IPAC2021 - List of Keywords (kicker)

Paper	Title	Other Keywords	Page
MOPAB009	Review of the Fixed Target Operation at RHIC in 2020	target, experiment, operation, controls	69
	C. Liu, P. Adams, E.N. Beebe, S. Binello, I. Blackler, M. Blaskiewicz, K.A. Brown, D. Bruno, B.D. Coe, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, K. Hock, H. Huang, R.L. Hulsart, T. Kanesue, D. Kayran, N.A. Kling, B. Lepore, Y. Luo, D. Maffei, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, J. Morris, C. Naylor, S. Nemesure, M. Okamura, I. Pinayev, S. Polizzo, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, P. Thieberger, M. Valette, A. Zaltsman, I. Zane, K. Zeno, W. Zhang BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. As part of the Beam Energy Scan (BES) physics program, RHIC operated in Fixed Target mode at various beam energies in 2020. The fixed target experiment, achieved by scraping the beam halo of the circulating beam on a gold ring inserted in the beam pipe upstream of the experimental detectors, extends the range of the center-of-mass energy for BES. The machine configuration, control of rates, and results of the fixed target experiment operation in 2020 will be presented in this report.
	Poster MOPAB009 [2.913 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB009
About •	paper received ※ 16 May 2021 paper accepted ※ 17 August 2021 issue date ※ 23 August 2021
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MOPAB017	Influence of Injection Kicker Post-pulses on Storage of Ion Stack in NICA Collider	electron, injection, collider, betatron	93
	E. Syresin, A. Tuzikov, N.O. Zagibin JINR, Dubna, Moscow Region, Russia
	The peculiarity of the injection kicker power supply in NICA collider is related to same post pulse of the magnetic field which is appeared after a regular injection pulse. The magnetic field of this post pulse became to an increase of the stack ion angle spread during each injection cycle. When the stack ion angles reaches the acceptance angle the ions are lost in the collider. Influence of the injection kicker post pulse on the storage of the ion stack is considered in this paper in presence of the electron cooling and ion electron recombination losses.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB017
About •	paper received ※ 17 May 2021 paper accepted ※ 20 May 2021 issue date ※ 13 August 2021
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MOPAB026	RHIC Delayed Abort Experiments	experiment, injection, quadrupole, dipole	126
	M. Valette, D. Bruno, K.A. Drees, K.M. Hartmann, G. Heppner, K. Mernick, C. Mi, J.-L. Mi, R.J. Michnoff, J. Morris, F. Orsatti, E. Rydout, T. Samms, J. Sandberg, V. Schoefer, C. Schultheiss, T.C. Shrey, C. Theisen BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. For RHIC to operate at its top energy (100 GeV/n) while protecting the future sPHENIX detector, spontaneous and asynchronous firing of abort kicker modules (pre-fires) have to be avoided. A new triggering circuit for the abort kickers was implemented with relatively slow mechanical relays in series with the standard fast thyratron tubes. The relays prevents unwanted pre-fires during operation, but comes at the expense of a long latency - about 7 milliseconds - between the removal of beam permit and the actual firing of the abort kickers. Protection considerations of RHIC’s superconducting magnets forbid delaying energy extraction from the main dipoles and quadrupoles for too long after a quench. The beam has thus to circulate in both RHIc rings for a few milliseconds as the current in dipole and quadrupole circuit is being extracted. We present the results of delayed abort experiments conducted in July 2018 with the analysis of fast orbit and tune measurements and discuss the safety implications of this implementation for future RHIC operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB026
About •	paper received ※ 19 May 2021 paper accepted ※ 26 May 2021 issue date ※ 23 August 2021
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MOPAB073	Beam Loss Simulations During Beam Dumping in Heps	lattice, simulation, dumping, photon	294
	X. Cui, Y. Jiao, Y.L. Zhao IHEP, Beijing, People’s Republic of China
	The High Energy Photon Source (HEPS) is a 6 GeV storage ring light source under construction in China. Several collimators installed in the vacuum chamber will be used as beam dump in the storage ring operation. Preliminary simulations showed that the temperature rise caused by the beam power deposited on the collimators will far exceed the melting point of the collimator material. In order to cure this problem, special kickers are proposed to be installed in the ring to modulate the beam during beam dumping, thereby increasing the size of the beam hit on the collimators. In this article, some simulation results of the density of particles on the collimators during beam dumping for different HEPS lattice and different kicker parameters are shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB073
About •	paper received ※ 17 May 2021 paper accepted ※ 07 June 2021 issue date ※ 31 August 2021
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MOPAB081	Feasibility Study of Using Multipole Injection Kicker (MIK) and Sextupole for TPS Injection	injection, sextupole, storage-ring, GUI	312
	C.-S. Fann, C.K. Chan, C.-C. Chang, H.-P. Chang, Y.-S. Cheng, M.-S. Chiu, Y.L. Chu, K.T. Hsu, S.Y. Hsu, K.H. Hu, J.C. Huang, C.-S. Hwang, S.H. Lee, K.-K. Lin, C.Y. Wu, C.S. Yang NSRRC, Hsinchu, Taiwan S.-Y. Lee Indiana University, Bloomington, Indiana, USA
	Feasibility of applying MIK/sextupole injection at TPS is evaluated in this study. This study adopts layout similar to MAX IV injection scheme and their collaboration project with SOLEIL for MIK. Although the light source service fulfills present user needs, yet the increasing demands for a transparent injection is inevitable in the foreseeable future. Notice that this preliminary study is constrained under routine user operation, the optional pinger ceramic chamber, located between existing injection kicker-3 and kicker-4, is chosen for the purpose. Kick strength requirement of the MIK is estimated with minor trajectory adjustment upstream at the booster to storage ring transfer line. Since the realization of MIK fabrication takes time, therefore a fast-built sextupole is prepared to examine the proposed injection scheme beforehand. The test result will be described in this report.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB081
About •	paper received ※ 17 May 2021 paper accepted ※ 20 May 2021 issue date ※ 21 August 2021
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MOPAB082	Implementation of Using IGBT Switch Based Pulser for TPS Booster Extraction Kicker	extraction, booster, injection, operation	315
	C.-S. Fann, H.-P. Chang, C.L. Chen, Y.-S. Cheng, K.T. Hsu, S.Y. Hsu, K.-K. Lin, K.L. Tsai, C.Y. Wu NSRRC, Hsinchu, Taiwan
	A pair of thyratron-switch-based pulse-forming-network (PFN) pulser has been operating successfully in the past 5 years for TPS booster extraction kickers. In order to improve the flattop of drive-current pulse and to extend possible electron bunch train adjusting knob required, an IGBT-switch-based pulser has been designed, fabricated, and installed onto the TPS booster for its characteristics verification. In this report, the overall technical considerations for the pulser upgrade is described and its beam commissioning results is given for illustration purpose.
	Poster MOPAB082 [0.621 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB082
About •	paper received ※ 20 May 2021 paper accepted ※ 27 May 2021 issue date ※ 13 August 2021
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MOPAB087	Design of a Multi-Bunch Feedback Kicker in SPEAR3	impedance, simulation, coupling, feedback	327
	K. Tian, J.B. Langton, NL. Parry, J.A. Safranek, J.J. Sebek SLAC, Menlo Park, California, USA
	The new Multi-bunch feedback kickers have been designed to replace the current device loaned from ALS. In this paper, we first present the specification of the kickers based on the beam physics requirements. Then the mechanical design of the kicker is elaborated. Numerical simulations, both in time domain and in frequency domain, are conducted for evaluating the shunt impedance and beam coupling impedance of the kicker. Surface heating induced from the beam or the external source is estimated from the numerical results as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB087
About •	paper received ※ 19 May 2021 paper accepted ※ 11 June 2021 issue date ※ 01 September 2021
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MOPAB114	Development of a Decoherence Kicker for the ALS Upgrade Project (ALS-U)	storage-ring, extraction, vacuum, injection	414
	C. Sun, S. De Santis, M.P. Ehrlichman, T. Hellert, T. Oliver, G. Penn, C. Steier, M. Venturini, W.L. Waldron LBNL, Berkeley, California, USA
	The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is upgrading the existing storage-ring lattice to a nine-bend-achromat lattice with on-axis swap-out injection. The upgraded storage ring will provide a highly focused beam of about 10 um in both horizontal and vertical directions with a single bunch train energy of about 60 J at 2.0 GeV. Such a small and intense beam could cause damage to the transfer line vacuum chambers in case of extraction element failures or damage to the storage ring vacuum chamber in case of RF failures. To mitigate these potential damages, a fast kicker magnet (so-called decoherence kicker) will be installed in the ALS-U storage ring and activated to dilute the beam charge density either on a train to be swapped out a few 100s turns before extraction or on the whole beam after RF failures. In this paper, we will present both physics and engineering designs of this decoherence kicker.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB114
About •	paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 20 August 2021
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MOPAB115	ATS/STA Transfer Line Design for the ALS Upgrade Project (ALS-U)	injection, storage-ring, optics, extraction	417
	C. Sun, M.P. Ehrlichman, T. Hellert, M. Juchno, J.-Y. Jung, M. Mardenfeld, J.R. Osborn, G. Penn, C. Steier, C.A. Swenson, M. Venturini LBNL, Berkeley, California, USA
	At the Advanced Light Source Upgrade (ALS-U), an on-axis swap-out injection will be used to replenish depleted bunches in the storage ring with refreshed bunches from the full energy accumulator ring. To implement this scheme, two transfer lines are required between the storage ring and the accumulator ring: the accumulator-to-storage-ring (ATS) transfer line and the storage-ring-to-accumulator (STA) transfer line. The design of the ATS/STA transfer lines is a challenging task as they must fit within a tight injection region while also accommodating the storage and accumulator rings at different elevations. Moreover, the ATS/STA design needs to meet both the boundary conditions and optics requirements. In this paper, we will present a design option for these ATS/STA transfer lines.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB115
About •	paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 15 August 2021
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MOPAB116	A Flexible Injection Scheme for the ESRF-EBS	injection, SRF, septum, storage-ring	421
	S.M. White, N. Carmignani, L.R. Carver, M. Dubrulle, L. Hoummi, S.M. Liuzzo, M. Morati, T.P. Perron ESRF, Grenoble, France
	The ESRF-EBS storage ring light source started commissioning in 2019 and successfully resumed users operation in 2020. Due to the smaller emittance and consequently reduced lifetime frequent injections are required that can potentially disturb beam lines experiments. In addition, operating the machine with low beta straight section and reduced insertion devices (ID) gaps are considered, therefore reducing the vertical aperture of the machine. Alternatives to the standard off-axis injection scheme allowing for efficient injection in reduced apertures with minimized perturbations are explored. A flexible layout for potential integration in the ESRF-EBS lattice is proposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB116
About •	paper received ※ 11 May 2021 paper accepted ※ 27 May 2021 issue date ※ 24 August 2021
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MOPAB118	The Impact of Short-Range Wakes on Injection Into the ALS-U Accumulator Ring	injection, wakefield, electron, booster	429
	G. Penn, M.P. Ehrlichman, T. Hellert, C. Steier, C. Sun, M. Venturini, D. Wang LBNL, Berkeley, California, USA
	Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DEAC02-05CH11231. As part of the ALS-U design, bunches with small charge will be added to the accumulator ring in a manner that initially leaves both the stored and injected bunches displaced from the nominal orbit. While the beam current is below instability thresholds, transient effects due to the combination of short-range wake fields and large initial displacements can have an impact on injection efficiency. In this paper, the impact of wake fields on the two bunches is detailed using the elegant simulation code, and different techniques to optimize the injection efficiency are explored.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB118
About •	paper received ※ 19 May 2021 paper accepted ※ 31 May 2021 issue date ※ 12 August 2021
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MOPAB128	Operational Use of Pinger Magnets to Counter Stored Beam Oscillations During Injection at Diamond Light Source	injection, operation, diagnostics, storage-ring	459
	R.T. Fielder, M. Apollonio, I.P.S. Martin DLS, Oxfordshire, United Kingdom
