IPAC2021 - List of Keywords (radiation)

Paper	Title	Other Keywords	Page
MOPAB012	Energy Deposition Study of the CERN HL-LHC Optics v1.5 in the ATLAS and CMS Insertions	luminosity, insertion, proton, optics	76
	M. Sabaté-Gilarte, F. Cerutti CERN, Meyrin, Switzerland
	Funding: Research supported by the HL-LHC project The High Luminosity Large Hadron Collider (HL-LHC) is the approved CERN project aiming at further increasing the integrated luminosity of the LHC by a factor 10. As such, it implies a complete redesign of the experimental high-luminosity insertions of ATLAS and CMS. The progressive evolution of the new layout and optics requires a continuous analysis of the radiation environment, to which magnets and other equipment are exposed to. This is assured by means of Monte Carlo simulations of the collision debris on the evolving machine model. The latter featured several developments, such as the explicit inclusion of the cold protection diodes of the final focusing circuits as well as the crab cavities cryomodule. This work presents the most updated characterization of the radiation field with FLUKA and its impact in the insertion region and the dispersion suppressor of Point 1 and 5, for the HL-LHC optics v1.5 released in 2019. Various optimization and mitigation studies are highlighted, providing key information for maximizing the lifetime of new and present magnets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB012
About •	paper received ※ 18 May 2021 paper accepted ※ 25 May 2021 issue date ※ 21 August 2021
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MOPAB013	Radiation to Electronics Impact on CERN LHC Operation: Run 2 Overview and HL-LHC Outlook	operation, luminosity, electron, target	80
	Y.Q. Aguiar, A. Apollonio, F. Cerutti, S. Danzeca, R. García Alía, G. Lerner, D. Prelipcean, M. Sabaté-Gilarte CERN, Geneva 23, Switzerland
	Funding: Research supported by the HL-LHC project After the mitigation measures implemented during Run 1 (2010-2012) and Long Shutdown 1 (LS1, 2013-2014), the number of equipment failures due to radiation effects on electronics (R2E) leading to LHC beam dumps and/or machine downtime has been sufficiently low as to yield a minor impact on the accelerator performance. During Run 2 (2015-2018) the R2E related failures per unit of integrated luminosity remained below the target value of 0.5 events/fb-1, with the sole exception of the 2015 run during which the machine commissioning took place. However, during 2018, an increase in the failure rate was observed, linked to the increased radiation levels in the dispersion suppressors of the ATLAS and CMS experimental insertions, significantly affecting the Quench Protection System located underneath the superconducting magnets in the tunnel. This work provides an overview of the Run 2 R2E events during LHC proton-proton operation, putting them in the context of the related radiation levels and equipment sensitivity, and providing an outlook for Run 3 and HL-LHC operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB013
About •	paper received ※ 19 May 2021 paper accepted ※ 23 July 2021 issue date ※ 23 August 2021
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MOPAB018	SASE Gain-Curve Measurements with MCP-Based Detectors at the European XFEL	FEL, detector, photon, undulator	96
	E. Syresin, O.I. Brovko, A.Yu. Grebentsov JINR, Dubna, Moscow Region, Russia W. Freund, J. Grünert, J. Liu, Th. Maltezopoulos, D. Mamchyk EuXFEL, Schenefeld, Germany M.V. Yurkov DESY, Hamburg, Germany
	Radiation detectors based on microchannel plates (MCP) are used for characterization of the Free-Electron Laser (FEL) radiation and measurements of the Self-amplified spontaneous emission (SASE) gain curve at the European XFEL. Photon pulse energies are measured by the MCPs with an anode and by a photodiode. There is one MCP-based detector unit installed in each of the three photon beamlines downstream of the SASE1, SASE2, and SASE3 undulators. MCP detectors operate in a wide dynamic range of pulse energies, from the level of spontaneous emission up to FEL saturation. Their wavelength operation range overlaps with the whole range of radiation wavelengths of SASE1 and SASE2 (from 0.05 nm to 0.4 nm), and SASE3 (from 0.4 nm to 5 nm). In this paper we present results of SASE gain-curve measurements by the MCP-based detectors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB018
About •	paper received ※ 18 May 2021 paper accepted ※ 17 August 2021 issue date ※ 23 August 2021
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MOPAB033	Monochromatization of e⁺e⁻ Colliders with a Large Crossing Angle	emittance, resonance, collider, luminosity	152
	V.I. Telnov BINP SB RAS, Novosibirsk, Russia
	The relative center-of-mass energy spread at e⁺e⁻ colliders is much larger than the widths of narrow resonances, which greatly lowers the resonance production rates of J/Psi, Psi-prime, Upsililon(nS), n=1-3. Thus, a significant reduction of the center-of-mass energy spread would open up great opportunities in the search for new physics in rare decays of narrow resonances, the search for new narrow states with small partial e⁺e⁻ width. The existing monochromatization scheme is only suitable for head-on collisions, while e⁺e⁻ colliders with crossing angles (the so-called Crab Waist collision scheme) can provide much higher luminosity. In this report, a new monochromatization method for colliders with a large crossing angle is discussed. The contribution of the beam energy spread to the spread of the center-of-mass energy is canceled by introducing an appropriate energy-angle correlation at the interaction point; the relative RMS mass spread of about (3-5)10^-6 seems possible. Limitations of the proposed method are also considered. This monochromatization scheme is very attractive for the Upsilon-meson region and below. V.I.Telnov, Monochromatization of e⁺e⁻ colliders with a large crossing angle, arXiv:2008.13668
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB033
About •	paper received ※ 22 May 2021 paper accepted ※ 26 May 2021 issue date ※ 31 August 2021
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MOPAB044	Gas Bremsstrahlung Measurements in the Advanced Photon Source Storage Ring	photon, operation, detector, injection	193
	J.C. Dooling, A.R. Brill, J.R. Calvey ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357. In the Advanced Photon Source Upgrade storage ring (SR), small-aperture vacuum chambers provide limited conductance for pumping. Non-evaporable getter (NEG) coatings will be used in the SR to support the vacuum. Ion pumps and cold-cathode gauges are typically located away from the vacuum chamber transporting the beam. Measuring gas bremsstrahlung (GB) photons in low-conductance chambers provides a method to determine the pressure at the beam location. We report on GB measurements made in the ID-25 beamline. A Pb:Glass calorimeter radiator generates Cherenkov radiation when high-energy photons cause pair-production within the glass. A photomultiplier tube converts the light pulses to electrical signals. Data was obtained during normal machine operations starting in January 2020. Data collection was facilitated using a 4-channel ITech Beam Loss Monitor FPGA that allows for control of thresholds and attenuation settings in both counting and pulse-height acquisition modes. Count rates and spectra were recorded for the three primary fill patterns typically used during SR operations as well as during gas injection experiments; results of these measurements will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB044
About •	paper received ※ 22 May 2021 paper accepted ※ 28 May 2021 issue date ※ 25 August 2021
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MOPAB054	Start-to-End Simulation of a Free-Electron Laser Driven by a Laser-Plasma Wakefield Accelerator	plasma, laser, bunching, electron	233
	W. Liu, Y. Jiao, S. Wang IHEP, Beijing, People’s Republic of China
	The rapid development of laser-plasma wakefield accelerator (LPA) has opened up a new possible way to achieve ultra-compact free-electron laser (FEL). To this end, LPA experts have made many efforts to generate electron beams with sub-micrometer emittance and low energy spread. Recently, a new laser modulation method was proposed for generating EUV coherent pulse in an LPA-driven FEL. The simulation demonstration of this scheme is based on the Gaussian beam. However, the distribution of the LPA beam is not Gaussian. To further verify the feasibility of the method mentioned above, a start-to-end simulation is required.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB054
About •	paper received ※ 18 May 2021 paper accepted ※ 27 May 2021 issue date ※ 22 August 2021
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MOPAB088	Beam-Based Measurement on the Performance of Ferrite Dampers in an In-Vacuum Undulator	damping, HOM, feedback, vacuum	331
	K. Tian, A. Ringwall, J.J. Sebek SLAC, Menlo Park, California, USA
	In this paper, we first present the tracking studies for SPEAR3 with the new BL17 ID and estimate its impact on the dynamic aperture of the low emittance lattice. Then the ferrite dampers installations in the device is briefly reviewed. After that, we will show that, based on beam-based measurements, the performance of the dampers is as being expected from earlier numerical studies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB088
About •	paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 24 August 2021
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MOPAB090	Status of HEPS Insertion Devices Design	undulator, photon, wiggler, insertion	339
	X.Y. Li, Y. Jiao, H.H. Lu, S.K. Tian IHEP, Beijing, People’s Republic of China
	HEPS is a 4th generation light source with the energy of 6 GeV and ultralow emittance of 34 pm.rad. A total of 14 beamlines with 19 insertion devices has been planned in the first phase, including 6 cryogenic undulators, 5 in-vacuum undulators, and two special non-planar IDs. The schemes and parameters of all the IDs are planned to be determined in this year. We report on the status of the design of these IDs and their effects on beam dynamics.
	Poster MOPAB090 [0.633 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB090
About •	paper received ※ 13 May 2021 paper accepted ※ 01 July 2021 issue date ※ 10 August 2021
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MOPAB093	Operational Status of Photon Factory Light Sources	injection, operation, electron, vacuum	350
	T. Honda, Y. Kobayashi, C. Mitsuda, S. Nagahashi, R. Takai, H. Takaki KEK, Ibaraki, Japan
	One of the recent topics of Photon Factory light sources, PF-ring and PF-AR, is a construction of a GeV-class beamline for testing detectors at the PF-AR. The bremsstrahlung photons generated by a thin carbon wire are brought to a copper target to generate e⁺e⁻ pairs. Sufficient count rates can be expected when the thin wire touching halo of the stored beam, and the test beamline can be used without disturbing the synchrotron radiation experiments. In addition to the usual 6.5-GeV operation, a low-energy operation at 5-GeV was started recently at PF-AR to secure operation time by saving electricity costs. At the PF-ring, the injection section has been upgraded with the septum-magnet replacement. By the top-up injection and improved bunch feedback, the hybrid-fill mode operation has become convenient for both single-bunch users and multi-bunch users, and about 30% or 40% of the user time is scheduled as the hybrid-fill mode now.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB093
About •	paper received ※ 21 May 2021 paper accepted ※ 25 May 2021 issue date ※ 13 August 2021
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MOPAB096	Rocking Curve Imaging Experiment at SSRL 10-2 Beamline	photon, wiggler, experiment, lattice	357
	A. Halavanau, R. Arthur, B. Johnson, J.P. MacArthur, G. Marcus, R.A. Margraf, Z. Qu, T. Rabedeau, T. Sato, C.J. Takacs, D. Zhu SLAC, Menlo Park, California, USA
	Stanford Synchrotron Radiation Lightsource (SSRL) serves a wide scientific community with its variety of X-ray capabilities. Recently, we have employed a wiggler source located at beamline 10-2 to perform high resolution rocking curve imaging (RCI) of diamond and silicon crystals. In-house X-ray RCI capability is important for the upcoming cavity-based x-ray source development projects at SLAC, such as cavity-based XFEL (CBXFEL) and X-ray laser oscillator (XLO). In this proceeding, we describe theoretical considerations, and provide experimental results, validating the design of our apparatus. We also provide a plan for future improvements of the RCI@SSRL program.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB096
About •	paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 10 August 2021
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MOPAB100	Progress Report on Population Inversion-Based X-Ray Laser Oscillator	FEL, laser, electron, experiment	373
	A. Halavanau, R. Alonso-Mori, A. Aquila, U. Bergmann, D. DePonte, F.-J. Decker, F. Fuller, M. Liang, A.A. Lutman, C. Pellegrini SLAC, Menlo Park, California, USA M. Doyle UCB, Berkeley, USA
	The population inversion X-ray Laser Oscillator (XLO) is a fully coherent, transform limited hard X-ray source. It operates by repetitively pumping inner-shell atomic transitions with an XFEL, in a closed Bragg cavity. XLO will produce very bright monochromatic X-ray pulses for applications in quantum optics, X-ray interferometry and metrology. We report the progress to build the first XLO operating at the copper alpha line, using LCLS 9 keV SASE X-ray pulses as a pump.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB100
About •	paper received ※ 20 May 2021 paper accepted ※ 29 July 2021 issue date ※ 02 September 2021
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MOPAB121	Progress Towards Soft X-Ray Beam Position Monitor Development	detector, undulator, laser, synchrotron	438
	B. Podobedov, C. Eng, S. Hulbert, C. Mazzoli BNL, Upton, New York, USA D. Donetski, K. Kucharczyk, J. Liu, R. Lutchman Stony Brook University, Stony Brook, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. X-ray beam position monitors (BPMs) are instrumental for storage ring light sources, where they reliably provide positional measurements of high-power beams in hard X-ray beamlines. However, despite a growing need, coming especially from coherent soft X-ray beamlines, non-invasive soft X-ray BPMs have not been demonstrated yet. We are presently working on a funded R&D proposal to develop a non-invasive soft X-ray BPM with micron-scale resolution for high-power white beams. In our approach, multi-pixel GaAs detector arrays are placed into the beam halo and beam position is inferred from the pixel photocurrent levels. Presently, the first detector array prototypes have been manufactured and are being prepared for low-power beam tests. The mechanical design of a BPM test-stand, which will be installed in the 23-ID canted soft X-ray undulator beamline at NSLS-II, is well under way. In addition, we are developing new algorithms of beam position calculation which take full advantage of extended multi-pixel detector arrays. In this paper we will review our design choices and discuss recent progress.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB121
About •	paper received ※ 03 June 2021 paper accepted ※ 13 July 2021 issue date ※ 28 August 2021
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MOPAB122	Present Status of HiSOR	synchrotron, storage-ring, injection, undulator	442
	M. Katoh UVSOR, Okazaki, Japan K. Goto, M. Katoh, M. Shimada HSRC, Higashi-Hiroshima, Japan H. Miyauchi KEK, Ibaraki, Japan
	HiSOR is a compact synchrotron light source of 700MeV. The circumference is 22m. The ring has two straight sections for undulators, which provide high brilliance VUV radiation. Two 180 bending magnets have 2.7 T field strength, which provide broadband radiation in VUV and soft X-ray range. The injector is a 150 MeV microtron. The beam injection is made twice a day with a 5 hour interval. Although the accelerators are being operated stably, the large emittance of 400nm makes it difficult to compete with high brilliance light sources of new generations. The compactness of the configuration makes it difficult to introduce new technologies. We have started seeking possible upgrades.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB122
About •	paper received ※ 18 May 2021 paper accepted ※ 20 May 2021 issue date ※ 30 August 2021
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MOPAB123	Radiation Safety Considerations For The APS Upgrade Injector	neutron, booster, survey, shielding	445
	K.C. Harkay, J.R. Calvey, S. Chitra, G.I. Fystro, M.J. Henry, E.E. Heyeck, B.J. Micklich, K.P. Wootton ANL, Lemont, Illinois, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The Advanced Photon Source Upgrade (APS-U) is a high-performance fourth-generation storage ring light source based on multibend achromat optics. As such, APS-U will require on-axis injection. The injectors will need to supply full-current bunch replacement in the ring; therefore, the injected bunch charge will be up to five times higher than what is typical for APS. A program was conducted to measure the radiation dose above the injector transport line to the APS storage ring for both normal operation conditions and controlled loss scenarios. Standard survey meters were used to record the dose. A review of the dose data identified opportunities to minimize the potential dose under normal APS-U high charge operation and fault conditions; these include improving the supplemental shielding and adding engineered controls. In addition, the dose data provide a benchmark for evaluating new radiation monitors for APS-U.
	Poster MOPAB123 [1.317 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB123
About •	paper received ※ 18 May 2021 paper accepted ※ 24 May 2021 issue date ※ 12 August 2021
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MOPAB126	BESSY III & MLS II - Status of the Development of the New Photon Science Facility in Berlin	undulator, lattice, photon, emittance	451
	P. Goslawski, M. Abo-Bakr, F. Andreas, M. Arlandoo, J. Bengtsson, V. Dürr, K. Holldack, J.-G. Hwang, A. Jankowiak, B.C. Kuske, J. Li, A.N. Matveenko, T. Mertens, A. Meseck, E.C.M. Rial, M. Ries, M.K. Sauerborn, A. Schälicke, M. Scheer, P. Schnizer, L. Shi, J. Viefhaus HZB, Berlin, Germany J. Lüning UPMC, Paris, France
	HZB operates and develops two synchrotron radiation sources at Berlin Adlershof. The larger one, BESSY II with an energy of 1.7 GeV and 240 m circumference is optimized for soft-X rays and in operation since 1999. The smaller one is the MLS (Metrology Light Source), owned by the Physikalische Technische Bundesanstalt (PTB) - Germany’s National Metrology Institute. It is designed to fulfill the special metrology needs of the PTB with an energy of 0.6 GeV and 48 m circumference, covering the spectral range from THz and IR to EUV/VUV. In 2020 a discussion process has been started to define the requirements for successors of BESSY II and MLS and to study the possibilities integrate them into a new photon science facility in Berlin Adlershof. Here, we give a status report and present a first envisaged parameter space to both machines (see also MOPAB262, MOPAB220, MOPAB048, MOPAB242).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB126
About •	paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 18 August 2021
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MOPAB137	Interaction Region Design for DWA Experiments at FACET-II	electron, experiment, alignment, diagnostics	478
	O. Williams, G. Andonian, A. Fukasawa, W.J. Lynn, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, Y. Sakai, M. Yadav, Y. Zhuang UCLA, Los Angeles, California, USA C.I. Clarke, M.J. Hogan, B.D. O’Shea, D.W. Storey, V. Yakimenko SLAC, Menlo Park, California, USA M. Ruelas RadiaBeam, Santa Monica, California, USA M. Yadav The University of Liverpool, Liverpool, United Kingdom
	Funding: DOE HEP Grant DE-SC0009914 The extremely intense beam generated at FACET-II provides the unique opportunity to investigate the effects of beam-driven GV/m fields in dielectrics exceeding meter-long interaction lengths. The diverse range of phenomena to be explored, such as material response in the terahertz regime, suppression of high-field pulse damping effects, advanced geometry structures, and methods for beam break up (BBU) mitigation, all within a single UHV vacuum vessel, requires flexibility and precision in the experimental layout. We present here details of the experimental design for the dielectric program at FACET-II. Specifically, consideration is given to the alignment of the dielectric structures due to the extreme fields associated with the electron beam, as well as implementation of electron beam and Cherenkov radiation-based diagnostics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB137
About •	paper received ※ 19 May 2021 paper accepted ※ 17 August 2021 issue date ※ 29 August 2021
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MOPAB141	Terahertz Driven Compression and Time-Stamping Technique for Single-Shot Ultrafast Electron Diffraction	electron, laser, FEM, resonance	492
	M.A.K. Othman, A.E. Gabriel, M.C. Hoffmann, F. Ji, E.A. Nanni, X. Shen, E.J.C. Snively, X.J. Wang SLAC, Menlo Park, California, USA
	Funding: This research has been supported by the U.S. Department of Energy (DOE) under Contract No. DE-AC02-76SF00515 and DE-AC02-05-CH11231. Ultrafast structural dynamics are well understood through pump-probe characterization using ultrafast electron diffraction (UED). Advancements in electron diffraction and spectroscopy techniques open new frontiers for scientific discovery through interrogation of ultrafast phenomena, such as quantum phase transitions. Previously, we have demonstrated that strong-field THz radiation can be utilized to efficiently manipulate and compress ultrafast electron probes , and also offer temporal diagnostics with sub-femtosecond resolution * enabled by the inherent phase locking of THz radiation to the photoemission optical drive. In this work, we demonstrate a novel THz compression and time-stamping technique to probe solid-state materials at time scales previously inaccessible with standard UED. A high-frequency THz generation method using the organic OH-1 crystals is employed to enable a threefold reduction in the electron probes length and overall timing jitter. These time-stamped probes are used to demonstrate a substantial enhancement in the UED temporal resolution using pump-probe measurement in both photoexcited single crystal and polycrystalline samples. * E. C. Snively et al., Phys. Rev. Lett, vol. 124, no. 6, p. 054801, 2020. ** R. K. Li et al., Phys. Rev. Accel. Beams, vol. 22, no. 1, p. 012803, Jan. 2019.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB141
About •	paper received ※ 20 May 2021 paper accepted ※ 21 June 2021 issue date ※ 19 August 2021
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MOPAB144	Investigation of Optimization of Dielectric Terahertz Acceleration Structures	simulation, laser, acceleration, impedance	502
	A.E. Gabriel, E.A. Nanni SLAC, Menlo Park, California, USA
	Funding: This work was supported by the Department of Energy Contract No. DE-AC02-76SF00515 (SLAC) and by NSF Grant No. PHY-1734015. THz-frequency accelerating structures could provide the accelerating gradients needed for next generation particle accelerators with compact, GV/m-scale devices. Current THz accelerators are limited by significant losses during transport of THz radiation from the generating nonlinear crystal to the electron acceleration structure. In addition, the spectral properties of high-field THz sources make it difficult to couple THz radiation into accelerating structures. Dielectric accelerator structures reduce these losses because THz radiation can be coupled laterally into the structure, as opposed to metallic structures where THz radiation must be coupled along the beam path. In order to utilize these advantages, we are investigating the optimization of THz accelerating structures for comparison between metallic and dielectric devices. These results will help to inform future designs of improved dielectric THz acceleration structures.
	Poster MOPAB144 [6.524 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB144
About •	paper received ※ 20 May 2021 paper accepted ※ 27 May 2021 issue date ※ 22 August 2021
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MOPAB146	Status of the C-Band Engineering Research Facility (CERF-NM) Test Stand Development at LANL	cavity, GUI, klystron, controls	509
	D. Gorelov Private Address, Los Alamos, USA R.L. Fleming, S.K. Lawrence, J.W. Lewellen, D. Perez, M.E. Schneider, E.I. Simakov, T. Tajima LANL, Los Alamos, New Mexico, USA M.E. Middendorf ANL, Lemont, Illinois, USA
	Funding: LDRD-DR Project 20200057DR C-Band structures research is of increasing interest to the accelerator community. The RF frequency range of 4-6 GHz gives the opportunity to achieve significant increase in the accelerating gradient, and having the wakefields at the manageable levels, while keeping the geometric dimensions of the structure technologically convenient. Strong team of scientists, including theorists researching properties of metals under stressful thermal conditions and high electromagnetic fields, metallurgists working with copper as well as alloys of interest, and accelerator scientists developing new structure designs, is formed at LANL to develop a CERF-NM facility. A 50 MW, 5.712 GHz Canon klystron, was purchased in 2019, and laid the basis for this facility. As of Jan-21, the construction of the Test Stand has been finished and the high gradient processing of the waveguide components has been started. Future plans include high gradient testing of various accelerating structures, including benchmark C-band accelerating cavity, a proton ß=0.5 cavity, and cavities made from different alloys. An upgrade to the facility is planned to allow for testing accelerator cavities at cryogenic temperatures.
	Poster MOPAB146 [3.778 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB146
About •	paper received ※ 17 May 2021 paper accepted ※ 26 May 2021 issue date ※ 19 August 2021
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MOPAB147	Efficient, High Power Terahertz Radiation Outcoupling From a Beam Driven Dielectric Wakefield Accelerator	wakefield, acceleration, electron, GUI	513
	M. Yadav, G. Andonian, C.E. Hansel, W.J. Lynn, N. Majernik, B. Naranjo, J.B. Rosenzweig, O. Williams UCLA, Los Angeles, California, USA G. Andonian RadiaBeam, Santa Monica, California, USA C.P. Welsch The University of Liverpool, Liverpool, United Kingdom C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by DE-SC0009914 (UCLA) and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. Wakefields in dielectric structures are a useful tool for beam diagnostics and manipulation with applications including acceleration, shaping, chirping, and THz radiation generation. It is possible to use the produced THz radiation to diagnose the fields produced during the DWA interaction but, to do so, it is necessary to effectively out-couple this radiation to free space for transport to diagnostics such as a bolometer or interferometer. To this end, simulations have been conducted using CST Studio for a 10 GeV beam with FACET-II parameters in a slab-symmetric, dielectric waveguide. Various termination geometries were studied including flat cuts, metal horns, and the "Vlasov antenna". Simulations indicate that the Vlasov antenna geometry is optimal and detailed studies were conducted on a variety of dielectrics including quartz, diamond, and silicon. Multiple modes were excited and coherent Cherenkov radiation (CCR) was computationally generated for both symmetric and asymmetric beams. Finally, we include witness beams to study transport and acceleration dynamics as well as the achievable field gradients.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB147
About •	paper received ※ 24 May 2021 paper accepted ※ 29 August 2021 issue date ※ 28 August 2021
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MOPAB148	Liénard-Wiechert Numerical Radiation Modeling for Plasma Acceleration Experiments at FACET-II	plasma, betatron, acceleration, experiment	517
	M. Yadav, G. Andonian, C.E. Hansel, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, O. Williams, Y. Zhuang UCLA, Los Angeles, California, USA G. Andonian RadiaBeam, Marina del Rey, California, USA O. Apsimon, A. Perera, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom O. Apsimon, A. Perera, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by DE-SC0009914 (UCLA) and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. Future plasma acceleration experiments at FACET-II will measure betatron radiation in order to provide single-shot non-destructive beam diagnostics. We discuss three models for betatron radiation: a new idealized particle tracking code with Liénard-Wiechert radiation, a Quasi-Static Particle-in-Cell (PIC) code with Liénard-Wiechert radiation, and a full PIC code with radiation computed via a Monte-Carlo QED Method. Predictions of the three models for the E-310 experiment are presented and compared. Finally, we discuss beam parameter reconstruction from the double differential radiation spectrum.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB148
About •	paper received ※ 24 May 2021 paper accepted ※ 01 June 2021 issue date ※ 17 August 2021
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MOPAB212	3-D Quantum Lifetime	simulation, electron, damping, emittance	700
	H. Zhao, M. Blaskiewicz BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The quantum lifetime of electron beam in storage rings is defined by the particle loss that caused by the aperture limitation. Based on the equilibrium beam distribution produced by radiation damping and quantum excitation, the 1-d quantum lifetime has been well studied by A. Piwinski. In this paper, we give the derivation of the 3-d quantum lifetime, which can be applied to the machines with elliptical aperture and momentum acceptance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB212
About •	paper received ※ 04 June 2021 paper accepted ※ 21 June 2021 issue date ※ 16 August 2021
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MOPAB240	Estimates of Damped Equilibrium Energy Spread and Emittance in a Dual Energy Storage Ring	emittance, storage-ring, damping, photon	774
	B. Dhital, G.A. Krafft ODU, Norfolk, Virginia, USA Y.S. Derbenev, D. Douglas, A. Hutton, G.A. Krafft, F. Lin, V.S. Morozov, Y. Zhang JLab, Newport News, Virginia, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, and Office of Nuclear Physics under Contracts DE-AC05-06OR23177 and DE-AC02-06CH11357. / Jefferson Lab EIC Fellowship2020. A dual energy storage ring design consists of two loops at markedly different energies. As in a single-energy storage ring, the linear optics in the ring design may be used to determine the damped equilibrium emittance and energy spread. Because the individual radiation events in the two rings are different and independent, we can provide analytical estimates of the damping times in a dual energy storage ring. Using the damping times, the values of damped energy spread, and emittance can be determined for a range of parameters related to lattice design and rings energies. We present analytical calculations along with simulation results to estimate the values of damped energy spread and emittance in a dual energy storage ring. We note that the damping time tends to be dominated by the damping time of the high energy ring in cases where the energy of the high energy rings is significantly greater than that of the low energy ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB240
About •	paper received ※ 17 May 2021 paper accepted ※ 27 May 2021 issue date ※ 13 August 2021
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MOPAB245	Theoretical Analysis of the Conditions for an Isochronous and CSR-Immune Triple-Bend Achromat with Stable Optics	emittance, dipole, optics, synchrotron-radiation	786
	C. Zhang, Y. Jiao IHEP, Beijing, People’s Republic of China C.-Y. Tsai HUST, Wuhan, People’s Republic of China
	Funding: National Natural Science Foundation of China (No. 11922512), Youth Innovation Promotion Association of Chinese Academy of Sciences (No. Y201904), National Key R&D Program of China (No. 2016YFA0401900) Transport of high-brightness beams with minimum degradation of the phase space quality is pursued in modern accelerators. For the beam transfer line which commonly consists of bending magnets, it would be desirable if the transfer line can be isochronous and coherent synchrotron radiation (CSR)-immune. For multi-pass transfer line, the achromatic cell designs with stable optics would bring great convenience. In this paper, based on the transfer matrix formalism and the CSR point-kick model, we report the detailed theoretical analysis and derive the condition for a triple-bend achromat with stable optics in which the first-order longitudinal dispersion (i.e., R56) and the CSR-induced emittance growth can be eliminated. The derived condition suggests a new way of designing the bending magnet beamline that can be applied to the free-electron laser (FEL) spreader and energy recovery linac (ERL) recirculation loop.
	Poster MOPAB245 [0.530 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB245
About •	paper received ※ 12 May 2021 paper accepted ※ 08 June 2021 issue date ※ 27 August 2021
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MOPAB262	First Thoughts on Lattices for a possible Metrology Light Source 2	lattice, emittance, dipole, sextupole	833
	M. Arlandoo, M. Abo-Bakr, P. Goslawski, J. Li HZB, Berlin, Germany
	The Physikalisch-Technische Bundesanstalt (PTB), in cooperation with the Helmholtz-Zentrum Berlin (HZB), operates the Metrology Light Source (MLS), which is a low-energy electron storage ring. The MLS can be operated in a low-alpha mode to produce coherent synchroton ration in the far-IR and THz spectral range. In the scope of the Conceptual Design process for a BESSY II successor, the PTB also requested for an MLS successor to cover their increasing demands on synchrotron radiation. A combination of two different machines, one optimized for low emittance (BESSY III) and one for flexible timing capabilities (MLS II), would provide best radiation capabilities for our user community. In this paper, we discuss the demands on the MLS II and propose first lattice candidates which may meet the needs of the PTB and HZB. Currently, we focus on linear lattices for standard user mode with first steps towards nonlinear optimization.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB262
About •	paper received ※ 18 May 2021 paper accepted ※ 02 June 2021 issue date ※ 17 August 2021
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MOPAB263	Preliminary Beam Dynamics Studies for 200 MeV Superconducting Linac Planned at KOMAC	linac, proton, DTL, lattice	837
	S. Lee, J.J. Dang, H.S. Kim, H.-J. Kwon Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea Y.-S. Cho KAERI, Daejon, Republic of Korea
	Funding: This work has been supported through KOMAC operation fund of KAERI by the Korea government (MSIT). Korea Multi-purpose Accelerator Complex (KOMAC) is planning an energy upgrade of the existing 100 MeV proton linac to 200 MeV using a superconducting Half Wave Resonator (HWR) operating at 350 MHz. A cryomodule is planned to house four HWR cavities with a warm doublet focusing lattice structure. Matching between the already existing DTL section and HWR section is designed and studied. We report the preliminary study of the beam dynamics of the 200 MeV superconducting linac carried out at KOMAC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB263
About •	paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 24 August 2021
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MOPAB266	Start-to-End Study on Laser and RF Jitter Effects for MAX-IV SXL	FEL, laser, linac, simulation	844
	S.P. Pirani, B.S. Kyle MAX IV Laboratory, Lund University, Lund, Sweden F. Curbis, M.A. Pop, S. Werin Lund University, Lund, Sweden W. Qin DESY, Hamburg, Germany
	A Soft X-ray free electron laser (FEL) for the MAX IV Laboratory is currently in the design phase and it will use the existing 3 GeV linac. Present stability limits in the RF and the photocathode laser will affect the performance of the FEL. One of the critical elements for the design of a FEL is to have an estimation on jitter effects of the accelerator parameters on the X-ray radiation. In this regard, we implemented a start-to-end study using Astra, Elegant and Genesis in order to assess possible variations in pulse energy, photon pulse length and spectral width in the Soft X-ray Laser (SXL) radiation. This investigation provides insights on the final SXL performance variation due to RF and laser related jitter affecting the electron beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB266
About •	paper received ※ 19 May 2021 paper accepted ※ 26 July 2021 issue date ※ 24 August 2021
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MOPAB276	Investigation on the injection of the Arronax Cyclotron 70XP	cyclotron, injection, background, solenoid	873
	F. Poirier, F. Bulteau-Harel, T. Durand, X. Goiziou, C. Koumeir, C. Lassalle, H. Trichet Cyclotron ARRONAX, Saint-Herblain, France F. Haddad SUBATECH, Nantes, France
	Funding: This work is supported by grants from the ANR program "Investissements d’Avenir", n°ANR-11-EQPX-0004, n°ANR-11-LABX-18-01 and n°ANR-16-IDE-0007 and by a PhD scholarship from CNRS/IN2P3. A 70 MeV cyclotron is being used at the Arronax GIP (Interest Public Group), France, for various types of R&D on nuclear, biological and chemical reactions with beams and radioisotopes production. In order to adapt its usage for experiments and users demands of high peak intensity, above an equivalent average of a few µA, the injection is being adapted. Several studies are thus being performed in this section. These include the newly installed chopper-based system and the injection collimator. This paper details the various studies, specifically the signal purity obtained in the pulsed mode. A mode particularly adapted for flash irradiation.
	Poster MOPAB276 [2.522 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB276
About •	paper received ※ 19 May 2021 paper accepted ※ 23 June 2021 issue date ※ 15 August 2021
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MOPAB294	Implementing Electro-Optical Diagnostics for Measuring the CSR Far-Field at KARA	laser, detector, synchrotron, storage-ring	931
	C. Widmann, E. Bründermann, M. Caselle, S. Funkner, A.-S. Müller, M.J. Nasse, G. Niehues, M.M. Patil, C. Sax, J.L. Steinmann, M. Weber KIT, Karlsruhe, Germany C. Mai DELTA, Dortmund, Germany
	Funding: This work was supported by BMBF ErUM-Pro project 05K19 STARTRAC, C.W. was funded under contract No. 05K19VDK, C.M. under contract No. 05K19PEC, S.F. under contract No. 05K16VKA. For measuring the temporal profile of the coherent synchrotron radiation (CSR) at the KIT storage ring KARA (Karlsruhe Research Accelerator) an experimental setup based on electro-optical spectral decoding (EOSD) is currently being implemented. The EOSD technique allows single-shot, phase-sensitive measurements of the far-field radiation on a turn-by-turn basis at rates in the MHz range. Therefore, the resulting THz radiation from the dynamics of the bunch evolution, e.g. the microbunching, can be observed with high temporal resolution. This far-field setup is part of the distributed sensor network at KARA. Additionally to the information acquired from the near-field EOSD spectral decoding and the horizontal bunch profile monitor, it enables to monitor the longitudinal phase-space of the bunch. In this contribution, the characterization of the far-field setup is summarized and its implementation is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB294
About •	paper received ※ 19 May 2021 paper accepted ※ 07 June 2021 issue date ※ 18 August 2021
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MOPAB296	Statistical Analysis of 2D Single-Shot PPRE Bunch Measurements	photon, operation, diagnostics, storage-ring	939
	M. Koopmans, J.-G. Hwang, A. Jankowiak, M. Ries, A. Schälicke, G. Schiwietz HZB, Berlin, Germany
	The pulse picking by resonant excitation (PPRE) method* is used to realize pseudo single-bunch radiation from a complex filling pattern at the BESSY II storage ring. The PPRE bunch is excited in the horizontal plane by a quasi-resonant incoherent perturbation to increase the emittance of this bunch. Therefore, the synchrotron light of the PPRE bunch can be separated by collimation from the radiation of the main bunch train at dedicated beamlines for timing users. The properties of the PPRE bunch depend on the storage ring settings and on the excitation parameters. It is not trivial to distinguish between the wanted intrinsic bunch broadening and an additional position fluctuation of the PPRE bunch. Using the potential of the new diagnostics beamline with the possibility to observe an additional spatial dimension with a fast streak camera, we introduce a new method to study the properties of the PPRE bunch. Applying a statistical analysis to a series of single-turn images enables distinguishing between horizontal orbit motion and the broadening of the bunch due to the excitation. Measurements are presented and the results are compared with data from the BPM system. K. Holldack et al., Nature Commun. 5 (2014) 4010. J.-G. Hwang et al., Nucl. Instrum. Methods A940 (2019) 387. * G. Schiwietz et al., Nucl. Instrum. Methods A990 (2021) 164992.
	Poster MOPAB296 [2.074 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB296
About •	paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 23 August 2021
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MOPAB300	Description of the Beam Diagnostics Systems for the SOCIT, SODIT and SODIB Applied Research Stations Based on the NICA Accelerator Complex	detector, controls, diagnostics, experiment	946
	A. Slivin, A. Agapov, A.A. Baldin, A.V. Butenko, G.A. Filatov, K.N. Shipulin, E. Syresin, G.N. Timoshenko, A. Tuzikov JINR, Dubna, Moscow Region, Russia D.V. Bobrovskiy, A.I. Chumakov, S. Soloviev MEPhI, Moscow, Russia I.L. Glebov, V.A. Luzanov GIRO-PROM, Dubna, Moscow Region, Russia A.S. Kubankin BelSU, Belgorod, Russia T. Kulevoy, Y.E. Titarenko ITEP, Moscow, Russia
	Within the framework of the NICA project an Innovation Block is being constructed. It includes an applied research station for microchips with a package for Single Event Effects (SEE) testing (energy range of 150-500 MeV/n, the SODIT station), an applied research station for testing of decapsulated microchips (ion energy up to 3,2 MeV/n, the SOCIT station), and an applied research station for space radiobiological research and modelling of influence of heavy charged particles on cognitive functions of the brain of small laboratory animals and primates (energy range 500-1000 MeV/n, the SODIB station). The systems for diagnostics and control of the beam characteristics during the certification and adjustment as well as the systems for online diagnostics and control of the beam characteristics of the SOCIT, SODIT and SODIB applied research stations are described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB300
About •	paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 23 August 2021
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MOPAB301	A Concept for Reconstruction of the Capsulated Microchip Structure Using Its Interaction with High-Energy Ion Beams of the NICA Accelerator Complex	detector, simulation, electron, electronics	949
	A. Slivin, A.V. Butenko, G.A. Filatov, E. Syresin, A. Tuzikov, A. Zhemchugov JINR, Dubna, Moscow Region, Russia
	Within the framework of the NICA project an applied research station for irradiation by long-range ions (SODIT) is being constructed for testing radiation hardness of semiconductor micro- and nanoelectronics products in the energy range of 150-350 MeV/n. Calculations for the interaction of high-energy gold ions with the microchip and strip detector structures are performed using the GEANT4 simulation toolkit. A concept was developed for reconstruction of the capsulated microchip structure in terms of depth and in terms of cross-section using interaction with high-energy ions at the technical station for irradiation by long-range ions. The possibility of localizing the radiation-vulnerable area of the microchip is evaluated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB301
About •	paper received ※ 19 May 2021 paper accepted ※ 20 May 2021 issue date ※ 17 August 2021
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MOPAB328	Beam Instrumentation for Linear Accelerator of SKIF Synchrotron Light Source	electron, diagnostics, photon, simulation	1016
	X.C. Ma BINP, Novosibirsk, Russia M.V. Arsentyeva, E.A. Bekhtenev, V.M. Borin, G.V. Karpov, Yu.I. Maltseva, O.I. Meshkov, D.A. Nikiforov, O.A. Pavlov, V.G. Tcheskidov, V. Volkov BINP SB RAS, Novosibirsk, Russia M.V. Arsentyeva, E.A. Bekhtenev, V.M. Borin, Yu.I. Maltseva, O.I. Meshkov, D.A. Nikiforov NSU, Novosibirsk, Russia V.M. Borin NSTU, Novosibirsk, Russia
	A new synchrotron light source SKIF of the 4th generation is under construction at BINP SB RAS (Novosibirsk, Russia). The linear accelerator is SKIF’s injector to provide 200 MeV electron beam. The set of diagnostics will be applied for tuning of the linear accelerator and measurements of beam parameters from electron RF gun to output of the accelerator. It includes 8 fluorescent screens for the beam transverse dimensions measurement, 2 Cherenkov probes for the beam duration measurement, magnetic spectrometer with range from 0.6 to 200 MeV, and some beam charge and current measurement devices, as Faraday cup, FCT, BPM along linear accelerator. Numerical simulations of diagnostics elements and results of beam dynamics simulations are introduced in paper. Brief description of the design and parameters of each diagnostics system is presented. Possible scenarios of linear accelerator tuning are also discussed.
	Poster MOPAB328 [2.324 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB328
About •	paper received ※ 19 May 2021 paper accepted ※ 21 May 2021 issue date ※ 31 August 2021
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MOPAB348	Portable 2.5 MeV X-Band Linear Accelerator Structure	linac, GUI, gun, target	1084
	A.V. Mishin, K. Brown, M. Denney, D. Fischer, N.P. Hanson, S. Proskin, J. Stammetti Varex Imaging, Salt Lake City, USA
	Two versions of 2.5 MeV X-Band linear accelerator structure have been designed and tested. The first is a traditional single input linac, and the other one is a dual input, two section linac with power input through a 3 dB coupler. The linac is designed for a portable linac system, which can be used for security screening, non-destructive testing, medical and industrial CT, and, perhaps, some other applications.
	Poster MOPAB348 [1.490 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB348
About •	paper received ※ 15 May 2021 paper accepted ※ 28 May 2021 issue date ※ 23 August 2021
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MOPAB379	Topological Optimization on SRF Cavities for Nuclear and High Energy Physics	cavity, niobium, superconducting-cavity, simulation	1162
	H. Gassot Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
	Topology optimization has been developed for more than twenty years. The progress of additive manufacturing boosts the development in topological optimization since the design can be completely innovated and realized by 3D printing. The potential for cost reductions thanks to weight minimization give an interesting perspective for the small production of niobium superconducting radio-frequency cavities, commonly used in accelerators. The traditional manufacturing technologies of cavities are based on multi-stage processes while additive manufacturing technologies can built fully functional parts in a single operation. For modern accelerators that use superconducting linac, including energy recovery linacs (ERLs), it is particularly important to know the perspectives of additive manufacturing for SRF cavities. In this paper, we try to build a preliminary perception of topological optimization in superconducting cavities manufacturing innovation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB379
About •	paper received ※ 11 May 2021 paper accepted ※ 17 August 2021 issue date ※ 15 August 2021
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MOPAB382	Synchrotron Light Shielding for the 166 MHz Superconducting RF Section at High Energy Photon Source	cavity, shielding, synchrotron, storage-ring	1169
	X.Y. Zhang, Z.Q. Li, Q. Ma, P. Zhang IHEP, Beijing, People’s Republic of China
	Funding: This work was supported by High Energy Photon Source, a major national science and technology infrastructure in China. The High Energy Photo Source (HEPS) project has been under construction since 2019, and will be first diffraction-limited synchrotron light source in China. A 6 GeV electron beam with 200 mA current will be stored in the main ring. If synchrotron light produced from this energetic electron beam hits the superconducting cavity’s surface, it would cause thermal breakdown of the superconductivity. In the current lattice design, these lights cannot be fully blocked by the collimator in the upstream lattice cell, therefore a shielding scheme inside the rf section is required. This however brings great challenges to the already limited space. The design of the collimator has been focused on fulfilling shielding requirements while optimizing beam impedance, synchrotron light power density, thermal and mechanical stabilities. Shielding materials are subsequently chosen with dedicated cooling to ensure long-term stable operations. In this paper, a shielding scheme inside the rf section of the HEPS storage ring is presented. The synchrotron light mainly from the upstream bending magnet is successfully block. The sensitivity to beam position movement and installation error is also analyzed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB382
