are equally aligned on a circle shaped circuit board and two circuit boards are stacked in series. A 14 kV-490 A-5 us pulse with a rise time of 430 ns in the long pulse mode and a 18 kV-318 A-1 us pulse with a rise time of 289 ns in the short pulse mode were successfully demonstrated. This switch will be installed as a turn-off switch for the injec-tion ES kicker in the KEK-DA.

Slides FRXXPLM3 [5.088 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-FRXXPLM3

About •

paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRXPLM1

Operations Experience of SNS at 1.4MW and Upgrade Plans for Doubling the Beam Power

target, proton, neutron, cryomodule

4380

J. Galambos
ORNL, Oak Ridge, Tennessee, USA

In 2018, the SNS begins operation at the design proton beam power of 1.4 MW. This talk will present the critical technical challenges that were overcome in order to take the final step in beam power with a higher than 90% reliability. In addition, the future project of the SNS for doubling the beam power from 1.4 MW to 2.8 MW and construction of second target station will be discussed.

Slides FRXPLM1 [22.095 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-FRXPLM1

About •

paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRYPLM2

Lasers for Novel Accelerators

laser, plasma, electron, photon

4385

L.A. Gizzi, P. Koester, L. Labate, G. Toci, M. Vannini
INO-CNR, Pisa, Italy
F. Mathieu
LULI, Palaiseau, France
Z. Mazzotta
ARCNL, Amsterdam, The Netherlands
Z. Mazzotta
Ecole Polytechnique, Palaiseau, France

Significant progress has been made over the last decade in optical laser performance including repetition rate, average and peak power, and laser-system footprint making these systems attractive for many applications including novel accelerators. Most novel acceleration schemes require high-power lasers. The talk will present drive laser requirements for current novel accelerator schemes, industry plans to meet these requirements, and the future for high-power lasers.

Slides FRYPLM2 [32.406 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-FRYPLM2

About •

paper received ※ 08 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)