	Diamond uses a four kicker bump injection scheme. Due to a variety of factors it has become more difficult to perfectly match the four kicks while maintaining injection efficiency, resulting in some disturbance to the stored beam during top-up. This has consequences for beamlines which may see degraded beam quality during injections. A gating signal is provided, but this is not appropriate for all experiments, and in any case ideally would not be required. The disturbance to the stored beam can be partly controlled using the existing diagnostic pinger magnets installed in the storage ring. We present here a comparison of different compensation schemes and tests with beamlines, along with initial experiences operating during user beam time. Use of these magnet also provides proof of principle for any future, purpose-built compensation kickers.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB128
About •	paper received ※ 18 May 2021 paper accepted ※ 20 May 2021 issue date ※ 01 September 2021
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MOPAB213	Characterization of Linear Optics and Beam Parameters for the APS Booster with Turn-by-Turn BPM Data	booster, betatron, synchrotron, optics	703
	X. Huang, H. Shang, C. Yao ANL, Lemont, Illinois, USA
	We take turn-by-turn (TBT) BPM data on the energy ramp of the APS Booster, and analyze the data with the independent component analysis. The extraction kicker was used to excite the betatron motion. The linear optics of the machine is characterized with the TBT BPM data. We also analyze the decoherence pattern of the kicked beam, from which we are able to derive beam distribution parameters, such as the momentum spread.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB213
About •	paper received ※ 13 May 2021 paper accepted ※ 11 June 2021 issue date ※ 19 August 2021
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MOPAB221	Developments of a Pulse Kicker System for the Three-Dimensional Spiral Beam Injection of the J-PARC Muon g-2/EDM Experiment	injection, experiment, power-supply, solenoid	726
	K. Oda, H. Hirayama, H. Iinuma, Y. Sato, M. Sugita Ibaraki University, Ibaraki, Japan M. Abe, K. Furukawa, T. Mibe, H. Nakayama, S. Ohsawa, M.A. Rehman, N. Saito, K. Sasaki KEK, Ibaraki, Japan R. Matsushita The University of Tokyo, Graduate School of Science, Tokyo, Japan
	The J-PARC muon g-2/EDM experiment aims to perform ultra-precise measurements of anomalous magnetic moments (g-2) and electric dipole moments (EDM) from the spin precession of muons in a precise magnetic field and to explore new physics beyond the Standard Model. On experimental requirements, the beam must be stored in a compact storage orbit with a diameter of 66 cm, which is about 1/20th smaller than that of the previous experiment. To be realized, we adopt an unprecedented injection technique called the three-dimensional spiral injection scheme. In this scheme, the beam is injected from upward of the solenoidal storage magnet. The vertical beam motion along the solenoid axis is controlled by a few 100 ns pulse kicker. Once the beam is guided into the center fiducial storage volume, the muon beam is stored by the weak focusing magnetic field. Therefore, stable and accurate control of the pulse kicker is one of the major technical challenges to realize the ultra-precise measurement of the muon spin precession. In this presentation, we discuss the performance of the prototype pulse kicker device and future plan for installation of it to our test bench with an electron beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB221
About •	paper received ※ 20 May 2021 paper accepted ※ 31 May 2021 issue date ※ 15 August 2021
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MOPAB256	Development of Pulsed Beam System for the Three Dimensional Spiral Injection Scheme in the J-PARC muon g-2/EDM Experiment	injection, experiment, power-supply, controls	809
	R. Matsushita The University of Tokyo, Graduate School of Science, Tokyo, Japan M. Abe, K. Hurukawa, T. Mibe, H. Nakayama, S. Ohsawa, M.A. Rehman, N. Saito, K. Sasaki KEK, Ibaraki, Japan H. Hirayama, H. Iinuma, K. Oda, Y. Sato, M. Sugita Ibaraki University, Ibaraki, Japan N. Saito J-PARC, KEK & JAEA, Ibaraki-ken, Japan T. Takayanagi JAEA/J-PARC, Tokai-mura, Japan
	The J-PARC muon g-2/EDM experiment aims to measure the anomalous magnetic moment(g-2) and electric dipole moment(EDM) of the muon with higher precision than the previous BNL E821 experiment. A brand-new three-dimensional spiral injection scheme is employed to inject and store muon beam into a 66 cm diameter of storage magnet. Feasibility studies are ongoing by use of 80 keV electron beam at KEK test bench, to develop skills on control transverse beam motion; so-called X-Y coupling, with DC beam. As a next step, towards store the beam by use of a kicker system, a pulsed beam should be generated from the DC beam with an intended time structure to meet a pulse kicker’s duration time, without changing transverse phase space characteristics. In this presentation, the development of a beam chopper device and the evaluation of pulse beam profile are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB256
About •	paper received ※ 20 May 2021 paper accepted ※ 15 June 2021 issue date ※ 16 August 2021
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MOPAB331	Design Consideration of a Longitudinal Kicker Cavity for Compensating Transient Beam Loading Effect in Synchrotron Light Sources	cavity, resonance, coupling, impedance	1027
	D. Naito, S. Sakanaka, T. Takahashi, N. Yamamoto KEK, Ibaraki, Japan T. Yamaguchi Sokendai, Ibaraki, Japan
	In ultra-low-emittance synchrotron light sources, bunch-lengthening using the combination of main and harmonic cavities is limited by the transient beam-loading (TBL) effect which is caused by gaps in the fill pattern. To manage this effect, we proposed a TBL compensation technique using a wide-band longitudinal kicker cavity. In the future KEK-LS storage ring, for example, the kicker cavity should provide a compensation voltage of 50 kV with a -3dB bandwidth (BW) of about 5 MHz, as well as its higher-order modes (HOM) should be damped sufficiently. In this presentation, we report our conceptual design of the kicker cavity. We employed the single-mode (SM) cavity concept so that harmful HOMs are dumped by rf absorbers on the beam pipes. The distinctive feature of the SM cavity is its simple structure since it has no HOM damper on the cavity. Another feature is its low R/Q by which the TBL effect in the kicker cavity itself can be reduced significantly. We employed a frequency of 1.5 GHz (third-harmonic) and R/Q of 60 orms through optimizations. Using this kicker cavity with a double rf system, a bunch lengthening by a factor of 4.3 (i.e., 40.9 ps) is expected for the KEK-LS case. N.Yamamoto et al., Phys. Rrev. Acc. Beams 21, 012001 (2018)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB331
About •	paper received ※ 19 May 2021 paper accepted ※ 11 June 2021 issue date ※ 01 September 2021
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TUPAB019	A High-Resolution, Low-Latency, Bunch-by-Bunch Feedback System for Nano-Beam Stabilization	feedback, cavity, dipole, collider	1378
	R.L. Ramjiawan, D.R. Bett, N. Blaskovic Kraljevic, T. Bromwich, P. Burrows, G.B. Christian, C. Perry JAI, Oxford, United Kingdom D.R. Bett CERN, Geneva, Switzerland N. Blaskovic Kraljevic ESS, Lund, Sweden G.B. Christian DLS, Oxfordshire, United Kingdom
	A low-latency, bunch-by-bunch feedback system employing high-resolution cavity Beam Position Monitors (BPMs) has been developed and tested at the Accelerator Test Facility (ATF2) at the High Energy Accelerator Research Organization (KEK), Japan. The feedback system was designed to demonstrate nanometer-level vertical stabilization at the focal point of the ATF2 and can be operated using either a single BPM to provide local beam stabilization, or by using two BPMs to stabilize the beam at an intermediate location. The feedback correction is implemented using a stripline kicker and the feedback calculations are performed on a digital board constructed around a Field Programmable Gate Array (FPGA). The feedback performance was tested with trains of two bunches, separated by 280ns, at a charge of ~1nC, where the vertical offset of the first bunch was measured and used to calculate the correction to be applied to the second bunch. The BPMs have been demonstrated to achieve an operational resolution of ~20nm. With the application of single-BPM and two-BPM feedback, beam stabilization of below 50nm and 41nm respectively has been achieved with a latency of 232ns.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB019
About •	paper received ※ 18 May 2021 paper accepted ※ 09 June 2021 issue date ※ 14 August 2021
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TUPAB020	A Sub-Micron Resolution, Bunch-by-Bunch Beam Trajectory Feedback System and Its Application to Reducing Wakefield Effects in Single-Pass Beamlines	feedback, wakefield, electron, cavity	1382
	D.R. Bett, P. Burrows, C. Perry, R.L. Ramjiawan JAI, Oxford, United Kingdom D.R. Bett CERN, Geneva, Switzerland K. Kubo, T. Okugi, N. Terunuma KEK, Ibaraki, Japan
	A high-precision intra-bunch-train beam orbit feedback correction system has been developed and tested at the KEK Accelerator Test Facility, ATF2. The system uses the vertical position of the bunch measured at two beam position monitors to calculate a pair of kicks which are applied to the next bunch using two upstream kickers, thereby correcting both the vertical position and trajectory angle. Using trains of two electron bunches separated in time by 187.6ns, the system was optimised so as to stabilize the beam offset at the feedback BPMs to better than 350nm, yielding a local trajectory angle correction to within 250nrad. The quality of the correction was verified using three downstream witness BPMs and the results were found to be in agreement with the predictions of a linear lattice model used to propagate the beam trajectory from the feedback region. This same model predicts a corrected be am jitter of c.1nm at the focal point of the accelerator. Measurements with a beam size monitor at this location demonstrate that reducing the trajectory jitter of the beam by a factor of 4 also reduces the increase in the measured beam size as a function of beam charge by a factor of ~1.6.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB020
About •	paper received ※ 13 May 2021 paper accepted ※ 01 July 2021 issue date ※ 11 August 2021
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TUPAB044	Preliminary Study of the on-Axis Swap-Out Injection Scheme for the Southern Advanced Photon Source	injection, storage-ring, septum, electron	1447
	Y. Han, X.H. Lu, Y. Zhao IHEP CSNS, Guangdong Province, People’s Republic of China L. Huang, Y. Jiao, X. Liu, S. Wang IHEP, Beijing, People’s Republic of China
	The Southern Advanced Photon Source (SAPS) is a project under design, which aims at constructing a 4th generation storage ring with emittance below 100 pm.rad at the electron beam energy of around 3.5 GeV. The extremely low emittance will result in a very small dynamic aperture for the storage ring which makes it difficult to use the conventional off-axis accumulation injection. In this case, it is probably necessary to consider the transverse on-axis injection or the longitudinal injection. In this paper, the transverse on-axis swap-out injection scheme for the SAPS storage ring is presented. The preliminary parameters of the septum magnets and fast kickers are carefully evaluated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB044
About •	paper received ※ 17 May 2021 paper accepted ※ 10 June 2021 issue date ※ 27 August 2021
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TUPAB058	Online Optimizations of Several Observable Parameters at the Advanced Photon Source	injection, storage-ring, photon, sextupole	1492
	Y.P. Sun ANL, Lemont, Illinois, USA
	Funding: The work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Online optimizations are known to be powerful tools which may quickly and efficiently improve the particle accelerator key performance parameters in a model-independent way. In this paper, it is presented on the online optimizations of several observable parameters at the Advanced Photon Source storage ring. These observable parameters include the beam lifetime, injection efficiency and topup efficiency, transverse beam sizes, and turn by turn beam position monitors. It is demonstrated that the particle accelerator performance may be greatly enhanced in a relatively short time frame, by optimizing these observable parameters.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB058
About •	paper received ※ 20 May 2021 paper accepted ※ 24 June 2021 issue date ※ 16 August 2021
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TUPAB080	Design and Status of the Beam Switchyard of the Shanghai Soft X-Ray FEL User Facility	FEL, electron, undulator, linac	1559
	S. Chen, R. Wang SSRF, Shanghai, People’s Republic of China H.X. Deng, C. Feng, X. Fu, B. Liu SARI-CAS, Pudong, Shanghai, People’s Republic of China
	SXFEL-UF, a soft X-ray FEL user facility located in Shanghai, has been upgraded from the existing test facility. Electron energy increases from 840 MeV to 1.5 GeV and a SASE FEL line will be added besides the existing seeding FEL line. It has started commissioning since early this year. In order for simultaneous operation of the two FEL lines, a beam switchyard is built between the linac and the two FEL lines. In this paper, the physics design of the beam switchyard is described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB080