About •	paper received ※ 17 May 2021 paper accepted ※ 11 June 2021 issue date ※ 23 August 2021
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MOPAB405	Study of Targets to Produce Molybdenum-99 Using 30 MeV Electron Linear Accelerator	target, electron, photon, linac	1222
	T.S. Dixit, A.P. Deshpande, R. Krishnan, A. Shaikh SAMEER, Mumbai, India
	Funding: Ministry of Electronics and Information Technology, Government of India (MeitY) Two approaches to produce 99Mo are studied using GEANT4 are reported in this paper. First, in converter target approach, bremsstrahlung photons are generated in a high Z target. The emitted photons then hit 100Mo secondary target, producing 99Mo through (gamma, n) reaction. Second, in direct target approach, high energy electron beam hits 100Mo target, where both (e, gamma) and (gamma, n) reactions take place simultaneously. A 30 MeV, 5-10 kW beam power electron linac is under development at SAMEER. The acceleration gradient required to achieve 30 MeV energy will be provided by two linacs operated in series configuration and the high average beam power will be achieved by running the system at high duty operation. Main aim of this study is to optimize experimental parameters to maximize specific activity of 99Mo. Since, 100Mo is very expensive material therefore judicious use of the material is very important. Hence, optimization of electron beam energy and target dimensions are studied in detail in both the approaches. It is found that the direct target approach gives higher specific activity compared to the converter target approach.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB405
About •	paper received ※ 19 May 2021 paper accepted ※ 06 June 2021 issue date ※ 14 August 2021
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MOPAB409	FLUKA Simulations of ²²⁵Ac Production Using Electron Accelerators: Validation Through Comparison with Published Experiments	electron, experiment, target, photon	1226
	T.V. Szabo, I.C. Moraes CNPEM, Campinas, SP, Brazil F.A. Bacchim Neto LNLS, Campinas, Brazil P.V. Guillaumon USP/LAL, Sao Paulo, Brazil H.B. de Oliveira IPEN, São Paulo, Brazil
	Targeted Alpha Therapy (TAT) is an active area of study worldwide. This technique has shown a potential in nuclear medicine to treat metastatic disease by alpha particles that deposit energy in small regions nearby cancer cells. Ac-225 is an important alpha-emitting that can be used for cancer TAT. This radioisotope shows good potential for medical applications, therefore is important to study ways of increase its production and availability. One possible path for the Ac-225 product is to radiate a radium target (Ra-226) on a linear electron accelerator (LINAC). Isotope production studies could be implemented using computational tools. In this work, Monte Carlo simulations with FLUKA code were performed and compared to experimental results . We studied Ac-225 production by photonuclear reactions using a 24 MeV electron beam LINAC hitting a tungsten electron-photon converter. Different energies and geometries were also simulated to obtain optimal production conditions. The specific activity values obtained with simulations had a good agreement with published experimental results. MASLOV, O., et. al. Preparation of 225Ac by 226Ra(g, n) photonuclear reaction on an mt25 microtron. Radiochemistry
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB409
About •	paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 30 August 2021
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MOPAB410	Preliminary Studies of a Compact VHEE Linear Accelerator System for FLASH Radiotherapy	linac, electron, operation, impedance	1229
	L. Giuliano, F. Bosco, M. Carillo, D. De Arcangelis, L. Faillace, L. Ficcadenti, M. Migliorati, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy D. Alesini, M. Behtouei, B. Spataro INFN/LNF, Frascati, Italy G. Cuttone, G. Torrisi INFN/LNS, Catania, Italy V. Favaudon, S. Heinrich, A. Patriarca Institut Curie - Centre de Protonthérapie d’Orsay, Orsay, France
	Funding: The work is supported by La Sapienza University, research grant "grandi progetti di ricerca 2020". The Flash Radio Therapy is a revolutionary new technique in the cancer cure: it spares healthy tissue from the damage of the ionizing radiation maintaining the tumor control as efficient as in conventional radiotherapy. To allow the implementation of the FLASH Therapy concept into actual clinical use, it is necessary to have a linear accelerator able to deliver the very high dose and very high dose rate (>10⁶ Gy/s) in a very short irradiation time (beam on time < 100ms). Low energy S-band Linacs (up to 7 MeV) are being used in Radiobiology and pre-clinic applications but in order to treat deep tumors, the energy of the electrons should achieve the range of 60-100 MeV. In this paper, we address the main issues in the design of a compact C band (5.712 GHz) electron linac-VHEE for FLASH Radio Therapy. We present preliminary studies on C-band structures at La Sapienza and at INFN-LNS, aiming to reach a high accelerating gradient and high current necessary to deliver a dose >1 Gy/pulse, with very short electron pulse.
	Poster MOPAB410 [0.650 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB410
About •	paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 21 August 2021
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MOPAB411	Quantifying DNA Damage in Comet Assay Images Using Neural Networks	network, proton, software, experiment	1233
	S.J.K. Dhinsey, T. Greenshaw, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom J.L. Parsons Cancer Research Centre, University of Liverpool, Liverpool, United Kingdom C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. Proton therapy for cancer treatment is a rapidly growing field and increasing evidence suggests it induces more complex DNA damage than photon therapy. Accurate comparison between the two treatments requires quantification of the DNA damage the cause, which can be assessed using the Comet Assay. The program outlined here is based on neural network architecture and aims to speed up analysis of Comet Assay images and provide accurate, quantifiable assessment of the DNA damage levels apparent in individual cells. The Comet Assay is an established technique in which DNA fragments are spread out under the influence of an electric field, producing a comet-like object. The elongation and intensity of the comet tail (consisting of DNA fragments) indicate the level of damage incurred. Many methods to measure this damage exist, using a variety of algorithms. However, these can be time consuming, so often only a small fraction of the comets available in an image are analysed. The automatic analysis presented in this contribution aims to improve this. To supplement the training and testing of the network, a Monte Carlo model will also be presented to create simulated comet assay images.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB411
About •	paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 16 August 2021
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MOPAB412	Accelerator Production of Mo-99 Using Mo-100	target, electron, operation, diagnostics	1237
	J.L. McCarter, M.J. Brennan, S.M. Burns, J.T. Harvey, S.W. Kelley, T.A. Montenegro, Q. Schiller NorthStar Medical Technologies, LLC, Beloit, USA
	Funding: DE-NA0001878 Tc-99m is an essential radionuclide for nearly 40,000 diagnostic nuclear medicine tests in the U.S. each day. Its daily production depends on Mo-99, which must be replenished weekly due to Mo-99’s 2.75 day half-life. Mo-99, in the past, was supplied from uranium fission production, depending on overseas nuclear reactors that average 50 years old. Their age in combination with shipment uncertainties make the availability of Mo-99 fragile and subject to severe shortages. The U.S. now has one domestic, FDA-approved supplier that produces Mo-99, NorthStar Medical Radioisotopes. Currently, NorthStar produces Mo-99 via the irradiation of Mo-98 in a nuclear reactor. In the future, NorthStar will also irradiate Mo-100 with accelerator created x-rays to produce Mo-99. This process will use 2 distinct, 40 MeV, 125 kW average electron accelerators, Rhodotrons produced by IBA. Accelerator produced Mo-99 has several advantages over that produced by reactors, including a dual supply and an ability to adjust irradiation timing to meet radiopharmacy demands, such as Sunday delivery. NorthStar is currently installing and commissioning this accelerator based system, entering production in late-2022.
	Poster MOPAB412 [2.150 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB412
About •	paper received ※ 24 May 2021 paper accepted ※ 07 June 2021 issue date ※ 19 August 2021
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MOPAB414	A Novel Facility for Cancer Therapy and Biomedical Research with Heavy Ions for the South East European International Institute for Sustainable Technologies	synchrotron, extraction, injection, experiment	1244
	S. Damjanovic, P. Grübling, H. Schopper SEEIIST, Geneva, Switzerland U. Amaldi, E. Benedetto, M. Sapinski TERA, Novara, Italy E. Benedetto, G. Bisoffi, M. Dosanjh, M. Sapinski, M. Vretenar CERN, Meyrin, Switzerland G. Bisoffi INFN/LNL, Legnaro (PD), Italy S. Damjanovic, M. Durante, P. Foka, C. Graeff GSI, Darmstadt, Germany Th. Haberer HIT, Heidelberg, Germany S. Rossi CNAO Foundation, Milan, Italy H.J. Specht Universität Heidelberg, Heidelberg, Germany
	The South East European International Institute for Sustainable Technologies (SEEIIST) proposes the construction of a major joint Research Infrastructure in the region, to rebuild cooperation after the recent wars and overcome lasting consequences like technology deficits and brain drain, having at its core a facility for cancer therapy and biomedical research with heavy ions. Beams of ions like Carbon are an advanced way to irradiate tumours but more research is needed, while the higher investment costs than for other radiation treatments have so far limited the European facilities to only four. This initiative aims at being strongly innovative, beyond the existing European designs. While the initial baseline relies on a conservative warm-magnet synchrotron, superconducting magnets for an advanced version of the synchrotron and for the gantry are being developed, with a potential for reductions in size, cost, and power consumption. Both warm and superconducting designs feature high beam intensity for faster treatment, and flexible extraction for novel treatment methods. A novel injector linac has the potential for producing radioisotopes in parallel with synchrotron injection.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB414
About •	paper received ※ 17 May 2021 paper accepted ※ 06 July 2021 issue date ※ 22 August 2021
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MOPAB415	Failure Rates and Downtimes of Multi-Leaf Collimators in Indonesia	linac, target, gun, power-supply	1248
	G.S. Peiris, S.L. Sheehy The University of Melbourne, Melbourne, Victoria, Australia M.F. Kasim, S.A. Pawiro University of Indonesia, Depok, Jawa Barat, Indonesia
	One of the greatest barriers to cancer treatment in Low and Middle-Income Countries (LMICs) is the access to Radiotherapy Linear Accelerators (LINACs). Not only are the LINACs complex, the harsh environment of LMICs cause frequent breakdowns resulting in downtimes ranging from days to months. Recent research has identified a disparity between LMICs and High Income Countries (HICs) and determined the Multi-Leaf Collimator (MLC) as a component needing re-evaluation. The MLC causes over 30% of the problems in RT LINACs, but the modes of failure and quantify the extent of the damage done are yet to be quantified. Using data from across Indonesia, we show the pathways to failure of RT Machines and frequency of breakdowns over time. A component of the MLC needs to be replaced every 9.98 faults per 1000 patients treated and the MLC itself breaks down on average every 36±1.8 days. When comparing the downtime by leaf width, the data shows 5mm leaves contribute 18.27±6.5% to all breakdowns while 10mm makes up 15.87±4.3%. These results outline the need to reassess the current generation of RT LINACs and ultimately work towards guiding future designs to be robust enough for all environments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB415
About •	paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 16 August 2021
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MOPAB416	BDSIM Developments for Hadron Therapy Centre Applications	proton, simulation, shielding, neutron	1252
	E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde ULB, Bruxelles, Belgium S.T. Boogert, L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom C. Hernalsteens CERN, Geneva, Switzerland W. Shields JAI, Egham, Surrey, United Kingdom
	Hadron therapy centres are evolving towards reduced-footprint layouts, often featuring a single treatment room. The evaluation of beam properties, radiation protection quantities, and concrete shielding activation via numerical simulations poses new challenges that can be tackled using the numerical beam transport and Monte-Carlo code Beam Delivery Simulation (BDSIM), allowing a seamless simulation of the dynamics as a whole. Specific developments have been carried out in BDSIM to advance its efficiency toward such applications, and a detailed 4D Monte-Carlo scoring mechanism has been implemented. It produces tallies such as the spatial-energy differential fluence in arbitrary scoring meshes. The feature makes use of the generic boost::histogram library and allows an event-by-event serialisation and storage in the ROOT data format. The pyg4ometry library is extended to improve the visualisation of critical features such as the complex geometries of BDSIM models, the beam tracks, and the scored quantities. Data are converted from Geant4 and ROOT to a 3D visualisation using the VTK framework. These features are applied to a complete IBA Proteus One model.
	Poster MOPAB416 [1.575 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB416
About •	paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 15 August 2021
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MOPAB417	Preliminary Study of a Large Energy Acceptance FFA Beam Delivery System for Particle Therapy	proton, optics, focusing, superconducting-magnet	1256
	J.S.L. Yap, E.R. Higgins, S.L. Sheehy The University of Melbourne, Melbourne, Victoria, Australia
	The availability and use of ion beams for radiotherapy has grown significantly, led by technological developments to exploit the dosimetric advantages offered by charged particles. The benefits of particle therapy (PT) are well identified however its utilisation is still limited by high facility costs and technological challenges. A possibility to address both of these can be considered by improvements to the beam delivery system (BDS). Existing beamlines and gantries transport beams with a momentum range of ±1% and consequently, adjustments in depth or beam energy require all the magnetic fields to be changed. The speed to switch energies is a limiting constraint of the BDS and a determinant of the overall treatment time. A novel concept using fixed field alternating gradient (FFA) optics enables a large energy acceptance (LEA) as beams of varying energies can traverse the beamline at multiple physical positions given the same magnetic field. This presents the potential to provide faster, higher quality treatments at lower costs, with the capability to deliver advanced PT techniques such as multi-ion therapy. We explore the applicability and benefits of a LEA BDS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB417
About •	paper received ※ 18 May 2021 paper accepted ※ 27 July 2021 issue date ※ 15 August 2021
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MOPAB418	Tracking and LET Measurements with the MiniPIX-TimePIX Detector for 60 MeV Clinical Protons	detector, proton, instrumentation, experiment	1260
	J.S.L. Yap, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom N.J.S. Bal NIKHEF, Amsterdam, The Netherlands M.D. Brooke University of Oxford, Oxford, United Kingdom C. Granja, C. Oancea ADVACAM s.r.o, Prague, Czech Republic A. Kacperek The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom C.P. Welsch, J.S.L. Yap The University of Liverpool, Liverpool, United Kingdom
	Funding: EU FP7 grant agreement 215080, H₂020 Marie Sklodowska-Curie grant agreement No 675265, OMA - Optimization of Medical Accelerators and the Cockcroft Institute core grant STGA00076-01. Recent advancements in accelerator technology have led the rapid emergence of particle therapy facilities worldwide, affirming the need for enhanced characterisation methods of radiation fields and radiobiological effects. The Clatterbridge Cancer Centre, UK operates a 60 MeV proton beam to treat ocular cancers and facilitates studies into proton induced radiobiological responses. Accordingly, an indicator of radiation quality is the linear energy transfer (LET), a challenging physical quantity to measure. The MiniPIX-Timepix is a miniaturised, hybrid semiconductor pixel detector with a Timepix ASIC, enabling wide-range measurements of the deposited energy, position and direction of individual charged particles. High resolution spectrometric tracking and simultaneous energy measurements of single particles enable the beam profile, time, spatial dose mapping and LET (0.1 to >100 keV/µm) to be resolved. Measurements were performed to determine the LET spectra in silicon, at different positions along the Bragg Peak (BP). We discuss the experimental setup, preliminary results and applicability of the MiniPIX for clinical environments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB418
About •	paper received ※ 18 May 2021 paper accepted ※ 23 July 2021 issue date ※ 25 August 2021
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MOPAB419	Acceleration and Measurement of Alpha Particles and Hydrogen Molecular Ions with the HZB Cyclotron	cyclotron, proton, vacuum, scattering	1264
	G. Kourkafas, J. Bundesmann, A. Denker, T. Fanselow, J. Röhrich HZB, Berlin, Germany J. Heufelder, A. Weber Charite, Berlin, Germany
	The HZB cyclotron has treated more than 4000 patients with eye tumors using protons. The accelerator can also provide heavier ions which could be suitable for ocular radiation therapy. Helium ions exhibit less lateral spread, increased relative biological effectiveness and a sharper Bragg-Peak compared to protons of the same range, while minimizing nuclear fragmentation and thus excessive dose downstream the irradiated volume compared to more heavy ions. When accelerating fully stripped helium ions (alpha particles), hydrogen molecular ions can also be accelerated to the same energy with a small tuning of the machine due to having almost the same mass-to-charge ratio, yielding a proton beam of double current after the beam exits the vacuum window towards the target. The acceleration and characterization of these two ion species are described in this paper, suggesting the feasibility of a corresponding clinical cyclotron for ocular or even deep-seated tumors.
	Poster MOPAB419 [0.806 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB419
About •	paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 13 August 2021
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TUPAB004	Comparison of Accelerator Codes for Simulation of Lepton Colliders	lattice, emittance, optics, lepton	1334
	L. van Riesen-Haupt, H. Burkhardt, T.H.B. Persson, R. Tomás García CERN, Meyrin, Switzerland
	This paper compares simulation results obtained with SAD, MAD-X and the PTC implementation in MADX for the design studies of the FCC-ee. On-momentum and off-momentum optics are explored for the various programs. Particle tracking with and without synchrotron radiation are used to compare amplitude detuning and emittance. Finally, this paper outlines how well-established SAD features such as tapering have recently been integrated into MADX.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB004
About •	paper received ※ 16 May 2021 paper accepted ※ 15 June 2021 issue date ※ 26 August 2021
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TUPAB010	Impact of Bunch Current on Optics Measurements in SuperKEKB	optics, damping, impedance, quadrupole	1356
	J. Keintzel, R. Tomás García, F. Zimmermann CERN, Geneva, Switzerland T. Ishibashi, H. Koiso, G. Mitsuka, A. Morita, K. Ohmi, Y. Ohnishi, H. Sugimoto, S. Terui, M. Tobiyama, R.J. Yang, D. Zhou KEK, Ibaraki, Japan
	SuperKEKB has recently achieved the world record instantaneous luminosity of 2.8 × 10³⁴ \si{cm^-2s^-1} and aims at reaching a target luminosity of about 6 × 10³⁵ \si{cm^-2s^-1}. To accomplish this goal it is planned to increase beam currents up to §I{3.6}{A} and §I{2.6}{A} for the positron and the electron ring, respectively. Increasing the beam currents and, in particular, the number of leptons per bunch, can impact the optics parameters obtained by turn-by-turn measurements, such as the betatron tune or phase advance. Optics measurements performed at various bunch currents can give first indications of possible intensity dependent effects. In this paper, the effect of varying bunch current on optics measurements at SuperKEKB is explored.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB010
About •	paper received ※ 18 May 2021 paper accepted ※ 10 June 2021 issue date ※ 30 August 2021
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TUPAB030	Superb Fixed Field Permanent Magnet Proton Therapy Gantry	permanent-magnet, proton, hadron, MMI	1405
	D. Trbojevic, S.J. Brooks, T. Roser, N. Tsoupas BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. We present the top notch design of the proton therapy gantry made of permanent magnets with very strong focusing. This represents a superb solution fulfilling all cancer treatment requirements for all energies without changing any parameters. The proton energy range is between 60-250 MeV. The beam arrives to the patient focused at each required treatment energy. The scanning system is place between the end of the gantry and the patient. There are multiple advantages of this design: easy operation, no significant electrical power - just for the correction system, low weight, low cost. The design is based on the recent very successful commissioning of the permanent magnet ERL ’CBETA’ at Cornell University.
	Poster TUPAB030 [7.816 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB030
About •	paper received ※ 17 May 2021 paper accepted ※ 07 June 2021 issue date ※ 21 August 2021
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TUPAB057	Carbon Beam at I-3 Injector for Semiconductor Implantation	laser, target, plasma, ion-source	1489
	A.A. Losev, P.N. Alekseev, N.N. Alexeev, T. Kulevoy, A.D. Milyachenko, Yu.A. Satov, A. Shumshurov ITEP, Moscow, Russia P.B. Lagov NUST MISIS, Moscow, Russia M.E. Letovaltseva MIREA, Moscow, Russia Y.S. Pavlov IPCE RAS, Moscow, Russia
	Carbon implantation can be effectively used for axial minority charge carriers lifetime control in various silicon bulk and epitaxial planar structures. When carbon is implanted, more stable recombination centers are formed and silicon is not doped with additional impurities, as for example, when irradiated with protons or helium ions. Economically, such a process competes with alternative methods, and is more efficient for obtaining small lifetimes (several nanoseconds). I-3 ion injector with laser-plasma ion source in Institute for theoretical and experimental physics (ITEP) is used as ion implanter in semiconductors. The ion source uses pulsed CO₂ laser setup with radiation-flux density of 10¹¹ W/cm² at target surface. The ion source produces beams of various ions from solid targets. The generated ion beam is accelerated in the two gap RF resonator at voltage of up to 2 MV per gap. Resulting beam energy is up to 4 MV per charge. Parameters of carbon ion beam generated and used for semiconductor samples irradiation during experiments for axial minority charge carriers lifetime control in various silicon bulk and epitaxial planar structures are presented.
	Poster TUPAB057 [0.630 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB057
About •	paper received ※ 15 May 2021 paper accepted ※ 28 May 2021 issue date ※ 01 September 2021
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TUPAB063	Study of PF-Ring Infrastructure Improvements Using Temperature Measurements in the Ring Tunnel	injection, controls, experiment, operation	1508
	N. Nakamura, K. Haga, T. Nogami, M. Tadano KEK, Ibaraki, Japan
	Temperature measurements have been performed in the PF-ring tunnel in order to understand the infrastructure performance and the temperature stability towards the PF upgrade project, where better beam stability will be required. Based on the temperature measurements, possible improvements of the PF-ring infrastructure such as an air-conditioning system have been studied to enhance the temperature stability in the PF-ring tunnel. In this paper, we present results of the temperature measurements in the PF-ring tunnel and a proposal of the PF-ring infrastructure improvements for the temperature stabilization.
	Poster TUPAB063 [6.169 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB063
About •	paper received ※ 18 May 2021 paper accepted ※ 26 May 2021 issue date ※ 16 August 2021
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TUPAB067	Production of 120 MeV Gamma-ray Beams at Duke FEL and HIGS Facility	FEL, operation, wiggler, diagnostics	1522
	S.F. Mikhailov, V. Popov, G. Swift, P.W. Wallace, Y.K. Wu, J. Yan FEL/Duke University, Durham, North Carolina, USA M.W. Ahmed, M. Sikora TUNL, Durham, North Carolina, USA H. Ehlers, L.O. Jensen, L. Kochanneck Laser Zentrum Hannover, Hannover, Germany
	Funding: This work is supported by the US DoE grant #DE-FG02-97ER41033 In this paper we report extension of the operational energy of the gamma ray beams produced at Duke High Intensity Gamma-ray Source (HIGS) up to ~120MeV, opening up a new high energy region of gamma rays for photonuclear physics research. This achievement is based upon development of radiation robust, thermally stable, high-reflectivity fluoride (LaF3/MgF2) multilayer VUV FEL mirrors, enabling us to maintain stable high intensity FEL lasing at the wavelengths of around 175nm. We discuss the challenges of HIGS operation at high gamma and high electron beam energies with the downstream FEL mirror exposed to extremely hush radiation. The experience of the first HIGS user operation with high intensity, high gamma-ray beam energies (85 and ~120MeV) using these new mirrors is also discussed.
	Poster TUPAB067 [1.023 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB067
About •	paper received ※ 30 May 2021 paper accepted ※ 09 June 2021 issue date ※ 31 August 2021
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TUPAB069	The Sabina Terahertz/Infrared Beamline at SPARC-Lab Facility	electron, experiment, photon, laser	1525
	S. Macis La Sapienza University of Rome, Rome, Italy M. Bellaveglia, M. Cestelli Guidi, E. Chiadroni, F. Dipace, A. Ghigo, L. Giannessi, A. Giribono, L. Sabbatini, C. Vaccarezza INFN/LNF, Frascati, Italy A. Doria, A. Petralia ENEA C.R. Frascati, Frascati (Roma), Italy S. Lupi Sapienza University of Rome, Roma, Italy V. Petrillo INFN-Milano, Milano, Italy
	Funding: SABINA is a project co-funded by Regione Lazio within POR-FESR 2014-2020 program. Following the EU Terahertz (THz) Road Map, high-intensity, ps-long, THz)/Infrared (IR) radiation is going to become a fundamental spectroscopy tool for probing and control low-energy quantum systems ranging from graphene, and Topological Insulators, to novel superconductors* **. In the framework of the SABINA project, a novel THz/IR beamline based on an APPLE-X undulator emission will be developed at the SPARC-Lab facility at LNF-INFN. Light will be propagated from the SPARC-Lab to a new user lab facility nearly 20 m far away. This beamline will cover a broad spectral region from 3 THz to 30 THz, showing ps- pulses and energy of tens of µJ with variable polarization from linear to circular. The corresponding electric fields up to 10 MV/cm, are able to induce non-linear phenomena in many quantum systems. The beamline, open to user experiments, will be equipped with a 5 T magnetic cryostat and will be synchronized with a fs laser for THz/IR pump, VIS/UV probe experiments. [] S.S. Dhillon et al., J. Phys. D: Appl. Phys. 50, 043001 (2017); [] F. Giorgianni et al., Nature Commun. 7, 11421 (2016); [*] P. Di Pietro et al., Phys. Rev. Lett. 124, 226403 (2020);
	Poster TUPAB069 [0.884 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB069
About •	paper received ※ 16 May 2021 paper accepted ※ 21 June 2021 issue date ※ 25 August 2021
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TUPAB071	Beam Line Design and Instrumentation for THz@PITZ - the Proof-of-Principle Experiment on a THz SASE FEL at the PITZ Facility	undulator, FEL, electron, experiment	1528
	T. Weilbach, P. Boonpornprasert, G.Z. Georgiev, G. Koss, M. Krasilnikov, X. Li, A. Lueangaramwong, F. Mueller, A. Oppelt, S. Philipp, F. Stephan, L.V. Vu DESY Zeuthen, Zeuthen, Germany H. Shaker CLS, Saskatoon, Saskatchewan, Canada
	In order to allow THz pump-X-ray probe experiments at full bunch repetition rate for users at the European XFEL, the Photo Injector Test Facility at DESY in Zeuthen (PITZ) is building a prototype of an accelerator-based THz source. The goal is to generate THz SASE FEL radiation with a mJ energy level per bunch using an LCLS-I undulator driven by the electron beam from PITZ. Therefore, the existing PITZ beam line is extended into a tunnel annex downstream of the existing accelerator tunnel. The beam line extension in the PITZ tunnel consists of three quadrupole magnets, a bunch compressor, a collimation system and a beam dump. In the second tunnel a dipole magnet allows to serve two beam lines, one of them the THz@PITZ beam line. It consists of one LCLS-I undulator for the production of the THz radiation, a quadrupole triplet in front of it and a quadrupole doublet behind it. For the electron beam diagnostic six new screen stations are built, three of them also allow for the observation of the THz radiation for measurements. In addition six BPMs and a new BLM system for machine protection and FEL gain curve measurement will be installed. The progress of this work will be presented.
	Poster TUPAB071 [1.978 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB071
About •	paper received ※ 18 May 2021 paper accepted ※ 14 June 2021 issue date ※ 13 August 2021
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TUPAB073	The Design of EEHG Cascaded Harmonic Lasing for SXFEL User Facility	FEL, undulator, electron, laser	1536
	K.Q. Zhang, C. Feng SSRF, Shanghai, People’s Republic of China H.X. Deng, B. Liu, T. Liu SARI-CAS, Pudong, Shanghai, People’s Republic of China
	The preliminary design and simulation results of EEHG cascaded harmonic lasing for the SXFEL user facility have been presented in this paper. Using the basic seeded beamline of the SXFEL user facility, the designed parameters are optimized to obtain full coherent FEL output at the 90th harmonic of a 265 nm seed laser. According to the designed parameters and the layout of the SXFEL user facility, the detailed simulations are carried out, the results show that the seeded beamline of the SXFEL user facility can generate 2.93 nm full coherent radiation by the proposed method, which indicates that the method can extend the photon energy range of a seeded FEL and the method can be achieved at the SXFEL user facility.
	Poster TUPAB073 [0.955 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB073
About •	paper received ※ 11 May 2021 paper accepted ※ 10 June 2021 issue date ※ 27 August 2021
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TUPAB078	Relative Timing Jitter Effects on Two-stage Seeded FEL at SHINE	FEL, laser, electron, timing	1551
	H.X. Yang SINAP, Shanghai, People’s Republic of China H.X. Deng, B. Liu, D. Wang, K.S. Zhou SARI-CAS, Pudong, Shanghai, People’s Republic of China
	Funding: The National Key Research and Development Program of China (Grants No. 2016YFA0401901, No. 2018YFE0103100) and the National Natural Science Foundation of China (Grants No. 11935020, No. 11775293). The synchronization between the ultrashort electron beam and external seed laser is essential for seeded FELs, especially for a multi-stage one. In this paper, we demonstrate a simple method to obtain the correlations between the pulse energy and relative timing jitter for evaluating the corresponding effects. In this method, the sensitivity of the output FEL performance against electron beam properties is demonstrated by scanning the electron beam and seed lasers, and the fitted curve is used to predict the pulse energy in different timing jitter by random sampling. The results indicate that the pulse energy of the first-stage EEHG is more stable than the second-stage HGHG. Meanwhile, the rise of bunch charge from 100 pC to 300 pC can reduce the timing control requirement by a factor of least 3 for the RMS timing jitter in our numerical simulations based on the parameters of Shanghai High-Repetition-Rate XFEL and Extreme Light Facility. The timing jitter study can demonstrate the feasibility of the EEHG-HGHG cascading scheme in different current profiles for generating Fourier-transform-limited soft X-ray FEL.
	Poster TUPAB078 [0.866 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB078
About •	paper received ※ 11 May 2021 paper accepted ※ 11 June 2021 issue date ※ 21 August 2021
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TUPAB084	An Empirically-Derived ABCD Matrix for Transverse Dynamics Studies in Seeded Free-Electron Lasers	FEL, electron, laser, free-electron-laser	1573
	R. Robles Stanford University, Stanford, California, USA Z. Huang, G. Marcus SLAC, Menlo Park, California, USA
	Funding: DOE Contract DE-AC02-76SF00515. We present a simple empirical method for deriving an ABCD matrix for studying the transverse dynamics of the radiation field in seeded, high-gain free-electron lasers before saturation. In spite of the inherently nonlinear nature of FEL optical guiding, the ABCD matrix we find is able to predict the evolution of the FEL mode size and centroid to a high degree of accuracy across a large range of input mode characteristics. This scheme enables extremely fast simulation of transverse dynamics, which in turn greatly simplifies numerical studies of seeded FEL systems. Of particular interest in that regard is the x-ray regenerative amplifier free-electron laser, in which the x-ray beam propagates through an optical cavity many hundreds of times, thereby making traditional simulation methods cumbersome and time consuming.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB084
About •	paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 11 August 2021
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TUPAB089	Proof-of-Principle Experiment Design for PEHG-FEL in SXFEL User Facility	FEL, laser, electron, experiment	1589
	Z. Qi, H.X. Deng, C. Feng, B. Liu SARI-CAS, Pudong, Shanghai, People’s Republic of China S. Chen, Z.T. Zhao SSRF, Shanghai, People’s Republic of China
	In this paper, we demonstrate a proof-of-principle experimental design for phase-merging enhanced harmonic generation (PEHG) free electron laser (FEL) in Shanghai Soft X-ray Free Electron Laser (SXFEL) user facility. The simulation results indicate that, taking advantage of the beam switchyard, the normal modulator and the seeded FEL line in SXFEL user facility, together with an oblique incident seed laser, we can perform the phase-merging effect in PEHG and finally get an 8.86nm FEL radiation through the undulator, which is the 30th harmonic of the seed laser.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB089
About •	paper received ※ 19 May 2021 paper accepted ※ 17 June 2021 issue date ※ 02 September 2021
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TUPAB100	FEL Design Elements of SABINA: A Free Electron Laser For THz-MIR Polarized Radiation Emission	undulator, electron, FEL, simulation	1612
	F. Dipace, E. Chiadroni, M. Ferrario, A. Ghigo, L. Giannessi, A. Giribono, L. Sabbatini, C. Vaccarezza INFN/LNF, Frascati, Italy A. Doria, A. Petralia ENEA C.R. Frascati, Frascati (Roma), Italy S. Lupi Sapienza University of Rome, Roma, Italy S. Macis La Sapienza University of Rome, Rome, Italy V. Petrillo Universita’ degli Studi di Milano, Milano, Italy V. Petrillo INFN-Milano, Milano, Italy
	Funding: SABINA is a project co-funded by Regione Lazio within POR-FESR 2014-2020 program. SABINA, acronym of "Source of Advanced Beam Imaging for Novel Applications", will be a Self-Amplified Spontaneous Emission Free Electron Laser (SASE FEL) providing a wide spectral range (from THz to MIR) of intense, short and variable polarization pulses for investigation in physics, chemistry, biology, cultural heritage, and material science. In order to reach these goals high brightness electron beams within a 30-100 MeV energy range, produced at SPARC photo-injector, will be transported up to an APPLE-X undulator through a dogleg. Space charge effects and Coherent Synchrotron Radiation (CSR) effects must be held under control to preserve beam quality. Studies on beam transport along the undulator and of the properties of the radiation field have been performed with "Genesis 1.3" simulation code. A downstream THz optics photon delivery system has also been designed to transport radiation on the long path from the undulator exit up to user experimental area.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB100
About •	paper received ※ 19 May 2021 paper accepted ※ 11 June 2021 issue date ※ 02 September 2021
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TUPAB101	Monte Carlo Simulations and Neutron and Gamma Fluence Measurements to Investigate Stray Radiation in the European XFEL Undulator System	undulator, electron, simulation, neutron	1615
	O.E. Falowska-Pietrzak, A. Hedqvist, F. Hellberg Stockholm University, Stockholm, Sweden N. Bassler DCPT, Aarhus N, Denmark A. Leuschner, D. Nölle DESY, Hamburg, Germany F. Wolff-Fabris EuXFEL, Schenefeld, Germany
	The European X-ray Free Electron Laser (XFEL) is an user facility research centre generating extremely bright and ultra-short SASE x-ray pulses. The laser flashes are generated when electrons of GeV energies pass the undulator systems. Even if the dominating contribution of the radiation field in the undulator is from spontaneous undulator radiation, also electron losses can be observed, e.g. during beam steering or due to beam halo, not captured by the upstream collimation system. The interactions of those particles with the vacuum vessel wall result in the emission of stray radiation. The LB 6419 detector allows to measure both the neutron and the gamma component in the pulsed radiation fields nearby the undulators. Usually, the real-time measurements show the dominance of the gamma signals. However, in case of particle loss occurs, a neutron signal is observed. In addition, Monte Carlo (MC) simulations conducted using the Geant4 code indicate that neutrons are also present within the undulator’s magnets volume. In this work, we present the LB 6419 measurement data and compare these to our MC simulations, to characterize the radiation field nearby the undulator segment. KLETT, A., LEUSCHNER, A., TESCH, N., A dose meter for pulsed neutron fields, Radiat Meas 45 (2010) 1242-1244
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB101
About •	paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 18 August 2021
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TUPAB106	Simulation Calculations of Compact THz Facility at IUAC, New Delhi	undulator, simulation, electron, optics	1633
	J. Karmakar, S. Ghosh IUAC, New Delhi, India
	A compact THz radiation source based on the principle of pre-bunched Free Electron Laser is at the commissioning stage at Inter University Accelerator Centre (IUAC), New Delhi. The facility will generate low emittance train of electron micro-bunches (2, 4, 8 or 16 numbers) from a RF photo-cathode gun in the energy range of 4 to 8 MeV and inject into a compact undulator to generate coherent THz radiation in the frequency range of ~0.18 to 3.0 THz. To optimize the intensity at a given frequency, the beam bunching factor and the betatron oscillation amplitude in the non-wiggling plane of the electronμbunches inside the undulator has been maximized and minimized respectively. The paper presents the optimized beam optics simulation results for two frequencies viz 0.5 and 2 THz. The on-axis radiation spectral intensity computed by in-house developed code using the trajectory data of the beam optics simulation is also presented for the two frequencies.
	Poster TUPAB106 [1.208 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB106
About •	paper received ※ 18 May 2021 paper accepted ※ 31 August 2021 issue date ※ 12 August 2021
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TUPAB116	Toward THz Coherent Undulator Radiation Experiment with a Combination of Velocity Bunchings	undulator, electron, bunching, acceleration	1663
	Y. Sumitomo, K. Hayakawa, Y. Hayakawa, K. Nogami, T. Sakai, T. Tanaka LEBRA, Funabashi, Japan
	Funding: Japan Society for the Promotion of Science (JSPS), Grant-in-Aid for Scientific Research (KAKENHI), Grant Number JP19K12631. We have launched a research program to generate the THz coherent undulator radiations, following the proposal of the combination of velocity bunchings * at Nihon University. The combination of velocity bunchings is an efficient way of bunch compression allowing a range of energy choices, in other words, a range of quasi-monochromatic radiation wavelengths generated at the undulator. In addition to the existing wideband THz light sources (0.1 - 2 THz) by the coherent edge and transition radiations currently available at Nihon Univ., the development of a high peak-power and quasi-monochromatic coherent radiation should accelerate the activities including the material science related to the THz bandwidths. In this presentation, we illustrate the program and report the current status of the experiment. * Y. Sumitomo et al., J. Phys. Conf. Ser., vol. 1067, p. 032017, 2018.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB116
About •	paper received ※ 19 May 2021 paper accepted ※ 15 June 2021 issue date ※ 15 August 2021
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TUPAB119	Beam Loss Study for the Implementation of Dechirper at the European XFEL	FEL, undulator, simulation, electron	1670
	J.J. Guo University of Chinese Academy of Sciences, Beijing, People’s Republic of China W. Decking, M.W. Guetg, J.J. Guo, S. Liu, W. Qin, I. Zagorodnov DESY, Hamburg, Germany Q. Gu, J.J. Guo SINAP, Shanghai, People’s Republic of China Q. Gu Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China
	The European XFEL is a free-electron laser facility based on superconducting linac with high repetition rate up to 4.5 MHz. Wakefield structure (also called dechirper module) is planned to be installed in front of the SASE beam line at the European FEL, which can be used as a kicker for two-color scheme or a dechirper to control the bandwidth of SASE radiation. When the beam pass through the dechirper module, strong longitudinal and transverse wakefields can be excited to introduce a correlated energy chirp and a kick along the bunch. However, due to the relatively small gap of dechirper, beam halo particles hitting the dechirper module can lead to energy deposition and generate additional radiation, which can cause serious damage to the downstream undulators. For this reason, simulations have been performed using BDSIM to define the maximum acceptable beam halo, and the results are presented in this paper.
	Poster TUPAB119 [1.489 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB119
About •	paper received ※ 16 May 2021 paper accepted ※ 15 June 2021 issue date ※ 12 August 2021
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TUPAB125	Studies of Particle Losses From the Beam in the EU-XFEL Following Scattering by a Slotted Foil	undulator, FEL, simulation, diagnostics	1681
	A.T. Potter, A. Wolski The University of Liverpool, Liverpool, United Kingdom W. Decking, S. Liu DESY, Hamburg, Germany F. Jackson STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	One technique for producing short radiation pulses in an FEL involves the use of a slotted foil in a bunch compressor. However, the scattering of particles from the foil can lead to increased particle losses and the generation of secondary particles. This is a particular concern for high rep-rate FELs, such as the European XFEL, where there are plans to implement the slotted-foil technique for short pulse generation. The study reported here aims to characterise the impact of a slotted foil in the European XFEL on the radiation dose in the front section of one of the undulators. Simulations were performed using BDSIM: this code tracks primary particles along the beamline, models the interaction between particles and accelerator components and tracks secondary particles produced by these interactions. The results indicate the amount of energy deposited in the front section of one of the FEL undulators, and provide a basis for optimisation of the collimation system to keep the energy deposition and radiation doses within acceptable limits.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB125
About •	paper received ※ 19 May 2021 paper accepted ※ 10 June 2021 issue date ※ 28 August 2021
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TUPAB131	Measurement of Coherent Smith-Purcell Radiation Using Ultra-Short Electron Bunch at T-Acts	electron, experiment, bunching, background	1696
	H. Yamada, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, K. Shibata, K. Takahashi Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
	The coherent Smith-Purcell radiation (SPR) emitted as a short electron bunch passes over a periodic metal surface is expected to be applied as a non-destructive beam diagnostic tool. The longitudinal profile of the electron bunch can be deduced by the measured spectrum of the coherent SPR, which is compared with the theoretical one for single electron. There are several theoretical models that explain the SPR mechanism, such as the surface current (SC) model and the van den Berg model. But the difference of estimation in radiation intensity between different models is not trivial, and also the experimental data to evaluate those validity is not enough. At test accelerator, t-ACTS, in Tohoku University we are conducting experimental research on coherent SPR in the terahertz frequency region using an ultra-short electron bunch of about 100 fs. The status and results of the experiment will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB131
About •	paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 13 August 2021
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TUPAB189	Design and Simulation of Beam Transport Lines of DC140 Cyclotron	quadrupole, cyclotron, target, heavy-ion	1845
	V.I. Lisov, N.S. Kirilkin, A.S. Zabanov JINR/FLNR, Moscow region, Russia I.V. Kalagin, N.Yu. Kazarinov, S.V. Mitrofanov, V.A. Semin JINR, Dubna, Moscow Region, Russia
	Flerov Laboratory of Nuclear Reaction of Joint Institute for Nuclear Research carries out the works under creating of FLNR JINR Irradiation Facility based on the cyclotron DC140. The DC140 cyclotron is intended for acceleration of heavy ions with mass-to-charge ratio A/Z within interval from 5 to 5.5 up to two fixed energies 2.124 and 4.8 MeV per unit mass. The intensity of the accelerated ions will be about 1 pmcA for light ions (A<86) and about 0.1 pmcA for heavier ions (A>132). The beam transport system has three lines: for SEE testing of microchip, for production of track membranes and for solving of applied physics problems. The design and simulation of the beam transport system from cyclotron is presented in this report. The beam focusing in the beam lines is provided by set of quadrupole lenses. The beam diagnostics system consists of the Faraday caps, luminophores and the magnetic scanning system.
	Poster TUPAB189 [0.958 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB189
About •	paper received ※ 14 May 2021 paper accepted ※ 02 June 2021 issue date ※ 17 August 2021
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TUPAB191	Design and Simulation of the Axial Injection Beam Line of DC140 Cyclotron of FLNR JINR	cyclotron, injection, ECR, simulation	1852
	N.Yu. Kazarinov, V. Bekhterev, G.G. Gulbekyan, I.A. Ivanenko, I.V. Kalagin, S.V. Mitrofanov, N.F. Osipov, V.A. Semin JINR, Dubna, Moscow Region, Russia V.I. Lisov JINR/FLNR, Moscow region, Russia
	Flerov Laboratory of Nuclear Reaction of Joint Institute for Nuclear Research carries out the works under creating of FLNR JINR Irradiation Facility based on the cyclotron DC140. The facility is intended for SEE testing of microchip, for production of track membranes and for solving of applied physics problems. The main systems of DC140 are based on the DC72 cyclotron ones that now are under reconstruction. The DC140 cyclotron is intended for acceleration of heavy ions with mass-to-charge ratio A/Z within interval from 5 to 5.5 up to two fixed energies 2.124 and 4.8 MeV per unit mass. The intensity of the accelerated ions will be about 1 pmcA for light ions (A<86) and about 0.1 pmcA for heavier ions (A>132). The injection into cyclotron will be realized from the external room temperature 18 GHz ECR ion source. The design and simulation of the axial injection system of the DC140 cyclotron is presented in this report.
	Poster TUPAB191 [1.090 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB191
About •	paper received ※ 14 May 2021 paper accepted ※ 28 May 2021 issue date ※ 22 August 2021
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Paper