About •	paper received ※ 19 May 2021 paper accepted ※ 11 June 2021 issue date ※ 20 August 2021
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TUPAB081	Design of the Beam Distribution System of SHINE	undulator, linac, electron, septum	1562
	S. Chen, M. Gu, R. Wang SSRF, Shanghai, People’s Republic of China H.X. Deng, X. Fu SARI-CAS, Pudong, Shanghai, People’s Republic of China
	In shanghai, a hard X-ray free electron laser project named SHINE is under design. It will be based on a superconducting linac running in CW mode. On the first stage, there will be three parallel undulator lines downstream the linac. For simultaneous operation of the three undulator lines, a beam distribution system based on fast kickers will be installed between linac and undulator lines. The physics design of this beam distribution system is described in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB081
About •	paper received ※ 19 May 2021 paper accepted ※ 14 June 2021 issue date ※ 22 August 2021
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TUPAB179	Design of an MBEC Cooler for the EIC	electron, proton, hadron, simulation	1819
	W.F. Bergan, P. Baxevanis, M. Blaskiewicz, E. Wang BNL, Upton, New York, USA G. Stupakov 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. Reaching maximal luminosity for the planned electron-ion collider (EIC) calls for some form of strong hadron cooling to counteract beam emittance increase from IBS. We discuss plans to use microbunched electron cooling (MBEC) to achieve this. The principle of this method is that the hadron beam will copropogate with a beam of electrons, imprinting its own density modulation on the electron beam. These electron phase space perturbations are amplified before copropogating with the hadrons again in a kicker section. By making the hadron transit time between modulator and kicker dependent on hadron energy and transverse offset, the energy kicks which they receive from the electrons will tend to reduce their longitudinal and transverse emittances. We discuss details of the analytic theory and searches for optimal realistic parameter settings to achieve a maximal cooling rate while limiting the effects of diffusion and electron beam saturation. We also place limits on the necessary electron beam quality. These results are corroborated by simulations.
	Poster TUPAB179 [4.006 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB179
About •	paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 24 August 2021
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TUPAB180	Plasma Simulations for an MBEC Cooler for the EIC	electron, hadron, simulation, proton	1823
	W.F. Bergan 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. In order to reach its maximum luminosity, the electron-ion collider (EIC) is being designed to use microbunched electron cooling (MBEC) to cool the hadron beam. This involves having the hadron beam imprint on a beam of electrons, enhancing the perturbations in the electron beam using the microbunching instability, and feeding back on the original hadron beam to correct deviations in hadron energy, and, through the use of dispersion, the transverse emittances. This process has been modelled analytically in the linear regime. However, in order to maximize the cooling rate, we wish to know how much saturation in the electron beam is acceptable before the effects of nonlinearity cause significant deviations from the analytic results. To understand this, we have developed a code to do fast one-dimensional plasma simulations of hadrons and electrons as they move through the MBEC section of the EIC. In addition to permitting us to understand the effects of saturation, other effects are included which do not fit easily in the analytic formalism. G. Stupakov and P. Baxevanis, PRAB 22, 034401 (2019).
	Poster TUPAB180 [1.955 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB180
About •	paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 18 August 2021
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TUPAB287	Application of Artificial Neural Network in the APS Linac Bunch Charge Transmission Efficiency	linac, operation, controls, photon	2155
	H. Shang, R. Maulik, Y. Sun ANL, Lemont, Illinois, USA T. Xu Northern Illinois University, DeKalb, Illinois, USA
	Funding: * Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. In recent years there has been a rapid growth in machine learning (ML) and artificial intelligence (AI) applications in accelerators. As the scale of complexity and sophistication of modern accelerators grows, the difficulties in modeling the machine increase greatly in order to include all the interacting subsystems and to consider the limitation of various diagnostics to benchmark against measurements. Tools based on ML can help substantially in revealing correlations of machine condition and beam parameters that are not easily discovered using traditional physics model-based simulations, reducing machine tuning up time etc among the many possible applications. While at APS we have many excellent tools for the optimization, diagnostics, and controls of the accelerators, we do not yet have ML-based tools established. It is our desire to test ML in our machine operation, optimization, and controls. In this paper, we introduce the application of neural networks to the APS linac bunch charge transmission efficiency.
	Poster TUPAB287 [0.781 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB287
About •	paper received ※ 12 May 2021 paper accepted ※ 16 June 2021 issue date ※ 29 August 2021
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TUPAB299	Tuned Delay Unit for a Stochastic Cooling System at NICA Collider	pick-up, FPGA, controls, collider	2186
	S.V. Barabin, T. Kulevoy, D.A. Liakin, A.Y. Orlov ITEP, Moscow, Russia I.V. Gorelyshev, K.G. Osipov, V.V. Peshkov, A.O. Sidorin JINR/VBLHEP, Dubna, Moscow region, Russia
	Stochastic cooling is one of the crucial NICA (Nuclotron-based Ion Collider fAcility) subsystems. This system requires fine tuning of the response delay to the kicker, for both longitudinal and transverse stochastic cooling systems. The use of a digital delay line allows to add additional features such as a frequency dependent group velocity correction. To analyse the capabilities of the digital delay unit, a prototype of the device was created and tested. The article presents the characteristics of the prototype, its architecture and principle of operation, test results and estimations for the future developments.
	Poster TUPAB299 [0.493 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB299
About •	paper received ※ 17 May 2021 paper accepted ※ 10 June 2021 issue date ※ 16 August 2021
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TUPAB359	Magnetic Field Measurement and Beam Performance Test of Ceramics Chamber with Integrated Pulsed Magnet at KEK-PF	vacuum, experiment, survey, dipole	2352
	Y. Lu Sokendai, Ibaraki, Japan K. Harada, Y. Kobayashi, C. Mitsuda, S. Nagahashi, T. Nogami, T. Obina, R. Takai, H. Takaki, T. Uchiyama, A. Ueda KEK, Ibaraki, Japan
	An air-core magnet named Ceramics Chamber with integrated Pulsed Magnet(CCiPM) is being developed at the photon factory of KEK(KEK-PF), which will have several applications for the future light source. One prototype has been developed as a dipole kicker, whose bore is only 30mm. Due to the type and structure, it’s expected to have strong magnetic field and high repetition rate. After finishing the offline measurement of magnetic field and evaluation of vacuum tightness, the CCiPM was installed in the beam transport-dump line of PF to have an online beam performance and durability test. The results of the magnetic field measurement and beam performance test will be reviewed.
	Poster TUPAB359 [1.164 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB359
About •	paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 16 August 2021
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TUPAB400	Manufacturing of Ceramic Vacuum Chambers for Sirius On-Axis Kicker	vacuum, HOM, niobium, target	2457
	R. Defavari, O.R. Bagnato, M.W.A. Feitosa, F.R. Francisco, D.Y. Kakizaki, R.L. Parise, R.D. Ribeiro LNLS, Campinas, Brazil
	Ceramic vacuum chambers were produced by LNLS for the Sirius kickers. Alumina tubes with an elliptical inner shape of 9.5 mm (V) x 29 mm (H) and 500 mm long were successfully manufactured by a Brazilian company. Metallic F136 titanium flanges were brazed to Nb inserts using Ag-58.5Cu-31.5Pd wt% alloy, these inserts were brazed to the ceramic using Ag-26.7Cu-4.5Ti wt% active filler metal. A titanium film was coated inside the chamber using argon plasma by RF Magnetron Sputtering technique. Samples have been investigated by Scanning Electron Microscopy (SEM) to measure film thickness along the inner section of the tube, coating morphology, chemical composition and homogeneity. The total electrical resistance of the tube was also monitored during the sputtering process to achieve the desired value (0.2 ohms/square). In this contribution, we present the results of an On-Axis kicker manufacturing process developed by LNLS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB400
About •	paper received ※ 18 May 2021 paper accepted ※ 31 May 2021 issue date ※ 29 August 2021
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WEXB07	Transverse Beam Profile Measurements from Extraction Losses in the PS	extraction, septum, emittance, proton	2548
	J.R. Hunt, F. Cerutti, L.S. Esposito, M. Giovannozzi, A. Huschauer, G. Russo CERN, Geneva, Switzerland G. Russo Goethe Universität Frankfurt, Frankfurt am Main, Germany
	During Multi-Turn Extraction (MTE) of continuous beams in the Proton Synchrotron (PS) at CERN, losses are generated on the blade of both the active and non-active septum during the rise time of the extraction kickers. Utilising pCVD Diamond detectors, secondary signal generated from these losses is measured. The high time resolution of these devices allows for insight into the detail of the horizontal beam distribution during extraction, and hence useful information such as the horizontal beam emittance may be computed. In this contribution, FLUKA simulations to relate the detector response to the beam impact conditions on the blades of the two septa are presented. The dependence on the beam angle, magnetic fringe field, and positioning of the detector is explored. Finally, realistic beam distributions are used to determine expected signal profiles at each septum.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXB07
About •	paper received ※ 18 May 2021 paper accepted ※ 20 July 2021 issue date ※ 27 August 2021
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WEPAB019	RF Harmonic Kicker R&D Demonstration and Its Application to the RCS Injection of the EIC	injection, cavity, electron, operation	2632
	G.-T. Park, M.W. Bruker, J.M. Grames, J. Guo, R.A. Rimmer, S.O. Solomon, H. Wang JLab, Newport News, Virginia, USA
	The Rapid Cycling Synchrotron (RCS) of the Electron-Ion Collider (EIC) at Brookhaven National Laboratory (BNL) * is an accelerating component of the electron injection complex, which provides polarized electrons in electron-ion collisions in the main Electron Storage Ring (ESR). We present the injection scheme into the RCS based on an ultra-fast harmonic kicker, whose "five odd-harmonic modes" prototype was developed in the context of the Jefferson Lab EIC (JLEIC) conceptual design . In its early stage of R&D, the sharp (~3 ns width) waveform construction, beam dynamics, and pulsed power operation with short ramping time (~10 us) will be discussed together with the fabrication work of the JLEIC prototype . BNL, "Electron Ion Collider Conceptual Design Report", 2020 G. Park et. al, JLAB-TN-044 * G. Park et. al., JLAB-TN-046
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB019
About •	paper received ※ 17 May 2021 paper accepted ※ 22 June 2021 issue date ※ 11 August 2021
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WEPAB113	Stripline Kickers for Injection Into PETRA IV	impedance, injection, electron, electronics	2863
	G. Loisch, I.V. Agapov, S.A. Antipov, J. Keil, F. Obier DESY, Hamburg, Germany M.A. Jebramcik CERN, Meyrin, Switzerland
	PETRA IV is the planned ultralow-emittance upgrade of the PETRA III synchrotron light source at DESY, Hamburg. The current design includes an on-axis beam injection scheme using fast stripline kickers. These kickers have to fulfill the requirements on kick-strength, field quality, pulse rise-rate and a matched beam impedance. 3D finite element simulations in conjunction with Bayesian optimisation are used to meet these requirements simultaneously. Here, we will discuss the requirements on the PETRA IV injection kickers and the current design status.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB113
About •	paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 15 August 2021
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WEPAB117	Injection Feedback for a Storage Ring	injection, HOM, feedback, simulation	2870
	A. Moutardier, C. Bruni, I. Chaikovska, S. Chancé, N. Delerue, E.E. Ergenlik, V. Kubytskyi, H. Monard Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
	Funding: Research Agency under the Equipex convention ANR-10-EQPX-0051. We report on an injection feedback scheme for the ThomX storage ring project. ThomX is a 50-MeV-electron accelerator prototype which will use Compton backscattering in a storage ring to generate a high flux of hard X-rays. Given the slow beam damping (in the ring), the injection must be performed with high accuracy to avoid large betatron oscillations. A homemade analytic code is used to compute the corrections that need to be applied before the beam injection to achieve a beam position accuracy of a few hundred micrometers in the first beam position monitors (BPMs). In order to do so the code needs the information provided by the ring’s diagnostic devices. The iterative feedback system has been tested using MadX simulations. Our simulations show that a performance that matches the BPMs’ accuracy can be achieved in less than 50 iterations in all cases. Details of this feedback algorithm, its efficiency and the simulations are discussed.
	Poster WEPAB117 [2.422 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB117
About •	paper received ※ 28 May 2021 paper accepted ※ 01 July 2021 issue date ※ 25 August 2021
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WEPAB121	Design and Simulation of Transparent Injection Upgrade for the CLS Storage Ring	injection, storage-ring, sextupole, simulation	2885
	P.J. Hunchak, M.J. Boland University of Saskatchewan, Saskatoon, Canada D. Bertwistle, M.J. Boland CLS, Saskatoon, Saskatchewan, Canada
	The Canadian Light Source (CLS) synchrotron uses four fast kicker magnets to inject electrons into the storage ring from a 2.9 GeV booster ring. The injection occurs over several turns of the stored beam, which is also perturbed by the injection kickers. The resultant oscillations of the stored beam can negatively affect beamline experiments, so it is desirable to implement an injection scheme which does not disturb the stored beam. Injection schemes of this type allow for transparent injection and are beneficial for planned top-up operations of the CLS storage ring. Many alternative injection techniques were examined as they apply to the CLS storage ring. Pulsed multipole magnets and a non-linear kicker (NLK) are the most viable options for integration with the current ring. Non-linear kicker designs are also being considered for the proposed CLS2 and studying the NLK in the limitations of the current machine provides insight to guide the work on the new machine. Simulation with the accelerator code ELEGANT shows the viability of the non-linear kicker design as developed at BESSY, MAX IV and SOLEIL for transparent injection at the CLS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB121
About •	paper received ※ 19 May 2021 paper accepted ※ 16 July 2021 issue date ※ 01 September 2021
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WEPAB122	Development of Fast and Super-Fast Kicker System for SLS 2.0 Injection	injection, impedance, electron, damping	2889
	M. Paraliev, M. Aiba, S. Dordevic, C.H. Gough, A. Streun PSI, Villigen PSI, Switzerland
	Swiss Light Source plans a major upgrade to turn the existing Storage Ring (SR) into a modern diffraction-limited light source called SLS 2.0. As part of this project, the injection system has to be upgraded as well in order to ensure reliable and efficient injection in the reduced beam aperture. A 4 kicker bump and a new thin septum will ensure the conventional injection in the SR. To further minimize the perturbation of the stored beam during injection two new schemes are in development: "Fast" and "Super-fast" one. The "Fast" injection scheme should be able to ensure single-bunch off-axis top-up injection affecting only 10 to 20 SR bunches that are 2 ns apart. The "Super-fast" one should bring the perturbed bunches down to only one. In on-axis mode it should be able to inject a top-up bunch between two SR bunches with minimum disturbance of the adjacent ones. To do this a combination of special beam injection schemes and an extremely fast (ns) kicker system is required. We will discuss the status of the development, the problems, and the solutions for reaching such a challenging goal.
	Poster WEPAB122 [1.371 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB122
About •	paper received ※ 18 May 2021 paper accepted ※ 09 June 2021 issue date ※ 28 August 2021
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WEPAB123	Multi-Bunch Resistive Wall Wake Field Tracking via Pseudomodes in the ALS-U Accumulator Ring	injection, damping, simulation, feedback	2893
	M.P. Ehrlichman, S. De Santis, T. Hellert, S.C. Leemann, G. Penn, C. Steier, C. Sun, M. Venturini, D. Wang LBNL, Berkeley, USA
	For the ALS-U project, particles will be injected from the booster to the accumulator ring utilizing an injection scheme that leaves the stored and injected particles with a non-trivial transient. This transient requires that multibunch feedback be masked for those buckets into which charge is injected. The masking significantly diminishes the damping capability of the multibunch feedback system. This problem is exacerbated by the large injection transient. The higher order resistive wall wake fields in the accumulator ring exceed the radiation damping time. To study whether the beam will remain multibunch stable during an injection cycle, a multibunch tracking simulation is used that simulates the multibunch feedback system and also pseudomode representation of resistive wall wake fields.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB123
About •	paper received ※ 20 May 2021 paper accepted ※ 01 September 2021 issue date ※ 23 August 2021
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WEPAB124	The Three Dipole Kicker Injection Scheme for the ALS-U Accumulator Ring	injection, septum, storage-ring, booster	2896
	M.P. Ehrlichman, T. Hellert, S.C. Leemann, G. Penn, C. Steier, C. Sun, M. Venturini, D. Wang LBNL, Berkeley, California, USA
	The ALS-U light source will implement on-axis swap-out injection of individual trains employing an accumulator between the booster and storage rings. The accumulator ring design is a twelve period triple-bend achromat that will be installed along the inner circumference of the storage-ring tunnel. A non-conventional injection scheme will be utilized for top-off off-axis injection from the booster into the accumulator ring meant to accommodate a relatively narrow vacuum-chamber aperture while maximizing injection efficiency. The scheme incorporates three dipole kickers distributed over three sectors, with two kickers perturbing the stored beam and the third affecting both the stored and the injected beam trajectories. This paper describes this ‘‘3DK’’ injection scheme, how it was chosen, designed and optimized, and how we evaluated its fitness as a solution for booster-to-accumulator ring injection against alternate injection schemes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB124
About •	paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 13 August 2021
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WEPAB125	Acceptance Analysis Method for the Scheme Design of Multipole Kicker Injection	injection, multipole, storage-ring, simulation	2900
	P.N. Wang, W. Li, G. Liu, L. Wang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	A pulsed multipole kicker has zero magnetic field at the center, consequently, this injection scheme can be transparent to the stored beam and users. In general, multipole kicker injection schemes are derived from the method of phase space analysis. In this paper, a new method of acceptance analysis based on multi-particles tracking is proposed. Using this method, we can quickly obtain multiple kicker injection schemes and easily make adjustments to them. The details of this method are presented and we apply it to the HALF storage ring as an example. A series of tracking simulations are carried out and results are also discussed.
	Poster WEPAB125 [0.930 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB125
About •	paper received ※ 18 May 2021 paper accepted ※ 09 June 2021 issue date ※ 13 August 2021
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WEPAB178	Non-Adiabatic Longitudinal Bunch Manipulation at Flattop of the J-PARC MR	bunching, extraction, experiment, flattop	3023
	F. Tamura JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan C. Ohmori, Y. Sugiyama, M. Yoshii KEK, Tokai, Ibaraki, Japan
	The J-PARC MR delivers the high-intensity proton beams for the neutrino experiment. Eight bunches of high peak current are extracted by the extraction kickers, therefore the neutrino beam has a similar time structure. The new Intermediate Water Cherenkov Detector (IWCD) will be constructed for the future neutrino experiment and a low peak time structure is desired by the IWCD. Thus, we consider bunch manipulation at flattop of the MR for reducing the peak current. The manipulation requires a longer repetition period to extend the flattop. This reduces the output beam power. The manipulation should be quickly done to minimize the loss of the beam power. Also, the beam gap must be kept for the rise time of the extraction kicker. We propose a non-adiabatic bunch manipulation using the multiharmonic rf voltage. By using the neighbor harmonic of the accelerating harmonic, the first and eighth bunches can be decelerated and accelerated, respectively. After a certain period, the rf phase is flipped to pi for debunching. Thanks to the initial deceleration and acceleration, the beam gap for the kickers is kept. We present the concept and the longitudinal simulation result.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB178
About •	paper received ※ 17 May 2021 paper accepted ※ 25 June 2021 issue date ※ 28 August 2021
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WEPAB193	Optimization of the Hadron Ring Stripline Injection Kicker for the EIC	impedance, simulation, injection, wakefield	3073
	M.P. Sangroula, C.J. Liaw, C. Liu, N. Tsoupas, B.P. Xiao, W. Zhang BNL, Upton, New York, USA X. Sun ANL, Lemont, Illinois, USA S. Verdú-Andrés Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy The Electron-Ion Collider (EIC) at Brookhaven National Laboratory is a high luminosity, ( ∼ 10³⁴ \textrm{cm}^-2 \textrm{s}^-1 ) accelerator facility colliding polarized electron beam with different ion species ranging from lighter nuclei (proton, deuterium) to heavier nuclei (gold, uranium). Design of a stripline injection kicker for the Hadron Storage Ring (HSR) of EIC for beams with the rigidity of ∼ 81 T-m poses some technical challenges due to expected shorter bunch spacing and higher peak current of EIC. This paper focuses on the optimization of the EIC hadron ring injection kicker. Starting from the 2D cross-section design which includes the selection of electrodes shape, we describe the optimization of the kicker’s cross-section. Then we discuss converting this 2D geometry to 3D by adding essential components for the stripline kicker and the 3D optimization techniques that we employed. Finally, we show simulation results for the optimized geometry including wakefields and Time Domain Reflection (TDR) from one feedthrough to another.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB193
About •	paper received ※ 21 May 2021 paper accepted ※ 28 June 2021 issue date ※ 14 August 2021
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WEPAB208	Energy Sweeping Beam Extraction by the Septum Magnet Assisted with Charge Exchange for a Hadron Therapy	extraction, septum, power-supply, acceleration	3109
	T.S. Dixit, A. Shaikh SAMEER, Mumbai, India T. Adachi, T. Kawakubo, K. Takayama KEK, Ibaraki, Japan
	An energy sweeping compact rapid cycling hadron therapy based on a fast cycling induction synchrotron has been proposed by KEK and SAMEER as the next generation of hadron therapy machine . For energy sweep extraction, a C+5 beam is injected, captured and trapped in the barrier bucket. A fraction of the beam is continuously released from the barrier bucket by controlling the timing of barrier pulse generation. Released C+5 ions merge into the coasting beam and moves inwards with ramping of the guiding main magnets. Ions in the coasting beam eventually hit the carbon foil placed inside the beam chamber wall. As a result, C+5 is converted to C+6 and beam orbit is largely changed as it traverses through the downstream bending magnet. This notably facilitates C+6 beam extraction, resulting in a relatively small kick angle of the septum magnet. When the septum is excited in the same way as that of the main magnets, the extracted C+6 beam always places on the center of the irradiation beam line. LISE++ simulations demonstrated the charge exchange efficiency of almost 100 % for expected beam energy. The feasibility of the switching power supply for the septum magnet has been studied. PRAB 24, 011601 (2021)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB208
About •	paper received ※ 14 May 2021 paper accepted ※ 22 June 2021 issue date ※ 16 August 2021
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WEPAB221	H⁰ Stark Stripping and Component Irradiation in Fermilab Booster	site, proton, booster, radiation	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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB221
About •	paper received ※ 11 May 2021 paper accepted ※ 09 June 2021 issue date ※ 20 August 2021
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WEPAB265	Simulations of Cooling Rate for Coherent Electron Cooling with Plasma Cascade Amplifier	electron, simulation, plasma, hadron	3261
	J. Ma, V. Litvinenko, G. Wang BNL, Upton, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Coherent electron cooling (CeC) is a novel technique for rapidly cooling high-energy, high-intensity hadron beams. A plasma cascade amplifier (PCA) has been proposed for the CeC experiment in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). The cooling rate of CeC experiment with PCA has been predicted in 3D start-to-end CeC simulations using code SPACE.
	Poster WEPAB265 [1.507 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB265