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Other Keywords

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MOPAB012

Energy Deposition Study of the CERN HL-LHC Optics v1.5 in the ATLAS and CMS Insertions

luminosity, insertion, proton, optics

76

M. Sabaté-Gilarte, F. Cerutti
CERN, Meyrin, Switzerland

Funding: Research supported by the HL-LHC project
The High Luminosity Large Hadron Collider (HL-LHC) is the approved CERN project aiming at further increasing the integrated luminosity of the LHC by a factor 10. As such, it implies a complete redesign of the experimental high-luminosity insertions of ATLAS and CMS. The progressive evolution of the new layout and optics requires a continuous analysis of the radiation environment, to which magnets and other equipment are exposed to. This is assured by means of Monte Carlo simulations of the collision debris on the evolving machine model. The latter featured several developments, such as the explicit inclusion of the cold protection diodes of the final focusing circuits as well as the crab cavities cryomodule. This work presents the most updated characterization of the radiation field with FLUKA and its impact in the insertion region and the dispersion suppressor of Point 1 and 5, for the HL-LHC optics v1.5 released in 2019. Various optimization and mitigation studies are highlighted, providing key information for maximizing the lifetime of new and present magnets.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB012

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paper received ※ 18 May 2021 paper accepted ※ 25 May 2021 issue date ※ 21 August 2021

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MOPAB013

Radiation to Electronics Impact on CERN LHC Operation: Run 2 Overview and HL-LHC Outlook

operation, luminosity, electron, target

80

Y.Q. Aguiar, A. Apollonio, F. Cerutti, S. Danzeca, R. García Alía, G. Lerner, D. Prelipcean, M. Sabaté-Gilarte
CERN, Geneva 23, Switzerland

Funding: Research supported by the HL-LHC project
After the mitigation measures implemented during Run 1 (2010-2012) and Long Shutdown 1 (LS1, 2013-2014), the number of equipment failures due to radiation effects on electronics (R2E) leading to LHC beam dumps and/or machine downtime has been sufficiently low as to yield a minor impact on the accelerator performance. During Run 2 (2015-2018) the R2E related failures per unit of integrated luminosity remained below the target value of 0.5 events/fb-1, with the sole exception of the 2015 run during which the machine commissioning took place. However, during 2018, an increase in the failure rate was observed, linked to the increased radiation levels in the dispersion suppressors of the ATLAS and CMS experimental insertions, significantly affecting the Quench Protection System located underneath the superconducting magnets in the tunnel. This work provides an overview of the Run 2 R2E events during LHC proton-proton operation, putting them in the context of the related radiation levels and equipment sensitivity, and providing an outlook for Run 3 and HL-LHC operation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB013

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paper received ※ 19 May 2021 paper accepted ※ 23 July 2021 issue date ※ 23 August 2021

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MOPAB018

SASE Gain-Curve Measurements with MCP-Based Detectors at the European XFEL

FEL, detector, photon, undulator

96

E. Syresin, O.I. Brovko, A.Yu. Grebentsov
JINR, Dubna, Moscow Region, Russia
W. Freund, J. Grünert, J. Liu, Th. Maltezopoulos, D. Mamchyk
EuXFEL, Schenefeld, Germany
M.V. Yurkov
DESY, Hamburg, Germany

Radiation detectors based on microchannel plates (MCP) are used for characterization of the Free-Electron Laser (FEL) radiation and measurements of the Self-amplified spontaneous emission (SASE) gain curve at the European XFEL. Photon pulse energies are measured by the MCPs with an anode and by a photodiode. There is one MCP-based detector unit installed in each of the three photon beamlines downstream of the SASE1, SASE2, and SASE3 undulators. MCP detectors operate in a wide dynamic range of pulse energies, from the level of spontaneous emission up to FEL saturation. Their wavelength operation range overlaps with the whole range of radiation wavelengths of SASE1 and SASE2 (from 0.05 nm to 0.4 nm), and SASE3 (from 0.4 nm to 5 nm). In this paper we present results of SASE gain-curve measurements by the MCP-based detectors.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB018

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paper received ※ 18 May 2021 paper accepted ※ 17 August 2021 issue date ※ 23 August 2021

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MOPAB033

Monochromatization of e⁺e⁻ Colliders with a Large Crossing Angle

emittance, resonance, collider, luminosity

152

V.I. Telnov
BINP SB RAS, Novosibirsk, Russia

The relative center-of-mass energy spread at e⁺e⁻ colliders is much larger than the widths of narrow resonances, which greatly lowers the resonance production rates of J/Psi, Psi-prime, Upsililon(nS), n=1-3. Thus, a significant reduction of the center-of-mass energy spread would open up great opportunities in the search for new physics in rare decays of narrow resonances, the search for new narrow states with small partial e⁺e⁻ width. The existing monochromatization scheme is only suitable for head-on collisions, while e⁺e⁻ colliders with crossing angles (the so-called Crab Waist collision scheme) can provide much higher luminosity. In this report, a new monochromatization method for colliders with a large crossing angle is discussed*. The contribution of the beam energy spread to the spread of the center-of-mass energy is canceled by introducing an appropriate energy-angle correlation at the interaction point; the relative RMS mass spread of about (3-5)10^-6 seems possible. Limitations of the proposed method are also considered. This monochromatization scheme is very attractive for the Upsilon-meson region and below.
* V.I.Telnov, Monochromatization of e⁺e⁻ colliders with a large crossing angle, arXiv:2008.13668

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB033

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paper received ※ 22 May 2021 paper accepted ※ 26 May 2021 issue date ※ 31 August 2021

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MOPAB044

Gas Bremsstrahlung Measurements in the Advanced Photon Source Storage Ring

photon, operation, detector, injection

193

J.C. Dooling, A.R. Brill, J.R. Calvey
ANL, Lemont, Illinois, USA

Funding: Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357.
In the Advanced Photon Source Upgrade storage ring (SR), small-aperture vacuum chambers provide limited conductance for pumping. Non-evaporable getter (NEG) coatings will be used in the SR to support the vacuum. Ion pumps and cold-cathode gauges are typically located away from the vacuum chamber transporting the beam. Measuring gas bremsstrahlung (GB) photons in low-conductance chambers provides a method to determine the pressure at the beam location. We report on GB measurements made in the ID-25 beamline. A Pb:Glass calorimeter radiator generates Cherenkov radiation when high-energy photons cause pair-production within the glass. A photomultiplier tube converts the light pulses to electrical signals. Data was obtained during normal machine operations starting in January 2020. Data collection was facilitated using a 4-channel ITech Beam Loss Monitor FPGA that allows for control of thresholds and attenuation settings in both counting and pulse-height acquisition modes. Count rates and spectra were recorded for the three primary fill patterns typically used during SR operations as well as during gas injection experiments; results of these measurements will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB044

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paper received ※ 22 May 2021 paper accepted ※ 28 May 2021 issue date ※ 25 August 2021

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MOPAB054

Start-to-End Simulation of a Free-Electron Laser Driven by a Laser-Plasma Wakefield Accelerator

plasma, laser, bunching, electron

233

W. Liu, Y. Jiao, S. Wang
IHEP, Beijing, People’s Republic of China

The rapid development of laser-plasma wakefield accelerator (LPA) has opened up a new possible way to achieve ultra-compact free-electron laser (FEL). To this end, LPA experts have made many efforts to generate electron beams with sub-micrometer emittance and low energy spread. Recently, a new laser modulation method was proposed for generating EUV coherent pulse in an LPA-driven FEL. The simulation demonstration of this scheme is based on the Gaussian beam. However, the distribution of the LPA beam is not Gaussian. To further verify the feasibility of the method mentioned above, a start-to-end simulation is required.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB054

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paper received ※ 18 May 2021 paper accepted ※ 27 May 2021 issue date ※ 22 August 2021

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MOPAB088

Beam-Based Measurement on the Performance of Ferrite Dampers in an In-Vacuum Undulator

damping, HOM, feedback, vacuum

331

K. Tian, A. Ringwall, J.J. Sebek
SLAC, Menlo Park, California, USA

In this paper, we first present the tracking studies for SPEAR3 with the new BL17 ID and estimate its impact on the dynamic aperture of the low emittance lattice. Then the ferrite dampers installations in the device is briefly reviewed. After that, we will show that, based on beam-based measurements, the performance of the dampers is as being expected from earlier numerical studies.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB088

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paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 24 August 2021

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MOPAB090

Status of HEPS Insertion Devices Design

undulator, photon, wiggler, insertion

339

X.Y. Li, Y. Jiao, H.H. Lu, S.K. Tian
IHEP, Beijing, People’s Republic of China

HEPS is a 4th generation light source with the energy of 6 GeV and ultralow emittance of 34 pm.rad. A total of 14 beamlines with 19 insertion devices has been planned in the first phase, including 6 cryogenic undulators, 5 in-vacuum undulators, and two special non-planar IDs. The schemes and parameters of all the IDs are planned to be determined in this year. We report on the status of the design of these IDs and their effects on beam dynamics.

Poster MOPAB090 [0.633 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB090

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paper received ※ 13 May 2021 paper accepted ※ 01 July 2021 issue date ※ 10 August 2021

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MOPAB093

Operational Status of Photon Factory Light Sources

injection, operation, electron, vacuum

350

T. Honda, Y. Kobayashi, C. Mitsuda, S. Nagahashi, R. Takai, H. Takaki
KEK, Ibaraki, Japan

One of the recent topics of Photon Factory light sources, PF-ring and PF-AR, is a construction of a GeV-class beamline for testing detectors at the PF-AR. The bremsstrahlung photons generated by a thin carbon wire are brought to a copper target to generate e⁺e⁻ pairs. Sufficient count rates can be expected when the thin wire touching halo of the stored beam, and the test beamline can be used without disturbing the synchrotron radiation experiments. In addition to the usual 6.5-GeV operation, a low-energy operation at 5-GeV was started recently at PF-AR to secure operation time by saving electricity costs. At the PF-ring, the injection section has been upgraded with the septum-magnet replacement. By the top-up injection and improved bunch feedback, the hybrid-fill mode operation has become convenient for both single-bunch users and multi-bunch users, and about 30% or 40% of the user time is scheduled as the hybrid-fill mode now.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB093

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paper received ※ 21 May 2021 paper accepted ※ 25 May 2021 issue date ※ 13 August 2021

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MOPAB096

Rocking Curve Imaging Experiment at SSRL 10-2 Beamline

photon, wiggler, experiment, lattice

357

A. Halavanau, R. Arthur, B. Johnson, J.P. MacArthur, G. Marcus, R.A. Margraf, Z. Qu, T. Rabedeau, T. Sato, C.J. Takacs, D. Zhu
SLAC, Menlo Park, California, USA

Stanford Synchrotron Radiation Lightsource (SSRL) serves a wide scientific community with its variety of X-ray capabilities. Recently, we have employed a wiggler source located at beamline 10-2 to perform high resolution rocking curve imaging (RCI) of diamond and silicon crystals. In-house X-ray RCI capability is important for the upcoming cavity-based x-ray source development projects at SLAC, such as cavity-based XFEL (CBXFEL) and X-ray laser oscillator (XLO). In this proceeding, we describe theoretical considerations, and provide experimental results, validating the design of our apparatus. We also provide a plan for future improvements of the RCI@SSRL program.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB096

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paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 10 August 2021

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MOPAB100

Progress Report on Population Inversion-Based X-Ray Laser Oscillator

FEL, laser, electron, experiment

373

A. Halavanau, R. Alonso-Mori, A. Aquila, U. Bergmann, D. DePonte, F.-J. Decker, F. Fuller, M. Liang, A.A. Lutman, C. Pellegrini
SLAC, Menlo Park, California, USA
M. Doyle
UCB, Berkeley, USA

The population inversion X-ray Laser Oscillator (XLO) is a fully coherent, transform limited hard X-ray source. It operates by repetitively pumping inner-shell atomic transitions with an XFEL, in a closed Bragg cavity. XLO will produce very bright monochromatic X-ray pulses for applications in quantum optics, X-ray interferometry and metrology. We report the progress to build the first XLO operating at the copper alpha line, using LCLS 9 keV SASE X-ray pulses as a pump.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB100

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paper received ※ 20 May 2021 paper accepted ※ 29 July 2021 issue date ※ 02 September 2021

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MOPAB121

Progress Towards Soft X-Ray Beam Position Monitor Development

detector, undulator, laser, synchrotron

438

B. Podobedov, C. Eng, S. Hulbert, C. Mazzoli
BNL, Upton, New York, USA
D. Donetski, K. Kucharczyk, J. Liu, R. Lutchman
Stony Brook University, Stony Brook, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
X-ray beam position monitors (BPMs) are instrumental for storage ring light sources, where they reliably provide positional measurements of high-power beams in hard X-ray beamlines. However, despite a growing need, coming especially from coherent soft X-ray beamlines, non-invasive soft X-ray BPMs have not been demonstrated yet. We are presently working on a funded R&D proposal to develop a non-invasive soft X-ray BPM with micron-scale resolution for high-power white beams. In our approach, multi-pixel GaAs detector arrays are placed into the beam halo and beam position is inferred from the pixel photocurrent levels. Presently, the first detector array prototypes have been manufactured and are being prepared for low-power beam tests. The mechanical design of a BPM test-stand, which will be installed in the 23-ID canted soft X-ray undulator beamline at NSLS-II, is well under way. In addition, we are developing new algorithms of beam position calculation which take full advantage of extended multi-pixel detector arrays. In this paper we will review our design choices and discuss recent progress.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB121

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paper received ※ 03 June 2021 paper accepted ※ 13 July 2021 issue date ※ 28 August 2021

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MOPAB122

Present Status of HiSOR

synchrotron, storage-ring, injection, undulator

442

M. Katoh
UVSOR, Okazaki, Japan
K. Goto, M. Katoh, M. Shimada
HSRC, Higashi-Hiroshima, Japan
H. Miyauchi
KEK, Ibaraki, Japan

HiSOR is a compact synchrotron light source of 700MeV. The circumference is 22m. The ring has two straight sections for undulators, which provide high brilliance VUV radiation. Two 180 bending magnets have 2.7 T field strength, which provide broadband radiation in VUV and soft X-ray range. The injector is a 150 MeV microtron. The beam injection is made twice a day with a 5 hour interval. Although the accelerators are being operated stably, the large emittance of 400nm makes it difficult to compete with high brilliance light sources of new generations. The compactness of the configuration makes it difficult to introduce new technologies. We have started seeking possible upgrades.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB122

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paper received ※ 18 May 2021 paper accepted ※ 20 May 2021 issue date ※ 30 August 2021

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MOPAB123

Radiation Safety Considerations For The APS Upgrade Injector

neutron, booster, survey, shielding

445

K.C. Harkay, J.R. Calvey, S. Chitra, G.I. Fystro, M.J. Henry, E.E. Heyeck, B.J. Micklich, K.P. Wootton
ANL, Lemont, Illinois, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source Upgrade (APS-U) is a high-performance fourth-generation storage ring light source based on multibend achromat optics. As such, APS-U will require on-axis injection. The injectors will need to supply full-current bunch replacement in the ring; therefore, the injected bunch charge will be up to five times higher than what is typical for APS. A program was conducted to measure the radiation dose above the injector transport line to the APS storage ring for both normal operation conditions and controlled loss scenarios. Standard survey meters were used to record the dose. A review of the dose data identified opportunities to minimize the potential dose under normal APS-U high charge operation and fault conditions; these include improving the supplemental shielding and adding engineered controls. In addition, the dose data provide a benchmark for evaluating new radiation monitors for APS-U.

Poster MOPAB123 [1.317 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB123

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paper received ※ 18 May 2021 paper accepted ※ 24 May 2021 issue date ※ 12 August 2021

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MOPAB126

BESSY III & MLS II - Status of the Development of the New Photon Science Facility in Berlin

undulator, lattice, photon, emittance

451

P. Goslawski, M. Abo-Bakr, F. Andreas, M. Arlandoo, J. Bengtsson, V. Dürr, K. Holldack, J.-G. Hwang, A. Jankowiak, B.C. Kuske, J. Li, A.N. Matveenko, T. Mertens, A. Meseck, E.C.M. Rial, M. Ries, M.K. Sauerborn, A. Schälicke, M. Scheer, P. Schnizer, L. Shi, J. Viefhaus
HZB, Berlin, Germany
J. Lüning
UPMC, Paris, France

HZB operates and develops two synchrotron radiation sources at Berlin Adlershof. The larger one, BESSY II with an energy of 1.7 GeV and 240 m circumference is optimized for soft-X rays and in operation since 1999. The smaller one is the MLS (Metrology Light Source), owned by the Physikalische Technische Bundesanstalt (PTB) - Germany’s National Metrology Institute. It is designed to fulfill the special metrology needs of the PTB with an energy of 0.6 GeV and 48 m circumference, covering the spectral range from THz and IR to EUV/VUV. In 2020 a discussion process has been started to define the requirements for successors of BESSY II and MLS and to study the possibilities integrate them into a new photon science facility in Berlin Adlershof. Here, we give a status report and present a first envisaged parameter space to both machines (see also MOPAB262, MOPAB220, MOPAB048, MOPAB242).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB126

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paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 18 August 2021

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MOPAB137

Interaction Region Design for DWA Experiments at FACET-II

electron, experiment, alignment, diagnostics

478

O. Williams, G. Andonian, A. Fukasawa, W.J. Lynn, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, Y. Sakai, M. Yadav, Y. Zhuang
UCLA, Los Angeles, California, USA
C.I. Clarke, M.J. Hogan, B.D. O’Shea, D.W. Storey, V. Yakimenko
SLAC, Menlo Park, California, USA
M. Ruelas
RadiaBeam, Santa Monica, California, USA
M. Yadav
The University of Liverpool, Liverpool, United Kingdom

Funding: DOE HEP Grant DE-SC0009914
The extremely intense beam generated at FACET-II provides the unique opportunity to investigate the effects of beam-driven GV/m fields in dielectrics exceeding meter-long interaction lengths. The diverse range of phenomena to be explored, such as material response in the terahertz regime, suppression of high-field pulse damping effects, advanced geometry structures, and methods for beam break up (BBU) mitigation, all within a single UHV vacuum vessel, requires flexibility and precision in the experimental layout. We present here details of the experimental design for the dielectric program at FACET-II. Specifically, consideration is given to the alignment of the dielectric structures due to the extreme fields associated with the electron beam, as well as implementation of electron beam and Cherenkov radiation-based diagnostics.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB137

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paper received ※ 19 May 2021 paper accepted ※ 17 August 2021 issue date ※ 29 August 2021

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MOPAB141

Terahertz Driven Compression and Time-Stamping Technique for Single-Shot Ultrafast Electron Diffraction

electron, laser, FEM, resonance

492

M.A.K. Othman, A.E. Gabriel, M.C. Hoffmann, F. Ji, E.A. Nanni, X. Shen, E.J.C. Snively, X.J. Wang
SLAC, Menlo Park, California, USA

Funding: This research has been supported by the U.S. Department of Energy (DOE) under Contract No. DE-AC02-76SF00515 and DE-AC02-05-CH11231.
Ultrafast structural dynamics are well understood through pump-probe characterization using ultrafast electron diffraction (UED). Advancements in electron diffraction and spectroscopy techniques open new frontiers for scientific discovery through interrogation of ultrafast phenomena, such as quantum phase transitions. Previously, we have demonstrated that strong-field THz radiation can be utilized to efficiently manipulate and compress ultrafast electron probes *, and also offer temporal diagnostics with sub-femtosecond resolution ** enabled by the inherent phase locking of THz radiation to the photoemission optical drive. In this work, we demonstrate a novel THz compression and time-stamping technique to probe solid-state materials at time scales previously inaccessible with standard UED. A high-frequency THz generation method using the organic OH-1 crystals is employed to enable a threefold reduction in the electron probes length and overall timing jitter. These time-stamped probes are used to demonstrate a substantial enhancement in the UED temporal resolution using pump-probe measurement in both photoexcited single crystal and polycrystalline samples.
* E. C. Snively et al., Phys. Rev. Lett, vol. 124, no. 6, p. 054801, 2020.
** R. K. Li et al., Phys. Rev. Accel. Beams, vol. 22, no. 1, p. 012803, Jan. 2019.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB141

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paper received ※ 20 May 2021 paper accepted ※ 21 June 2021 issue date ※ 19 August 2021

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MOPAB144

Investigation of Optimization of Dielectric Terahertz Acceleration Structures

simulation, laser, acceleration, impedance

502

A.E. Gabriel, E.A. Nanni
SLAC, Menlo Park, California, USA

Funding: This work was supported by the Department of Energy Contract No. DE-AC02-76SF00515 (SLAC) and by NSF Grant No. PHY-1734015.
THz-frequency accelerating structures could provide the accelerating gradients needed for next generation particle accelerators with compact, GV/m-scale devices. Current THz accelerators are limited by significant losses during transport of THz radiation from the generating nonlinear crystal to the electron acceleration structure. In addition, the spectral properties of high-field THz sources make it difficult to couple THz radiation into accelerating structures. Dielectric accelerator structures reduce these losses because THz radiation can be coupled laterally into the structure, as opposed to metallic structures where THz radiation must be coupled along the beam path. In order to utilize these advantages, we are investigating the optimization of THz accelerating structures for comparison between metallic and dielectric devices. These results will help to inform future designs of improved dielectric THz acceleration structures.

Poster MOPAB144 [6.524 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB144

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paper received ※ 20 May 2021 paper accepted ※ 27 May 2021 issue date ※ 22 August 2021

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MOPAB146

Status of the C-Band Engineering Research Facility (CERF-NM) Test Stand Development at LANL

cavity, GUI, klystron, controls

509

D. Gorelov
Private Address, Los Alamos, USA
R.L. Fleming, S.K. Lawrence, J.W. Lewellen, D. Perez, M.E. Schneider, E.I. Simakov, T. Tajima
LANL, Los Alamos, New Mexico, USA
M.E. Middendorf
ANL, Lemont, Illinois, USA

Funding: LDRD-DR Project 20200057DR
C-Band structures research is of increasing interest to the accelerator community. The RF frequency range of 4-6 GHz gives the opportunity to achieve significant increase in the accelerating gradient, and having the wakefields at the manageable levels, while keeping the geometric dimensions of the structure technologically convenient. Strong team of scientists, including theorists researching properties of metals under stressful thermal conditions and high electromagnetic fields, metallurgists working with copper as well as alloys of interest, and accelerator scientists developing new structure designs, is formed at LANL to develop a CERF-NM facility. A 50 MW, 5.712 GHz Canon klystron, was purchased in 2019, and laid the basis for this facility. As of Jan-21, the construction of the Test Stand has been finished and the high gradient processing of the waveguide components has been started. Future plans include high gradient testing of various accelerating structures, including benchmark C-band accelerating cavity, a proton ß=0.5 cavity, and cavities made from different alloys. An upgrade to the facility is planned to allow for testing accelerator cavities at cryogenic temperatures.