About •	paper received ※ 13 May 2021 paper accepted ※ 10 June 2021 issue date ※ 18 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, radiation, experiment, simulation	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]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB270
About •	paper received ※ 16 May 2021 paper accepted ※ 05 July 2021 issue date ※ 22 August 2021
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WEPAB273	Cooling and Diffusion Rates in Coherent Electron Cooling Concepts	electron, proton, plasma, hadron	3281
	S. Nagaitsev, V.A. Lebedev Fermilab, Batavia, Illinois, USA W.F. Bergan, E. Wang BNL, Upton, New York, USA G. Stupakov SLAC, Menlo Park, California, USA
	Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. We present analytic cooling and diffusion rates for a simplified model of coherent electron cooling (CEC), based on a proton energy kick at each turn. This model also allows to estimate analytically the rms value of electron beam density fluctuations in the "kicker" section. Having such analytic expressions should allow for better understanding of the CEC mechanism, and for a quicker analysis and optimization of main system parameters. Our analysis is applicable to any CEC amplification mechanism, as long as the wake (kick) function is available.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB273
About •	paper received ※ 10 May 2021 paper accepted ※ 28 July 2021 issue date ※ 29 August 2021
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WEPAB317	Online Model Developments for BESSY II and MLS	controls, EPICS, MMI, synchrotron	3413
	P. Schnizer, J. Bengtsson, T. Birke, J. Li, T. Mertens, M. Ries, A. Schälicke, L. Vera Ramirez HZB, Berlin, Germany
	Digital models have been developed over a long time for preparing accelerator commissioning next to benchmarking theory predictions to machine measurements. These digital models are nowadays being realized as digital shadows or digital twins. Accelerator commissioning requires periodic setup and review of the machine status. Furthermore, different measurements are only practical by comparison to the machine model (e.g. beam based alignment). In this paper we describe the architecture chosen for our models, describe the framework Bluesky for measurement orchestration and report on our experience exemplifying on dynamic aperture scans. Furthermore we describe our plans to extend the models applied to BESSY~II and MLS to the currently planned machines BESSY~III and MLS~II.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB317
About •	paper received ※ 19 May 2021 paper accepted ※ 28 July 2021 issue date ※ 21 August 2021
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WEPAB341	Injection and Extraction Kickers for the Advanced Light Source Upgrade Project (ALS-U)	storage-ring, impedance, extraction, injection	3487
	W.L. Waldron, D.A. Dawson, S. De Santis, T. Oliver, C. Steier LBNL, Berkeley, California, USA
	Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Advanced Light Source upgrade project (ALS-U) at Lawrence Berkeley National Laboratory includes the construction of a new accumulator ring and the replacement of the existing storage ring. Both ferrite-loaded kickers and stripline kickers are used in the ALS-U design for injection, extraction, and decohering the beam before storage ring extraction. In the accumulator ring, the rise and fall time requirements are based on the single bunch revolution time of 608 ns which allows the use of ferrite-loaded kickers. The 10 ns spacing between bunch trains in the storage ring requires stripline kickers to meet the rise and fall time requirements. Both types of kickers are driven by solid-state inductive voltage adders using MOSFETs. Modeling and prototyping efforts have characterized the kicker impedance and beam-induced heating, and explored the effects of beam strike on electrodes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB341
About •	paper received ※ 20 May 2021 paper accepted ※ 27 July 2021 issue date ※ 24 August 2021
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WEPAB342	Beam Induced Power Deposition in CERN SPS Injection Kickers	impedance, simulation, HOM, coupling	3490
	M.J. Barnes, O. Bjorkqvist CERN, Geneva 23, Switzerland K. Kodama KEK, Ibaraki, Japan
	The SPS injection kicker magnets (MKP) were developed in the 1970’s, before beam power deposition was considered an issue and before any advanced tools for analysing beam coupling impedance were available in their current form. These magnets are very lossy from a beam impedance perspective, and the beam induced power deposition is highly non-uniform. This is expected to be an issue during SPS operation with the higher intensity beams needed in the future for HL-LHC. There is an existing design, with serigraphy, that will mitigate the heating issues, which is presently being implemented on a prototype for test and measurement. Models have been developed to aid in predicting the safe operating regions until the upgraded MKPs are installed in the SPS: these are reported herein. A novel measurement technique is also presented to confirm the non-uniform power deposition in the ferrite yoke. Beam coupling impedance, power deposition, field rise time and field uniformity data are also presented for an upgraded, prototype, MKP.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB342
About •	paper received ※ 16 May 2021 paper accepted ※ 02 July 2021 issue date ※ 25 August 2021
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WEPAB343	Inductive Adder Prototype for FCC-hh Injection Kicker System	injection, flattop, simulation, collider	3494
	D. Woog, M.J. Barnes, T. Kramer CERN, Geneva, Switzerland H. De Gersem TEMF, TU Darmstadt, Darmstadt, Germany
	The future circular collider (FCC) requires a highly reliable injection kicker system. Present day kicker systems often rely on thyratron-based pulse generators and a pulse forming network or line: the thyratron is susceptible to self-triggering. Hence, an alternative pulse generator topology, based on fast semiconductor switches, is considered for the FCC. One possibility is an inductive adder (IA). A prototype IA has been designed and built: the main challenges are the fast rise time, high output current, low system impedance and a 2.3 us pulse duration combined with low droop. This paper presents the results of measurements on the prototype IA where the rated output current and output voltage were achieved separately. Suggested improvements to the IA hardware are identified and proposals are presented that could help improve the kicker system performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB343
About •	paper received ※ 16 May 2021 paper accepted ※ 01 July 2021 issue date ※ 17 August 2021
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WEPAB344	Studies for Mitigating Flashover of CERN-LHC Dilution Kicker Magnets	electron, simulation, vacuum, high-voltage	3498
	A.M. Loebner, M.J. Barnes, W. Bartmann, C. Bracco, L. Ducimetière, V. Namora, V. Senaj CERN, Geneva 23, Switzerland
	The LHC beam dump system is used for extracting beam from the LHC and, as such, is a safety critical system whose proper functionality must be assured. Dilution kicker magnets (MKBs) sweep the extracted beam over the cross-sectional area of a dump block as the energy density would otherwise be too high and damage the block. In 2018, a high voltage flashover occurred in a vertical MKB (MKBV) vacuum tank, during a beam dump, which resulted in non-ideal sweep of the beam over the block. The location of the flashover could not be identified during a subsequent inspection of the magnet. Hence, electrical field simulations have been carried out to identify potentially critical regions, to determine the most probable region of the flashover. One potentially critical region is a rectangular beam pipe (RBP) between the end of the tank and the MKBV magnet, whose purpose is to reduce plasma propagation to the adjacent tank in the event of a flashover. Mitigating measures were studied and are reported in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB344
About •	paper received ※ 16 May 2021 paper accepted ※ 06 July 2021 issue date ※ 22 August 2021
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WEPAB345	Impedance and Thermal Studies of the LHC Injection Kicker Magnet Upgrade	impedance, injection, simulation, coupling	3502
	M.J. Barnes, O. Bjorkqvist, F. Motschmann CERN, Geneva 23, Switzerland
	The bunch intensities of High Luminosity (HL) LHC are predicted to lead to heating of the ferrite yokes of the LHC injection kicker magnets (MKI), in their current configuration, to their Curie temperature. Hence, the MKIs are being upgraded to meet the requirements of HL-LHC, which is planned to start in the mid-2020s. The upgraded design features an RF damping ferrite loaded structure at the upstream end of each magnet, which will absorb a large portion of the beam induced power deposition of the magnet. The ferrite damper is cooled via a copper sleeve, brazed to the ferrite, and a set of water pipes. The thermal contact conductance (TCC) between ferrite and copper is very important, as are the properties of the ferrite. In this paper, we present measurements of the TCC and ferrite properties. This data is used to predict temperatures during operation of the LHC. In addition, a measurement and prediction is shown for the longitudinal impedance of the magnet. The models developed in this study will be benchmarked during run III of the LHC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB345
About •	paper received ※ 19 May 2021 paper accepted ※ 06 July 2021 issue date ※ 13 August 2021
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WEPAB346	Electromagnetic Modelling of Kicker Magnets to Derive Equivalent Circuits	coupling, simulation, impedance, extraction	3506
	M.J. Barnes, O. Bjorkqvist CERN, Geneva 23, Switzerland L. Jensen, O.A. Nielsen Aarhus University, Aarhus, Denmark
	An equivalent circuit model of a kicker magnet system is an invaluable tool for predicting the performance, studying possible modifications and for helping to diagnose faults. The frequency content of pulses associated with a ferrite loaded transmission line kicker magnet generally extend up to a few tens of MHz: hence, it is feasible to accurately model such a kicker magnet using lumped elements. This modelling technique is powerful since it in general has a run time several orders of magnitude shorter than a full wave electromagnetic simulation. In this paper, we determine values, including those of parasitic components, using modern simulation tools, for use in the lumped equivalent circuit models. In addition, the paper describes a method to simulate coupling between beam and the electrical circuit of a kicker magnet at relatively low frequencies: this allows one to use circuit analysis tools to study means of mitigating beam induced resonances.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB346
About •	paper received ※ 16 May 2021 paper accepted ※ 02 July 2021 issue date ※ 14 August 2021
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WEPAB347	Design, Construction and Testing of a Magnetic Probe for Fast Kicker Magnets	vacuum, impedance, injection, operation	3510
	N. Ayala, A. Ferrero Colomo, T. Kramer CERN, Geneva, Switzerland
	The CERN PS injection kicker has been modified in the framework of the LHC Injector Upgrade (LIU) project to allow injecting proton beams with an energy of 2 GeV. One of the most important items of the system parameter validation is the measurement and analysis of the magnetic field in the magnet aperture. To meet the required measurement precision without compromising the magnet vacuum performance, a dedicated magnetic probe has been designed, constructed and tested. The results are presented in this paper highlighting the mitigations of electrical, mechanical and vacuum complications. The paper concludes with an analysis of the probe performance during the first magnetic field measurements in the laboratory.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB347
About •	paper received ※ 19 May 2021 paper accepted ※ 07 July 2021 issue date ※ 02 September 2021
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WEPAB348	Injection and Extraction Systems of the SIS100 Heavy Ion Synchrotron at FAIR	extraction, injection, vacuum, septum	3514
	I.J. Petzenhauser, U. Blell, S. Heberer GSI, Darmstadt, Germany
	The "Facility for Antiproton and Ion Research" (FAIR) is a new international accelerator complex, which is currently built in Darmstadt, Germany. Part of this complex is the SIS100 heavy ion synchrotron with a circumference of ~1086 m. To inject ions into the SIS100, an injection kicker system will we required. For fast extraction of the particle beam from the SIS100, an extraction kicker is used. This extraction kicker will be a bipolar system, this way it works as an emergency kicker at the same time. The fast kicker systems have to produce a current pulse >6 kA. To achieve this, energy storages are charged up to voltages >70 kV and are quickly discharged. The pulse durations vary from 0.5 us to 7 us, depending on the kicker type and the operation mode. Slow extraction of the ion beam will include an electrostatic septum, operating with voltages up to 160 kV. The requirements of these injection/extraction devices will be described in detail and the status of the projects will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB348
About •	paper received ※ 17 May 2021 paper accepted ※ 11 June 2021 issue date ※ 20 August 2021
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WEPAB351	Requirements for an Inductive Voltage Adder as Driver for a Kicker Magnet with Short Circuit Termination	impedance, simulation, timing, flattop	3521
	J. Ruf, M.J. Barnes, T. Kramer CERN, Geneva 23, Switzerland M. Sack KIT, Karlsruhe, Germany
	At CERN pulse generators based on Thyratron switches and SF6 gas filled pulse forming lines, used for driving kicker magnets, are to be replaced with semiconductor technology. Preliminary investigations show the inductive voltage adder is suitable as a pulse generator for this application. To increase the magnetic field without raising the system voltage, a short-circuit termination is often applied to a kicker magnet. Because of the electrical length of a transmission line magnet, wave propagation needs to be considered. To allow for the wavefront reflected from the short-circuit termination back to the generator, a novel approach for an inductive adder architecture has been investigated. It is based on a modified generator interface, circulating the current back into the load, until the stored energy is absorbed at the end of the pulse. This approach allows for a smaller magnetic core size compared to a conventional design with a matched load. Moreover, it enables more energy-efficient operation involving smaller storage capacitors. This paper summarizes the conceptual design features and furthermore gives an overview of the parameter space for possible applications at CERN.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB351
About •	paper received ※ 18 May 2021 paper accepted ※ 11 June 2021 issue date ※ 17 August 2021
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WEPAB353	Design and Commissioning of a Multipole Injection Kicker for the SOLEIL Storage Ring	injection, synchrotron, storage-ring, operation	3525
	R. Ollier, P. Alexandre, R. Ben El Fekih, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	In third-generation synchrotron light sources, achieving an orbit distortion below 10% of the stored beam size is very challenging. The standard injection scheme of SOLEIL is made of 2 septa and 4 kicker magnets installed in a 12 m long straight section. Tuning the 4 kickers, to reduce perturbations, revealed to be almost impossible since it requires having 4 identical magnets, electronics, and Ti coated ceramic chambers. To reach the position stability requirement of the stored beam, a single pulsed magnet with no field on the stored beam path can replace the 4 kickers. Such a device, called MIK (Multipole Injection Kicker), was developed by SOLEIL and successfully commissioned in the MAX-IV 3-GeV ring as the key device used in the standard injection scheme for user operation, reducing the beam orbit distortion below 1 micron in peak value in both planes. A copy of the MIK has been installed in a short straight section of the SOLEIL storage ring, in January 2021. We report MIK positioning studies, the constraints of the project, sapphire chamber coating challenges and the first commissioning results. The R&D MIK is a demonstrator for the injection scheme of SOLEIL upgrade as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB353
About •	paper received ※ 21 May 2021 paper accepted ※ 23 July 2021 issue date ※ 31 August 2021
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THPAB031	Dump Line Layout and Beam Dilution Pattern Optimization of the Future Circular Collider	quadrupole, target, extraction, hardware	3815
	B. Facskó, D. Barna Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary A. Lechner, E. Renner CERN, Geneva, Switzerland
	To avoid any damage to the beam dump target in the Future Circular Collider, the beam will be swept over its surface using oscillating kickers in the x/y planes with a 90-degree phase difference, and an amplitude changing in time, creating a spiral pattern. The ideal pattern must have an increasing spiral pitch towards smaller radii to produce an even energy deposition density. We recommend the realization of the optimal pattern using two beating frequencies. This method enables a flat energy deposition density while only using simple independent damped oscillators. In this poster, we also present the study of the beamline optics and hardware that can realize the needed pattern. Two different possible hardware layouts were examined and optimized as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB031
About •	paper received ※ 19 May 2021 paper accepted ※ 28 July 2021 issue date ※ 18 August 2021
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THPAB168	Optics Measurement by Excitation of Betatron Oscillations in the CERN PSB	injection, optics, dipole, MMI	4078
	E.H. Maclean, F. Antoniou, F. Asvesta, H. Bartosik, C. Bracco, J. Dilly, E. Fol, H. Garcia Morales, M. Hofer, J. Keintzel, M. Le Garrec, T.E. Levens, L. Malina, T.H.B. Persson, T. Prebibaj, E. Renner, P.K. Skowroński, F. Soubelet, R. Tomás García, A. Wegscheider, L. van Riesen-Haupt CERN, Geneva, Switzerland
	Optics measurement from analysis of turn-by-turn BPM data of betatron oscillations excited with a kicker magnet has been employed very successfully in many machines but faces particular challenges in the CERN PSB where BPM to BPM phase advances are sub-optimal for optics reconstruction. Experience using turn-by-turn oscillation data for linear optics measurements during PSB commissioning in2021 is presented, with implications for the prospect of such techniques in the PSB more generally.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB168
About •	paper received ※ 19 May 2021 paper accepted ※ 14 July 2021 issue date ※ 27 August 2021
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THPAB178	The SIS100 Extraction and Emergency Kicker Magnet System	vacuum, extraction, high-voltage, HOM	4115
	J.H. Hottenbacher, K. Dunkel, M. Eisengruber, M. Osemann, A. Padvi, C. Piel RI Research Instruments GmbH, Bergisch Gladbach, Germany S. Heberer, I.J. Petzenhauser GSI, Darmstadt, Germany
	The extraction and emergency kicker system for SIS100 is a bipolar kicker system that allows for an in-situ choice between two directions: extraction to the experiments or to the beam dump. For that, both magnet ends are connected to a PFN each which are being charged simultaneously up to 80kV continuously. Due to the static HV operation, different to usually in other pulsed kicker systems, not only displacement current is flowing in the ferrite material. After less than 1s, the ferrite material is nearly field-free and the E-field is concentrated in the surrounding ceramic magnet clamp mechanism. As the field is further concentrated in gaps between ceramic and metallic parts, the HV layout of the magnet is a critical design task. As a magnetic field homogeneity of ±1% is required, special shaping of the coil is required as found during iterative 3D field simulations. The kicker chamber is designed to operate at a pressure level of 3·10^-11 mBar. As one 3 meter-chamber contains 3.5 m² ferrite surface, careful vacuum heat treatment of the ferrite is required to reach this pressure level. The paper will describe design principles for HV and UHV and effects found by 3D modeling.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB178
About •	paper received ※ 18 May 2021 paper accepted ※ 28 July 2021 issue date ※ 26 August 2021
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THPAB324	PIP-II 800 MeV Proton Linac Beam Pattern Generator	booster, injection, linac, MEBT	4426
	H. Maniar, B.E. Chase Fermilab, Batavia, Illinois, USA J.E. Dusatko SLAC, Menlo Park, California, USA S. Khole BARC, Trombay, Mumbai, India D. Sharma RRCAT, Indore (M.P.), India
	The PIP2 IT Beam Pattern Generator is the system that synchronizes beam injection and the RF systems between the PIP2 LINAC to the Booster. The RF frequencies of these two accelerator systems are not harmonically related. Synchronization is accomplished by controlling two MEBT Beam Choppers, which select 162.5MHz beam bunches from the LEBT and RFQ to produce an appropriate reduced beam bunch pattern that enables bucket-to-bucket transfer to the Booster RF at 46.46MHz (84th harmonic). This chopping pattern also reduces the beam current to an average of 2mA over the Booster injection, matching the Linac nominal beam current. The BPG also generates the RF frequency/phase reference which the Booster will phase lock to during injection. The BPG is fully programmable, allowing for arbitrary beam patterns with adjustable timing parameters, having a fine adjustment resolution of 38ps. The latter is accomplished using digital signal processing techniques. This paper discusses the design of the BPG, its construction, test results, and operational experience after being integrated into the PIP2 IT test accelerator and concludes with a discussion of the system’s performance and future plans.
	Poster THPAB324 [0.676 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB324
About •	paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 13 August 2021
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THPAB340	Sub-Nanosecond Switching of HV SiC MOS Transistors for Impact Ionisation Triggering	plasma, electron, laser, high-voltage	4454
	V. Senaj, T. Kramer, A.A. del Barrio Montañés CERN, Geneva 23, Switzerland M. Sack KIT, Karlsruhe, Germany
	Pulse generators with multi kV/kA pulses are necessary for the particle accelerator environment for beam transfer magnets. Traditionally these generators are using thyratrons - until recently the only switches capable of switching such pulses within tens of ns. There is a strong demand to replace thyratrons with semiconductor switches to avoid their future obsolescence. Very promising candidates are components from the family of fast ionization dynistors triggered by impact ionization. Their sub-nanosecond switching time and extreme current densities can provide performances superior to that of thyratrons. Recent investigations showed that impact ionization triggering is feasible also in cheap industrial thyristors. The main issue is the generation of triggering pulses with slew rates in the multi kV/ns region and with the required output current for charging the parasitic capacitance of the thyristor. We present an approach of generating > 1 kV/ns pulses by ultra-boosted gate driving of HV SiC MOS transistors. We found that the MOS lifetime under these extreme triggering conditions can still reach more than 10⁸ pulses, enough for kicker generator applications.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB340
About •	paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 27 August 2021
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THPAB354	Deployment and Commissioning of the CERN PS Injection Kicker System for Operation with 2 GeV Beams in Short Circuit Mode	injection, operation, MMI, controls	4489
	T. Kramer, N. Ayala, J.C.C.M. Borburgh, P.A.H. Burkel, E. Carlier, L. Ducimetière, L.M.C. Feliciano, A. Ferrero Colomo, M.A. Fraser, L.A. Govertsen, R. Noulibos, S. Pavis, L. Sermeus CERN, Geneva, Switzerland
	Within the framework of the LHC Injector Upgrade (LIU) project, the feasibility and design of an upgrade of the existing CERN PS proton injection kicker system have been outlined in previous publications already. This paper describes the adjustments of final design choices, testing, and deployment as well as the validation and commissioning of the new 2 GeV injection kicker system. The upgrade pays particular attention to the reduction of pulse reflections unavoidably induced by a magnet in short circuit mode configuration whilst keeping a fast 10⁴ ns rise and fall time. An adapted thyratron triggering system to reduce jitter and enhance thyratron lifetime is outlined. Additionally, improvements to the magnet entry box and the elimination of SF6 gas in the magnet connection box and the associated pulse transmission lines are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB354
About •	paper received ※ 19 May 2021 paper accepted ※ 14 July 2021 issue date ※ 10 August 2021
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FRXB04	Newly Development of Ceramics Chamber with Integrated Pulsed Magnet for Super-Narrow Bore in KEK-PF	injection, multipole, dipole, vacuum	4524
	C. Mitsuda, K. Harada, Y. Kobayashi, S. Nagahashi, T. Nogami, T. Obina, R. Takai, H. Takaki, T. Uchiyama, A. Ueda KEK, Ibaraki, Japan K. Hamaji, K. Iwamoto, A. Sasagawa, A. Yokoyama KYOCERA Corporation, Higashiomi-city, Shiga, Japan Y. Lu Sokendai, Ibaraki, Japan
	Ceramics chamber with integrated pulsed magnet (CCiPM) is a new air-core type magnet that has a plan to be used as a multipole injection magnet, a dipole injection kicker, and a fast correction kicker in the next-generation light source. The magnet coils are implanted completely into the thickness of cylindrical ceramic and integrated with ceramic structurally. The first CCiPM was developed for an internal diameter of 60 mm as a magnet bore to establish the basic production techniques. The technique has been enhanced to realize narrower bore over 3 years, and finally, the achieved internal diameters were 40 and 30 mm in newly developed CCiPM. These super small bores have an expectation to conform to the size of the vacuum beam duct in the ring of a future light source. New CCiPMs are under the off-line test to confirm the vacuum durability, electrical characteristics, and magnetic performance, and the beam test for the CCiPM with 30 mm diameter has also proceeded in parallel. The points of production technique and the recent results of the off-line test will be presented in this conference.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-FRXB04
About •	paper received ※ 19 May 2021 paper accepted ※ 19 July 2021 issue date ※ 31 August 2021
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MOPAB009