Poster MOPAB146 [3.778 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB146

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paper received ※ 17 May 2021 paper accepted ※ 26 May 2021 issue date ※ 19 August 2021

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MOPAB147

Efficient, High Power Terahertz Radiation Outcoupling From a Beam Driven Dielectric Wakefield Accelerator

wakefield, acceleration, electron, GUI

513

M. Yadav, G. Andonian, C.E. Hansel, W.J. Lynn, N. Majernik, B. Naranjo, J.B. Rosenzweig, O. Williams
UCLA, Los Angeles, California, USA
G. Andonian
RadiaBeam, Santa Monica, California, USA
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work was supported by DE-SC0009914 (UCLA) and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1.
Wakefields in dielectric structures are a useful tool for beam diagnostics and manipulation with applications including acceleration, shaping, chirping, and THz radiation generation. It is possible to use the produced THz radiation to diagnose the fields produced during the DWA interaction but, to do so, it is necessary to effectively out-couple this radiation to free space for transport to diagnostics such as a bolometer or interferometer. To this end, simulations have been conducted using CST Studio for a 10 GeV beam with FACET-II parameters in a slab-symmetric, dielectric waveguide. Various termination geometries were studied including flat cuts, metal horns, and the "Vlasov antenna". Simulations indicate that the Vlasov antenna geometry is optimal and detailed studies were conducted on a variety of dielectrics including quartz, diamond, and silicon. Multiple modes were excited and coherent Cherenkov radiation (CCR) was computationally generated for both symmetric and asymmetric beams. Finally, we include witness beams to study transport and acceleration dynamics as well as the achievable field gradients.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB147

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paper received ※ 24 May 2021 paper accepted ※ 29 August 2021 issue date ※ 28 August 2021

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MOPAB148

Liénard-Wiechert Numerical Radiation Modeling for Plasma Acceleration Experiments at FACET-II

plasma, betatron, acceleration, experiment

517

M. Yadav, G. Andonian, C.E. Hansel, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, O. Williams, Y. Zhuang
UCLA, Los Angeles, California, USA
G. Andonian
RadiaBeam, Marina del Rey, California, USA
O. Apsimon, A. Perera, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
O. Apsimon, A. Perera, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work was supported by DE-SC0009914 (UCLA) and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1.
Future plasma acceleration experiments at FACET-II will measure betatron radiation in order to provide single-shot non-destructive beam diagnostics. We discuss three models for betatron radiation: a new idealized particle tracking code with Liénard-Wiechert radiation, a Quasi-Static Particle-in-Cell (PIC) code with Liénard-Wiechert radiation, and a full PIC code with radiation computed via a Monte-Carlo QED Method. Predictions of the three models for the E-310 experiment are presented and compared. Finally, we discuss beam parameter reconstruction from the double differential radiation spectrum.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB148

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paper received ※ 24 May 2021 paper accepted ※ 01 June 2021 issue date ※ 17 August 2021

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MOPAB212

3-D Quantum Lifetime

simulation, electron, damping, emittance

700

H. Zhao, M. Blaskiewicz
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The quantum lifetime of electron beam in storage rings is defined by the particle loss that caused by the aperture limitation. Based on the equilibrium beam distribution produced by radiation damping and quantum excitation, the 1-d quantum lifetime has been well studied by A. Piwinski. In this paper, we give the derivation of the 3-d quantum lifetime, which can be applied to the machines with elliptical aperture and momentum acceptance.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB212

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paper received ※ 04 June 2021 paper accepted ※ 21 June 2021 issue date ※ 16 August 2021

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MOPAB240

Estimates of Damped Equilibrium Energy Spread and Emittance in a Dual Energy Storage Ring

emittance, storage-ring, damping, photon

774

B. Dhital, G.A. Krafft
ODU, Norfolk, Virginia, USA
Y.S. Derbenev, D. Douglas, A. Hutton, G.A. Krafft, F. Lin, V.S. Morozov, Y. Zhang
JLab, Newport News, Virginia, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, and Office of Nuclear Physics under Contracts DE-AC05-06OR23177 and DE-AC02-06CH11357. / Jefferson Lab EIC Fellowship2020.
A dual energy storage ring design consists of two loops at markedly different energies. As in a single-energy storage ring, the linear optics in the ring design may be used to determine the damped equilibrium emittance and energy spread. Because the individual radiation events in the two rings are different and independent, we can provide analytical estimates of the damping times in a dual energy storage ring. Using the damping times, the values of damped energy spread, and emittance can be determined for a range of parameters related to lattice design and rings energies. We present analytical calculations along with simulation results to estimate the values of damped energy spread and emittance in a dual energy storage ring. We note that the damping time tends to be dominated by the damping time of the high energy ring in cases where the energy of the high energy rings is significantly greater than that of the low energy ring.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB240

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paper received ※ 17 May 2021 paper accepted ※ 27 May 2021 issue date ※ 13 August 2021

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MOPAB245

Theoretical Analysis of the Conditions for an Isochronous and CSR-Immune Triple-Bend Achromat with Stable Optics

emittance, dipole, optics, synchrotron-radiation

786

C. Zhang, Y. Jiao
IHEP, Beijing, People’s Republic of China
C.-Y. Tsai
HUST, Wuhan, People’s Republic of China

Funding: National Natural Science Foundation of China (No. 11922512), Youth Innovation Promotion Association of Chinese Academy of Sciences (No. Y201904), National Key R&D Program of China (No. 2016YFA0401900)
Transport of high-brightness beams with minimum degradation of the phase space quality is pursued in modern accelerators. For the beam transfer line which commonly consists of bending magnets, it would be desirable if the transfer line can be isochronous and coherent synchrotron radiation (CSR)-immune. For multi-pass transfer line, the achromatic cell designs with stable optics would bring great convenience. In this paper, based on the transfer matrix formalism and the CSR point-kick model, we report the detailed theoretical analysis and derive the condition for a triple-bend achromat with stable optics in which the first-order longitudinal dispersion (i.e., R56) and the CSR-induced emittance growth can be eliminated. The derived condition suggests a new way of designing the bending magnet beamline that can be applied to the free-electron laser (FEL) spreader and energy recovery linac (ERL) recirculation loop.

Poster MOPAB245 [0.530 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB245

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paper received ※ 12 May 2021 paper accepted ※ 08 June 2021 issue date ※ 27 August 2021

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MOPAB262

First Thoughts on Lattices for a possible Metrology Light Source 2

lattice, emittance, dipole, sextupole

833

M. Arlandoo, M. Abo-Bakr, P. Goslawski, J. Li
HZB, Berlin, Germany

The Physikalisch-Technische Bundesanstalt (PTB), in cooperation with the Helmholtz-Zentrum Berlin (HZB), operates the Metrology Light Source (MLS), which is a low-energy electron storage ring. The MLS can be operated in a low-alpha mode to produce coherent synchroton ration in the far-IR and THz spectral range. In the scope of the Conceptual Design process for a BESSY II successor, the PTB also requested for an MLS successor to cover their increasing demands on synchrotron radiation. A combination of two different machines, one optimized for low emittance (BESSY III) and one for flexible timing capabilities (MLS II), would provide best radiation capabilities for our user community. In this paper, we discuss the demands on the MLS II and propose first lattice candidates which may meet the needs of the PTB and HZB. Currently, we focus on linear lattices for standard user mode with first steps towards nonlinear optimization.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB262

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paper received ※ 18 May 2021 paper accepted ※ 02 June 2021 issue date ※ 17 August 2021

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MOPAB263

Preliminary Beam Dynamics Studies for 200 MeV Superconducting Linac Planned at KOMAC

linac, proton, DTL, lattice

837

S. Lee, J.J. Dang, H.S. Kim, H.-J. Kwon
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
Y.-S. Cho
KAERI, Daejon, Republic of Korea

Funding: This work has been supported through KOMAC operation fund of KAERI by the Korea government (MSIT).
Korea Multi-purpose Accelerator Complex (KOMAC) is planning an energy upgrade of the existing 100 MeV proton linac to 200 MeV using a superconducting Half Wave Resonator (HWR) operating at 350 MHz. A cryomodule is planned to house four HWR cavities with a warm doublet focusing lattice structure. Matching between the already existing DTL section and HWR section is designed and studied. We report the preliminary study of the beam dynamics of the 200 MeV superconducting linac carried out at KOMAC.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB263

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paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 24 August 2021

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MOPAB266

Start-to-End Study on Laser and RF Jitter Effects for MAX-IV SXL

FEL, laser, linac, simulation

844

S.P. Pirani, B.S. Kyle
MAX IV Laboratory, Lund University, Lund, Sweden
F. Curbis, M.A. Pop, S. Werin
Lund University, Lund, Sweden
W. Qin
DESY, Hamburg, Germany

A Soft X-ray free electron laser (FEL) for the MAX IV Laboratory is currently in the design phase and it will use the existing 3 GeV linac. Present stability limits in the RF and the photocathode laser will affect the performance of the FEL. One of the critical elements for the design of a FEL is to have an estimation on jitter effects of the accelerator parameters on the X-ray radiation. In this regard, we implemented a start-to-end study using Astra, Elegant and Genesis in order to assess possible variations in pulse energy, photon pulse length and spectral width in the Soft X-ray Laser (SXL) radiation. This investigation provides insights on the final SXL performance variation due to RF and laser related jitter affecting the electron beam.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB266

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paper received ※ 19 May 2021 paper accepted ※ 26 July 2021 issue date ※ 24 August 2021

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MOPAB276

Investigation on the injection of the Arronax Cyclotron 70XP

cyclotron, injection, background, solenoid

873

F. Poirier, F. Bulteau-Harel, T. Durand, X. Goiziou, C. Koumeir, C. Lassalle, H. Trichet
Cyclotron ARRONAX, Saint-Herblain, France
F. Haddad
SUBATECH, Nantes, France

Funding: This work is supported by grants from the ANR program "Investissements d’Avenir", n°ANR-11-EQPX-0004, n°ANR-11-LABX-18-01 and n°ANR-16-IDE-0007 and by a PhD scholarship from CNRS/IN2P3.
A 70 MeV cyclotron is being used at the Arronax GIP (Interest Public Group), France, for various types of R&D on nuclear, biological and chemical reactions with beams and radioisotopes production. In order to adapt its usage for experiments and users demands of high peak intensity, above an equivalent average of a few µA, the injection is being adapted. Several studies are thus being performed in this section. These include the newly installed chopper-based system and the injection collimator. This paper details the various studies, specifically the signal purity obtained in the pulsed mode. A mode particularly adapted for flash irradiation.

Poster MOPAB276 [2.522 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB276

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paper received ※ 19 May 2021 paper accepted ※ 23 June 2021 issue date ※ 15 August 2021

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MOPAB294

Implementing Electro-Optical Diagnostics for Measuring the CSR Far-Field at KARA

laser, detector, synchrotron, storage-ring

931

C. Widmann, E. Bründermann, M. Caselle, S. Funkner, A.-S. Müller, M.J. Nasse, G. Niehues, M.M. Patil, C. Sax, J.L. Steinmann, M. Weber
KIT, Karlsruhe, Germany
C. Mai
DELTA, Dortmund, Germany

Funding: This work was supported by BMBF ErUM-Pro project 05K19 STARTRAC, C.W. was funded under contract No. 05K19VDK, C.M. under contract No. 05K19PEC, S.F. under contract No. 05K16VKA.
For measuring the temporal profile of the coherent synchrotron radiation (CSR) at the KIT storage ring KARA (Karlsruhe Research Accelerator) an experimental setup based on electro-optical spectral decoding (EOSD) is currently being implemented. The EOSD technique allows single-shot, phase-sensitive measurements of the far-field radiation on a turn-by-turn basis at rates in the MHz range. Therefore, the resulting THz radiation from the dynamics of the bunch evolution, e.g. the microbunching, can be observed with high temporal resolution. This far-field setup is part of the distributed sensor network at KARA. Additionally to the information acquired from the near-field EOSD spectral decoding and the horizontal bunch profile monitor, it enables to monitor the longitudinal phase-space of the bunch. In this contribution, the characterization of the far-field setup is summarized and its implementation is discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB294

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paper received ※ 19 May 2021 paper accepted ※ 07 June 2021 issue date ※ 18 August 2021

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MOPAB296

Statistical Analysis of 2D Single-Shot PPRE Bunch Measurements

photon, operation, diagnostics, storage-ring

939

M. Koopmans, J.-G. Hwang, A. Jankowiak, M. Ries, A. Schälicke, G. Schiwietz
HZB, Berlin, Germany

The pulse picking by resonant excitation (PPRE) method* is used to realize pseudo single-bunch radiation from a complex filling pattern at the BESSY II storage ring. The PPRE bunch is excited in the horizontal plane by a quasi-resonant incoherent perturbation to increase the emittance of this bunch**. Therefore, the synchrotron light of the PPRE bunch can be separated by collimation from the radiation of the main bunch train at dedicated beamlines for timing users. The properties of the PPRE bunch depend on the storage ring settings and on the excitation parameters. It is not trivial to distinguish between the wanted intrinsic bunch broadening and an additional position fluctuation of the PPRE bunch. Using the potential of the new diagnostics beamline with the possibility to observe an additional spatial dimension with a fast streak camera, we introduce a new method to study the properties of the PPRE bunch***. Applying a statistical analysis to a series of single-turn images enables distinguishing between horizontal orbit motion and the broadening of the bunch due to the excitation. Measurements are presented and the results are compared with data from the BPM system.
* K. Holldack et al., Nature Commun. 5 (2014) 4010.
** J.-G. Hwang et al., Nucl. Instrum. Methods A940 (2019) 387.
*** G. Schiwietz et al., Nucl. Instrum. Methods A990 (2021) 164992.

Poster MOPAB296 [2.074 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB296

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paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 23 August 2021

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MOPAB300

Description of the Beam Diagnostics Systems for the SOCIT, SODIT and SODIB Applied Research Stations Based on the NICA Accelerator Complex

detector, controls, diagnostics, experiment

946

A. Slivin, A. Agapov, A.A. Baldin, A.V. Butenko, G.A. Filatov, K.N. Shipulin, E. Syresin, G.N. Timoshenko, A. Tuzikov
JINR, Dubna, Moscow Region, Russia
D.V. Bobrovskiy, A.I. Chumakov, S. Soloviev
MEPhI, Moscow, Russia
I.L. Glebov, V.A. Luzanov
GIRO-PROM, Dubna, Moscow Region, Russia
A.S. Kubankin
BelSU, Belgorod, Russia
T. Kulevoy, Y.E. Titarenko
ITEP, Moscow, Russia

Within the framework of the NICA project an Innovation Block is being constructed. It includes an applied research station for microchips with a package for Single Event Effects (SEE) testing (energy range of 150-500 MeV/n, the SODIT station), an applied research station for testing of decapsulated microchips (ion energy up to 3,2 MeV/n, the SOCIT station), and an applied research station for space radiobiological research and modelling of influence of heavy charged particles on cognitive functions of the brain of small laboratory animals and primates (energy range 500-1000 MeV/n, the SODIB station). The systems for diagnostics and control of the beam characteristics during the certification and adjustment as well as the systems for online diagnostics and control of the beam characteristics of the SOCIT, SODIT and SODIB applied research stations are described.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB300

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paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 23 August 2021

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MOPAB301

A Concept for Reconstruction of the Capsulated Microchip Structure Using Its Interaction with High-Energy Ion Beams of the NICA Accelerator Complex

detector, simulation, electron, electronics

949

A. Slivin, A.V. Butenko, G.A. Filatov, E. Syresin, A. Tuzikov, A. Zhemchugov
JINR, Dubna, Moscow Region, Russia

Within the framework of the NICA project an applied research station for irradiation by long-range ions (SODIT) is being constructed for testing radiation hardness of semiconductor micro- and nanoelectronics products in the energy range of 150-350 MeV/n. Calculations for the interaction of high-energy gold ions with the microchip and strip detector structures are performed using the GEANT4 simulation toolkit. A concept was developed for reconstruction of the capsulated microchip structure in terms of depth and in terms of cross-section using interaction with high-energy ions at the technical station for irradiation by long-range ions. The possibility of localizing the radiation-vulnerable area of the microchip is evaluated.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB301

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paper received ※ 19 May 2021 paper accepted ※ 20 May 2021 issue date ※ 17 August 2021

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MOPAB328

Beam Instrumentation for Linear Accelerator of SKIF Synchrotron Light Source

electron, diagnostics, photon, simulation

1016

X.C. Ma
BINP, Novosibirsk, Russia
M.V. Arsentyeva, E.A. Bekhtenev, V.M. Borin, G.V. Karpov, Yu.I. Maltseva, O.I. Meshkov, D.A. Nikiforov, O.A. Pavlov, V.G. Tcheskidov, V. Volkov
BINP SB RAS, Novosibirsk, Russia
M.V. Arsentyeva, E.A. Bekhtenev, V.M. Borin, Yu.I. Maltseva, O.I. Meshkov, D.A. Nikiforov
NSU, Novosibirsk, Russia
V.M. Borin
NSTU, Novosibirsk, Russia

A new synchrotron light source SKIF of the 4th generation is under construction at BINP SB RAS (Novosibirsk, Russia). The linear accelerator is SKIF’s injector to provide 200 MeV electron beam. The set of diagnostics will be applied for tuning of the linear accelerator and measurements of beam parameters from electron RF gun to output of the accelerator. It includes 8 fluorescent screens for the beam transverse dimensions measurement, 2 Cherenkov probes for the beam duration measurement, magnetic spectrometer with range from 0.6 to 200 MeV, and some beam charge and current measurement devices, as Faraday cup, FCT, BPM along linear accelerator. Numerical simulations of diagnostics elements and results of beam dynamics simulations are introduced in paper. Brief description of the design and parameters of each diagnostics system is presented. Possible scenarios of linear accelerator tuning are also discussed.

Poster MOPAB328 [2.324 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB328

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paper received ※ 19 May 2021 paper accepted ※ 21 May 2021 issue date ※ 31 August 2021

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MOPAB348

Portable 2.5 MeV X-Band Linear Accelerator Structure

linac, GUI, gun, target

1084

A.V. Mishin, K. Brown, M. Denney, D. Fischer, N.P. Hanson, S. Proskin, J. Stammetti
Varex Imaging, Salt Lake City, USA

Two versions of 2.5 MeV X-Band linear accelerator structure have been designed and tested. The first is a traditional single input linac, and the other one is a dual input, two section linac with power input through a 3 dB coupler. The linac is designed for a portable linac system, which can be used for security screening, non-destructive testing, medical and industrial CT, and, perhaps, some other applications.

Poster MOPAB348 [1.490 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB348

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paper received ※ 15 May 2021 paper accepted ※ 28 May 2021 issue date ※ 23 August 2021

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MOPAB379

Topological Optimization on SRF Cavities for Nuclear and High Energy Physics

cavity, niobium, superconducting-cavity, simulation

1162

H. Gassot
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France

Topology optimization has been developed for more than twenty years. The progress of additive manufacturing boosts the development in topological optimization since the design can be completely innovated and realized by 3D printing. The potential for cost reductions thanks to weight minimization give an interesting perspective for the small production of niobium superconducting radio-frequency cavities, commonly used in accelerators. The traditional manufacturing technologies of cavities are based on multi-stage processes while additive manufacturing technologies can built fully functional parts in a single operation. For modern accelerators that use superconducting linac, including energy recovery linacs (ERLs), it is particularly important to know the perspectives of additive manufacturing for SRF cavities. In this paper, we try to build a preliminary perception of topological optimization in superconducting cavities manufacturing innovation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB379

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paper received ※ 11 May 2021 paper accepted ※ 17 August 2021 issue date ※ 15 August 2021

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MOPAB382

Synchrotron Light Shielding for the 166 MHz Superconducting RF Section at High Energy Photon Source

cavity, shielding, synchrotron, storage-ring

1169

X.Y. Zhang, Z.Q. Li, Q. Ma, P. Zhang
IHEP, Beijing, People’s Republic of China

Funding: This work was supported by High Energy Photon Source, a major national science and technology infrastructure in China.
The High Energy Photo Source (HEPS) project has been under construction since 2019, and will be first diffraction-limited synchrotron light source in China. A 6 GeV electron beam with 200 mA current will be stored in the main ring. If synchrotron light produced from this energetic electron beam hits the superconducting cavity’s surface, it would cause thermal breakdown of the superconductivity. In the current lattice design, these lights cannot be fully blocked by the collimator in the upstream lattice cell, therefore a shielding scheme inside the rf section is required. This however brings great challenges to the already limited space. The design of the collimator has been focused on fulfilling shielding requirements while optimizing beam impedance, synchrotron light power density, thermal and mechanical stabilities. Shielding materials are subsequently chosen with dedicated cooling to ensure long-term stable operations. In this paper, a shielding scheme inside the rf section of the HEPS storage ring is presented. The synchrotron light mainly from the upstream bending magnet is successfully block. The sensitivity to beam position movement and installation error is also analyzed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB382

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paper received ※ 17 May 2021 paper accepted ※ 11 June 2021 issue date ※ 23 August 2021

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MOPAB405

Study of Targets to Produce Molybdenum-99 Using 30 MeV Electron Linear Accelerator

target, electron, photon, linac

1222

T.S. Dixit, A.P. Deshpande, R. Krishnan, A. Shaikh
SAMEER, Mumbai, India

Funding: Ministry of Electronics and Information Technology, Government of India (MeitY)
Two approaches to produce 99Mo are studied using GEANT4 are reported in this paper. First, in converter target approach, bremsstrahlung photons are generated in a high Z target. The emitted photons then hit 100Mo secondary target, producing 99Mo through (gamma, n) reaction. Second, in direct target approach, high energy electron beam hits 100Mo target, where both (e, gamma) and (gamma, n) reactions take place simultaneously. A 30 MeV, 5-10 kW beam power electron linac is under development at SAMEER. The acceleration gradient required to achieve 30 MeV energy will be provided by two linacs operated in series configuration and the high average beam power will be achieved by running the system at high duty operation. Main aim of this study is to optimize experimental parameters to maximize specific activity of 99Mo. Since, 100Mo is very expensive material therefore judicious use of the material is very important. Hence, optimization of electron beam energy and target dimensions are studied in detail in both the approaches. It is found that the direct target approach gives higher specific activity compared to the converter target approach.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB405

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paper received ※ 19 May 2021 paper accepted ※ 06 June 2021 issue date ※ 14 August 2021

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MOPAB409

FLUKA Simulations of ²²⁵Ac Production Using Electron Accelerators: Validation Through Comparison with Published Experiments

electron, experiment, target, photon

1226

T.V. Szabo, I.C. Moraes
CNPEM, Campinas, SP, Brazil
F.A. Bacchim Neto
LNLS, Campinas, Brazil
P.V. Guillaumon
USP/LAL, Sao Paulo, Brazil
H.B. de Oliveira
IPEN, São Paulo, Brazil

Targeted Alpha Therapy (TAT) is an active area of study worldwide. This technique has shown a potential in nuclear medicine to treat metastatic disease by alpha particles that deposit energy in small regions nearby cancer cells. Ac-225 is an important alpha-emitting that can be used for cancer TAT. This radioisotope shows good potential for medical applications, therefore is important to study ways of increase its production and availability. One possible path for the Ac-225 product is to radiate a radium target (Ra-226) on a linear electron accelerator (LINAC). Isotope production studies could be implemented using computational tools. In this work, Monte Carlo simulations with FLUKA code were performed and compared to experimental results *. We studied Ac-225 production by photonuclear reactions using a 24 MeV electron beam LINAC hitting a tungsten electron-photon converter. Different energies and geometries were also simulated to obtain optimal production conditions. The specific activity values obtained with simulations had a good agreement with published experimental results.
* MASLOV, O., et. al. Preparation of 225Ac by 226Ra(g, n) photonuclear reaction on an mt25 microtron. Radiochemistry

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB409

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paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 30 August 2021

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MOPAB410

Preliminary Studies of a Compact VHEE Linear Accelerator System for FLASH Radiotherapy

linac, electron, operation, impedance

1229

L. Giuliano, F. Bosco, M. Carillo, D. De Arcangelis, L. Faillace, L. Ficcadenti, M. Migliorati, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
D. Alesini, M. Behtouei, B. Spataro
INFN/LNF, Frascati, Italy
G. Cuttone, G. Torrisi
INFN/LNS, Catania, Italy
V. Favaudon, S. Heinrich, A. Patriarca
Institut Curie - Centre de Protonthérapie d’Orsay, Orsay, France

Funding: The work is supported by La Sapienza University, research grant "grandi progetti di ricerca 2020".
The Flash Radio Therapy is a revolutionary new technique in the cancer cure: it spares healthy tissue from the damage of the ionizing radiation maintaining the tumor control as efficient as in conventional radiotherapy. To allow the implementation of the FLASH Therapy concept into actual clinical use, it is necessary to have a linear accelerator able to deliver the very high dose and very high dose rate (>10⁶ Gy/s) in a very short irradiation time (beam on time < 100ms). Low energy S-band Linacs (up to 7 MeV) are being used in Radiobiology and pre-clinic applications but in order to treat deep tumors, the energy of the electrons should achieve the range of 60-100 MeV. In this paper, we address the main issues in the design of a compact C band (5.712 GHz) electron linac-VHEE for FLASH Radio Therapy. We present preliminary studies on C-band structures at La Sapienza and at INFN-LNS, aiming to reach a high accelerating gradient and high current necessary to deliver a dose >1 Gy/pulse, with very short electron pulse.

Poster MOPAB410 [0.650 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB410

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paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 21 August 2021

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MOPAB411

Quantifying DNA Damage in Comet Assay Images Using Neural Networks

network, proton, software, experiment

1233

S.J.K. Dhinsey, T. Greenshaw, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
J.L. Parsons
Cancer Research Centre, University of Liverpool, Liverpool, United Kingdom
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work was supported by the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1.
Proton therapy for cancer treatment is a rapidly growing field and increasing evidence suggests it induces more complex DNA damage than photon therapy. Accurate comparison between the two treatments requires quantification of the DNA damage the cause, which can be assessed using the Comet Assay. The program outlined here is based on neural network architecture and aims to speed up analysis of Comet Assay images and provide accurate, quantifiable assessment of the DNA damage levels apparent in individual cells. The Comet Assay is an established technique in which DNA fragments are spread out under the influence of an electric field, producing a comet-like object. The elongation and intensity of the comet tail (consisting of DNA fragments) indicate the level of damage incurred. Many methods to measure this damage exist, using a variety of algorithms. However, these can be time consuming, so often only a small fraction of the comets available in an image are analysed. The automatic analysis presented in this contribution aims to improve this. To supplement the training and testing of the network, a Monte Carlo model will also be presented to create simulated comet assay images.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB411

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paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 16 August 2021

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MOPAB412

Accelerator Production of Mo-99 Using Mo-100

target, electron, operation, diagnostics

1237

J.L. McCarter, M.J. Brennan, S.M. Burns, J.T. Harvey, S.W. Kelley, T.A. Montenegro, Q. Schiller
NorthStar Medical Technologies, LLC, Beloit, USA

Funding: DE-NA0001878
Tc-99m is an essential radionuclide for nearly 40,000 diagnostic nuclear medicine tests in the U.S. each day. Its daily production depends on Mo-99, which must be replenished weekly due to Mo-99’s 2.75 day half-life. Mo-99, in the past, was supplied from uranium fission production, depending on overseas nuclear reactors that average 50 years old. Their age in combination with shipment uncertainties make the availability of Mo-99 fragile and subject to severe shortages. The U.S. now has one domestic, FDA-approved supplier that produces Mo-99, NorthStar Medical Radioisotopes. Currently, NorthStar produces Mo-99 via the irradiation of Mo-98 in a nuclear reactor. In the future, NorthStar will also irradiate Mo-100 with accelerator created x-rays to produce Mo-99. This process will use 2 distinct, 40 MeV, 125 kW average electron accelerators, Rhodotrons produced by IBA. Accelerator produced Mo-99 has several advantages over that produced by reactors, including a dual supply and an ability to adjust irradiation timing to meet radiopharmacy demands, such as Sunday delivery. NorthStar is currently installing and commissioning this accelerator based system, entering production in late-2022.

Poster MOPAB412 [2.150 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB412

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paper received ※ 24 May 2021 paper accepted ※ 07 June 2021 issue date ※ 19 August 2021

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MOPAB414

A Novel Facility for Cancer Therapy and Biomedical Research with Heavy Ions for the South East European International Institute for Sustainable Technologies

synchrotron, extraction, injection, experiment

1244

S. Damjanovic, P. Grübling, H. Schopper
SEEIIST, Geneva, Switzerland
U. Amaldi, E. Benedetto, M. Sapinski
TERA, Novara, Italy
E. Benedetto, G. Bisoffi, M. Dosanjh, M. Sapinski, M. Vretenar
CERN, Meyrin, Switzerland
G. Bisoffi
INFN/LNL, Legnaro (PD), Italy
S. Damjanovic, M. Durante, P. Foka, C. Graeff
GSI, Darmstadt, Germany
Th. Haberer
HIT, Heidelberg, Germany
S. Rossi
CNAO Foundation, Milan, Italy
H.J. Specht
Universität Heidelberg, Heidelberg, Germany

The South East European International Institute for Sustainable Technologies (SEEIIST) proposes the construction of a major joint Research Infrastructure in the region, to rebuild cooperation after the recent wars and overcome lasting consequences like technology deficits and brain drain, having at its core a facility for cancer therapy and biomedical research with heavy ions. Beams of ions like Carbon are an advanced way to irradiate tumours but more research is needed, while the higher investment costs than for other radiation treatments have so far limited the European facilities to only four. This initiative aims at being strongly innovative, beyond the existing European designs. While the initial baseline relies on a conservative warm-magnet synchrotron, superconducting magnets for an advanced version of the synchrotron and for the gantry are being developed, with a potential for reductions in size, cost, and power consumption. Both warm and superconducting designs feature high beam intensity for faster treatment, and flexible extraction for novel treatment methods. A novel injector linac has the potential for producing radioisotopes in parallel with synchrotron injection.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB414

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paper received ※ 17 May 2021 paper accepted ※ 06 July 2021 issue date ※ 22 August 2021

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MOPAB415

Failure Rates and Downtimes of Multi-Leaf Collimators in Indonesia

linac, target, gun, power-supply

1248

G.S. Peiris, S.L. Sheehy
The University of Melbourne, Melbourne, Victoria, Australia
M.F. Kasim, S.A. Pawiro
University of Indonesia, Depok, Jawa Barat, Indonesia

One of the greatest barriers to cancer treatment in Low and Middle-Income Countries (LMICs) is the access to Radiotherapy Linear Accelerators (LINACs). Not only are the LINACs complex, the harsh environment of LMICs cause frequent breakdowns resulting in downtimes ranging from days to months. Recent research has identified a disparity between LMICs and High Income Countries (HICs) and determined the Multi-Leaf Collimator (MLC) as a component needing re-evaluation. The MLC causes over 30% of the problems in RT LINACs, but the modes of failure and quantify the extent of the damage done are yet to be quantified. Using data from across Indonesia, we show the pathways to failure of RT Machines and frequency of breakdowns over time. A component of the MLC needs to be replaced every 9.98 faults per 1000 patients treated and the MLC itself breaks down on average every 36±1.8 days. When comparing the downtime by leaf width, the data shows 5mm leaves contribute 18.27±6.5% to all breakdowns while 10mm makes up 15.87±4.3%. These results outline the need to reassess the current generation of RT LINACs and ultimately work towards guiding future designs to be robust enough for all environments.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB415

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paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 16 August 2021

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MOPAB416

BDSIM Developments for Hadron Therapy Centre Applications

proton, simulation, shielding, neutron

1252

E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde
ULB, Bruxelles, Belgium
S.T. Boogert, L.J. Nevay
Royal Holloway, University of London, Surrey, United Kingdom
C. Hernalsteens
CERN, Geneva, Switzerland
W. Shields
JAI, Egham, Surrey, United Kingdom

Hadron therapy centres are evolving towards reduced-footprint layouts, often featuring a single treatment room. The evaluation of beam properties, radiation protection quantities, and concrete shielding activation via numerical simulations poses new challenges that can be tackled using the numerical beam transport and Monte-Carlo code Beam Delivery Simulation (BDSIM), allowing a seamless simulation of the dynamics as a whole. Specific developments have been carried out in BDSIM to advance its efficiency toward such applications, and a detailed 4D Monte-Carlo scoring mechanism has been implemented. It produces tallies such as the spatial-energy differential fluence in arbitrary scoring meshes. The feature makes use of the generic boost::histogram library and allows an event-by-event serialisation and storage in the ROOT data format. The pyg4ometry library is extended to improve the visualisation of critical features such as the complex geometries of BDSIM models, the beam tracks, and the scored quantities. Data are converted from Geant4 and ROOT to a 3D visualisation using the VTK framework. These features are applied to a complete IBA Proteus One model.

Poster MOPAB416 [1.575 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB416

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paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 15 August 2021

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MOPAB417

Preliminary Study of a Large Energy Acceptance FFA Beam Delivery System for Particle Therapy

proton, optics, focusing, superconducting-magnet

1256

J.S.L. Yap, E.R. Higgins, S.L. Sheehy
The University of Melbourne, Melbourne, Victoria, Australia

The availability and use of ion beams for radiotherapy has grown significantly, led by technological developments to exploit the dosimetric advantages offered by charged particles. The benefits of particle therapy (PT) are well identified however its utilisation is still limited by high facility costs and technological challenges. A possibility to address both of these can be considered by improvements to the beam delivery system (BDS). Existing beamlines and gantries transport beams with a momentum range of ±1% and consequently, adjustments in depth or beam energy require all the magnetic fields to be changed. The speed to switch energies is a limiting constraint of the BDS and a determinant of the overall treatment time. A novel concept using fixed field alternating gradient (FFA) optics enables a large energy acceptance (LEA) as beams of varying energies can traverse the beamline at multiple physical positions given the same magnetic field. This presents the potential to provide faster, higher quality treatments at lower costs, with the capability to deliver advanced PT techniques such as multi-ion therapy. We explore the applicability and benefits of a LEA BDS.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB417

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paper received ※ 18 May 2021 paper accepted ※ 27 July 2021 issue date ※ 15 August 2021

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MOPAB418

Tracking and LET Measurements with the MiniPIX-TimePIX Detector for 60 MeV Clinical Protons

detector, proton, instrumentation, experiment

1260

J.S.L. Yap, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
N.J.S. Bal
NIKHEF, Amsterdam, The Netherlands
M.D. Brooke
University of Oxford, Oxford, United Kingdom
C. Granja, C. Oancea
ADVACAM s.r.o, Prague, Czech Republic
A. Kacperek
The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom
C.P. Welsch, J.S.L. Yap
The University of Liverpool, Liverpool, United Kingdom

Funding: EU FP7 grant agreement 215080, H₂020 Marie Sklodowska-Curie grant agreement No 675265, OMA - Optimization of Medical Accelerators and the Cockcroft Institute core grant STGA00076-01.
Recent advancements in accelerator technology have led the rapid emergence of particle therapy facilities worldwide, affirming the need for enhanced characterisation methods of radiation fields and radiobiological effects. The Clatterbridge Cancer Centre, UK operates a 60 MeV proton beam to treat ocular cancers and facilitates studies into proton induced radiobiological responses. Accordingly, an indicator of radiation quality is the linear energy transfer (LET), a challenging physical quantity to measure. The MiniPIX-Timepix is a miniaturised, hybrid semiconductor pixel detector with a Timepix ASIC, enabling wide-range measurements of the deposited energy, position and direction of individual charged particles. High resolution spectrometric tracking and simultaneous energy measurements of single particles enable the beam profile, time, spatial dose mapping and LET (0.1 to >100 keV/µm) to be resolved. Measurements were performed to determine the LET spectra in silicon, at different positions along the Bragg Peak (BP). We discuss the experimental setup, preliminary results and applicability of the MiniPIX for clinical environments.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB418

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paper received ※ 18 May 2021 paper accepted ※ 23 July 2021 issue date ※ 25 August 2021

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MOPAB419

Acceleration and Measurement of Alpha Particles and Hydrogen Molecular Ions with the HZB Cyclotron

cyclotron, proton, vacuum, scattering

1264

G. Kourkafas, J. Bundesmann, A. Denker, T. Fanselow, J. Röhrich
HZB, Berlin, Germany
J. Heufelder, A. Weber
Charite, Berlin, Germany

The HZB cyclotron has treated more than 4000 patients with eye tumors using protons. The accelerator can also provide heavier ions which could be suitable for ocular radiation therapy. Helium ions exhibit less lateral spread, increased relative biological effectiveness and a sharper Bragg-Peak compared to protons of the same range, while minimizing nuclear fragmentation and thus excessive dose downstream the irradiated volume compared to more heavy ions. When accelerating fully stripped helium ions (alpha particles), hydrogen molecular ions can also be accelerated to the same energy with a small tuning of the machine due to having almost the same mass-to-charge ratio, yielding a proton beam of double current after the beam exits the vacuum window towards the target. The acceleration and characterization of these two ion species are described in this paper, suggesting the feasibility of a corresponding clinical cyclotron for ocular or even deep-seated tumors.

Poster MOPAB419 [0.806 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB419

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paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 13 August 2021

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TUPAB004

Comparison of Accelerator Codes for Simulation of Lepton Colliders

lattice, emittance, optics, lepton

1334

L. van Riesen-Haupt, H. Burkhardt, T.H.B. Persson, R. Tomás García
CERN, Meyrin, Switzerland

This paper compares simulation results obtained with SAD, MAD-X and the PTC implementation in MADX for the design studies of the FCC-ee. On-momentum and off-momentum optics are explored for the various programs. Particle tracking with and without synchrotron radiation are used to compare amplitude detuning and emittance. Finally, this paper outlines how well-established SAD features such as tapering have recently been integrated into MADX.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB004

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paper received ※ 16 May 2021 paper accepted ※ 15 June 2021 issue date ※ 26 August 2021

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TUPAB010

Impact of Bunch Current on Optics Measurements in SuperKEKB

optics, damping, impedance, quadrupole

1356

J. Keintzel, R. Tomás García, F. Zimmermann
CERN, Geneva, Switzerland
T. Ishibashi, H. Koiso, G. Mitsuka, A. Morita, K. Ohmi, Y. Ohnishi, H. Sugimoto, S. Terui, M. Tobiyama, R.J. Yang, D. Zhou
KEK, Ibaraki, Japan

SuperKEKB has recently achieved the world record instantaneous luminosity of 2.8 × 10³⁴ \si{cm^-2s^-1} and aims at reaching a target luminosity of about 6 × 10³⁵ \si{cm^-2s^-1}. To accomplish this goal it is planned to increase beam currents up to §I{3.6}{A} and §I{2.6}{A} for the positron and the electron ring, respectively. Increasing the beam currents and, in particular, the number of leptons per bunch, can impact the optics parameters obtained by turn-by-turn measurements, such as the betatron tune or phase advance. Optics measurements performed at various bunch currents can give first indications of possible intensity dependent effects. In this paper, the effect of varying bunch current on optics measurements at SuperKEKB is explored.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB010

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paper received ※ 18 May 2021 paper accepted ※ 10 June 2021 issue date ※ 30 August 2021

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TUPAB030

Superb Fixed Field Permanent Magnet Proton Therapy Gantry

permanent-magnet, proton, hadron, MMI

1405

D. Trbojevic, S.J. Brooks, T. Roser, N. Tsoupas
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
We present the top notch design of the proton therapy gantry made of permanent magnets with very strong focusing. This represents a superb solution fulfilling all cancer treatment requirements for all energies without changing any parameters. The proton energy range is between 60-250 MeV. The beam arrives to the patient focused at each required treatment energy. The scanning system is place between the end of the gantry and the patient. There are multiple advantages of this design: easy operation, no significant electrical power - just for the correction system, low weight, low cost. The design is based on the recent very successful commissioning of the permanent magnet ERL ’CBETA’ at Cornell University.