Review of the Fixed Target Operation at RHIC in 2020

target, experiment, operation, controls

69

C. Liu, P. Adams, E.N. Beebe, S. Binello, I. Blackler, M. Blaskiewicz, K.A. Brown, D. Bruno, B.D. Coe, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, K. Hock, H. Huang, R.L. Hulsart, T. Kanesue, D. Kayran, N.A. Kling, B. Lepore, Y. Luo, D. Maffei, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, J. Morris, C. Naylor, S. Nemesure, M. Okamura, I. Pinayev, S. Polizzo, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, P. Thieberger, M. Valette, A. Zaltsman, I. Zane, K. Zeno, W. Zhang
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
As part of the Beam Energy Scan (BES) physics program, RHIC operated in Fixed Target mode at various beam energies in 2020. The fixed target experiment, achieved by scraping the beam halo of the circulating beam on a gold ring inserted in the beam pipe upstream of the experimental detectors, extends the range of the center-of-mass energy for BES. The machine configuration, control of rates, and results of the fixed target experiment operation in 2020 will be presented in this report.

Poster MOPAB009 [2.913 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB009

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paper received ※ 16 May 2021 paper accepted ※ 17 August 2021 issue date ※ 23 August 2021

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MOPAB017

Influence of Injection Kicker Post-pulses on Storage of Ion Stack in NICA Collider

electron, injection, collider, betatron

93

E. Syresin, A. Tuzikov, N.O. Zagibin
JINR, Dubna, Moscow Region, Russia

The peculiarity of the injection kicker power supply in NICA collider is related to same post pulse of the magnetic field which is appeared after a regular injection pulse. The magnetic field of this post pulse became to an increase of the stack ion angle spread during each injection cycle. When the stack ion angles reaches the acceptance angle the ions are lost in the collider. Influence of the injection kicker post pulse on the storage of the ion stack is considered in this paper in presence of the electron cooling and ion electron recombination losses.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB017

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paper received ※ 17 May 2021 paper accepted ※ 20 May 2021 issue date ※ 13 August 2021

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MOPAB026

RHIC Delayed Abort Experiments

experiment, injection, quadrupole, dipole

126

M. Valette, D. Bruno, K.A. Drees, K.M. Hartmann, G. Heppner, K. Mernick, C. Mi, J.-L. Mi, R.J. Michnoff, J. Morris, F. Orsatti, E. Rydout, T. Samms, J. Sandberg, V. Schoefer, C. Schultheiss, T.C. Shrey, C. Theisen
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
For RHIC to operate at its top energy (100 GeV/n) while protecting the future sPHENIX detector, spontaneous and asynchronous firing of abort kicker modules (pre-fires) have to be avoided. A new triggering circuit for the abort kickers was implemented with relatively slow mechanical relays in series with the standard fast thyratron tubes. The relays prevents unwanted pre-fires during operation, but comes at the expense of a long latency - about 7 milliseconds - between the removal of beam permit and the actual firing of the abort kickers. Protection considerations of RHIC’s superconducting magnets forbid delaying energy extraction from the main dipoles and quadrupoles for too long after a quench. The beam has thus to circulate in both RHIc rings for a few milliseconds as the current in dipole and quadrupole circuit is being extracted. We present the results of delayed abort experiments conducted in July 2018 with the analysis of fast orbit and tune measurements and discuss the safety implications of this implementation for future RHIC operation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB026

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paper received ※ 19 May 2021 paper accepted ※ 26 May 2021 issue date ※ 23 August 2021

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MOPAB073

Beam Loss Simulations During Beam Dumping in Heps

lattice, simulation, dumping, photon

294

X. Cui, Y. Jiao, Y.L. Zhao
IHEP, Beijing, People’s Republic of China

The High Energy Photon Source (HEPS) is a 6 GeV storage ring light source under construction in China. Several collimators installed in the vacuum chamber will be used as beam dump in the storage ring operation. Preliminary simulations showed that the temperature rise caused by the beam power deposited on the collimators will far exceed the melting point of the collimator material. In order to cure this problem, special kickers are proposed to be installed in the ring to modulate the beam during beam dumping, thereby increasing the size of the beam hit on the collimators. In this article, some simulation results of the density of particles on the collimators during beam dumping for different HEPS lattice and different kicker parameters are shown.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB073

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paper received ※ 17 May 2021 paper accepted ※ 07 June 2021 issue date ※ 31 August 2021

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MOPAB081

Feasibility Study of Using Multipole Injection Kicker (MIK) and Sextupole for TPS Injection

injection, sextupole, storage-ring, GUI

312

C.-S. Fann, C.K. Chan, C.-C. Chang, H.-P. Chang, Y.-S. Cheng, M.-S. Chiu, Y.L. Chu, K.T. Hsu, S.Y. Hsu, K.H. Hu, J.C. Huang, C.-S. Hwang, S.H. Lee, K.-K. Lin, C.Y. Wu, C.S. Yang
NSRRC, Hsinchu, Taiwan
S.-Y. Lee
Indiana University, Bloomington, Indiana, USA

Feasibility of applying MIK/sextupole injection at TPS is evaluated in this study. This study adopts layout similar to MAX IV injection scheme and their collaboration project with SOLEIL for MIK. Although the light source service fulfills present user needs, yet the increasing demands for a transparent injection is inevitable in the foreseeable future. Notice that this preliminary study is constrained under routine user operation, the optional pinger ceramic chamber, located between existing injection kicker-3 and kicker-4, is chosen for the purpose. Kick strength requirement of the MIK is estimated with minor trajectory adjustment upstream at the booster to storage ring transfer line. Since the realization of MIK fabrication takes time, therefore a fast-built sextupole is prepared to examine the proposed injection scheme beforehand. The test result will be described in this report.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB081

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paper received ※ 17 May 2021 paper accepted ※ 20 May 2021 issue date ※ 21 August 2021

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MOPAB082

Implementation of Using IGBT Switch Based Pulser for TPS Booster Extraction Kicker

extraction, booster, injection, operation

315

C.-S. Fann, H.-P. Chang, C.L. Chen, Y.-S. Cheng, K.T. Hsu, S.Y. Hsu, K.-K. Lin, K.L. Tsai, C.Y. Wu
NSRRC, Hsinchu, Taiwan

A pair of thyratron-switch-based pulse-forming-network (PFN) pulser has been operating successfully in the past 5 years for TPS booster extraction kickers. In order to improve the flattop of drive-current pulse and to extend possible electron bunch train adjusting knob required, an IGBT-switch-based pulser has been designed, fabricated, and installed onto the TPS booster for its characteristics verification. In this report, the overall technical considerations for the pulser upgrade is described and its beam commissioning results is given for illustration purpose.

Poster MOPAB082 [0.621 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB082

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paper received ※ 20 May 2021 paper accepted ※ 27 May 2021 issue date ※ 13 August 2021

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MOPAB087

Design of a Multi-Bunch Feedback Kicker in SPEAR3

impedance, simulation, coupling, feedback

327

K. Tian, J.B. Langton, NL. Parry, J.A. Safranek, J.J. Sebek
SLAC, Menlo Park, California, USA

The new Multi-bunch feedback kickers have been designed to replace the current device loaned from ALS. In this paper, we first present the specification of the kickers based on the beam physics requirements. Then the mechanical design of the kicker is elaborated. Numerical simulations, both in time domain and in frequency domain, are conducted for evaluating the shunt impedance and beam coupling impedance of the kicker. Surface heating induced from the beam or the external source is estimated from the numerical results as well.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB087

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paper received ※ 19 May 2021 paper accepted ※ 11 June 2021 issue date ※ 01 September 2021

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MOPAB114

Development of a Decoherence Kicker for the ALS Upgrade Project (ALS-U)

storage-ring, extraction, vacuum, injection

414

C. Sun, S. De Santis, M.P. Ehrlichman, T. Hellert, T. Oliver, G. Penn, C. Steier, M. Venturini, W.L. Waldron
LBNL, Berkeley, California, USA

The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is upgrading the existing storage-ring lattice to a nine-bend-achromat lattice with on-axis swap-out injection. The upgraded storage ring will provide a highly focused beam of about 10 um in both horizontal and vertical directions with a single bunch train energy of about 60 J at 2.0 GeV. Such a small and intense beam could cause damage to the transfer line vacuum chambers in case of extraction element failures or damage to the storage ring vacuum chamber in case of RF failures. To mitigate these potential damages, a fast kicker magnet (so-called decoherence kicker) will be installed in the ALS-U storage ring and activated to dilute the beam charge density either on a train to be swapped out a few 100s turns before extraction or on the whole beam after RF failures. In this paper, we will present both physics and engineering designs of this decoherence kicker.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB114

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paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 20 August 2021

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MOPAB115

ATS/STA Transfer Line Design for the ALS Upgrade Project (ALS-U)

injection, storage-ring, optics, extraction

417

C. Sun, M.P. Ehrlichman, T. Hellert, M. Juchno, J.-Y. Jung, M. Mardenfeld, J.R. Osborn, G. Penn, C. Steier, C.A. Swenson, M. Venturini
LBNL, Berkeley, California, USA

At the Advanced Light Source Upgrade (ALS-U), an on-axis swap-out injection will be used to replenish depleted bunches in the storage ring with refreshed bunches from the full energy accumulator ring. To implement this scheme, two transfer lines are required between the storage ring and the accumulator ring: the accumulator-to-storage-ring (ATS) transfer line and the storage-ring-to-accumulator (STA) transfer line. The design of the ATS/STA transfer lines is a challenging task as they must fit within a tight injection region while also accommodating the storage and accumulator rings at different elevations. Moreover, the ATS/STA design needs to meet both the boundary conditions and optics requirements. In this paper, we will present a design option for these ATS/STA transfer lines.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB115

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paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 15 August 2021

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MOPAB116

A Flexible Injection Scheme for the ESRF-EBS

injection, SRF, septum, storage-ring

421

S.M. White, N. Carmignani, L.R. Carver, M. Dubrulle, L. Hoummi, S.M. Liuzzo, M. Morati, T.P. Perron
ESRF, Grenoble, France

The ESRF-EBS storage ring light source started commissioning in 2019 and successfully resumed users operation in 2020. Due to the smaller emittance and consequently reduced lifetime frequent injections are required that can potentially disturb beam lines experiments. In addition, operating the machine with low beta straight section and reduced insertion devices (ID) gaps are considered, therefore reducing the vertical aperture of the machine. Alternatives to the standard off-axis injection scheme allowing for efficient injection in reduced apertures with minimized perturbations are explored. A flexible layout for potential integration in the ESRF-EBS lattice is proposed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB116

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paper received ※ 11 May 2021 paper accepted ※ 27 May 2021 issue date ※ 24 August 2021

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MOPAB118

The Impact of Short-Range Wakes on Injection Into the ALS-U Accumulator Ring

injection, wakefield, electron, booster

429

G. Penn, M.P. Ehrlichman, T. Hellert, C. Steier, C. Sun, M. Venturini, D. Wang
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DEAC02-05CH11231.
As part of the ALS-U design, bunches with small charge will be added to the accumulator ring in a manner that initially leaves both the stored and injected bunches displaced from the nominal orbit. While the beam current is below instability thresholds, transient effects due to the combination of short-range wake fields and large initial displacements can have an impact on injection efficiency. In this paper, the impact of wake fields on the two bunches is detailed using the elegant simulation code, and different techniques to optimize the injection efficiency are explored.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB118

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paper received ※ 19 May 2021 paper accepted ※ 31 May 2021 issue date ※ 12 August 2021

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MOPAB128

Operational Use of Pinger Magnets to Counter Stored Beam Oscillations During Injection at Diamond Light Source

injection, operation, diagnostics, storage-ring

459

R.T. Fielder, M. Apollonio, I.P.S. Martin
DLS, Oxfordshire, United Kingdom

Diamond uses a four kicker bump injection scheme. Due to a variety of factors it has become more difficult to perfectly match the four kicks while maintaining injection efficiency, resulting in some disturbance to the stored beam during top-up. This has consequences for beamlines which may see degraded beam quality during injections. A gating signal is provided, but this is not appropriate for all experiments, and in any case ideally would not be required. The disturbance to the stored beam can be partly controlled using the existing diagnostic pinger magnets installed in the storage ring. We present here a comparison of different compensation schemes and tests with beamlines, along with initial experiences operating during user beam time. Use of these magnet also provides proof of principle for any future, purpose-built compensation kickers.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB128

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

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MOPAB213

Characterization of Linear Optics and Beam Parameters for the APS Booster with Turn-by-Turn BPM Data

booster, betatron, synchrotron, optics

703

X. Huang, H. Shang, C. Yao
ANL, Lemont, Illinois, USA

We take turn-by-turn (TBT) BPM data on the energy ramp of the APS Booster, and analyze the data with the independent component analysis. The extraction kicker was used to excite the betatron motion. The linear optics of the machine is characterized with the TBT BPM data. We also analyze the decoherence pattern of the kicked beam, from which we are able to derive beam distribution parameters, such as the momentum spread.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB213