Poster TUPAB030 [7.816 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB030

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paper received ※ 17 May 2021 paper accepted ※ 07 June 2021 issue date ※ 21 August 2021

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TUPAB057

Carbon Beam at I-3 Injector for Semiconductor Implantation

laser, target, plasma, ion-source

1489

A.A. Losev, P.N. Alekseev, N.N. Alexeev, T. Kulevoy, A.D. Milyachenko, Yu.A. Satov, A. Shumshurov
ITEP, Moscow, Russia
P.B. Lagov
NUST MISIS, Moscow, Russia
M.E. Letovaltseva
MIREA, Moscow, Russia
Y.S. Pavlov
IPCE RAS, Moscow, Russia

Carbon implantation can be effectively used for axial minority charge carriers lifetime control in various silicon bulk and epitaxial planar structures. When carbon is implanted, more stable recombination centers are formed and silicon is not doped with additional impurities, as for example, when irradiated with protons or helium ions. Economically, such a process competes with alternative methods, and is more efficient for obtaining small lifetimes (several nanoseconds). I-3 ion injector with laser-plasma ion source in Institute for theoretical and experimental physics (ITEP) is used as ion implanter in semiconductors. The ion source uses pulsed CO₂ laser setup with radiation-flux density of 10¹¹ W/cm² at target surface. The ion source produces beams of various ions from solid targets. The generated ion beam is accelerated in the two gap RF resonator at voltage of up to 2 MV per gap. Resulting beam energy is up to 4 MV per charge. Parameters of carbon ion beam generated and used for semiconductor samples irradiation during experiments for axial minority charge carriers lifetime control in various silicon bulk and epitaxial planar structures are presented.

Poster TUPAB057 [0.630 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB057

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paper received ※ 15 May 2021 paper accepted ※ 28 May 2021 issue date ※ 01 September 2021

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TUPAB063

Study of PF-Ring Infrastructure Improvements Using Temperature Measurements in the Ring Tunnel

injection, controls, experiment, operation

1508

N. Nakamura, K. Haga, T. Nogami, M. Tadano
KEK, Ibaraki, Japan

Temperature measurements have been performed in the PF-ring tunnel in order to understand the infrastructure performance and the temperature stability towards the PF upgrade project, where better beam stability will be required. Based on the temperature measurements, possible improvements of the PF-ring infrastructure such as an air-conditioning system have been studied to enhance the temperature stability in the PF-ring tunnel. In this paper, we present results of the temperature measurements in the PF-ring tunnel and a proposal of the PF-ring infrastructure improvements for the temperature stabilization.

Poster TUPAB063 [6.169 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB063

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paper received ※ 18 May 2021 paper accepted ※ 26 May 2021 issue date ※ 16 August 2021

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TUPAB067

Production of 120 MeV Gamma-ray Beams at Duke FEL and HIGS Facility

FEL, operation, wiggler, diagnostics

1522

S.F. Mikhailov, V. Popov, G. Swift, P.W. Wallace, Y.K. Wu, J. Yan
FEL/Duke University, Durham, North Carolina, USA
M.W. Ahmed, M. Sikora
TUNL, Durham, North Carolina, USA
H. Ehlers, L.O. Jensen, L. Kochanneck
Laser Zentrum Hannover, Hannover, Germany

Funding: This work is supported by the US DoE grant #DE-FG02-97ER41033
In this paper we report extension of the operational energy of the gamma ray beams produced at Duke High Intensity Gamma-ray Source (HIGS) up to ~120MeV, opening up a new high energy region of gamma rays for photonuclear physics research. This achievement is based upon development of radiation robust, thermally stable, high-reflectivity fluoride (LaF3/MgF2) multilayer VUV FEL mirrors, enabling us to maintain stable high intensity FEL lasing at the wavelengths of around 175nm. We discuss the challenges of HIGS operation at high gamma and high electron beam energies with the downstream FEL mirror exposed to extremely hush radiation. The experience of the first HIGS user operation with high intensity, high gamma-ray beam energies (85 and ~120MeV) using these new mirrors is also discussed.

Poster TUPAB067 [1.023 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB067

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paper received ※ 30 May 2021 paper accepted ※ 09 June 2021 issue date ※ 31 August 2021

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TUPAB069

The Sabina Terahertz/Infrared Beamline at SPARC-Lab Facility

electron, experiment, photon, laser

1525

S. Macis
La Sapienza University of Rome, Rome, Italy
M. Bellaveglia, M. Cestelli Guidi, E. Chiadroni, F. Dipace, A. Ghigo, L. Giannessi, A. Giribono, L. Sabbatini, C. Vaccarezza
INFN/LNF, Frascati, Italy
A. Doria, A. Petralia
ENEA C.R. Frascati, Frascati (Roma), Italy
S. Lupi
Sapienza University of Rome, Roma, Italy
V. Petrillo
INFN-Milano, Milano, Italy

Funding: SABINA is a project co-funded by Regione Lazio within POR-FESR 2014-2020 program.
Following the EU Terahertz (THz) Road Map*, high-intensity, ps-long, THz)/Infrared (IR) radiation is going to become a fundamental spectroscopy tool for probing and control low-energy quantum systems ranging from graphene, and Topological Insulators, to novel superconductors** ***. In the framework of the SABINA project, a novel THz/IR beamline based on an APPLE-X undulator emission will be developed at the SPARC-Lab facility at LNF-INFN. Light will be propagated from the SPARC-Lab to a new user lab facility nearly 20 m far away. This beamline will cover a broad spectral region from 3 THz to 30 THz, showing ps- pulses and energy of tens of µJ with variable polarization from linear to circular. The corresponding electric fields up to 10 MV/cm, are able to induce non-linear phenomena in many quantum systems. The beamline, open to user experiments, will be equipped with a 5 T magnetic cryostat and will be synchronized with a fs laser for THz/IR pump, VIS/UV probe experiments.
[*] S.S. Dhillon et al., J. Phys. D: Appl. Phys. 50, 043001 (2017);
[**] F. Giorgianni et al., Nature Commun. 7, 11421 (2016);
[***] P. Di Pietro et al., Phys. Rev. Lett. 124, 226403 (2020);

Poster TUPAB069 [0.884 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB069

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paper received ※ 16 May 2021 paper accepted ※ 21 June 2021 issue date ※ 25 August 2021

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TUPAB071

Beam Line Design and Instrumentation for THz@PITZ - the Proof-of-Principle Experiment on a THz SASE FEL at the PITZ Facility

undulator, FEL, electron, experiment

1528

T. Weilbach, P. Boonpornprasert, G.Z. Georgiev, G. Koss, M. Krasilnikov, X. Li, A. Lueangaramwong, F. Mueller, A. Oppelt, S. Philipp, F. Stephan, L.V. Vu
DESY Zeuthen, Zeuthen, Germany
H. Shaker
CLS, Saskatoon, Saskatchewan, Canada

In order to allow THz pump-X-ray probe experiments at full bunch repetition rate for users at the European XFEL, the Photo Injector Test Facility at DESY in Zeuthen (PITZ) is building a prototype of an accelerator-based THz source. The goal is to generate THz SASE FEL radiation with a mJ energy level per bunch using an LCLS-I undulator driven by the electron beam from PITZ. Therefore, the existing PITZ beam line is extended into a tunnel annex downstream of the existing accelerator tunnel. The beam line extension in the PITZ tunnel consists of three quadrupole magnets, a bunch compressor, a collimation system and a beam dump. In the second tunnel a dipole magnet allows to serve two beam lines, one of them the THz@PITZ beam line. It consists of one LCLS-I undulator for the production of the THz radiation, a quadrupole triplet in front of it and a quadrupole doublet behind it. For the electron beam diagnostic six new screen stations are built, three of them also allow for the observation of the THz radiation for measurements. In addition six BPMs and a new BLM system for machine protection and FEL gain curve measurement will be installed. The progress of this work will be presented.

Poster TUPAB071 [1.978 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB071

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paper received ※ 18 May 2021 paper accepted ※ 14 June 2021 issue date ※ 13 August 2021

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TUPAB073

The Design of EEHG Cascaded Harmonic Lasing for SXFEL User Facility

FEL, undulator, electron, laser

1536

K.Q. Zhang, C. Feng
SSRF, Shanghai, People’s Republic of China
H.X. Deng, B. Liu, T. Liu
SARI-CAS, Pudong, Shanghai, People’s Republic of China

The preliminary design and simulation results of EEHG cascaded harmonic lasing for the SXFEL user facility have been presented in this paper. Using the basic seeded beamline of the SXFEL user facility, the designed parameters are optimized to obtain full coherent FEL output at the 90th harmonic of a 265 nm seed laser. According to the designed parameters and the layout of the SXFEL user facility, the detailed simulations are carried out, the results show that the seeded beamline of the SXFEL user facility can generate 2.93 nm full coherent radiation by the proposed method, which indicates that the method can extend the photon energy range of a seeded FEL and the method can be achieved at the SXFEL user facility.

Poster TUPAB073 [0.955 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB073

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paper received ※ 11 May 2021 paper accepted ※ 10 June 2021 issue date ※ 27 August 2021

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TUPAB078

Relative Timing Jitter Effects on Two-stage Seeded FEL at SHINE

FEL, laser, electron, timing

1551

H.X. Yang
SINAP, Shanghai, People’s Republic of China
H.X. Deng, B. Liu, D. Wang, K.S. Zhou
SARI-CAS, Pudong, Shanghai, People’s Republic of China

Funding: The National Key Research and Development Program of China (Grants No. 2016YFA0401901, No. 2018YFE0103100) and the National Natural Science Foundation of China (Grants No. 11935020, No. 11775293).
The synchronization between the ultrashort electron beam and external seed laser is essential for seeded FELs, especially for a multi-stage one. In this paper, we demonstrate a simple method to obtain the correlations between the pulse energy and relative timing jitter for evaluating the corresponding effects. In this method, the sensitivity of the output FEL performance against electron beam properties is demonstrated by scanning the electron beam and seed lasers, and the fitted curve is used to predict the pulse energy in different timing jitter by random sampling. The results indicate that the pulse energy of the first-stage EEHG is more stable than the second-stage HGHG. Meanwhile, the rise of bunch charge from 100 pC to 300 pC can reduce the timing control requirement by a factor of least 3 for the RMS timing jitter in our numerical simulations based on the parameters of Shanghai High-Repetition-Rate XFEL and Extreme Light Facility. The timing jitter study can demonstrate the feasibility of the EEHG-HGHG cascading scheme in different current profiles for generating Fourier-transform-limited soft X-ray FEL.

Poster TUPAB078 [0.866 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB078

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paper received ※ 11 May 2021 paper accepted ※ 11 June 2021 issue date ※ 21 August 2021

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TUPAB084

An Empirically-Derived ABCD Matrix for Transverse Dynamics Studies in Seeded Free-Electron Lasers

FEL, electron, laser, free-electron-laser

1573

R. Robles
Stanford University, Stanford, California, USA
Z. Huang, G. Marcus
SLAC, Menlo Park, California, USA

Funding: DOE Contract DE-AC02-76SF00515.
We present a simple empirical method for deriving an ABCD matrix for studying the transverse dynamics of the radiation field in seeded, high-gain free-electron lasers before saturation. In spite of the inherently nonlinear nature of FEL optical guiding, the ABCD matrix we find is able to predict the evolution of the FEL mode size and centroid to a high degree of accuracy across a large range of input mode characteristics. This scheme enables extremely fast simulation of transverse dynamics, which in turn greatly simplifies numerical studies of seeded FEL systems. Of particular interest in that regard is the x-ray regenerative amplifier free-electron laser, in which the x-ray beam propagates through an optical cavity many hundreds of times, thereby making traditional simulation methods cumbersome and time consuming.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB084

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 11 August 2021

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TUPAB089

Proof-of-Principle Experiment Design for PEHG-FEL in SXFEL User Facility

FEL, laser, electron, experiment

1589

Z. Qi, H.X. Deng, C. Feng, B. Liu
SARI-CAS, Pudong, Shanghai, People’s Republic of China
S. Chen, Z.T. Zhao
SSRF, Shanghai, People’s Republic of China

In this paper, we demonstrate a proof-of-principle experimental design for phase-merging enhanced harmonic generation (PEHG) free electron laser (FEL) in Shanghai Soft X-ray Free Electron Laser (SXFEL) user facility. The simulation results indicate that, taking advantage of the beam switchyard, the normal modulator and the seeded FEL line in SXFEL user facility, together with an oblique incident seed laser, we can perform the phase-merging effect in PEHG and finally get an 8.86nm FEL radiation through the undulator, which is the 30th harmonic of the seed laser.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB089

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paper received ※ 19 May 2021 paper accepted ※ 17 June 2021 issue date ※ 02 September 2021

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TUPAB100

FEL Design Elements of SABINA: A Free Electron Laser For THz-MIR Polarized Radiation Emission

undulator, electron, FEL, simulation

1612

F. Dipace, E. Chiadroni, M. Ferrario, A. Ghigo, L. Giannessi, A. Giribono, L. Sabbatini, C. Vaccarezza
INFN/LNF, Frascati, Italy
A. Doria, A. Petralia
ENEA C.R. Frascati, Frascati (Roma), Italy
S. Lupi
Sapienza University of Rome, Roma, Italy
S. Macis
La Sapienza University of Rome, Rome, Italy
V. Petrillo
Universita’ degli Studi di Milano, Milano, Italy
V. Petrillo
INFN-Milano, Milano, Italy

Funding: SABINA is a project co-funded by Regione Lazio within POR-FESR 2014-2020 program.
SABINA, acronym of "Source of Advanced Beam Imaging for Novel Applications", will be a Self-Amplified Spontaneous Emission Free Electron Laser (SASE FEL) providing a wide spectral range (from THz to MIR) of intense, short and variable polarization pulses for investigation in physics, chemistry, biology, cultural heritage, and material science. In order to reach these goals high brightness electron beams within a 30-100 MeV energy range, produced at SPARC photo-injector, will be transported up to an APPLE-X undulator through a dogleg. Space charge effects and Coherent Synchrotron Radiation (CSR) effects must be held under control to preserve beam quality. Studies on beam transport along the undulator and of the properties of the radiation field have been performed with "Genesis 1.3" simulation code. A downstream THz optics photon delivery system has also been designed to transport radiation on the long path from the undulator exit up to user experimental area.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB100

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paper received ※ 19 May 2021 paper accepted ※ 11 June 2021 issue date ※ 02 September 2021

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TUPAB101

Monte Carlo Simulations and Neutron and Gamma Fluence Measurements to Investigate Stray Radiation in the European XFEL Undulator System

undulator, electron, simulation, neutron

1615

O.E. Falowska-Pietrzak, A. Hedqvist, F. Hellberg
Stockholm University, Stockholm, Sweden
N. Bassler
DCPT, Aarhus N, Denmark
A. Leuschner, D. Nölle
DESY, Hamburg, Germany
F. Wolff-Fabris
EuXFEL, Schenefeld, Germany

The European X-ray Free Electron Laser (XFEL) is an user facility research centre generating extremely bright and ultra-short SASE x-ray pulses. The laser flashes are generated when electrons of GeV energies pass the undulator systems. Even if the dominating contribution of the radiation field in the undulator is from spontaneous undulator radiation, also electron losses can be observed, e.g. during beam steering or due to beam halo, not captured by the upstream collimation system. The interactions of those particles with the vacuum vessel wall result in the emission of stray radiation. The LB 6419 detector allows to measure both the neutron and the gamma component in the pulsed radiation fields nearby the undulators*. Usually, the real-time measurements show the dominance of the gamma signals. However, in case of particle loss occurs, a neutron signal is observed. In addition, Monte Carlo (MC) simulations conducted using the Geant4 code indicate that neutrons are also present within the undulator’s magnets volume. In this work, we present the LB 6419 measurement data and compare these to our MC simulations, to characterize the radiation field nearby the undulator segment.
* KLETT, A., LEUSCHNER, A., TESCH, N., A dose meter for pulsed neutron fields, Radiat Meas 45 (2010) 1242-1244

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB101

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paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 18 August 2021

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TUPAB106

Simulation Calculations of Compact THz Facility at IUAC, New Delhi

undulator, simulation, electron, optics

1633

J. Karmakar, S. Ghosh
IUAC, New Delhi, India

A compact THz radiation source based on the principle of pre-bunched Free Electron Laser is at the commissioning stage at Inter University Accelerator Centre (IUAC), New Delhi. The facility will generate low emittance train of electron micro-bunches (2, 4, 8 or 16 numbers) from a RF photo-cathode gun in the energy range of 4 to 8 MeV and inject into a compact undulator to generate coherent THz radiation in the frequency range of ~0.18 to 3.0 THz. To optimize the intensity at a given frequency, the beam bunching factor and the betatron oscillation amplitude in the non-wiggling plane of the electronμbunches inside the undulator has been maximized and minimized respectively. The paper presents the optimized beam optics simulation results for two frequencies viz 0.5 and 2 THz. The on-axis radiation spectral intensity computed by in-house developed code using the trajectory data of the beam optics simulation is also presented for the two frequencies.

Poster TUPAB106 [1.208 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB106

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paper received ※ 18 May 2021 paper accepted ※ 31 August 2021 issue date ※ 12 August 2021

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TUPAB116

Toward THz Coherent Undulator Radiation Experiment with a Combination of Velocity Bunchings

undulator, electron, bunching, acceleration

1663

Y. Sumitomo, K. Hayakawa, Y. Hayakawa, K. Nogami, T. Sakai, T. Tanaka
LEBRA, Funabashi, Japan

Funding: Japan Society for the Promotion of Science (JSPS), Grant-in-Aid for Scientific Research (KAKENHI), Grant Number JP19K12631.
We have launched a research program to generate the THz coherent undulator radiations, following the proposal of the combination of velocity bunchings * at Nihon University. The combination of velocity bunchings is an efficient way of bunch compression allowing a range of energy choices, in other words, a range of quasi-monochromatic radiation wavelengths generated at the undulator. In addition to the existing wideband THz light sources (0.1 - 2 THz) by the coherent edge and transition radiations currently available at Nihon Univ., the development of a high peak-power and quasi-monochromatic coherent radiation should accelerate the activities including the material science related to the THz bandwidths. In this presentation, we illustrate the program and report the current status of the experiment.
* Y. Sumitomo et al., J. Phys. Conf. Ser., vol. 1067, p. 032017, 2018.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB116

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paper received ※ 19 May 2021 paper accepted ※ 15 June 2021 issue date ※ 15 August 2021

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TUPAB119

Beam Loss Study for the Implementation of Dechirper at the European XFEL

FEL, undulator, simulation, electron

1670

J.J. Guo
University of Chinese Academy of Sciences, Beijing, People’s Republic of China
W. Decking, M.W. Guetg, J.J. Guo, S. Liu, W. Qin, I. Zagorodnov
DESY, Hamburg, Germany
Q. Gu, J.J. Guo
SINAP, Shanghai, People’s Republic of China
Q. Gu
Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China

The European XFEL is a free-electron laser facility based on superconducting linac with high repetition rate up to 4.5 MHz. Wakefield structure (also called dechirper module) is planned to be installed in front of the SASE beam line at the European FEL, which can be used as a kicker for two-color scheme or a dechirper to control the bandwidth of SASE radiation. When the beam pass through the dechirper module, strong longitudinal and transverse wakefields can be excited to introduce a correlated energy chirp and a kick along the bunch. However, due to the relatively small gap of dechirper, beam halo particles hitting the dechirper module can lead to energy deposition and generate additional radiation, which can cause serious damage to the downstream undulators. For this reason, simulations have been performed using BDSIM to define the maximum acceptable beam halo, and the results are presented in this paper.

Poster TUPAB119 [1.489 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB119

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paper received ※ 16 May 2021 paper accepted ※ 15 June 2021 issue date ※ 12 August 2021

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TUPAB125

Studies of Particle Losses From the Beam in the EU-XFEL Following Scattering by a Slotted Foil

undulator, FEL, simulation, diagnostics

1681

A.T. Potter, A. Wolski
The University of Liverpool, Liverpool, United Kingdom
W. Decking, S. Liu
DESY, Hamburg, Germany
F. Jackson
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

One technique for producing short radiation pulses in an FEL involves the use of a slotted foil in a bunch compressor. However, the scattering of particles from the foil can lead to increased particle losses and the generation of secondary particles. This is a particular concern for high rep-rate FELs, such as the European XFEL, where there are plans to implement the slotted-foil technique for short pulse generation. The study reported here aims to characterise the impact of a slotted foil in the European XFEL on the radiation dose in the front section of one of the undulators. Simulations were performed using BDSIM: this code tracks primary particles along the beamline, models the interaction between particles and accelerator components and tracks secondary particles produced by these interactions. The results indicate the amount of energy deposited in the front section of one of the FEL undulators, and provide a basis for optimisation of the collimation system to keep the energy deposition and radiation doses within acceptable limits.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB125

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paper received ※ 19 May 2021 paper accepted ※ 10 June 2021 issue date ※ 28 August 2021

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TUPAB131

Measurement of Coherent Smith-Purcell Radiation Using Ultra-Short Electron Bunch at T-Acts

electron, experiment, bunching, background

1696

H. Yamada, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, K. Shibata, K. Takahashi
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan

The coherent Smith-Purcell radiation (SPR) emitted as a short electron bunch passes over a periodic metal surface is expected to be applied as a non-destructive beam diagnostic tool. The longitudinal profile of the electron bunch can be deduced by the measured spectrum of the coherent SPR, which is compared with the theoretical one for single electron. There are several theoretical models that explain the SPR mechanism, such as the surface current (SC) model and the van den Berg model. But the difference of estimation in radiation intensity between different models is not trivial, and also the experimental data to evaluate those validity is not enough. At test accelerator, t-ACTS, in Tohoku University we are conducting experimental research on coherent SPR in the terahertz frequency region using an ultra-short electron bunch of about 100 fs. The status and results of the experiment will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB131

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paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 13 August 2021

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TUPAB189

Design and Simulation of Beam Transport Lines of DC140 Cyclotron

quadrupole, cyclotron, target, heavy-ion

1845

V.I. Lisov, N.S. Kirilkin, A.S. Zabanov
JINR/FLNR, Moscow region, Russia
I.V. Kalagin, N.Yu. Kazarinov, S.V. Mitrofanov, V.A. Semin
JINR, Dubna, Moscow Region, Russia

Flerov Laboratory of Nuclear Reaction of Joint Institute for Nuclear Research carries out the works under creating of FLNR JINR Irradiation Facility based on the cyclotron DC140. The DC140 cyclotron is intended for acceleration of heavy ions with mass-to-charge ratio A/Z within interval from 5 to 5.5 up to two fixed energies 2.124 and 4.8 MeV per unit mass. The intensity of the accelerated ions will be about 1 pmcA for light ions (A<86) and about 0.1 pmcA for heavier ions (A>132). The beam transport system has three lines: for SEE testing of microchip, for production of track membranes and for solving of applied physics problems. The design and simulation of the beam transport system from cyclotron is presented in this report. The beam focusing in the beam lines is provided by set of quadrupole lenses. The beam diagnostics system consists of the Faraday caps, luminophores and the magnetic scanning system.

Poster TUPAB189 [0.958 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB189

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paper received ※ 14 May 2021 paper accepted ※ 02 June 2021 issue date ※ 17 August 2021

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TUPAB191

Design and Simulation of the Axial Injection Beam Line of DC140 Cyclotron of FLNR JINR

cyclotron, injection, ECR, simulation

1852

N.Yu. Kazarinov, V. Bekhterev, G.G. Gulbekyan, I.A. Ivanenko, I.V. Kalagin, S.V. Mitrofanov, N.F. Osipov, V.A. Semin
JINR, Dubna, Moscow Region, Russia
V.I. Lisov
JINR/FLNR, Moscow region, Russia

Flerov Laboratory of Nuclear Reaction of Joint Institute for Nuclear Research carries out the works under creating of FLNR JINR Irradiation Facility based on the cyclotron DC140. The facility is intended for SEE testing of microchip, for production of track membranes and for solving of applied physics problems. The main systems of DC140 are based on the DC72 cyclotron ones that now are under reconstruction. The DC140 cyclotron is intended for acceleration of heavy ions with mass-to-charge ratio A/Z within interval from 5 to 5.5 up to two fixed energies 2.124 and 4.8 MeV per unit mass. The intensity of the accelerated ions will be about 1 pmcA for light ions (A<86) and about 0.1 pmcA for heavier ions (A>132). The injection into cyclotron will be realized from the external room temperature 18 GHz ECR ion source. The design and simulation of the axial injection system of the DC140 cyclotron is presented in this report.

Poster TUPAB191 [1.090 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB191

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paper received ※ 14 May 2021 paper accepted ※ 28 May 2021 issue date ※ 22 August 2021

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TUPAB193

Operation and Maintenance of Chinese Spallation Neutron Source Stripper Foil

operation, injection, neutron, site

1858

J.X. Chen, X.J. Nie, A.X. Wang, Y.J. Yu
IHEP CSNS, Guangdong Province, People’s Republic of China
L. Kang, L. Liu
IHEP, Beijing, People’s Republic of China
J.B. Yu
DNSC, Dongguan, People’s Republic of China

Funding: The project is supported by the National Natural Science Foundation of China (Grant No.11975253) and Natural Science Foundation of Guangdong Province (Grant No.2018A030313959)
The stripper foil system is the essential equipment of the spallation neutron source to achieve negative hydrogen injection. More than 99% of negative hydrogen ions complete the charge stripper in the primary stripper foil during the injection process. The remaining ions will lead to the in-dump after the secondary foil or absorbed by the negative hydrogen scraper. This paper introduces some work records of operation and maintenance of stripper foil system.
stripper foil, maintenance, operation

Poster TUPAB193 [0.395 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB193

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paper received ※ 12 May 2021 paper accepted ※ 11 June 2021 issue date ※ 21 August 2021

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TUPAB194

Operation Status of CSNS/RCS Transverse Collimation System

collimation, shielding, radioactivity, monitoring

1862

J.B. Yu, J.X. Chen, L. Liu, X.J. Nie, C.J. Ning, G.Y. Wang, A.X. Wang, J.S. Zhang
IHEP CSNS, Guangdong Province, People’s Republic of China
L. Kang, Q.B. Wu, S.Y. Xu
IHEP, Beijing, People’s Republic of China

Funding: Natural Science Foundation of Guangdong Province 2018A030313959
In order to meet the requirements of daily maintenance of CSNS/RCS, the transverse collimation system was designed to concentrate the uncontrollable beam loss in this region. Based on physical parameters, considering the processing technology, the area was rationally arranged; combined with the requirements of physical and radiation protection, under the premise of meeting the use requirements, fully consider the limit switch, mechanical hard limit and other components, increasing the output control signals of rotary encoder and displacement sensor, the movement of the absorbers were monitored. At present, the beam collimation system has been running with no mechanical failure for two years on CSNS, and it plays an active role in beam power boost and beam loss control, which proves that the structural design of the system is reasonable.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB194

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paper received ※ 17 May 2021 paper accepted ※ 11 June 2021 issue date ※ 17 August 2021

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TUPAB204

Upgrade of Los Alamos Accelerator Facility as a Fusion Prototypic Neutron Source

target, neutron, linac, proton

1890

Y.K. Batygin, E.J. Pitcher
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by US DOE under contract 89233218CNA000001
The Fusion Prototypic Neutron Source (FPNS) is considered to be a testbed for scientific understanding of material degradation in future nuclear fusion reactors. The primary mission of FPNS is to provide a damage rate in samples of 8-11 dpa/calendar year with He/dpa ratio of 10 appm in irradiation volume of 50 cubic cm or larger with irradiation temperature 300-1000 deg C and flux gradient less than 20%/cm in the plane of the sample. Los Alamos Neutron Science Center (LANSCE) is an attractive candidate for FPNS project. Accelerator Facility was designed and operated for an extended period as a 0.8-MW Meson Factory. Existing setup of the LANSCE accelerator complex can nearly fulfill requirements of the fusion neutron source station. The primary function of the upgraded accelerator systems is the safe and reliable delivery of a 1.25-mA continuous proton beam current at 800-MeV beam energy from the switchyard to the target assembly to create 1 MW power of proton beam interacting with a solid tungsten target. The present study describes existing accelerator setup and further development required to meet the needs of FPNS project.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB204

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paper received ※ 14 May 2021 paper accepted ※ 02 June 2021 issue date ※ 21 August 2021

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TUPAB210

Construction Status of the COMET Experimental Facility

target, experiment, solenoid, proton

1907

Y. Fukao, K. Agari, H. Akiyama, E. Hirose, M. Ieiri, Y. Igarashi, M.I. Iio, N. Kamei, Y. Katoh, Y. Komatsu, R. Kurasaki, M. Maki, S. Makimura, S. Mihara, M. Minakawa, Y. Morino, F. Muto, H. Nishiguchi, T. Okamura, K. Sasaki, Y. Sato, S. Sawada, N. Sumi, H. Takahashi, K.H. Tanaka, A. Toyoda, K. Ueno, H. Watanabe, Y. Yamanoi, M.Y. Yoshida
KEK, Tsukuba, Japan

COMET (COherent Muon to Electron Transition) is an experimental project that hunts for a phenomenon of the conversion from the muon to the electron (mu-e conversion). The mu-e conversion violates the lepton flavor universality and its discovery indicates a proof of the physics beyond the standard model of the particle physics. The experiment utilizes a high-intensity primary proton-beam of J-PARC (Japan Proton Accelerator Research Complex). The proton beam is injected to a target about 700mm long to generate a high intensity muon beam so as to accumulate huge statistics and achieve the final goal of a sensitivity of 10^-16. Construction of the experimental facility is underway at a high pace towards an engineering run in 2022 and the first physics run in 2023. In this presentation, we would like to present a current status of the COMET facility construction.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB210

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paper received ※ 17 June 2021 paper accepted ※ 21 June 2021 issue date ※ 13 August 2021

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TUPAB239

Radiation of a Charged Particle Bunch Moving Along a Deep Corrugated Surface with a Small Period

ECR, electromagnetic-fields, impedance, GUI

1999

E.S. Simakov, A.V. Tyukhtin
Saint Petersburg State University, Saint Petersburg, Russia

Funding: This work was supported by the Russian Science Foundation (Grant No. 18-72-10137).
We investigate the electromagnetic radiation of a bunch moving along a corrugated conductive surface. It is assumed that wavelengths under consideration are much more than the period of the corrugation. In this case, the corrugated structure can be replaced with a smooth surface on which so-called equivalent boundary conditions (EBC) are fulfilled*. In fact, we deal with anisotropic surface characterized by certain matrix impedance. Here, we consider the case of deep corrugation, i.e. we assume that the depth of the structure is much more than its period (the case of shallow corrugation was studied earlier**). Using the EBC we obtain electromagnetic field components which are presented in form of spectral integrals. It is shown that the bunch generates surface waves propagating in the plane of the structure, whereas volume radiation is absent at the frequencies under consideration. We also consider the energy losses of the bunch. Typical dependences of a spectral density of the energy losses on corrugation parameters are obtained and analyzed. It is demonstrated that the features of the surface waves can be used for the bunch diagnostics.
* E.I. Nefedov, A.N. Sivov. Electrodynamics of periodic structures. Moscow, Nauka, 1977, 208 p. (in Russian).
** E.S. Simakov, A.V. Tyukhtin, S.N. Galyamin, Phys. Rev. AB, 22, 061301 (2019).

Poster TUPAB239 [0.637 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB239

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 23 August 2021

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TUPAB249

Diffraction at the Open-Ended Dielectric-Loaded Circular Waveguide

GUI, wakefield, electron, acceleration

2033

S.N. Galyamin, A.V. Tyukhtin, V.V. Vorobev
Saint Petersburg State University, Saint Petersburg, Russia

Funding: Work supported by Russian Science Foundation (Grant No. 18-72-10137).
Contemporary beam and THz technologies are tightly interlaced during last years. Strong THz fields allow realization of THz driven electron guns, THz bunch compression, streaking* and THz driven wakefield acceleration**. Inversely, dielectric capillaries similar to those used for THz bunch manipulation can be in turn utilized for development of high-power narrow-band THz sources***. Mentioned cases involve interaction of THz waves and particle bunches with an open end of certain dielectric loaded waveguide structure, most frequently a circular capillary. For further development of the discussed prospective topics a rigorous approach allowing analytical investigation of both radiation from open-ended capillaries and their excitation by external source would be extremely useful. We present an elegant and efficient rigorous method for solving circular open-ended dielectric-loaded waveguide diffraction problems based on Wiener-Hopf technique. We deal with the case of uniform dielectric loading and internal excitation by a waveguide mode. S-parameters, near-field and far-field distributions are presented. The obtained results can be also applied to the narrow band wakefield.
* L. Zhao et al., Phys. Rev. Lett., 124, 054802 (2020).
** M.T. Hibberd et al., Nat. Photonics, 14, 755-759 (2020).
*** D. Wang et al., Rev. Sci. Instr., 89(9), 093301 (2018).

Poster TUPAB249 [2.160 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB249

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 21 August 2021

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TUPAB250

Axicon-Based Concentrator for Cherenkov Radiation

target, focusing, diagnostics, simulation

2036

S.N. Galyamin, A.V. Tyukhtin
Saint Petersburg State University, Saint Petersburg, Russia

Funding: Work supported by Russian Science Foundation (Grant No. 18-72-10137).
We propose a new type of axisymmetric dielectric target - an "axicon-based concentrator" - which effectively concentrates generated Cherenkov radiation (CR) into a small vicinity of a focus point. It consists of two "glued" bodies of revolution: a hollow axicon and a hollow "lens." A theoretical investigation of the radiation field produced by a charge moving through the discussed radiator is performed for the general case where a charge trajectory is shifted with respect to the structure axis. The idea of a dielectric target with a specific profile of the outer surface and suitable analytical methods were presented and developed in our preceding papers *, **. An essential advantage of the current version of the device is that it allows the efficient concentration of CR energy from relativistic particles, making this device extremely prospective for various applications such as beam-driven THz sources and bunch diagnostic systems.
* S.N. Galyamin et al., Phys. Rev. Accel. Beams 22, 083001 (2019); 22, 109901 (2019).
** A.V. Tyukhtin et al., Phys. Rev. A 102, 053514 (2020).

Poster TUPAB250 [1.255 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB250

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paper received ※ 24 May 2021 paper accepted ※ 21 June 2021 issue date ※ 12 August 2021

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TUPAB251

Impedance Studies of a Corrugated Pipe for KARA

impedance, resonance, simulation, electron

2039

S. Maier, M. Brosi, A. Mochihashi, A.-S. Müller, M.J. Nasse, M. Schwarz
KIT, Karlsruhe, Germany

Funding: DFG project 431704792 in the ANR-DFG collaboration project ULTRASYNC and the DFG-funded Doctoral School "Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology".
At the KIT storage ring KARA (KArlsruhe Research Accelerator) it is planned to install an impedance manipulation structure in a versatile chamber to study and eventually control the influence of an additional impedance on the beam dynamics and the emitted coherent synchrotron radiation. For this purpose the impedance of a corrugated pipe is under investigation. In this contribution, we present first results of simulations showing the impact of different structure parameters on its impedance and wake potential.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB251

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paper received ※ 19 May 2021 paper accepted ※ 17 June 2021 issue date ※ 26 August 2021

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TUPAB255

Longitudinal Beam Dynamics and Coherent Synchrotron Radiation at cSTART

synchrotron, electron, storage-ring, synchrotron-radiation

2050

M. Schwarz, E. Bründermann, D. El Khechen, B. Härer, A. Malygin, A.-S. Müller, M.J. Nasse, A.I. Papash, R. Ruprecht, J. Schäfer, M. Schuh, P. Wesolowski
KIT, Karlsruhe, Germany

The compact STorage ring for Accelerator Research and Technology (cSTART) project aims to store electron bunches of LWFA-like beams in a very large momentum acceptance storage ring. The project will be realized at the Karlsruhe Institute of Technology (KIT, Germany). Initially, the Ferninfrarot Linac- Und Test-Experiment (FLUTE), a source of ultra-short bunches, will serve as an injector for cSTART to benchmark and emulate laser-wakefield accelerator-like beams. In a second stage a laser-plasma accelerator will be used as an injector, which is being developed as part of the ATHENA project in collaboration with DESY and Helmholtz Institute Jena (HIJ). With an energy of 50 MeV and damping times of several seconds, the electron beam does not reach equilibrium emittance. Furthermore, the critical frequency of synchrotron radiation is 53 THz and in the same order as the bunch spectrum, which implies that the entire bunch radiates coherently. We perform longitudinal particle tracking simulations to investigate the evolution of the bunch length and spectrum as well as the emitted coherent synchrotron radiation. Finally, different options for the RF system are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB255

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paper received ※ 17 May 2021 paper accepted ※ 21 June 2021 issue date ※ 29 August 2021

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TUPAB264

Shielding of CSR Wake in a Drift

impedance, shielding, wakefield, synchrotron-radiation

2079

G. Stupakov
SLAC, Menlo Park, California, USA

Funding: Work supported by the Department of Energy, contract DE-AC03-76SF00515.
A one-dimensional model of coherent synchrotron radiation (CSR) wakefield developed in Refs. [*,**] is used in computer codes for the simulation of relativistic electron beams. It includes transient effects at the entrance and exit from a bending magnet of finite length. In the ultra-relativistic limit, v=c, the exit CSR wake decays inversely proportional to the distance from the magnet end. To calculate the total energy loss of the beam one needs to integrate this wake to infinity, but the integral diverges. This means that one has to either drop the assumption of the infinite value of the Lorentz factor or take into account the shielding effect of the metal walls in the vacuum chamber. In practice, the latter effect is often dominant. In this work, we derive formulas for the CSR wake in the drift after an exit from the magnet that incorporates the shielding by two parallel metal plates. They allow computing the energy loss of different particles in the beam.
* E. L. Saldin, E. A. Schneidmiller, and M. V. Yurkov. NIMA v. 398, p. 373 (1997).
** G. Stupakov and P. Emma. In: Proceedings of 8th EPAC. Paris, France, 2002, p. 1479.

Poster TUPAB264 [0.661 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB264

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paper received ※ 10 May 2021 paper accepted ※ 25 June 2021 issue date ※ 22 August 2021

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TUPAB269

Transverse Impedance of Lossy Circular Metal-Dielectric Waveguides

impedance, GUI, resonance, wakefield

2093

M. Ivanyan, L.V. Aslyan
CANDLE SRI, Yerevan, Armenia
K. Flöttmann, F. Lemery
DESY, Hamburg, Germany

The properties of the transverse impedance of a dielectric-loaded metallic circular waveguide are investigated taking into account losses in the outer metallic pipe and in the inner dielectric layer. The dispersion relations, impedances, and wake functions for dipole modes are analyzed and compared for thin and thick dielectric layer cases. The correspondence of the resonant frequencies of the longitudinal monopole and transverse dipole impedances is established.

Poster TUPAB269 [0.906 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB269

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paper received ※ 16 May 2021 paper accepted ※ 28 May 2021 issue date ※ 10 August 2021

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TUPAB275

Enhanced Orthogonal Polarization Component Treatment in COTRI Model for Microbunched Beam Diagnostics

bunching, diagnostics, polarization, laser

2113

D.W. Rule
Private Address, Silver Spring, USA
A.H. Lumpkin
ANL, Lemont, Illinois, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
We present the results of modifying our coherent optical transition radiation interferometry (COTRI) model’s treatment of the perpendicular polarization of OTR, Iperp. Our previous analytic approximation for Iperp was for beam divergences, sy << 1/g, where g is the Lorentz factor and sy is the rms y-component of the beam divergence. We have replaced our analytical form with a Gaussian quadrature for the convolution of Iperp with the divergence in theta-y. This extends the range of divergences we reliably model to sy > 1/g. Ipar, the parallel polarization in the model, is unchanged. Iperp is polarized along the y-axis and is proportional to the square of the y-component of the beam’s velocity distribution. We illustrate our results with two cases: 1) beam energy E=1 GeV, OTR wavelength 633 nm, Q=235 pC, microbunching fraction, bf=1%, divergences of 0.1-0.7 mrad, and rms beam sizes 2,10, and 30 microns; 2) E=375 MeV, wavelength 266 nm, Q=300 pC, bf=10%, divergences of 0.1-0,7 mrad, and rms beam sizes of 10,25,50, and 100 microns. We will present two cases that would be of interest for the diagnostics of laser-plasma accelerator beams* and pre-bunched FELs**, respectively.
* A. H. Lumpkin et al., Phys. Rev. Lett. 125, 014801 (2020).
** A. H. Lumpkin and D. W. Rule, in Proc., 39th International FEL Conference, FEL 2019 (JACoW Pub., Hamburg, Germany, 2019), pp. 408-411.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB275

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paper received ※ 22 May 2021 paper accepted ※ 10 June 2021 issue date ※ 20 August 2021

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TUPAB277

Bunch Length Characterizations for the Solaris Injector LINAC

linac, electron, diagnostics, experiment

2117

A. Curcio, M.A. Knafel, G.W. Kowalski, R. Panaś, M. Waniczek, A.I. Wawrzyniak
NSRC SOLARIS, Kraków, Poland

During 2020 the first characterization of bunch length and bunch profile in the Solaris injector LINAC has been performed since the start of its operation. In absence of more sophisticated bunch length diagnostics, we have adopted an inversion algorithm applied to beam energy spectra. In practice, the method applies a transformation matrix which maps the particle energy into the particle longitudinal coordinate along the bunch. The construction of this matrix is made analytically, based on the solution of the Liouville equation for the study of the longitudinal beam dynamics. The analytic approach has been benchmarked with experimental measurements of the beam properties along the machine and cross-checked with other tools, as particle tracking and/or beam optics codes. The final results are presented. Moreover, a new diagnostic station at the end of the LINAC has been installed which will host experiments of coherent radiation emission that will be used to confirm the validity of our observations. Preliminary simulations of the coherent spectra are finally reported.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB277

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paper received ※ 18 May 2021 paper accepted ※ 17 June 2021 issue date ※ 12 August 2021

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TUPAB283

Feasibility Study of ChDR Diagnostic Device in the LHC

diagnostics, proton, flattop, electron

2139

K. Łasocha
Jagiellonian University, Kraków, Poland
M. Bergamaschi, M. Krupa, K. Łasocha, T. Lefèvre, S. Mazzoni, N. Mounet, E. Senes
CERN, Geneva, Switzerland
D.M. Harryman
JAI, Egham, Surrey, United Kingdom
P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
A. Potylitsyn
TPU, Tomsk, Russia
A. Schloegelhofer
TU Vienna, Wien, Austria

In recent years Cherenkov Diffraction Radiation (ChDR) has been reported as a phenomenon suitable for various types of particle accelerator diagnostics. As it would typically work best for highly relativistic beam, past studies and experiments have been mostly focusing on the lepton machines. This contribution investigates the prospects on the utilization of ChDR as a diagnostic tool for the Large Hadron Collider (LHC). Based on theoretical considerations and simulation results we estimate the properties of the expected radiation, both in the incoherent and coherent domain, and we compare them with the requirements of the existing diagnostic systems. We also address the potential problem of the use of dielectric radiators in circular machines, where secondary electrons could potentially lead to the creation of electron clouds inside the beam pipe that may affect the radiator.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB283

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paper received ※ 14 May 2021 paper accepted ※ 18 June 2021 issue date ※ 02 September 2021

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TUPAB285

Broadband Imaging of Coherent Radiation as a Single-Shot Bunch Length Monitor with Femtosecond Resolution

electron, simulation, detector, network

2147

J. Wolfenden, R.B. Fiorito, E. Kukstas, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
M. Brandin, B.S. Kyle, E. Mansten, S. Thorin
MAX IV Laboratory, Lund University, Lund, Sweden
R.B. Fiorito, C.P. Welsch, J. Wolfenden
Cockcroft Institute, Warrington, Cheshire, United Kingdom
E. Mansten
Lund University, Division of Atomic Physics, Lund, Sweden
T.H. Pacey
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: This work is supported by the AWAKE-UK project funded by STFC and the STFC Cockcroft core grant No. ST/G008248/1
Bunch length measurements with femtosecond resolution are a key component in the optimisation of beam quality in FELs, storage rings, and plasma-based accelerators. This contribution presents the development of a novel single-shot bunch length monitor with femtosecond resolution, based on broadband imaging of the spatial distribution of emitted coherent radiation. The technique can be applied to many radiation sources; in this study the focus is coherent transition radiation (CTR) at the MAX IV Short Pulse Facility. Bunch lengths of interest at this facility are <100 fs FWHM; therefore the CTR is in the THz to Far-IR range. To this end, a THz imaging system has been developed, utilising high resistivity float zone silicon lenses and a pyroelectric camera; building upon previous results where single-shot compression monitoring was achieved. This contribution presents simulations of this new CTR imaging system to demonstrate the synchrotron radiation mitigation and imaging capability provided, alongside initial measurements and a bunch length fitting algorithm, capable of shot-to-shot operation. A new machine learning analysis method is also discussed.

Poster TUPAB285 [2.008 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB285

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paper received ※ 17 May 2021 paper accepted ※ 24 June 2021 issue date ※ 23 August 2021

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TUPAB307

Robust Optical Instrumentation for Accelerator Alignment Using Frequency Scanning Interferometry

monitoring, target, laser, instrumentation

2203

M. Sosin, H. Mainaud Durand, F. Micolon, V. Rude, J.M. Rutkowski
CERN, Meyrin, Switzerland

The precise alignment of components inside particle accelerators is an important engineering challenge in high-energy physics. Optical interferometry, being a precise, optical distance measurement technique, is often a method of choice in such applications. However, classical fringe-counting interferometers present several drawbacks in terms of system complexity. Due to the increasing availability of broadband, high-speed, sweeping laser sources, Frequency Scanning Interferometry (FSI) based systems, using Fourier analysis of the interference signal, are becoming a subject of growing interest. In the framework of the High-Luminosity LHC project at CERN, a range of FSI-based sensor solutions have been developed and tested. It includes the optical equipment for monitoring the position of cryogenic components inside their cryostats and FSI instrumentation like inclinometers and water-based levelling sensors. This paper presents the results of preliminary tests of these components.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB307

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paper received ※ 17 May 2021 paper accepted ※ 07 June 2021 issue date ※ 12 August 2021

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TUPAB309

Alignment Verification and Monitoring Strategies for the Sirius Light Source

alignment, network, monitoring, survey

2210

R. Oliveira Neto, R. Junqueira Leão, L.R. Leão
CNPEM, Campinas, SP, Brazil

The approach for the alignment of Sirius is the use of portable coordinate metrology instruments in a common reference, via a network of stable points previously surveyed. This type of network is composed of a dense distribution of points materialized in the form of embedded target holders on the special slab and radiation shielding. Phenomena such as ground movements, temperature gradients and vibrations could lead to misalignment of the components, possibly causing a degradation in machine performance. Therefore, the relative positions of the accelerator magnets need to be periodically verified along with the structures surrounding it to ensure a good reference to future alignment operations. This paper will present the status of Sirius monitoring systems, including data from the first months of operation of the hydrostatic levelling sensors. Also, possibilities with simplified network measurements for detecting structural deformations and assessing its stability will be presented, along with a proposal of a photogrammetric reconstruction of the alignment profile of the storage ring. Finally, it will be shown a compilation of analysis on the deformation of the Sirius facilities.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB309

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paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 27 August 2021

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TUPAB315

Development of Disaster Prevention System for Accelerator Tunnel

operation, network, neutron, real-time

2228

K. Ishii, K. Bessho, M. Yoshioka
KEK, Ibaraki, Japan
Y. Kawabata, H. Matsuda, K. Matsumoto
Tobishima Corp., Tokyo, Japan
S. Tagashira
Kansai University, Osaka, Japan
N. Yamamoto
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Funding: This work is supported by Health Labor Sciences Research Grant of Japan
In an enclosed space such as a particle accelerator tunnel, ensuring worker safety during a disaster is an issue of critical importance. It is necessary to have a system in which the manager can know from outside the tunnel whether there is any worker left behind and whether the worker is escaping in the right direction. Because a global positioning system (GPS) is not available in the tunnel, we are developing a disaster prevention system that uses Wi-Fi to transmit the positioning of workers and two-way communication. The Wi-Fi access point (AP) installed in the tunnel should be radiation resistant. Additionally, the equipment carried by the worker is convenient and easy to carry. We tested the radiation hardness of commercial AP devices and developed a smartphone application to perform location information transmission and simultaneous character transmission. In 2019, we installed the system on the J-PARC Main Ring and started its operation. In this paper, the functions of the developed system and its prospects are described.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB315

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paper received ※ 19 May 2021 paper accepted ※ 10 June 2021 issue date ※ 25 August 2021

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TUPAB316

New Operational Quantities for Radiation Protection by ICRU and ICRP: Impact on Workplaces at Accelerators

operation, photon, MMI, target

2231

Th. Otto, M. Widorski
CERN, Meyrin, Switzerland

In radiation protection, Effective Dose E quantifies stochastic radiation detriment. E is defined as a weighted sum of absorbed dose to organs and tissues and cannot be measured directly. ICRU has defined operational quantities to measure effective dose approximately, such as Ambient dose equivalent H*(10). At high energies, the estimates provided by H*(10) deviate strongly from effective dose. In 2020, ICRU and ICRP have recommended new operational quantities for external radiation with a definition close to the one of effective dose, and published an extensive collection of conversion coefficients from particle fluence to the new quantities (1). Ambient dose H* serves for operational monitoring purposes. The new definition alleviates the observed discrepancies of H*(10) with effective dose. In this paper, we present a numerical study of effective dose E, ambient dose equivalent H*(10) and ambient dose H* in radiation fields at workplaces at proton- and electron accelerators. These places include locations behind primary shielding, in access mazes and in the vicinity of activated accelerator components.
(1) ICRU Report 95, Operational quantities for external radiation

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB316

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paper received ※ 11 May 2021 paper accepted ※ 02 July 2021 issue date ※ 23 August 2021

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TUPAB317

Benchmarking of the Radiation Environment Simulations for CMS Experiment at LHC

simulation, detector, experiment, neutron

2235

I.L. Azhgirey, I.A. Kurochkin, A.D. Riabchikova
IHEP, Moscow Region, Russia
D. Bozzato, A.E. Dabrowski, P. Kicsiny, S. Mallows, J. Wanczyk
CERN, Geneva, Switzerland

Radiation Simulations group of the Beam Radiation Instrumentation and Luminosity Project of the CMS experiment provide for CMS radiation environment and radiation effects simulation and benchmarking of these calculations with CMS data and other data from LHC measuring devices. We present some results of such benchmarking and the reliability analysis of the simulation procedures for radiation environment calculations at the LHC.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB317

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paper received ※ 19 May 2021 paper accepted ※ 16 June 2021 issue date ※ 29 August 2021

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TUPAB318

The Beamline Safety Interlock System of Taiwan Photon Source

vacuum, photon, controls, synchrotron-radiation

2239

C.F. Chang, C.Y. Chang, C.Y. Liu, H.Y. Yan
NSRRC, Hsinchu, Taiwan

The energy of synchrotron radiation generated by bremsstrahlung radiation and magnet is rather high, which may cause serious radiation damage to human body or even imperil people’s life. The beamline therefore must be equipped with radiation-protection system; in addition, the overheat of optical components exposed to synchrotron radiation will lead to the damage of optical components and devices. In consequence, the beamline should be furnished with the cooling-protection system to cool down optical components and devices. The Beamline Safety Interlock System targets at protecting the personnel and the safety of devices, limiting the radiation dose to a security value for experimental personnel or staffs exposing to radiation on the site as well as preventing beamline components from being exposed to overheat or vacuum damages to improve the effectiveness of beamline.

Poster TUPAB318 [3.440 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB318

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paper received ※ 09 May 2021 paper accepted ※ 10 June 2021 issue date ※ 31 August 2021

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TUPAB320

Physical Design of the Radiation Shielding for the CMS Experiment at LHC

simulation, detector, experiment, shielding

2246

I.L. Azhgirey, I.A. Kurochkin, A.D. Riabchikova
IHEP, Moscow Region, Russia
D. Bozzato, A.E. Dabrowski, S. Mallows
CERN, Meyrin, Switzerland

The design of the radiation shielding for the CMS experiment at the LHC requires a simulation of the radiation environment using a model of the CMS experimental setup, accelerator components and the experimental hall infrastructure. The radiation simulations are used to optimise the design of the CMS detectors components and also the interface of the CMS detector with LHC accelerator. The Beam Radiation Instrumentation and Luminosity Project of CMS is responsible for giving important input into the optimisation and upgrade of radiation shielding used in CMS and also the radiation environment simulations software infrastructure. This contribution describes the organization of this work, the simulation software environment used for this part of CMS experiment activity and recent radiation simulation results used to optimise the forward shielding for CMS.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB320

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paper received ※ 19 May 2021 paper accepted ※ 16 June 2021 issue date ※ 10 August 2021

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TUPAB323

Modular Type Quick Splicing Method for TPS Beamline Radiation Shielding Hutch

shielding, synchrotron, scattering, neutron

2252

C.Y. Chang, C.H. Chang, S.H. Chang, C.L. Chen, Y.C. Lin, J.C. Liu, D.G. Liu, H.Y. Yan
NSRRC, Hsinchu, Taiwan

The synchrotron light source is transported to the experimental station through a beamline with specified optics, such as mask, mirror, slit, monochromator. Generally, standard beamline should use solid materials (stainless steel, tungsten, lead, and PE) to block bremsstrahlung and synchrotron radiations, even the neutron. The radiation-shielded hutch surrounds the peripheral area of the beamline with iron and lead panels. It requires blocking the scattering radiation to protect the person against radiation hazards. A modularized radiation shielding hutch includes the frame, wall, and ceiling cover that can assemble on-site through splicing. This method could greatly shorten the installation. Besides, we designed the modular ceiling cover units with a quick mounting/opening function to easily enable the maintenance and installation of large optical components. The details of the concept design for the fixed-point radiation shielding hutch in the TPS beamline are also reported that includes the configurations of the radiation shielding wall panels, frames, and pipes/cables arrangements.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB323

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paper received ※ 13 May 2021 paper accepted ※ 10 June 2021 issue date ※ 21 August 2021

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TUPAB324

Real-Time Radiation Monitoring System with Interlock Protection Mechanism in Taiwan Photon Source

monitoring, neutron, synchrotron, electron

2256

Y.C. Lin, A.Y. Chen, C.-R. Chen, S.J. Huang, S.P. Kao, S.Y. Lin, J.C. Liu, P.J. Wen
NSRRC, Hsinchu, Taiwan

To ensure radiation safety for personnel working in the facility, the Radiation and Operation Safety Division has installed a real-time radiation monitoring system in the working area to monitor gamma rays and neutrons, for which the annual dosage limit is designed to be less than 1 mSv/year. Considering 2000 working hours for users and staff members, we have derived a control dose rate limit 2 µSv/4h for interlock protection. If the accumulated radiation dose monitored with the system exceeds 2µSv within a 4-h counting interval, the radiation monitoring station sends a signal to the interlock system to stop injection until the next counting period interval. This paper introduces the radiation monitoring system and its related design information in Taiwan Photon Source.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB324

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paper received ※ 14 May 2021 paper accepted ※ 21 June 2021 issue date ※ 27 August 2021

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TUPAB357

Development of the X-Band Megawatt-Class Coaxial Magnetrons

linac, high-voltage, electron, experiment

2346

J.Y. Liu, H.B. Chen, Y.S. Han, J. Shi, C.-X. Tang, C.J. Wang, J. Wang, H. Zha
TUB, Beijing, People’s Republic of China

X-band coaxial magnetrons are preferred for industrial and medical accelerators owing to the compact size, low cost and high efficiency. A conditioning and high power test stand for X-band magnetrons has been built in Tsinghua University. Two X-band magnetrons named "MGT-1#" and "MGT-2#" were tested at this stand. The maximum anode currents of both magnetrons reached 100 A after the conditioning process. Maximum peak output power of 1.71 MW and 1.89 MW was achieved for "MGT-1#" and "MGT-2#", respectively. The efficiencies of the two magnetrons are both about 50%.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB357

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paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 28 August 2021

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TUPAB365

Demonstration of ‘ZEPTO’ Permanent Magnet Technology on Diamond Light Source

quadrupole, permanent-magnet, vacuum, lattice

2370

A.R. Bainbridge, B.J.A. Shepherd
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
N. Krumpa
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
I.P.S. Martin, W. Tizzano
DLS, Oxfordshire, United Kingdom

The use of permanent magnets (PM’s) in place of traditional electromagnets is becoming more common in accelerator systems around the world. This change is being driven by the desire to reduce both the energy costs and carbon footprint of accelerators. However, the problem remains that it is difficult to adjust the field strength of PM systems. STFC and CERN have a longstanding collaboration in the Zero-Power Tuneable Optics (ZEPTO) project which aims to develop PM systems that are tuneable via moving the PM blocks within a static pole structure. This collaboration has previously produced 3 prototype magnets (2 quadrupoles and 1 dipole) for the proposed CLIC accelerator and aims to expand suitability to a variety of accelerators. We are now demonstrating this technology on a real machine by installing a ZEPTO magnet on Diamond Light Source. We outline the design, construction, and improvement of this technology demonstrator, highlighting the innovations over previous generations of ZEPTO technology that account for previously observed drawbacks.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB365

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paper received ※ 18 May 2021 paper accepted ※ 22 June 2021 issue date ※ 12 August 2021

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TUPAB373

Design of a Delta-type Superconducting Undulator at the IHEP

undulator, polarization, photon, permanent-magnet

2391

J.H. Wei
IHEP CSNS, Guangdong Province, People’s Republic of China
C.D. Deng
DNSC, Dongguan, People’s Republic of China
L. Gong, X.Y. Li, X.C. Yang
IHEP, Beijing, People’s Republic of China
Y. Li
DESY, Hamburg, Germany

Undulators play an important role in the 4th generation radiation light source. In order to satisfy different requirements of the experiments, various undulator structures have been proposed. The Delta-type undulator can provide circular polarized radiation. Conventional undulators are usually made of permanent magnets, but the application of the superconducting technology in the undulator is developing quickly. Compared to the permanent magnet undulators, superconducting undulators can provide higher photon flux with the same magnetic pole gap and period length, especially when the period length is longer than 20 mm. An R&D project is underway to produce a protype of a Delta-type superconducting undulator with 28 mm long period and 12 mm gap at the IHEP. The structure design and the simulation results of the magnetic field are presented in this paper.

Poster TUPAB373 [1.752 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB373

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paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 15 August 2021

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TUPAB396

The Thermal Outgassing Rate of Materials Used in Vacuum Systems

vacuum, experiment, diagnostics, cathode

2447

A.M. Semenov
BINP & NSTU, Novosibirsk, Russia
A. Burdakov, A.A. Krasnov, B.P. Tolochko, A.V. Varand
BINP SB RAS, Novosibirsk, Russia
S.R. Ivanova
GPI, Moscow, Russia
A.A. Krasnov
NSU, Novosibirsk, Russia
M.A. Mikhailenko
ISSCM SB RAS, Novosibirsk, Russia
A.A. Shoshin
Budker INP & NSU, Novosibirsk, Russia

There are many rarely used materials in vacuum systems that are poorly investigated in terms of vacuum properties. For example, phosphors, scintillating materials, ferrites, various adhesives, etc. In addition, new organic materials are being developed with mechanical properties similar to those of conventional steel. The use of such materials is very promising in vacuum technology. This article presents the thermal degassing performance of several rarely used materials and promising materials for vacuum applications.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB396

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paper received ※ 18 May 2021 paper accepted ※ 31 August 2021 issue date ※ 20 August 2021

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TUPAB404

Monte Carlo Studies for Shielding Design for High Energy Linac for Medical Isotope Generation

neutron, shielding, photon, target

2469

N. Upadhyay, S. Chacko
University of Mumbai, Mumbai, India
A.P. Deshpande, T.S. Dixit, P.S. Jadhav, R. Krishnan
SAMEER, Mumbai, India

The widely used radioactive tracer Technetium-99m (99mTc) is traditionally produced from Uranium via 235U (n, f) 99Mo reactions which depends heavily on nuclear reactors. Design studies for an alternative, cleaner approach for radioisotope generation using a high energy electron linac were initiated at SAMEER to generate 99Mo. The electron beam from a 30 MeV linac with an average current of 350 µA will be bombarded on a convertor target to produce X-rays which will be bombarded on enriched 100Mo target to produce 99Mo via (g, n) reaction. 99mTc will be eluted from 99Mo. The photons and neutrons produced in the process should be shielded appropriately to ensure radiation safety. This paper brings out the use of Monte Carlo techniques for photon and neutron shielding for our application. We used FLUKA to calculate the fluence, angular distribution and dose for photons and neutrons. Then, we introduced various layers of lead followed by HDPE, 5% borated HDPE and 40% boron rubber to ensure that the proposed shielding is sufficient to completely shield the photon as well as neutron radiation and hence is safe for operation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB404

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paper received ※ 19 May 2021 paper accepted ※ 22 June 2021 issue date ※ 25 August 2021

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TUPAB408

A Novel Automatic Focusing System for the Production of Radioisotopes for Theranostics

target, cyclotron, detector, focusing

2480

P. Häffner, C. Belver-Aguilar, S. Braccini, P. Casolaro, G. Dellepiane, I. Mateu, P. Scampoli, M. Schmid
AEC, Bern, Switzerland
P. Scampoli
Naples University Federico II, Napoli, Italy

Funding: This research was partially funded by the Swiss National Science Foundation (SNSF). Grants:200021₁75749, CRSII5₁80352, CR23I2₁56852.
A research program on the production of novel radioisotopes for theranostics is ongoing at the 18 MeV Bern medical cyclotron laboratory equipped with a solid target station. Targets are made of rare and expensive isotope enriched materials in form of compressed 6 mm diameter pellets. The irradiation of such a small target is challenging. A specific capsule has been developed made of two aluminum halves kept together by permanent magnets. Since the beam extracted from a medical cyclotron is about 12 mm FWHM, an automatic compact focusing system was conceived and constructed to optimise the irradiation procedure. It is based on a 0.5 m long magnetic system, embedding two quadrupoles and two steering magnets, and a non-destructive beam monitoring detector located in front of the target. The profiles measured by the detector are elaborated by a specific software that, through a feedback optimisation algorithm, acts on the magnets and keeps the beam focused on target. Being about 1 m long, it can be installed in any existing medical cyclotron facility. The design of the first prototype together with the results of the first beam tests are presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB408

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paper received ※ 17 May 2021 paper accepted ※ 24 June 2021 issue date ※ 19 August 2021

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TUPAB415

Irradiation Methods and Infrastructure Concepts of New Beam Lines for NICA Applied Research

quadrupole, target, detector, diagnostics

2498

G.A. Filatov, A. Agapov, A.V. Butenko, K.N. Shipulin, A. Slivin, E. Syresin, A. Tuzikov, A.S. Vorozhtsov
JINR, Dubna, Moscow Region, Russia
S. Antoine, W. Beeckman, X.G. Duveau, J. Guerra-Phillips, P.J. Jehanno
SIGMAPHI S.A., Vannes, France

Nowadays space exploration has faced the issue of radiation risk to microelectronics and biological objects. The new beamlines and irradiation stations of the Nuclotron-based Ion Collider fAcility (NICA) at JINR are currently under construction to study this issue. The beamline parameters, different methods for homogeneous irradiation of targets such as scanning, and beam profile shaping by octupole magnets are discussed. A short description of the building infrastructure, magnet elements, and detectors for these beamlines is also given.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB415

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paper received ※ 11 May 2021 paper accepted ※ 02 June 2021 issue date ※ 13 August 2021

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TUPAB416

Depth-Dose Distribution Dependence on the Energy Profile of Linear and Laser Wakefield Accelerator Electron Beams

electron, linac, simulation, HOM

2502

T.A. Nguyen
VNUHCM, Ho Chi Minh, Viet Nam
C. Rangacharyulu
University of Saskatchewan, Saskatoon, Canada
C.V. Tao
HCMUS, Ho Chi Minh City, Viet Nam

The depth-dose distributions of 10 MeV electron beams used for food irradiation and sterilization purposes at Research and Development Center for Radiation Technology, HCMC, Vietnam are measured and the results are well reproduced by the MCNP simulations. We extend the simulations to predict the dose depth distribution for 10 MeV electron beams with the energy profiles of a model Laser Wake Field accelerator (LWFA). The dosimetry and simulation results show that the maximum dose of the depth-dose curve inside the product is 1.4 times surface dose with an area density limit of 8.6 g/cm² for two-sided irradiation with nearly mono-energetic beams from the linear accelerator and the corresponding parameters for LWFA are 1.2 times surface dose and 13.0 g/cm², respectively.

Poster TUPAB416 [1.506 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB416

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paper received ※ 17 May 2021 paper accepted ※ 11 June 2021 issue date ※ 31 August 2021

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WEXC04

Simulations of Beam Strikes on Advanced Photon Source Upgrade Collimators using FLASH, MARS, and elegant

simulation, electron, photon, storage-ring

2562

J.C. Dooling, M. Borland, A.M. Grannan, C.J. Graziani, R.R. Lindberg, G. Navrotski
ANL, Lemont, Illinois, USA
N.M. Cook
RadiaSoft LLC, Boulder, Colorado, USA
D.W. Lee, Y. Lee
UCSC, Santa Cruz, California, USA

Funding: Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357.
Modeling of high-energy-density electron beams on collimators proposed for the Advanced Photon Source Upgrade (APS-U) storage ring (SR) is carried out with codes FLASH, MARS, and elegant. Code results are compared with experimental data from two separate beam dump studies conducted in the present APS SR. Whole beam dumps of the 6-GeV, 200 mA, ultra-low emittance beam will deposit acute doses of 30 MGy within 10 to 20 microseconds, leading to hydrodynamic behavior in the collimator material. Goals for coupling the codes include accurate modeling of the hydrodynamic behavior, methods to mitigate damage, and understanding the effects of the resulting shower downstream of the collimator. Relevant experiments, though valuable, are difficult and expensive to conduct. The coupled codes will provide a method to model differing geometries, materials, and loss scenarios. Efforts thus far have been directed toward using FLASH to reproduce observed damage seen in aluminum test pieces subjected to varying beam strike currents. Stabilizing the Eulerian mesh against large energy density gradients as well as establishing release criteria from solid to fluid forms are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXC04

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paper received ※ 19 May 2021 paper accepted ※ 23 July 2021 issue date ※ 30 August 2021

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WEPAB002

The Interaction Region of the Electron-Ion Collider EIC

electron, synchrotron-radiation, synchrotron, detector

2574

H. Witte, J. Adam, M. Anerella, E.C. Aschenauer, J.S. Berg, M. Blaskiewicz, A. Blednykh, W. Christie, J.P. Cozzolino, K.A. Drees, D.M. Gassner, K. Hamdi, C. Hetzel, H.M. Hocker, D. Holmes, A. Jentsch, A. Kiselev, P. Kovach, H. Lovelace III, Y. Luo, G.J. Mahler, A. Marone, G.T. McIntyre, C. Montag, R.B. Palmer, B. Parker, S. Peggs, S.R. Plate, V. Ptitsyn, G. Robert-Demolaize, C.E. Runyan, J. Schmalzle, K.S. Smith, S. Tepikian, P. Thieberger, J.E. Tuozzolo, F.J. Willeke, Q. Wu, Z. Zhang
BNL, Upton, New York, USA
B.R. Gamage, T.J. Michalski, V.S. Morozov, M.L. Stutzman, W. Wittmer
JLab, Newport News, Virginia, USA
M.K. Sullivan
SLAC, Menlo Park, California, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
This paper presents an overview of the Interaction Region (IR) design for the planned Electron-Ion Collider (EIC) at Brookhaven National Laboratory. The IR is designed to meet the requirements of the nuclear physics community *. The IR design features a ±4.5 m free space for the detector; a forward spectrometer magnet is used for the detection of hadrons scattered under small angles. The hadrons are separated from the neutrons allowing detection of neutrons up to ±4 mrad. On the rear side, the electrons are separated from photons using a weak dipole magnet for the luminosity monitor and to detect scattered electrons (e-tagger). To avoid synchrotron radiation backgrounds in the detector no strong electron bending magnet is placed within 40 m upstream of the IP. The magnet apertures on the rear side are large enough to allow synchrotron radiation to pass through the magnets. The beam pipe has been optimized to reduce the impedance; the total power loss in the central vacuum chamber is expected to be less than 90 W. To reduce risk and cost the IR is designed to employ standard NbTi superconducting magnets, which are described in a separate paper.
* An Assessment of U.S.-Based Electron-Ion Collider Science. (2018). Washington, D.C.: National Academies Press. https://doi.org/10.17226/25171

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB002

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paper received ※ 18 May 2021 paper accepted ※ 25 June 2021 issue date ※ 31 August 2021

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WEPAB012

Preliminary Investigation into Accelerators for In-Situ Cultural Heritage Research

rfq, proton, linac, detector

2605

T.K. Charles
The University of Liverpool, Liverpool, United Kingdom
A. Castilla
CERN, Meyrin, Switzerland
A. Castilla
Lancaster University, Lancaster, United Kingdom

Ion Beam Analysis (IBA) centres have provided researchers with powerful techniques to analyse objects of cultural significance in a non-destructive and non-invasive manner. However, in some cases it is not be feasible to remove an object from the field or museum and transport it to the laboratory. In this conference proceedings, we report the initial results of an investigation into the feasibility of a compact accelerator that can be taken to sites of cultural significance, for PIXE analysis. In particular, we consider the application of a compact, robust accelerator that is capable to producing 2 MeV protons that can be taken into the field to perform PIXE measurements on rock art. We detail the main challenges and considerations for such a device, as well as highlighting the potential benefits of this new accelerator application.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB012

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paper received ※ 18 May 2021 paper accepted ※ 25 June 2021 issue date ※ 10 August 2021

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WEPAB017

General Approach to Physics Limits of Ultimate Colliders

collider, luminosity, acceleration, plasma

2624

V.D. Shiltsev
Fermilab, Batavia, Illinois, USA

The future of the particle physics is critically dependent on feasibility of future energy frontier colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity, and feasibility of cost and construction time. Here we discuss major beam physics limits of ultimate accelerators, take a look into ultimate energy reach of possible future colliders. We also foresee a looming paradigm change for the HEP research as the thrust for higher energies by necessity will mean lower luminosity.

Poster WEPAB017 [1.720 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB017

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paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 17 August 2021

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WEPAB028

MAD-X for Future Accelerators

solenoid, lattice, simulation, collider

2664

T.H.B. Persson, H. Burkhardt, L. Deniau, A. Latina, P.K. Skowroński
CERN, Geneva, Switzerland

The feasibility and performance of the future accelerators must, to a large extent, be predicted by simulation codes. This implies that simulation codes need to include effects that previously played a minor role. For example, in large electron machines like the FCC-ee the large energy variation along the ring requires that the magnets strength is adjusted to the beam energy at that location, normally referred to as tapering. In this article, we present new features implemented in the MAD-X code to enable and facilitate simulations of future colliders.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB028

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paper received ※ 17 May 2021 paper accepted ※ 06 July 2021 issue date ※ 27 August 2021

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WEPAB043

Consolidation and Future Upgrades to the CLEAR User Facility at CERN

experiment, laser, gun, electron

2700

L.A. Dyks, P. Korysko
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
P. Burrows
JAI, Oxford, United Kingdom
R. Corsini, S. Curt, W. Farabolini, D. Gamba, L. Garolfi, A. Gilardi, E. Granados, G. McMonagle, H. Panuganti
CERN, Geneva, Switzerland
W. Farabolini
CEA-DRF-IRFU, France
A. Gilardi
University of Napoli Federico II, Napoli, Italy
K.N. Sjobak
University of Oslo, Oslo, Norway

The CERN Linear Electron Accelerator for Research (CLEAR) at CERN has been operating since 2017 as a dedicated user facility providing beams for a varied range of experiments. CLEAR consists of a 20 m long linear accelerator (linac), able to produce beams from a Cs₂Te photocathode and accelerate them to energies of between 60 MeV and 220 MeV. Following the linac, an experimental beamline is located, in which irradiation tests, wakefield and impedances tudies, plasma lens experiments, beam diagnostics development, and terahertz (THz) emission studies, are performed. In this paper, we present recent upgrades to the entire beamline, as well as the design of future upgrades, such as a dogleg section connecting to an additional proposed experimental beamline. The gain in performance due to these upgrades is presented with a full range of available beam properties documented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB043

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paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 19 August 2021

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WEPAB044

Status of VHEE Radiotherapy Related Studies at the CLEAR User Facility at CERN

electron, experiment, linac, focusing

2704

R. Corsini, W. Farabolini, A. Gilardi
CERN, Geneva, Switzerland
L.A. Dyks, P. Korysko
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
W. Farabolini
CEA-DRF-IRFU, France
A. Gilardi
University of Napoli Federico II, Napoli, Italy
K.N. Sjobak
University of Oslo, Oslo, Norway

Despite the increase in interest in using Very High Energy Electron (VHEE) beams for cancer radiotherapy many unanswered questions in its development remain. The use of test facilities will be an essential tool used to solve these issues. The 200 MeV electron beam from the CERN Linear Accelerator for Research (CLEAR) has been used extensively, in collaboration with several research institutes, to perform dosimetry studies and explore potential applications of VHEE beams to radiotherapy, including the exploitation of the so called FLASH effect. In this paper, we present an overview of past studies with emphasis on the more recent results. We describe methods, techniques and equipment developed at CERN in this framework, and give an outlook on future activities.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB044

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paper received ※ 18 May 2021 paper accepted ※ 23 June 2021 issue date ※ 27 August 2021

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WEPAB048

Design of an Optical Cavity for Generating Intense THz Pulse Based on Coherent Cherenkov Radiation

electron, cavity, gun, experiment

2711

P. Wang, Y. Koshiba, T. Murakami, K. Murakoshi, K. Sakaue, Y. Tadenuma, M. Washio
Waseda University, Tokyo, Japan
R. Kuroda
AIST, Tsukuba, Japan
K. Sakaue
The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan

We have been studying terahertz (THz) generation via Cherenkov radiation with high-quality electron beams from a photocathode rf (radio frequency) gun. In our early studies, we have succeeded in the generation of coherent Cherenkov radiation by controlling the tilt of the electron beam using an rf-deflector. For further enhancement, we are planning to stack the THz pulses in an optical cavity. Multi-bunch operation of the rf-gun will generate electron beams with a repetition rate of 119 MHz, and THz pulses as well. These pulses will be accumulated in the cavity for up to 150 pulses. In this conference, we report the design study of the enhancement cavity and discuss the performance of the THz source.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB048

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paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 18 August 2021

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WEPAB052

Development of an EO Sampling System for the Analysis of THz Waves Generated by Coherent Cherenkov Radiation

electron, laser, experiment, timing

2718

K. Murakoshi, Y. Koshiba, T. Murakami, K. Sakaue, Y. Tadenuma, P. Wang, M. Washio
Waseda University, Tokyo, Japan
R. Kuroda
AIST, Tsukuba, Japan
K. Sakaue
The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan

THz waves, located between microwaves and light waves, have transparency, directionality and fingerprint spectrum of specific materials. Therefore, they are expected to be useful for various applications. We have been studying THz waves generation via Cherenkov radiation with electron beams from a photocathode rf-gun. In our early studies, we have succeeded in the generation of coherent Cherenkov radiation by tilted electron beams using an rf-deflector. Furthermore, we have generated quasi-monochromatic THz waves by spatially modulated electron beams and have succeeded in its measurement by bandpass filters. This study aims to obtain the THz wave form in time domain by electro-optic (EO) sampling, which is an useful detection system for obtaining the information of the electric field and the phase simultaneously with high S/N. In this conference, we report about our probe laser system, results of the time-domain spectroscopy measurement of THz waves by EO sampling, and future prospects.

Poster WEPAB052 [0.861 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB052

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paper received ※ 19 May 2021 paper accepted ※ 07 June 2021 issue date ※ 31 August 2021

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WEPAB064

Front-to-End Simulations of the Energy Recovery Linac for the LHeC Project

emittance, electron, proton, linac

2740

K.D.J. André, B.J. Holzer
CERN, Geneva, Switzerland

The LHeC project aims to study the electron-proton deep inelastic scattering at the TeV energy scale with an innovative accelerator program. It exploits the promising energy recovery technology in order to collide an intense 50 GeV lepton beam with one hadron beam from the High Luminosity Large Hadron Collider (HL-LHC) in parallel to the hadron-hadron operation. The paper presents the studies that have been performed to assess the performance of the machine and the efficiency of the energy recovery process for different scalings of the ERL. The studies include emittance blow-up due to synchrotron radiation emission and beam-disruption created by the strong beam-beam force at the interaction point. The design principles of the ERL structure are discussed, including the particle detector bypass and the interaction region, and the results of the tracking simulations are presented, considering the complete multi-turn ERL process. Special attention is turned to the lepton beam emittance budget and the resulting energy recovery performance.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB064

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paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 28 August 2021

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WEPAB065

Studies of the Energy Recovery Performance of the PERLE Project

linac, cavity, HOM, electron

2744

K.D.J. André, B.J. Holzer
CERN, Geneva, Switzerland
S.A. Bogacz
JLab, Newport News, Virginia, USA

The Powerful Energy Recovery Linac for Experiments (PERLE) is an accelerator facility for the development and application of the energy recovery technique for an intense 500 MeV electron beam. The paper presents the studies that have been performed to assess the quality of the ERL lattice design and beam optics. The studies include the Coherent Synchrotron Radiation (CSR) emission and wakefields in the superconducting radio-frequency structures of the linacs. The lattice design and optics principles of the ERL structure are discussed, involving the vertical deflection system and the 180° arcs. Finally, the results of the front-to-end tracking simulations that consider the complete multi-turn energy recovery process are presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB065

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paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 30 August 2021

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WEPAB071

Design and Construction of an Intense Terahertz-Wave Source Based on Coherent Cherenkov Radiation Matched to Circle Plane Wave

electron, FEL, experiment, controls

2751

N. Sei, H. Ogawa
AIST, Tsukuba, Ibaraki, Japan
K. Hayakawa, Y. Hayakawa, K. Nogami, T. Sakai, Y. Sumitomo, Y. Takahashi, T. Tanaka
LEBRA, Funabashi, Japan
T. Takahashi
Kyoto University, Research Reactor Institute, Osaka, Japan

Funding: This work was supported by Japan Society for the Promotion of Science KAKENHI JP19H04406 and the Visiting Researchers Program of Kyoto University Research Reactor Institute (R2013).
National Institute of Advanced Industrial Science and Technology has been studied terahertz (THz) coherent radiation in collaboration with Nihon University and Kyoto University. We have been developed a coherent transition radiation (CTR) source with macropulse power of 1 mJ using a screen monitor in the parametric X-ray line at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University. However, to obtain a THz-wave source with higher intensity, we have undertaken a development of a new THz-wave source based on coherent Cherenkov radiation (CCR) matched to circle plane wave. Bypassing an electron beam through a hollow conical dielectric having an apex angle equal to the Cherenkov angle, the wavefront of the CCR generated on the inner surface of the hollow conical dielectric matches on the basal plane. Therefore, it is possible to obtain a high-power beam that is easy to transport. We have already produced a hollow conical dielectric made of high-resistivity silicon and considered a position controller for the hollow conical dielectric. In this presentation, the status of the new THz-wave source will be reported.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB071

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paper received ※ 18 May 2021 paper accepted ※ 22 June 2021 issue date ※ 21 August 2021

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WEPAB077

High Power Terahertz Cherenkov Free Electron Laser from a Waveguide with a Thin Dielectric Layer by a Near-Relativistic Electron Beam

electron, GUI, wakefield, bunching

2769

W.W. Li, T.L. He, Z.G. He, R. Huang, Q.K. Jia, S.M. Jiang, L. Wang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Funding: National Natural Science Foundation of China (11705198, 11775216, 11805200) Fundamental Research Funds for the Central Universities (No. WK2310000082 and No. WK2310000090)
Corrugated and dielectric structures have been widely used for producing accelerator based terahertz radiation source. Recently, the novel schemes of the sub-terahertz free electron laser (FEL) from a metallic waveguide with corrugated walls and a normal dielectric loaded waveguide driven by a near-relativistic (beam energy of a few MeV) picosecond electron beam were studied respectively. Such a beam is used for driving resonant modes in the waveguide, and if the pipe is long enough, the interaction of these modes with the co-propagating electron beam will result in micro-bunching and the coherent enhancement of the wakefield radiation. It offers a promising candidate for compact accelerator-based high power terahertz source which can be realized with relatively low energy and low peak-current electron beams. However the choices of the waveguide above is less effective in order to obtain high power with frequency around 1THz. In this paper, we propose to use the waveguide with a thin dielectric layer instead, and high power radiation (>~10 MW) around 1 THz is expected to obtain in the proposed structure according to the simulation results.

Poster WEPAB077 [1.332 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB077

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paper received ※ 12 May 2021 paper accepted ※ 23 June 2021 issue date ※ 22 August 2021

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WEPAB087

Observation of Undulator Radiation Generated by a Single Electron Circulating in a Storage Ring and Possible Applications

synchrotron, electron, photon, undulator

2790

I. Lobach
University of Chicago, Chicago, Illinois, USA
A. Halavanau, Z. Huang
SLAC, Menlo Park, California, USA
K. Kim
ANL, Lemont, Illinois, USA
S. Nagaitsev, A.L. Romanov, G. Stancari, A. Valishev
Fermilab, Batavia, Illinois, USA

An experimental study into the undulator radiation, generated by a single electron was carried out at the Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab. The individual photons were detected by a Single Photon Avalanche Diode (SPAD) at an average rate of 1 detection per 300 revolutions in the ring. The detection events were continuously recorded by a picosecond event timer for as long as 1 minute at a time. The collected data were used to test if there is any deviation from the classically predicted Poissonian photostatistics. It was motivated by the observation * of sub-Poissonian statistics in a similar experiment. The observation * could be an instrumentation effect related to low detection efficiency and long detector dead time. In our experiment, the detector (SPAD) has a much higher efficiency (65%) and a much lower dead time. In addition, we show that the collected data (recorded detection times) can be used to study the synchrotron motion of a single electron and infer some parameters of the ring. For example, by comparing the results of simulation and measurement for the synchrotron motion we were able to estimate the magnitude of the RF phase jitter.
* Teng Chen and John M. J. Madey, Phys. Rev. Lett. 86, 5906, June 2001

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB087

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paper received ※ 17 May 2021 paper accepted ※ 24 June 2021 issue date ※ 16 August 2021

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WEPAB088

Transverse Beam Emittance Measurement by Undulator Radiation Power Noise

emittance, undulator, optics, synchrotron

2794

I. Lobach
University of Chicago, Chicago, Illinois, USA
A. Halavanau, Z. Huang
SLAC, Menlo Park, California, USA
K. Kim
ANL, Lemont, Illinois, USA
V.A. Lebedev, S. Nagaitsev, A.L. Romanov, G. Stancari, A. Valishev
Fermilab, Batavia, Illinois, USA

Generally, turn-to-turn power fluctuations of incoherent spontaneous synchrotron radiation in a storage ring depend on the 6D phase-space distribution of the electron bunch. In some cases, if only one parameter of the distribution is unknown, this parameter can be determined from the measured magnitude of these power fluctuations. In this contribution, we report the results of our experiment at the Integrable Optics Test Accelerator (IOTA) storage ring, where we carried out an absolute measurement (no free parameters or calibration) of a small vertical emittance (5–15 nm rms) of a flat beam by this new method, under conditions, when the small vertical emittance is unresolvable by a conventional synchrotron light beam size monitor.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB088

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paper received ※ 17 May 2021 paper accepted ※ 24 June 2021 issue date ※ 12 August 2021

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WEPAB129

A New Method of Undulator Phase Tuning with Mechanical Shimming

undulator, MMI, operation, permanent-magnet

2912

M.F. Qian, R.J. Dejus, Y. Piao, I. Vasserman, J.Z. Xu
ANL, Lemont, Illinois, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, under contract number DEAC02-06CH11357.
We developed a new method for tuning the undulator phase errors by shimming the undulator gap profile mechanically. First, the phase errors of a device are calculated based on the initial field measurement; then the desired field strength modulation along the device length is derived from the phase errors; and finally, the gap profile is mechanically shimmed to produce the desire field strength modulation. The method has been successfully applied to the tuning of many new and reused APS Upgrade (APS-U) hybrid permanent magnet undulators. The method is especially effective for tuning the legacy undulators with large phase errors. For instance, an old 33-mm-period undulator with a 23 degree initial rms phase error largely due to radiation damage has been tuned to better than 3 degrees.

Poster WEPAB129 [0.500 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB129

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paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 13 August 2021

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WEPAB130

Experience with Algorithm-Guided Tuning of APS-U Undulators

undulator, MMI, electron, permanent-magnet

2915

M.F. Qian, R.J. Dejus, Y. Piao, I. Vasserman, J.Z. Xu
ANL, Lemont, Illinois, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, under contract number DE AC02-06CH11357.
The Advanced Photon Source (APS) is undergoing a major upgrade to its storage ring. The APS Upgrade (APS-U) project plans to build over 40 new hybrid permanent magnet undulators (HPMUs) and rebuild over 20 existing HPMUs. To meet the APS-U undulator requirements, the quality of the undulator magnetic field needs to be fine-tuned to the specifications. The traditional methods that depend on the tuning specialist experience are not desirable for tuning large quantities of undulators. We developed algorithms that automate the tuning of permanent magnet undulators. For tuning of the undulator trajectory and phase, the algorithms optimize the tuning parameters with differential evolution-based global optimization. The algorithms have been successfully applied to over 18 APS HPMUs. The results and experiences of the tuning are reported in detail.

Poster WEPAB130 [0.543 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB130

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paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 12 August 2021

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WEPAB135

Progress of the Development of a Superconducting Undulator as a THz Source for FELs

undulator, FEL, electron, experiment

2933

J. Gethmann, S. Casalbuoni, N. Glamann, A.W. Grau, A.-S. Müller, D. Saez de Jauregui
KIT, Karlsruhe, Germany
D. Astapovych, H. De Gersem, E. Gjonaj
TEMF, TU Darmstadt, Darmstadt, Germany
S. Casalbuoni
EuXFEL, Schenefeld, Germany

Funding: This work is supported by the BMBF project 05K19VK2 SCUXFEL (Federal Ministry of Education and Research) and by the DFG-funded Doctoral School KSETA: Science and Technology.
To produce radiation in the THz frequency range at X-ray Free Electron Lasers, undulators with large period length, high fields, and large gaps are required. These demands can be fulfilled by superconducting undulators. In this contribution, the actual requirements on the main parameters of such a superconducting undulator will be discussed and the progress of the design will be discussed. In addition, beam impedance and heat load results obtained analytically as well as by large-scale wakefield simulations will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB135

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paper received ※ 19 May 2021 paper accepted ※ 02 July 2021 issue date ※ 31 August 2021

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WEPAB164

Electrodeless Diamond Beam Halo Monitor

electron, experiment, coupling, vacuum

2990

S.V. Kuzikov, S.P. Antipov, P.V. Avrakhov, E. Dosov, E.W. Knight, Y. Zhao
Euclid TechLabs, Solon, Ohio, USA
J.G. Power, J. Shao
ANL, Lemont, Illinois, USA

Funding: This work was supported by DoE SBIR grant # DE-SC0019642.
Beam halo measurement is important for novel x-ray free-electron lasers which have remarkably high repetition rate and average power. We propose diamond as a radiation hard material that can be used to measure the flux of passing particles based on a particle-induced conductivity effect. Our diamond electrodeless monitor is based on a microwave measurement of the change in the resonator coupling and eigenfrequency. For measurements, we put a sensitive diamond sample in a resonator that intercepts the halo. By measuring the change in RF properties of the resonator, one can infer the beam halo parameters scanning across the beam to map its transverse distribution. In recent experiments we used a Vertical Beam Test Stand (VBS), delivered DC electron beam of the 20-200 keV energy with the current up to 50 µA, to characterize several diamond samples. We have designed and fabricated a scanning diamond monitor, based on an X-band resonator, which was tested at Argonne Wakefield Accelerator (AWA) with a multi-MeV electron beam.

Poster WEPAB164 [5.138 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB164

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paper received ※ 14 May 2021 paper accepted ※ 07 June 2021 issue date ※ 31 August 2021

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WEPAB166

Concept of an Accelerator-Driven Neutron Source for the Production of Atmospheric Radiations

neutron, target, shielding, proton

2998

P. Lee, N.-W. Kang
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
M. Moon
KAERI, Daejon, Republic of Korea

Funding: This work has been supported through KOMAC operation fund of KAERI and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2021R1C1C1007100).
At the Korea Multi-purpose Accelerator Complex (KOMAC) of Korea Atomic Energy Research Institute (KAERI), we are studying an accelerator-driven neutron source for the production of white neutron beams that resemble the atmospheric radiations on the earth. In the concept of the neutron source, high-energy neutrons are generated by using a 200-MeV proton beam on a heavy-metal target in a target station, which is consisted of a target, moderator, reflector, and biological shields, and a part of the high-energy neutrons are guided in a forward direction to make neutron beams with the atmospheric-like energy spectrum. The conceptual design has 6 more thermal-neutron beamlines at the separation of 30 degrees for the fundamental research on neutron science. Here, we present the concepts of the target station and basic parameters regarding the neutron source.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB166

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paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 28 August 2021

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WEPAB183

Big Data Techniques for Accelerator Optimization

plasma, laser, experiment, wakefield

3039

C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This project has received funding from STFC under grant reference ST/P006752/1.
Accelerators and the experiments that they enable are some of the largest, most data-intensive, and most complex scientific systems in existence. The interrelations between machine subsystems are complicated and often nonlinear. The system dynamics involve large parameter spaces that evolve over multiple relevant time scales and accelerator systems. Any accelerator-based experiments and applications are almost always difficult to model. LIV. DAT, the Liverpool Centre for Doctoral Training in Data-intensive science, was established in 2017 as a hub for training students in Big Data science. The centre currently has 36 PhD students that are working across nuclear, particle and astrophysics, as well as in accelerator science. This paper presents results from R&D into betatron radiation models and beam parameter reconstruction for plasma acceleration experiments at FACET-II, simulations for MeV energy gain in dielectric structures driven by a CO₂ laser, and modelling of seeded self-modulation of long elliptical bunches in plasma. It also gives an overview of the training program offered to the LIV. DAT students.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB183

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paper received ※ 16 May 2021 paper accepted ※ 16 June 2021 issue date ※ 23 August 2021

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WEPAB221

H⁰ Stark Stripping and Component Irradiation in Fermilab Booster

site, proton, booster, kicker

3142

J.A. Johnstone, D.E. Johnson
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Fermi Research Alliance, LLC under contract no. DE-AC02-07CH11359
In foil stripping of H⁻ some fraction of the emerging neutral H⁰ will be in excited states, which can then strip through the Stark effect in the magnetic field of the downstream orbit bump magnet. The resultant H⁺ will experience a depleted net kick compared to protons emerging from the foil and will track on trajectories different from the nominal circulating beam. This will lead to irradiation of downstream machine components. An analysis of these processes is of particular importance looking forward to the much higher beam power of the Fermilab PIP-II era. This study investigates where these errant protons will be lost, how much power is deposited, and whether this will be a shielding concern.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB221

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paper received ※ 11 May 2021 paper accepted ※ 09 June 2021 issue date ※ 20 August 2021

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WEPAB222

Impedance Evaluation of Masks in the HEPS Storage Ring

impedance, resonance, wakefield, synchrotron

3145

N. Wang, S.K. Tian, J.Q. Wang
IHEP, Beijing, People’s Republic of China
J.Q. Wang
University of Chinese Academy of Sciences, Beijing, People’s Republic of China

Masks are commonly used in photon light sources to protect sensitive elements from synchrotron radiations. In the ultra-low emittance rings, small aperture vacuum chambers are adopted in order to reach the very high gradient in the quadrupoles, while many masks are required due to the high radiation power density. Therefore, the impedance of the masks becomes one of the dominant contributors to the impedance budget. In this paper, the impedance is evaluated among different mask designs. Meanwhile, the impedance cross-talk between adjacent masks is discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB222

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paper received ※ 18 May 2021 paper accepted ※ 06 July 2021 issue date ※ 15 August 2021

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WEPAB233

Excitation of Micro-Bunching in Short Electron Bunches Using RF Amplitude Modulation

bunching, synchrotron, electron, experiment

3173

T. Boltz, E. Blomley, M. Brosi, E. Bründermann, B. Härer, A. Mochihashi, A.-S. Müller, P. Schreiber, M. Schuh, M. Yan
KIT, Karlsruhe, Germany

In its short-bunch operation mode, the KIT storage ring KARA provides picosecond-long electron bunches, which emit coherent synchrotron radiation (CSR) up to the terahertz frequency range. Due to the high spatial compression under these conditions, the self-interaction of the bunch with its own emitted CSR induces a wake-field, which significantly influences the longitudinal charge distribution. Above a given threshold current, this leads to the formation of dynamically evolving micro-structures within the bunch and is thus called micro-bunching instability. As CSR is emitted at wavelengths corresponding to the spatial dimension of the emitter, these small structures lead to an increased emission of CSR at higher frequencies. The instability is therefore deliberately induced at KARA to provide intense THz radiation to dedicated experiments. To further increase the emitted power in the desired frequency range, we consider the potential of RF amplitude modulations to intentionally excite this form of micro-bunching in short electron bunches. This work is supported by the BMBF project 05K19VKC TiMo (Federal Ministry of Education and Research).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB233

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paper received ※ 19 May 2021 paper accepted ※ 01 July 2021 issue date ※ 17 August 2021

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WEPAB234

Simulating Two Dimensional Coherent Synchrotron Radiation in Python

emittance, simulation, synchrotron-radiation, electron

3177

W. Lou, Y. Cai, C.E. Mayes, G.R. White
SLAC, Menlo Park, California, USA

Coherent Synchrotron Radiation (CSR) in bending magnets poses an important limit for electron beams to reach high brightness in novel accelerators. While the longitudinal wakefield has been well studied in one-dimensional CSR theory and implemented in various simulation codes, transverse wakefields have received less attention. Following the recently developed two-dimensional CSR theory, we developed a Python code simulating the steady-state two-dimensional CSR effects. The computed CSR wakes have been benchmarked with theory and other simulation codes. To speed up computation speed, the code applies vectorization, parallel processing, and Numba in Python.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB234

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paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 20 August 2021

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WEPAB240

Increasing the Single-Bunch Instability Threshold by Bunch Splitting Due to RF Phase Modulation

synchrotron, detector, electron, synchrotron-radiation

3193

J.L. Steinmann, E. Blomley, M. Brosi, E. Bründermann, A. Mochihashi, A.-S. Müller, M. Schuh, P. Schönfeldt
KIT, Karlsruhe, Germany

Funding: This work is funded by the BMBF contract number: 05K16VKA.
RF phase modulation at twice the synchrotron frequency can be used to split a stored electron bunch into two or more bunchlets orbiting each other. We report on time-resolved measurements at the Karlsruhe Research Accelerator (KARA), where this bunch splitting was used to increase the threshold current of the microbunching instability, happening in the short-bunch operation mode. Turning the modulation on and off reproducibly affects the sawtooth behavior of the emitted coherent synchrotron radiation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB240

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paper received ※ 19 May 2021 paper accepted ※ 08 July 2021 issue date ※ 18 August 2021

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WEPAB246

Influence of Different Beam Energies on the Micro-Bunching Instability

bunching, damping, synchrotron, operation

3209

M. Brosi, A.-S. Müller, P. Schreiber, M. Schuh
KIT, Karlsruhe, Germany

During the operation of an electron synchrotron with short electron bunches, the beam dynamics are influenced by the occurrence of the micro-bunching instability. This collective instability is caused by the self-interaction of a short electron bunch with its own emitted coherent synchrotron radiation (CSR). Above a certain threshold bunch current dynamic micro-structures start to occur on the longitudinal phase space density. The resulting dynamics depend on various parameters and were previously investigated in relation to, amongst others, the momentum compaction factor and the acceleration voltage. In this contribution, the influence of the energy of the electrons on the dynamics of the micro-bunching instability is studied based on measurements at the KIT storage ring KARA (Karlsruhe Research Accelerator).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB246

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paper received ※ 19 May 2021 paper accepted ※ 08 July 2021 issue date ※ 11 August 2021

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WEPAB251

Beam Dynamics Optimization of LCLS-II HE Linear Accelerator Design

emittance, electron, undulator, FEL

3224

J. Qiang
LBNL, Berkeley, California, USA
T.O. Raubenheimer, M.D. Woodley
SLAC, Menlo Park, California, USA

The LCLS-II-HE as a high energy upgrade of the high repetition rate X-ray FEL under construction at SLAC will provide great opportunities for scientific discovery by generating coherent, high brightness hard X-ray radiation. In this paper, we report on beam dynamics optimization of the LCLS-II HE linear accelerator design with a 100pC and a 20pC charge beam to attain high quality electron beam for X-ray FEL radiation. We also present preliminary results of beam dynamics optimization of a 100pC beam from a low emittance superconducting injector.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB251

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paper received ※ 18 May 2021 paper accepted ※ 21 June 2021 issue date ※ 30 August 2021

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WEPAB254

Design of a 10 MeV Beamline at the Upgraded Injector Test Facility for e-Beam Irradiation

electron, solenoid, focusing, cavity

3232

X. Li, H. Baumgart, G. Ciovati
ODU, Norfolk, Virginia, USA
G. Ciovati, F.E. Hannon, S. Wang
JLab, Newport News, Virginia, USA

Funding: Jefferson lab LDRD.
Electron beam irradiation near 10 MeV is suitable for wastewater treatment. The Upgraded Injector Test Facility (UITF) at Jefferson Lab is a CW superconducting linear accelerator capable of providing an electron beam of energy up to 10 MeV and up to 100 µA current. This contribution presents the beam transport simulations for a beamline to be used for the irradiation of wastewater samples at the UITF. The simulations were done using the code General Particle Tracer with the goal of obtaining an 8 MeV electron beam of radius (3-σ) of ~2.4 cm. The achieved energy spread is ~74.5 keV. The space charge effects were investigated when the bunch charge is varied to be up to 1000 times and the results showed that they do not affect the beam quality significantly.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB254

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paper received ※ 20 May 2021 paper accepted ※ 25 June 2021 issue date ※ 13 August 2021

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WEPAB255

Simulation Studies on the Interactions of Electron Beam with Wastewater

electron, simulation, photon, target

3236

X. Li, H. Baumgart, G. Ciovati
ODU, Norfolk, Virginia, USA
G. Ciovati, F.E. Hannon, S. Wang
JLab, Newport News, Virginia, USA

Funding: Jefferson Lab LDRD
The manufactured chemical pollutants, like 1,4 dioxane and PFAS (per- and polyfluroralkyl substances), found in the underground water and/or drinking water are challenging to be removed or biodegraded. Energetic electrons are capable of mediating and removing them. This paper utilizes FLUKA code to evaluate the beam-wastewater interaction effects with different energy, space and divergence distributions of the electron beam. With 8 MeV average energy, the electron beam exits from a 0.0127 cm thick titanium window, travels through a 4.3 cm distance air and a second 0.0127 cm thick stainless water container window with 2.43 cm radius, and finally is injected into the water area, where the volume of water is around 75 cubic cm. The distribution parameters of the electron beam are from the GPT (General Particle Tracer) simulations for UITF (Upgraded Injector Test Facility) in Jefferson lab. By varying the distributions, several measurements including the dose (or energy deposition) distribution, electron fluence, photon fluence are scored and compared. Taking the comparisons into consideration, this paper is aiming to find better electron beams for the wastewater irradiation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB255

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paper received ※ 20 May 2021 paper accepted ※ 25 June 2021 issue date ※ 14 August 2021

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WEPAB264

MOGA Optimization of Superconducting Longitudinal Gradient Bend Based on NbTi Wire

solenoid, emittance, lattice, storage-ring

3257

C. Chen, Z.H. Bai, G.Y. Feng, Z.L. Ren, Zh.X. Tang, L. Wang, H. Xu
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Funding: Work supported by National Key Research and Development Program of China, (2016YFA0402001)
Multi-bend achromat lattices with unit cells have been used in diffraction-limited storage ring designs. The longitudinal gradient bend can reduce the horizontal emittance below the theoretical minimum of a given magnet structure, and generally the horizontal emittance reduces with the peak field grows. Therefore superconducting longitudinal gradient bend (SLGB) can produce higher peak field value and quasi-hyperbolic field profile to minimize emittance at location of radiation and generate better hard X-rays. NbTi conductor, rather than Nb₃Sn conductor, is selected to keep the design and manufacture of SLGB magnet as simple as possible. In this paper, how the field profiles of race-track type coil and solenoid coil change with their geometric parameters is studied, and multi-objective genetic algorithm is used to optimize SLGB magnet structure considering Hefei Advanced Light Facility lattice design demand and NbTi critical current.

Poster WEPAB264 [1.476 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB264

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paper received ※ 14 May 2021 paper accepted ※ 05 July 2021 issue date ※ 14 August 2021

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WEPAB270

Characterization and Simulation of Optical Delay System for the Proof-of-Principle Experiment of Optical Stochastic Cooling at IOTA

undulator, experiment, simulation, kicker

3269

A.J. Dick, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
J.D. Jarvis
Fermilab, Batavia, Illinois, USA
P. Piot
ANL, Lemont, Illinois, USA

Funding: CBB NSF-PHY-1549132 DOE DE-SC0018656 DOE DE-AC02-07CH11359
The Optical Stochastic Cooling (OSC) experiment at Fermilab’s IOTA storage ring uses two undulators to cool the beam over many turns. The radiation emitted by electrons in the first undulator is delayed and imaged in the second undulator where it applies a corrective energy kick on the electrons. Imperfections in the manufacturing of the delay plates can lead to a source of error. This paper presents the experimental characterization of the absolute thickness of these delay plates using an interferometric technique. The measured "thickness maps" are implemented in the Synchrotron Radiation Workshop (SRW) program to assess their impact on the delayed radiation pulse.

Poster WEPAB270 [2.578 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB270

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paper received ※ 16 May 2021 paper accepted ※ 05 July 2021 issue date ※ 22 August 2021

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WEPAB271

Numerical Modelling of the Optical Stochastic Cooling Experiment at IOTA

simulation, damping, undulator, emittance

3273

A.J. Dick, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
J.D. Jarvis
Fermilab, Batavia, Illinois, USA
P. Piot
ANL, Lemont, Illinois, USA

Funding: CBB NSF-PHY-1549132 DOE DE-SC0018656 DOE DE-AC02-07CH11359
A proof-of-principle optical-stochastic cooling (OSC) experiment is currently in its commissioning phase at the Fermilab’s IOTA ring. In support of this experiment, we recently implemented an OSC element in the ELEGANT tracking program. The model, based on a semi-analytic description of OSC [*], supports the simulation of a large number of macroparticles (10⁴-10⁶) over many turns (10⁶). This paper showcases the simulation capabilities to investigate the beam dynamics in the presence of cooling (or self-interacting radiation field in general) and quantify the impact of various sources of error (e.g. transverse and phase jitter), guide data analysis.
* B. Andorf, V. A. Lebedev, J. Jarvis, and P. Piot Rev. Accel. Beams 21, 100702 (2018)

Poster WEPAB271 [1.649 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB271

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paper received ※ 16 May 2021 paper accepted ※ 06 July 2021 issue date ※ 13 August 2021

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WEPAB272

Field-Off Multiple Coulomb Scattering in the MICE Liquid Hydrogen Absorber

experiment, scattering, emittance, beam-cooling

3277

G.T. Chatzitheodoridis
USTRAT/SUPA, Glasgow, United Kingdom

It is anticipated that high brightness muon beams will be used primarily in two types of accelerators, a muon collider and a neutrino factory. The primary challenge posed by using muons as the working particle of an accelerator physics system, and the reason it has not been used extensively in modern particle physics experiments, is its short life-time (2.2μseconds at rest) and the relatively long cooling periods required by current cooling techniques. The Muon Ionization Cooling Experiment (MICE), is a multi-national accelerator physics initiative which has demonstrated Ionization Cooling (IC); a new, rapid beam-cooling technique suitable for the short-lived muon. The performance of IC depends on two key processes - energy loss due to collisional ionization, and Multiple Coulomb Scattering (MCS) - for which accurate models are crucial in parametrizing the method and enabling quantitative design of future muon accelerators. Experimental measurements of MCS of positive straight-track muons with momenta in the range 170-240 MeV/c in liquid H₂ are reported in this study.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB272

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paper received ※ 19 May 2021 paper accepted ※ 19 July 2021 issue date ※ 31 August 2021

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WEPAB283

CERN SPS Sprinkler System: A Customized Industrial Solution for a Non-Conventional Site

controls, monitoring, operation, GUI

3313

A. Suwalska, A. Arnalich, F. Deperraz, M. Munoz Codoceo, P. Ninin
CERN, Meyrin, Switzerland

Until 2018, the limited firefighting means in the SPS complex largely exposed it to the consequences of self-ignition or accidental fire. In 2015 the SPS Fire Safety project was launched with the objective of improving life safety and property protection by deploying a whole set of automatic actions to protect SPS in case of fire outbreak. If nothing was done, an unmanaged fire could be a threat to lives of those working underground and could mean losing a vast majority of the SPS machine and its equipment. In 2020, CERN has completed the consolidation of its SPS fire safety systems. Among these, a water based sprinkler system, following principles of standard industrial design but customized and tailor-made for SPS and its irradiated areas, is ready to operate. The system must take into account limitations related to the presence of fragile accelerator equipment, radioactive zones, integration constraints and comply with European norms, in particular EN12845. This paper presents the risk assessment, our experience from the planning and installation phase while discussing the custom-chosen and radiation tested equipment to end up with the lessons learned and outlook for the future.

Poster WEPAB283 [2.224 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB283

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paper received ※ 13 May 2021 paper accepted ※ 14 June 2021 issue date ※ 16 August 2021

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WEPAB328

Rapid Surface Microanalysis Using a Low Temperature Plasma

plasma, cathode, electron, target

3440

V.G. Dudnikov, M.A. Cummings, R.P. Johnson
Muons, Inc, Illinois, USA

There is a need for rapid, high-resolution (micron or sub-micron) scanning of surfaces of special nuclear materials (SNM) and surrogate materials to locate and identify regions of abnormalities. One technique that is commonly used to analyze the composition of solid surfaces and thin films is secondary-ion mass spectrometry (SIMS). SIMS devices are very complex and expensive. We propose to develop simpler, less expensive surface analysis devices, based on glow-discharge optical emission spectroscopy (GOES) that can provide excellent spatial resolution. Ions from a plasma discharge sputtered atoms from the surface and the discharge electrons effectively excite and ionize the sputtered atoms. GOES uses the light emitted by the excited particles for quantitative analysis. In the GOES device, the ion flux is extracted from the gas-discharge plasma and focused to a micron size on the sample, providing very local sputtering and local elemental analysis. The radiation from the sputtered atoms is passed through an optical fiber to an optical spectrometer and recorded. To register the distribution of elements over the sample, the sample is scanned electro-mechanically.

Poster WEPAB328 [0.385 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB328

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paper received ※ 19 May 2021 paper accepted ※ 29 July 2021 issue date ※ 02 September 2021

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WEPAB361

New Generation CERN LHC Injection Dump - Assembly and Installation (TDIS)

vacuum, injection, alignment, operation

3548

D. Carbajo Perez, E. Berthomé, C. Bertone, N. Biancacci, C. Bracco, G. Bregliozzi, B. Bulat, C. Cadiou, M. Calviani, G. Cattenoz, A. Cherif, P. Costa Pinto, A. Dallocchio, M. Di Castro, P. Fessia, M.I. Frankl, R. Franqueira Ximenes, J.-F. Fuchs, H. Garcia Gavela, J.-M. Geisser, L. Gentini, S.S. Gilardoni, M.A. Gonzalez De La Aleja Cabana, J.L. Grenard, J.M. Heredia, S. Joly, A. Lechner, J. Lendaro, J. Maestre, E. Page, M. Perez Ornedo, A. Perillo-Marcone, D. Pugnat, E. Rigutto, B. Salvant, A. Sapountzis, K. Scibor, R. Seidenbinder, J. Sola Merino, M. Taborelli, E. Urrutia, A. Vieille, C. Vollinger, C. Yin Vallgren
CERN, Meyrin, Switzerland

Funding: Work supported by the Hilumi Project
During CERN’s LS2, several upgrades were performed to beam intercepting devices in the framework of the HL-LHC Project. Upgraded equipment includes two internal beam dumps (TDIS) intended for machine protection located at the injection points from the SPS to the LHC. These two devices have been assembled, tested, and installed around LHC Point 2 and Point 8 and are currently ready to get commissioned with the beam. They are 5.8m-long, three-module-segmented vacuum chambers, with large aperture to accommodate the injected and circulating beam and equipped with absorbing materials, These comprise graphite and higher Z alloys that are embedded on sub-assemblies reinforced with back-stiffeners made of TZM. The current contribution covers three main matters. First, it details the TDIS design and its key technical features. The second topic discussed is the outcome of an experiment where a prototype module was tested under high-energy beam impacts at CERN’s HiRadMat facility. To conclude it is presented the return of experience from the pre-series construction, validation and installation in the LHC tunnel.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB361

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paper received ※ 18 May 2021 paper accepted ※ 11 June 2021 issue date ※ 17 August 2021

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WEPAB364

Third-Generation CERN n_TOF Spallation Target: Final Design and Examinations of Irradiated Prototype

target, neutron, proton, experiment

3555

R. Esposito, O. Aberle, M. Calviani, T. Coiffet, M.D. Crouvizier, R. Franqueira Ximenes, V. Maire, A.T. Perez Fontenla, M.A. Timmins
CERN, Geneva, Switzerland

The new neutron spallation target for the CERN neutron Time-Of-Flight (n_TOF) facility is based on a nitrogen-cooled Pb core impacted by short high-intensity proton beam pulses. An extensive material characterization campaign has been carried out to define the constitutive behavior of lead and assess its response under pulsed proton beam irradiation. The activities carried out include a beam irradiation test in the CERN HiRadMat facility. The tests and inspections performed show a robust behavior of the core material during operation and prominent static hardening recovery already at room temperature.

Poster WEPAB364 [1.011 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB364

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paper received ※ 18 May 2021 paper accepted ※ 11 June 2021 issue date ※ 20 August 2021

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WEPAB365

CERN BDF Prototype Target Operation, Removal and Autopsy Steps

target, extraction, interface, operation

3559

R. Franqueira Ximenes, O. Aberle, C. Ahdida, P. Avigni, M. Battistin, L. Bianchi, L.R. Buonocore, S. Burger, J. Busom, M. Calviani, J.P. Canhoto Espadanal, M. Casolino, M. Di Castro, M.A. Fraser, S.S. Gilardoni, S. Girod, J.L. Grenard, D. Grenier, M. Guinchard, R. Jacobsson, M. Lamont, E. Lopez Sola, A. Ortega Rolo, A. Perillo-Marcone, Y. Pira, B. Riffaud, V. Vlachoudis, L. Zuccalli
CERN, Meyrin, Switzerland

The Beam Dump Facility (BDF), currently in the study phase, is a proposed general-purpose fixed target facility at CERN. Initially will host the Search for Hidden Particles (SHiP) experiment, intended to investigate the origin of dark matter and other weakly interacting particles. The BDF particle production target is located at the core of the facility and is employed to fully absorb the high intensity (400 GeV/c) Super Proton Synchrotron (SPS) beam. To validate the design of the production target, a downscaled prototype was tested with the beam at CERN in 2018 in the North Area primary area in a dedicated test at 35 kW average beam power. This contribution details the BDF prototype target operation, fully remote removal intervention, and foreseen post-irradiation examination plans.

Poster WEPAB365 [1.691 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB365

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paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 25 August 2021

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WEPAB368

Sigraflex® Studies for LHC CERN Beam Dump: Summary and Perspective

operation, experiment, target, extraction

3571

J.M. Heredia, M. Calviani, R. Franqueira Ximenes, D. Grenier, K. Kershaw, A. Lechner, P.A. Andreu-Muñoz, F.-X. Nuiry, A. Perillo-Marcone, V. Rizzoglio, C. Torregrosa
CERN, Geneva 23, Switzerland
A. Alvaro
SINTEF, Trondheim, Norway
F. Berto, S. Solfiti
NTNU, Trondheim, Norway

The Large Hadron Collider (LHC) beam dump (TDE) is essential for safe and reliable operation of the collider. It absorbs particles extracted from the accelerator whenever required. The original design of the TDE dates from the mid 2000 and it is constituted of an eight-meter-long cylindrical stainless-steel tube, filled with low-Z carbon-based materials from different grades and densities. The Sigraflex®, an expanded low-density graphite, is employed in the middle section of the TDE core. Due to unexpected behaviour observed in the past LHC runs, several major upgrades were recently implemented in order for the TDE to be ready for LHC Run3 (2021-2024), where up to 555 MJ beam energy is expected to be dumped every few hours. According simulations, temperatures in the Sigraflex core will reach locally up to 1500°C in the regular dump cases, and above 2300°C for failure scenarios. The objective of this contribution is to summarize the LS2 hardware upgrades and the plan for the evaluation of the Sigraflex performance during LHC Run3. This work will also detail the last experimental and numerical findings applied to the Sigraflex®, and possible alternative materials for the future.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB368

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paper received ※ 18 May 2021 paper accepted ※ 11 August 2021 issue date ※ 16 August 2021

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WEPAB370

Study of an L-Band CW Linac

electron, linac, emittance, solenoid

3575

J. Gao, H.B. Chen, J.Y. Liu, J. Shi, H. Zha
TUB, Beijing, People’s Republic of China

We have studied an L-band linac based on a cheap industrial magnetron, which works at CW mode with 75kW averaged output-power. The designed energy-gain of electrons is 500keV. Low accelerating gradient was the dominant problem encountered during the structure design. We adopted a standing-wave structure with magnetically coupling and nose cones to increase the effective shunt impedance. A 7-cell design has been completed, of which the transverse dynamics and thermodynamics were simulated. Results showed that this accelerating structure could work stably at 59 C and 100 mA output beam current was achieved. This L-band design provided a cheap and efficient way to generate low-energy electrons for industrial irradiation processing.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB370

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 19 August 2021

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WEPAB373

The Energy Management System in NSRRC

operation, network, controls, MMI

3585

C.S. Chen, W.S. Chan, Y.Y. Cheng, Y.F. Chiu, Y.-C. Chung, K.C. Kuo, M.T. Lee, Y.C. Lin, C.Y. Liu, Z.-D. Tsai
NSRRC, Hsinchu, Taiwan

Taiwan has been suffering from a shortage of natural resources for more than two decades. As stated by the Energy Statistics Handbook 2019 of Taiwan, up to 97.90% of energy supply was imported from abroad. This kind of energy consumption structure is fragile relatively. Not mention to the total domestic energy consumption annual growth rate is 1.97% in twenty years. Either the semiconductor or the integrated circuit-related industry is developed vigorously in Taiwan. All the facts cause us to face the energy problems squarely. Therefore, an energy management system (EnMS) was installed in NSRRC in 2019 to pursue more efficient energy use. With the advantages of the Archive Viewer - a utility supervisory control and data acquisition system in NSRRC, the data of energy use could be traced conveniently and widely. The model of energy use has been built to review periodically, furthermore, it provides us the accordance to replace the degraded equipment and alerts us if the failure occurs.

Poster WEPAB373 [0.497 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB373

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paper received ※ 21 May 2021 paper accepted ※ 22 July 2021 issue date ※ 11 August 2021

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WEPAB380

Measurements of Field Emission Induced Optical Spectra

alignment, site, experiment, electron

3602

R.C. Peacock, G. Burt
Lancaster University, Lancaster, United Kingdom
S. Calatroni, W. Wuensch
CERN, Meyrin, Switzerland

Field emission induced optical spectra in a dc electrode system have been measured using a spectrometer and CCD camera system in order to gain insight into the nature of field emissions sites. Spectra were measured from between 2 ridged parallel copper electrodes with a gap ranging from 60µm to 100µm and a bias voltage of up to 8000V under high vacuum conditions. A strong correlation between the light intensity of the spectra and the measured field emitted current was observed as a function of applied voltage. A characteristic broadband spectrum ranging from 550nm and 850nm wavelength was observed but there were important features which varied as a function of observation angle, polarity, and conditioning state and also with time. Possible causes of the optical spectra being considered include black body radiation, optical transition radiation and cathode luminescence of copper. Further experiments are ongoing with an improved optical setup to increase optical alignment for measurements with different materials of electrodes, developing further understanding of the cause of the optical spectra, to provide understanding into characteristics and evolution of emission sites.

Poster WEPAB380 [1.158 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB380

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paper received ※ 11 May 2021 paper accepted ※ 24 June 2021 issue date ※ 24 August 2021

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WEPAB405

Supercontinuum Generation for the Improvement of Pulse Radiolysis System

laser, polarization, photon, electron

3657

M. Sato, Y. Kaneko, Y. Koshiba, M. Washio
RISE, Tokyo, Japan
K. Sakaue
The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan

Pulse radiolysis is one of the absorption measurement methods for investigating the fundamental, ultrafast process of radiation chemical reactions. Analytical light is transmitted simultaneously with the timing of electron beam irradiation, and its absorption by reactive species is detected. Since the target reactions arise in pico second time scale or even shorter, analytical light is required to have such duration. Besides, so as not to be buried in noise of the radiation source, the optical power of the analytical light must be high enough. Furthermore, it is desirable that the analytical light covers visible region because important absorptions caused by irradiation products such as hydrated electron, hydroxyl radical, or so exist in the region. We considered that the supercontinuum light generated from an ultrashort pulse laser is suitable as an analytical light because it has all these characteristics. In this study, we generate the second harmonic (775 nm) of an erbium fiber laser (1550 nm) as a seed laser for supercontinuum generation. In this presentation, we report the current situation of our laser system and prospects.

Poster WEPAB405 [0.734 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB405

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paper received ※ 18 May 2021 paper accepted ※ 01 September 2021 issue date ※ 20 August 2021

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WEPAB418

The Power Supply System for 10 MeV & 20 kW Industry Irradiation Facility

power-supply, gun, electron, high-voltage

3678

F.L. Shang, L. Shang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Funding: Work supported by National Key R&D Program of China 2018YFF0109204
The 10 MeV and 20 kW industry irradiation facility (IIF) has been designed by National Synchrotron Radiation Laboratory (NSRL) for years. Modular design power supplies are employed for the latest version, depend on the performance of these power supplies with high precision and high stability, the operating reliability of the IIF has been greatly improved.

Poster WEPAB418 [0.991 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB418

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paper received ※ 15 May 2021 paper accepted ※ 23 June 2021 issue date ※ 13 August 2021

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THXA05

A Fast Method of 2D Calculation of Coherent Synchrotron Radiation Wakefield in Relativistic Beams

electron, dipole, synchrotron, synchrotron-radiation

3696

J. Tang, Z. Huang, G. Stupakov
SLAC, Menlo Park, California, USA

Coherent Synchrotron Radiation (CSR) is regarded as one of the most important reasons that limit beam brightness in modern accelerators. CSR wakefield is often computed in a 1D assuming a line charge, which can become invalid when the beam has a large transverse extension and small bunch length. On the other hand, the existing 2D or 3D codes are often computationally inefficient or incomplete. In our previous work * we developed a new model for fast computation of 2D CSR wakefield in relativistic beams with Gaussian distribution. Here we further generalize this model to achieve self-consistent computation compatible with arbitrary beam distribution and nonlinear magnetic lattice with particle tracking. These new features can enable us to perform realistic simulations and study the physics of CSR beyond 1D in electron beams with extreme short bunch length and high peak current.
* J. Tang and G. Stupakov. NAPAC2019, paper WEPLS09 (2019).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXA05

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paper received ※ 19 May 2021 paper accepted ※ 20 July 2021 issue date ※ 21 August 2021

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THXB01

3D Tracking of a Single Electron in IOTA

electron, experiment, synchrotron, storage-ring

3708

A.L. Romanov, S. Nagaitsev, J.K. Santucci, G. Stancari, A. Valishev
Fermilab, Batavia, Illinois, USA
N. Kuklev, I. Lobach
University of Chicago, Chicago, Illinois, USA

High-resolution observations of single-particle dynamics have potential as a powerful tool in the diagnostics, tuning and design of storage rings. We are presenting the results of experiments with single electrons that were conducted at Fermilab’s IOTA ring to explore the feasibility of this approach. A set of sensitive, high-resolution digital cameras was used to detect the synchrotron radiation emitted by an electron, and the resulting images were used to reconstruct the time evolution of oscillation amplitudes in all three degrees of freedom. From the evolution of the oscillation amplitudes, we deduce transverse emittances, momentum spread, damping times, beam energy and estimated residual-gas density and composition. To our knowledge, this is the first time that the dynamics of a single particle in a storage ring has been tracked in all three dimensions. We discuss farther development of a single particle diagnostics that may allow reconstruction of its turn-by-turn coordinates over macroscopic periods of time facilitating ultra-precise lattice diagnostics and direct benchmarking of tracking codes.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXB01

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paper received ※ 24 May 2021 paper accepted ※ 29 July 2021 issue date ※ 11 August 2021

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THXB07

Coherent Radiation From Inverse Compton Scattering Sources by Means of Particle Trapping

electron, laser, undulator, FEL

3732

A. Fallahi, L. Novotny
ETH Zurich, Photonics Laboratory, Zurich, Switzerland
N. Kuster
ETH, Zurich, Switzerland

Funding: This work is supported by the Swiss National Science Foundation (SNSF) under the Spark grant CRSK-2-190840.
Inverse Compton scattering (ICS) sources are one of the promising compact tools to generate short wavelength radiation from electron beams based on the relativistic Doppler effect. Nonetheless, these sources suffer from a few shortcomings such as incoherent radiation and low-efficiency in radiation generation. This contribution presents a novel scheme based on the scattering of an optical beam from a trapped electron beam inside an optical cavity. Inverse-Compton scattering off both free and trapped electrons are simulated using a full-wave solution of first-principle equations based on FDTD/PIC in the co-moving frame of electron beams. It is shown that the strong space-charge effect in low-energies is the main obstacle in acquiring coherent gain through the ICS mechanism. Subsequently, it is shown that by trapping the electron beam to the high-intensity spots, the space-charge effect is compensated, and additionally, the ultrahigh charge density enables high FEL-gain at trapping spots, thereby augmenting the coherence of the output radiation and concurrently increasing the source efficiency by three orders of magnitude.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXB07

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paper received ※ 28 May 2021 paper accepted ※ 01 July 2021 issue date ※ 24 August 2021

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THPAB007

Technology Spinoff and Lessons Learned from the 4-Turn ERL CBETA

permanent-magnet, cavity, SRF, linac

3762

K.E. Deitrick, N. Banerjee, A.C. Bartnik, D.C. Burke, J.A. Crittenden, J. Dobbins, C.M. Gulliford, G.H. Hoffstaetter, Y. Li, W. Lou, P. Quigley, D. Sagan, K.W. Smolenski
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
J.S. Berg, S.J. Brooks, R.L. Hulsart, G.J. Mahler, F. Méot, R.J. Michnoff, S. Peggs, T. Roser, D. Trbojevic, N. Tsoupas
BNL, Upton, New York, USA
T. Miyajima
KEK, Ibaraki, Japan

The Cornell-BNL ERL Test Accelerator (CBETA) developed several energy-saving measures: multi-turn energy recovery, low-loss superconducting radiofrequency (SRF) cavities, and permanent magnets. With green technology becoming imperative for new high-power accelerators, the lessons learned will be important for projects like the FCC-ee or new light sources, where spinoffs and lessons learned from CBETA are already considered for modern designs.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB007

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paper received ※ 20 May 2021 paper accepted ※ 05 July 2021 issue date ※ 12 August 2021

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THPAB017

The International Muon Collider Collaboration

collider, luminosity, emittance, target

3792

D. Schulte
CERN, Meyrin, Switzerland

A muon collider offers a unique opportunity for high-energy, high-luminosity lepton collisions and could push the frontiers of particle physics by providing excellent discovery reach with excellent precision. A scheme has been developed by the MAP collaboration. The updated European Strategy for Particle Physics recommended the development of an Accelerator R&D Roadmap for Europe and CERN Council has charged the LDG to develop it. LDG has initiated panels to provide input including one on the use of muon beams, in particular in view of a high-energy, high luminosity muon collider. A new international collaboration, is forming to develop a muon collider design and address the associated challenges, which are mainly due to the limited muon lifetime. The focus is on two energy ranges, around 3 TeV and above 10 TeV. Ambitious magnets, RF systems, targets and shielding are key for the design.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB017

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paper received ※ 19 May 2021 paper accepted ※ 26 July 2021 issue date ※ 11 August 2021

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THPAB040

A Phase Shifter for Inline Undulators at the Advanced Photon Source Upgrade Project

undulator, photon, electron, permanent-magnet

3830

E.R. Moog, R.J. Dejus, A.T. Donnelly, Y. Piao, M.F. Qian, I. Vasserman, J.Z. Xu
ANL, Lemont, Illinois, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, under contract number DE AC02-06CH11357.
Several undulator lines for the Advanced Photon Source Upgrade (APS-U) will consist of two inline undulators. In order to keep the undulators operating with optimal phasing over the full range of gaps, a phase shifter will be included between the undulators. A design has been developed for a phase shifter that will serve for a variety of undulator period lengths and gap ranges. The permanent-magnet phase shifter will use SmCo magnets to reduce the risk of radiation-induced demagnetization. The available space between the undulators is tight, so magnetic shields are placed between the undulators, the phase shifter, and the corrector magnet that is also located in the inter-undulator space. While these shields guard against magnetic cross-talk between the devices as the undulator and phase shifter gaps change, they do have an effect on the end fields of the devices. These end-field effects are examined and relevant tolerances are set and presented.

Poster THPAB040 [0.429 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB040

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paper received ※ 23 May 2021 paper accepted ※ 21 June 2021 issue date ※ 14 August 2021

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THPAB056

Conceptual Design of a Multiple Period Staggered Undulator

undulator, solenoid, electron, synchrotron

3879

I. Asparuhov, J. Chavanne, G. Le Bec
ESRF, Grenoble, France

In staggered undulators, a ferromagnetic pole structure paired to a solenoid generates a sinusoidal field. Interest of such insertion devices has been studied for application to FEL systems in the end of the previous century. However, the concept has never been used in synchrotron radiation sources due to the undesirable magnetic effect of the solenoid on electron beam parameters in storage rings. Advent of fourth-generation low emittance light sources is foreseen to change this situation. Indeed, consequent electron beam transverse size and divergence reduction for such new storage rings give promise for a beam less sensitive to the presence of a longitudinal solenoidal field. Relating to this, a staggered concept can be an adequate design choice for short-period undulators producing high-energy photon flux. Such undulators would have a low K value a priori limiting their photon energy tunability. Considering integration of separate magnetic arrays of distinct periods in a solenoid to compose a global assembly can help suppress this possible drawback. Magnetic design and radiative performance of such an insertion device are presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB056

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paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 02 September 2021

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THPAB057

Goubau-Line Set Up for Bench Testing Impedance of In-Vacuum Undulator Components

impedance, undulator, vacuum, wakefield

3883

P.I. Volz, S. Grimmer, M. Huck, A. Meseck
HZB, Berlin, Germany
A. Meseck
KPH, Mainz, Germany

The worldwide first in-vacuum elliptical undulator, IVUE32, is being developed at Helmholtz Zentrum Berlin. The 2.5 m long device with a period length of 3.2 cm and a minimum gap of about 7 mm is to be installed in the BESSY II storage ring. It will deliver soft X-radiation to several beamlines. The proximity of the undulator structure to the electron beam makes the device susceptible to wakefield effects which can influence beam stability. A complete understanding of its impedance characteristics is required prior to installation and operation, as unforeseen heating of components could have catastrophic consequences. Since its complex structure makes numerical calculations, such as CST simulations, at high frequency very resource intensive, bench testing the device may proof invaluable. A Goubau-line is a single wire transmission line for high frequency surface waves with a transverse electric field resembling that of a charged particle beam out to a certain radial distance. This can be used to measure the impedance of vacuum chamber components. A concept optimized for bench testing IVUE32-components will be discussed and progress towards the test bench set up will be shown.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB057

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paper received ※ 19 May 2021 paper accepted ※ 23 July 2021 issue date ※ 21 August 2021

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THPAB065

Experimental Verification of the Source of Excessive Helical SCU Heat Load at APS

vacuum, photon, synchrotron-radiation, synchrotron

3904

V. Sajaev, J.C. Dooling, K.C. Harkay
ANL, Lemont, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Immediately after the installation of the Helical superconducting undulator (HSCU) in the APS storage ring, higher than expected heating was observed in the cryogenic cooling system. Steering the electron beam orbit in the upstream dipole reduced the amount of synchrotron radiation reaching into the HSCU and allowed the device to properly cool and operate. The simplest explanation of the excessive heat load was higher than expected heat transfer from the vacuum chamber to the magnet coils. However, modeling of the synchrotron radiation interaction with the HSCU vacuum chamber showed that Compton scattering could also result in synchrotron radiation penetrating the vacuum chamber and depositing energy directly into the HSCU coils**. In this paper, we present experimental evidence that the excessive heat load of the HSCU coils is not caused by the heat transfer from the vacuum chamber but resulted from the synchrotron radiation penetrating the vacuum chamber.
* M. Kasa et. al., Phys. Rev. AB, v. 23 050701 (2020)
** J. Dooling et. al., IPAC 2019 Proc., THPTS093 (2019)

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB065

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paper received ※ 12 May 2021 paper accepted ※ 02 September 2021 issue date ※ 16 August 2021

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THPAB079

Design Study on Beam Size Measurement System Using SR Interferometry for Low Beam Current

electron, synchrotron, synchrotron-radiation, storage-ring

3949

W. Li, P. Liu, Y.K. Wu, J. Yan
FEL/Duke University, Durham, North Carolina, USA

Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033.
To enable reliable measurements of the small vertical size of the electron beam in the Duke storage ring, a measurement system is being developed using synchrotron radiation interferometry (SRI). By relating the transverse beam size to the transverse spatial coherence of synchrotron radiation from a dipole magnet according to the Van Cittert-Zernike theorem, the transverse beam size can be inferred by recording and fitting the interference fringe as a function of the characteristic features of the interference filter used. In this paper, we describe the preliminary design of such a measurement system and present design considerations to make it possible to measure the electron beam vertical size for a wide range of electron beam energies and currents. Especially this system will be optimized to measure the electron beam size for low current operation down to 50 to 100~μA. This beam size measurement system will be used as an important beam diagnostic for the intrabeam scattering research at the Duke storage ring.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB079

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paper received ※ 27 May 2021 paper accepted ※ 12 July 2021 issue date ※ 28 August 2021

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THPAB080

Correcting the Magnetic Field Offsets Inside the Undulators of the EuXFEL Using the K-Monochromator

undulator, FEL, electron, synchrotron

3953

F. Brinker
DESY, Hamburg, Germany
S. Casalbuoni, W. Freund
EuXFEL, Schenefeld, Germany

Hard X-ray free-electron lasers (XFELs) generate intense coherent X-ray beams by passing electrons through undulators, i.e. very long periodic magnet structures, which extend over hundreds of meters. A crucial condition for the lasing process is the spatial overlap of the electrons with the electromagnetic field. Well-established electron beam-based procedures allow finding a straight trajectory for the electrons defined by the beam position monitors (BPM) between the undulators. A bending of the trajectory in between the BPMs cannot be seen by these methods. A general field offset inside the undulators has the effect that the synchrotron radiation is emitted at a different angle at the beginning and the end of the undulator which can result in a degradation of the FEL-gain especially for very short wavelengths. We report on how the spectral and spatial characteristics of the monochromatized radiation of a single undulator can be used to minimize the field offset in situ with the help of correction coils.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB080

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paper received ※ 19 May 2021 paper accepted ※ 25 June 2021 issue date ※ 12 August 2021

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THPAB097

Towards Arbitrary Pulse Shapes in the Terahertz Domain

laser, electron, storage-ring, controls

3977

C. Mai, B. Büsing, A. Held, S. Khan, D. Krieg
DELTA, Dortmund, Germany

Funding: Work supported by the BMBF (05K19PEC).
The TU Dortmund University operates the 1.5-GeV electron storage ring DELTA as a synchrotron light source in user operation and for accererator physics research. At a dedicated beamline, experiments with (sub-)THz radiation are carried out. Here, an interaction of short laser pulses with electron bunches is used to modulate the electron energy which causes the formation of a dip in the longitudinal electron density, giving rise to the coherent emission of radiation between 75 GHz and 6 THz. The standard mode of operation is the generation of broadband radiation. However, more sophisticated energy modulation schemes were implemented using a liquid-crystal phase modulator. Here, a modulation of the spectral phase of the laser is used to control the spectral shape of the THz pulses. The resulting THz spectra have a relative bandwidth of about 2 %. Measurement results from the different THz generation schemes are presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB097

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paper received ※ 18 May 2021 paper accepted ※ 12 July 2021 issue date ※ 24 August 2021

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THPAB131

Spatio-Temporal Measurements of THz Pulses

electron, polarization, laser, FEM

4021

G.A. Hine
ORNL, Oak Ridge, Tennessee, USA

Funding: This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory under Contract No. DEAC05-00OR22725.
The 3D characterization of single-cycle Terahertz (THz) pulses in its transverse and temporal dimensions is presented. The high fields and short wavelengths of THz pulses make them an intriguing prospect for novel accelerator technologies. Effective application for free-space THz pulses requires high beam quality and concomitant measuring techniques. The combination of conventional electro-optic sampling to measure the temporal profile and detectors like microbolometer focal plane arrays to measure the transverse profile does not capture the correlations that can arise in single-cycle THz pulses. To capture these correlations, a modified version electro-optic sampling using a CCD is implemented. THz pulses generated by optical rectification in organic crystals are measured using this technique and their spatiotemporal correlations characterized.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB131

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paper received ※ 19 May 2021 paper accepted ※ 14 July 2021 issue date ※ 17 August 2021

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THPAB209

Tracking Complex Re-Circulating Machines with PLACET2

wakefield, synchrotron-radiation, electron, synchrotron

4197

R.A.J. Costa, A. Latina
CERN, Geneva, Switzerland

We present the latest version of the multi-particle tracking package PLACET2. This software was designed to track multiple electron bunches through re-circulating machines with complex topologies, such as the recombination complex of the Compact Linear Collider (CLIC), energy-recovery linacs such as the Large Hadron-Electron Collider (LHeC), racetracks and others. This update also expands the capabilities of PLACET2 to track heavier particles such as muons. In addition to simulation, PLACET2 was also developed to allow beamline optimization scans, evaluating beam properties and tuning the beamline parameters at runtime either standalone or accessing the optimization tools present in the Octave and Python packages, with which it interfaces. This paper presents and benchmarks PLACET2’s latest features, such as coherent and incoherent synchrotron radiation, long and short wakefields and power extraction.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB209

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paper received ※ 18 May 2021 paper accepted ※ 13 July 2021 issue date ※ 27 August 2021

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THPAB214

Recent BDSIM Related Developments and Modeling of Accelerators

laser, simulation, experiment, shielding

4208

L.J. Nevay, A. Abramov, S.E. Alden, S.T. Boogert, G. D’Alessandro, S.M. Gibson, H. Lefebvre, W. Shields, S.D. Walker
JAI, Egham, Surrey, United Kingdom
A. Abramov, G. D’Alessandro, C. Hernalsteens
CERN, Meyrin, Switzerland
E. Gnacadja, C. Hernalsteens, E. Ramoisiaux, R. Tesse
ULB, Bruxelles, Belgium
S. Liu
DESY, Hamburg, Germany

Funding: This work is supported by the STFC (UK) grants: JAI ST/P00203X/1, HL-LHC-UK1 ST/N001583/1, HL-LHC-UK2 ST/T001925/1, and ST/P003028/1.
Beam Delivery Simulation (BDSIM) is a program based on Geant4 that creates 3D radiation transport models of accelerators from a simple optical description in a vastly reduced time frame with great flexibility. It also uses ROOT and CLHEP to create a single simulation model that can accurately track all particle species in an accelerator to predict and understand beam losses, secondary radiation, dosimetric quantities and their origin. BDSIM provides a library of scalable generic geometry for a variety of applications. Our Python package, Pyg4ometry, allows rapid preparation and conversion of geometries for BDSIM and other radiation transport simulations including FLUKA. We present a broad overview of BDSIM developments related to a variety of experiments at several facilities. We present a model of the forward experiment FASER at the LHC, CERN where the geometry is composited from multiple sources using Pyg4ometry. The analysis of particle history is presented as well as production mechanisms. We also present the application of recently introduced laser interactions in Geant4 to Compton photons from a laserwire diagnostic at the ATF2.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB214

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paper received ※ 20 May 2021 paper accepted ※ 19 July 2021 issue date ※ 22 August 2021

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THPAB249

X-Ray Beam Position Monitor (XBPM) Calibration at NSRC Solaris

controls, photon, undulator, insertion

4292

M. Waniczek, A. Curcio, G.W. Kowalski, R. Panaś, A.I. Wawrzyniak
NSRC SOLARIS, Kraków, Poland

During the installation of Front-ends in sections 4th (XMCD beamline frontend) and 6th (PHELIX beamline frontend) at National Synchrotron Radiation Centre Solaris (NSRC Solaris), two units (one for each front end) of X-ray Beam Position Monitors (XBPM) have been installed as a diagnostic tool enabling for measurement of photon beam position. Hardware units of XBPM were manufactured, delivered, and eventually installed in Solaris by FMB Berlin. In order to get readouts of beam position from XBPM units, Libera Photon 2016 controller has been used as a complementary electronic device. Since XBPM units are supposed to be used along with the insertion device, an on-site Libera calibration was necessary. Libera’s calibration required few iterations of scans involving gap and phase movement of insertion devices at the 4th and 6th sections of the Solaris ring. The main focus was put on the derivation of Kx, and Ky coefficients. The content of this document describes step by step the procedure of Libera’s Kx, Ky coefficients value derivation at NSRC Solaris.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB249

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paper received ※ 19 May 2021 paper accepted ※ 17 July 2021 issue date ※ 13 August 2021

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THPAB284

Analytical and Numerical Characterization of Cherenkov Diffraction Radiation as a Longitudinal Electron Bunch Profile Monitor for AWAKE Run 2

electron, plasma, proton, wakefield

4355

C. Davut, G.X. Xia
UMAN, Manchester, United Kingdom
O. Apsimon
The University of Liverpool, Liverpool, United Kingdom
O. Apsimon
Cockcroft Institute, Warrington, Cheshire, United Kingdom
P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
P. Karataev
JAI, Egham, Surrey, United Kingdom
T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland

In this paper, CST simulations of the coherent Cherenkov Diffraction Radiation with a range of parameters for different dielectric target materials and geometries are discussed and compared with the theoretical investigation of the Polarization Current Approach to design a prototype of a radiator for the bunch length/profile monitor for AWAKE Run 2. It was found that the result of PCA theory and CST simulation are consistent with each other regarding the shape of the emitted ChDR cone.
* Karlovets, D. V. (2011). JETP, 113(1), 27-45.
** Shevelev, M. V., & Konkov, A. S. (2014). JETP, 118(4), 501-511.
*** Curcio, A., et al.(2020). PRAB, 23(2), 022802.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB284

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paper received ※ 16 May 2021 paper accepted ※ 14 July 2021 issue date ※ 10 August 2021

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THPAB290

Evolution of the LHC Beam Screen Surface Conditioning Upon Electron Irradiation

electron, ECR, gun, vacuum

4370

S. Bilgen, S. Della-Negra, D. Jacquet, B. Mercier, I. Ribaud, G. Sattonnay
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
V. Baglin
CERN, Meyrin, Switzerland

For the vacuum scientists and the accelerator community, finding solutions to mitigate pressure rises induced by electron, photon, and ion desorption, and also beam instabilities induced by ion and electron clouds is a major issue. Moreover, it is worth noting that the OFE copper beam screen of the LHC is initially cleaned with standard industrial processes, leading to residual chemical contamination. Along the time, changes in the surface chemistry of vacuum chambers are observed during beam operations, leading to modifications of outgassing rates, stimulated desorption processes, and secondary emission yields (SEY). The impact of ions on molecule desorption and electron production was investigated to identify their influence on the global pressure rises and to quantify the ion conditioning effect on copper surfaces: (i) SEY evolution was measured to understand the changes of surface conditioning upon particle irradiation; (ii) surface chemistry evolution after electron irradiation was investigated by both XPS and TOF-SIMS analyses using the ANDROMEDE facility at IJCLab. Finally, the relationship between surface chemistry and the conditioning phenomenon will be discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB290

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paper received ※ 19 May 2021 paper accepted ※ 14 July 2021 issue date ※ 10 August 2021

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THPAB295

Application of CMM Technology in Accelerator Magnet Detection

software, quadrupole, detector, hardware

4381

S. Li, F.S. Chen, C.D. Deng, W. Kang, Y.Q. Liu, X. Wu, Y.W. Wu
IHEP, Beijing, People’s Republic of China

Accelerator magnet is one of the most difficult equipment in accelerator hardware system. With the improvement of physical requirements, more and more high technical requirements are put forward for magnets. This paper mainly introduces the new application of three coordinate measurement technology in the detection of accelerator magnet, and introduces the working process of CMM in the detection of accelerator magnet polar profile.

Poster THPAB295 [0.677 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB295

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paper received ※ 14 May 2021 paper accepted ※ 02 September 2021 issue date ※ 29 August 2021

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THPAB300

Structure Design and Motion Analysis of 6-DOF Sample Positioning Platform

controls, synchrotron-radiation, GUI, synchrotron

4387

G.Y. Wang, J.X. Chen, L. Liu, R.H. Liu, C.J. Ning, A.X. Wang, J.B. Yu, Y.J. Yu, J.S. Zhang
IHEP CSNS, Guangdong Province, People’s Republic of China
L. Kang
IHEP, Beijing, People’s Republic of China

with the development of synchrotron radiation (SR) light source technology, in order to meet the requirements of sample positioning platform of some beamline stations, such as adjusting resolution at the nanometer level and having larger sample scanning distance, a six degree of freedom positioning platform based on spacefab structure was developed. The key technologies such as coordinate parameter transformation, kinematics analysis, and adjustment decoupling algorithm of 6-DOF pose adjustment system of SpaceFAB positioning platform are mainly studied. A 6-DOF platform driven by a stepping motor is designed and manufactured. The control system of the 6-DOF Platform Based on bus control is developed, and the adjustment accuracy is tested. The repeated positioning accuracy of the platform in three directions is 0.019 mm, and that of rotation is 0.011 ° in three directions. The test results verify the correctness of the theoretical analysis of SpaceFAB structure and the rationality of mechanism design. The research on the platform motion algorithm and control system has important reference value for the follow-up research of large stroke nano-6-dof positioning platform.

Poster THPAB300 [1.517 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB300

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paper received ※ 16 May 2021 paper accepted ※ 06 July 2021 issue date ※ 02 September 2021

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THPAB309

New Working Tune Feedback System for TLS

feedback, quadrupole, insertion, insertion-device

4394

S.J. Huang, Y.K. Lin, Y.C. Lin
NSRRC, Hsinchu, Taiwan

TLS storage ring has two sets of working tuning feedback systems: one is used to correct the working tune deviation caused by insertion device U90; another system uses a local trim coil to correct the working tune deviation caused by all insertion devices. This article describes a new working tune feedback system in TLS that can correct the working tune effectively back to the required conditions for operation; the two existing feedback systems do not cause problems. We can both avoid increasing the local radiation dose and decreasing the injection efficiency.

Poster THPAB309 [0.831 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB309

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paper received ※ 15 May 2021 paper accepted ※ 02 July 2021 issue date ※ 23 August 2021

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THPAB318

Uniformization of the Transverse Beam Profile with Nonlinear Magnet

target, HOM, synchrotron, extraction

4413

Y. Li, X. Guan, X.Y. Liu, X.W. Wang, Q.Z. Xing, Y. Yang, H.J. Yao, W.B. Ye, S.X. Zheng
TUB, Beijing, People’s Republic of China
Y. Yang
NINT, Shannxi, People’s Republic of China

The beam generated after slow extraction of the synchrotron is always not uniform and asymmetrical in transverse distribution. In practice, radiation therapy or radiation irradiation requires a high degree of uniformity of beam spot. Therefore, it is necessary to adjust the beam distribution with a nonlinear magnet and other elements on the transport line from synchrotron ring to beam target station. Nonlinear magnet has high requirements on beam quality. Before passing through the nonlinear magnet field, the beam center can be adjusted by taking advantage of the gradient change distribution of the nonlinear magnet’s transverse field map to achieve uniform distribution at the target station. As an example, we use the parameters of heavy ions of XiPAF (Xi’an 200MeV Proton Application Facility) to simulate the beam transport from synchrotron ring to beam target station.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB318

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paper received ※ 20 May 2021 paper accepted ※ 08 July 2021 issue date ※ 21 August 2021

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THPAB335

Optical Phase Space Mapping Using a Digital Micro-Mirror Device

experiment, GUI, optics, controls

4439

M. Vujanovic, R.B. Fiorito, C.P. Welsch, J. Wolfenden
The University of Liverpool, Liverpool, United Kingdom
A.L. Kippax
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This project has received funding from European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 721559.
Optical transition radiation (OTR) is routinely used to measure transverse beam size, divergence , and emittance of charged particle beams. Presented here is an experimental method, which uses micro-mirror device (DMD) to conduct optical phase space mapping (OPSM). OPSM will be a next step and significant enhancement of the measurements capabilities of an adaptive optics-based beam characterization system. For this measurements, a DMD will be used to generate a reflective mask that replicates the double slit. Since the DMD makes it possible to easily change the size, shape and position of the mask, the use of the DMD will greatly simplify OPSM and make it more flexible, faster and more useful for diagnostics applications. The process can be automated and integrated into a control system that can be used to optimize the beam transport.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB335

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paper received ※ 20 May 2021 paper accepted ※ 27 July 2021 issue date ※ 28 August 2021

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THPAB356

Progress and Status on Civil Construction of the SIS100 Accelerator Building

site, controls, status, HOM

4493

M. Draisbach, N. Pyka, P.J. Spiller
GSI, Darmstadt, Germany
J. Blaurock, M. Ossendorf
FAIR, Darmstadt, Germany

Besides the accelerator machine itself, civil construction of the accelerator ring tunnel building in the northern area of the FAIR campus is a core activity of the rapidly progressing FAIR project. It will facilitate and supply the future SIS100 accelerator at 17m underground level and has been growing continuously and according to schedule since groundbreaking in 2017. This contribution presents the current status of the civil construction progress and gives an optimistic forecast for the preparation of machine installation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB356

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paper received ※ 20 May 2021 paper accepted ※ 06 July 2021 issue date ※ 15 August 2021

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THPAB372

SABINA: A Research Infrastructure at LNF

laser, experiment, electron, focusing

4505

L. Sabbatini, D. Alesini, M.P. Anania, M. Bellaveglia, A. Biagioni, B. Buonomo, S. Cantarella, F. Cardelli, E. Chiadroni, G. Costa, G. Di Pirro, F. Dipace, A. Esposito, M. Ferrario, M. Galletti, A. Gallo, A. Ghigo, L. Giannessi, A. Giribono, S. Incremona, L. Pellegrino, L. Piersanti, R. Pompili, R. Ricci, J. Scifo, A. Stecchi, A. Stella, C. Vaccarezza, A. Vannozzi, S. Vescovi, F. Villa
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
A. Cianchi
INFN-Roma II, Roma, Italy
A. Doria, A. Petralia
ENEA C.R. Frascati, Frascati (Roma), Italy
L. Giannessi
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
S. Lupi
Sapienza University of Rome, Roma, Italy
S. Macis
La Sapienza University of Rome, Rome, Italy
V. Petrillo
Universita’ degli Studi di Milano, Milano, Italy
V. Petrillo
INFN-Milano, Milano, Italy

Funding: SABINA is a project co-funded by Regione Lazio within POR-FESR 2014-2020 program.
SABINA (Source of Advanced Beam Imaging for Novel Applications) is a project aimed at the enhancement of the SPARC_LAB research facility. This enhancement is carried out through the following actions: first, the increase of the uptime through the consolidation of technological systems and the replacement of some critical equipment in order to limit the number and extent of faults; then, the improvement of the accelerator performances, by replacing some devices with updated ones. The effect will be greater reliability of the accelerator, which will allow it to be opened as a facility for external users, both industrial and scientific, with the goal of increasing the competitiveness of industries in a broad range of technological areas and enhancing collaborations with research institutions. The two user lines that will be implemented are a power laser target area and a THz radiation line, by using a dedicated undulator. The undulator and the THz line are also described in other contributions to this conference. A brief description of the project and potential exploitations are reported.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB372

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paper received ※ 24 May 2021 paper accepted ※ 01 July 2021 issue date ※ 20 August 2021

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