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paper received ※ 13 May 2021 paper accepted ※ 11 June 2021 issue date ※ 19 August 2021

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MOPAB221

Developments of a Pulse Kicker System for the Three-Dimensional Spiral Beam Injection of the J-PARC Muon g-2/EDM Experiment

injection, experiment, power-supply, solenoid

726

K. Oda, H. Hirayama, H. Iinuma, Y. Sato, M. Sugita
Ibaraki University, Ibaraki, Japan
M. Abe, K. Furukawa, T. Mibe, H. Nakayama, S. Ohsawa, M.A. Rehman, N. Saito, K. Sasaki
KEK, Ibaraki, Japan
R. Matsushita
The University of Tokyo, Graduate School of Science, Tokyo, Japan

The J-PARC muon g-2/EDM experiment aims to perform ultra-precise measurements of anomalous magnetic moments (g-2) and electric dipole moments (EDM) from the spin precession of muons in a precise magnetic field and to explore new physics beyond the Standard Model. On experimental requirements, the beam must be stored in a compact storage orbit with a diameter of 66 cm, which is about 1/20th smaller than that of the previous experiment. To be realized, we adopt an unprecedented injection technique called the three-dimensional spiral injection scheme. In this scheme, the beam is injected from upward of the solenoidal storage magnet. The vertical beam motion along the solenoid axis is controlled by a few 100 ns pulse kicker. Once the beam is guided into the center fiducial storage volume, the muon beam is stored by the weak focusing magnetic field. Therefore, stable and accurate control of the pulse kicker is one of the major technical challenges to realize the ultra-precise measurement of the muon spin precession. In this presentation, we discuss the performance of the prototype pulse kicker device and future plan for installation of it to our test bench with an electron beam.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB221

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paper received ※ 20 May 2021 paper accepted ※ 31 May 2021 issue date ※ 15 August 2021

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MOPAB256

Development of Pulsed Beam System for the Three Dimensional Spiral Injection Scheme in the J-PARC muon g-2/EDM Experiment

injection, experiment, power-supply, controls

809

R. Matsushita
The University of Tokyo, Graduate School of Science, Tokyo, Japan
M. Abe, K. Hurukawa, T. Mibe, H. Nakayama, S. Ohsawa, M.A. Rehman, N. Saito, K. Sasaki
KEK, Ibaraki, Japan
H. Hirayama, H. Iinuma, K. Oda, Y. Sato, M. Sugita
Ibaraki University, Ibaraki, Japan
N. Saito
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
T. Takayanagi
JAEA/J-PARC, Tokai-mura, Japan

The J-PARC muon g-2/EDM experiment aims to measure the anomalous magnetic moment(g-2) and electric dipole moment(EDM) of the muon with higher precision than the previous BNL E821 experiment. A brand-new three-dimensional spiral injection scheme is employed to inject and store muon beam into a 66 cm diameter of storage magnet. Feasibility studies are ongoing by use of 80 keV electron beam at KEK test bench, to develop skills on control transverse beam motion; so-called X-Y coupling, with DC beam. As a next step, towards store the beam by use of a kicker system, a pulsed beam should be generated from the DC beam with an intended time structure to meet a pulse kicker’s duration time, without changing transverse phase space characteristics. In this presentation, the development of a beam chopper device and the evaluation of pulse beam profile are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB256

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paper received ※ 20 May 2021 paper accepted ※ 15 June 2021 issue date ※ 16 August 2021

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MOPAB331

Design Consideration of a Longitudinal Kicker Cavity for Compensating Transient Beam Loading Effect in Synchrotron Light Sources

cavity, resonance, coupling, impedance

1027

D. Naito, S. Sakanaka, T. Takahashi, N. Yamamoto
KEK, Ibaraki, Japan
T. Yamaguchi
Sokendai, Ibaraki, Japan

In ultra-low-emittance synchrotron light sources, bunch-lengthening using the combination of main and harmonic cavities is limited by the transient beam-loading (TBL) effect which is caused by gaps in the fill pattern. To manage this effect, we proposed a TBL compensation technique using a wide-band longitudinal kicker cavity*. In the future KEK-LS storage ring, for example, the kicker cavity should provide a compensation voltage of 50 kV with a -3dB bandwidth (BW) of about 5 MHz, as well as its higher-order modes (HOM) should be damped sufficiently. In this presentation, we report our conceptual design of the kicker cavity. We employed the single-mode (SM) cavity concept so that harmful HOMs are dumped by rf absorbers on the beam pipes. The distinctive feature of the SM cavity is its simple structure since it has no HOM damper on the cavity. Another feature is its low R/Q by which the TBL effect in the kicker cavity itself can be reduced significantly. We employed a frequency of 1.5 GHz (third-harmonic) and R/Q of 60 orms through optimizations. Using this kicker cavity with a double rf system, a bunch lengthening by a factor of 4.3 (i.e., 40.9 ps) is expected for the KEK-LS case.
* N.Yamamoto et al., Phys. Rrev. Acc. Beams 21, 012001 (2018)

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB331

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paper received ※ 19 May 2021 paper accepted ※ 11 June 2021 issue date ※ 01 September 2021

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TUPAB019

A High-Resolution, Low-Latency, Bunch-by-Bunch Feedback System for Nano-Beam Stabilization

feedback, cavity, dipole, collider

1378

R.L. Ramjiawan, D.R. Bett, N. Blaskovic Kraljevic, T. Bromwich, P. Burrows, G.B. Christian, C. Perry
JAI, Oxford, United Kingdom
D.R. Bett
CERN, Geneva, Switzerland
N. Blaskovic Kraljevic
ESS, Lund, Sweden
G.B. Christian
DLS, Oxfordshire, United Kingdom

A low-latency, bunch-by-bunch feedback system employing high-resolution cavity Beam Position Monitors (BPMs) has been developed and tested at the Accelerator Test Facility (ATF2) at the High Energy Accelerator Research Organization (KEK), Japan. The feedback system was designed to demonstrate nanometer-level vertical stabilization at the focal point of the ATF2 and can be operated using either a single BPM to provide local beam stabilization, or by using two BPMs to stabilize the beam at an intermediate location. The feedback correction is implemented using a stripline kicker and the feedback calculations are performed on a digital board constructed around a Field Programmable Gate Array (FPGA). The feedback performance was tested with trains of two bunches, separated by 280ns, at a charge of ~1nC, where the vertical offset of the first bunch was measured and used to calculate the correction to be applied to the second bunch. The BPMs have been demonstrated to achieve an operational resolution of ~20nm. With the application of single-BPM and two-BPM feedback, beam stabilization of below 50nm and 41nm respectively has been achieved with a latency of 232ns.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB019

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paper received ※ 18 May 2021 paper accepted ※ 09 June 2021 issue date ※ 14 August 2021

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TUPAB020

A Sub-Micron Resolution, Bunch-by-Bunch Beam Trajectory Feedback System and Its Application to Reducing Wakefield Effects in Single-Pass Beamlines

feedback, wakefield, electron, cavity

1382

D.R. Bett, P. Burrows, C. Perry, R.L. Ramjiawan
JAI, Oxford, United Kingdom
D.R. Bett
CERN, Geneva, Switzerland
K. Kubo, T. Okugi, N. Terunuma
KEK, Ibaraki, Japan

A high-precision intra-bunch-train beam orbit feedback correction system has been developed and tested at the KEK Accelerator Test Facility, ATF2. The system uses the vertical position of the bunch measured at two beam position monitors to calculate a pair of kicks which are applied to the next bunch using two upstream kickers, thereby correcting both the vertical position and trajectory angle. Using trains of two electron bunches separated in time by 187.6ns, the system was optimised so as to stabilize the beam offset at the feedback BPMs to better than 350nm, yielding a local trajectory angle correction to within 250nrad. The quality of the correction was verified using three downstream witness BPMs and the results were found to be in agreement with the predictions of a linear lattice model used to propagate the beam trajectory from the feedback region. This same model predicts a corrected be am jitter of c.1nm at the focal point of the accelerator. Measurements with a beam size monitor at this location demonstrate that reducing the trajectory jitter of the beam by a factor of 4 also reduces the increase in the measured beam size as a function of beam charge by a factor of ~1.6.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB020

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paper received ※ 13 May 2021 paper accepted ※ 01 July 2021 issue date ※ 11 August 2021

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TUPAB044

Preliminary Study of the on-Axis Swap-Out Injection Scheme for the Southern Advanced Photon Source

injection, storage-ring, septum, electron

1447

Y. Han, X.H. Lu, Y. Zhao
IHEP CSNS, Guangdong Province, People’s Republic of China
L. Huang, Y. Jiao, X. Liu, S. Wang
IHEP, Beijing, People’s Republic of China

The Southern Advanced Photon Source (SAPS) is a project under design, which aims at constructing a 4th generation storage ring with emittance below 100 pm.rad at the electron beam energy of around 3.5 GeV. The extremely low emittance will result in a very small dynamic aperture for the storage ring which makes it difficult to use the conventional off-axis accumulation injection. In this case, it is probably necessary to consider the transverse on-axis injection or the longitudinal injection. In this paper, the transverse on-axis swap-out injection scheme for the SAPS storage ring is presented. The preliminary parameters of the septum magnets and fast kickers are carefully evaluated.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB044

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paper received ※ 17 May 2021 paper accepted ※ 10 June 2021 issue date ※ 27 August 2021

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TUPAB058

Online Optimizations of Several Observable Parameters at the Advanced Photon Source

injection, storage-ring, photon, sextupole

1492

Y.P. Sun
ANL, Lemont, Illinois, USA

Funding: The work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Online optimizations are known to be powerful tools which may quickly and efficiently improve the particle accelerator key performance parameters in a model-independent way. In this paper, it is presented on the online optimizations of several observable parameters at the Advanced Photon Source storage ring. These observable parameters include the beam lifetime, injection efficiency and topup efficiency, transverse beam sizes, and turn by turn beam position monitors. It is demonstrated that the particle accelerator performance may be greatly enhanced in a relatively short time frame, by optimizing these observable parameters.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB058

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paper received ※ 20 May 2021 paper accepted ※ 24 June 2021 issue date ※ 16 August 2021

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TUPAB080

Design and Status of the Beam Switchyard of the Shanghai Soft X-Ray FEL User Facility

FEL, electron, undulator, linac

1559

S. Chen, R. Wang
SSRF, Shanghai, People’s Republic of China
H.X. Deng, C. Feng, X. Fu, B. Liu
SARI-CAS, Pudong, Shanghai, People’s Republic of China

SXFEL-UF, a soft X-ray FEL user facility located in Shanghai, has been upgraded from the existing test facility. Electron energy increases from 840 MeV to 1.5 GeV and a SASE FEL line will be added besides the existing seeding FEL line. It has started commissioning since early this year. In order for simultaneous operation of the two FEL lines, a beam switchyard is built between the linac and the two FEL lines. In this paper, the physics design of the beam switchyard is described.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB080

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paper received ※ 19 May 2021 paper accepted ※ 11 June 2021 issue date ※ 20 August 2021

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TUPAB081

Design of the Beam Distribution System of SHINE

undulator, linac, electron, septum

1562

S. Chen, M. Gu, R. Wang
SSRF, Shanghai, People’s Republic of China
H.X. Deng, X. Fu
SARI-CAS, Pudong, Shanghai, People’s Republic of China

In shanghai, a hard X-ray free electron laser project named SHINE is under design. It will be based on a superconducting linac running in CW mode. On the first stage, there will be three parallel undulator lines downstream the linac. For simultaneous operation of the three undulator lines, a beam distribution system based on fast kickers will be installed between linac and undulator lines. The physics design of this beam distribution system is described in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB081

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paper received ※ 19 May 2021 paper accepted ※ 14 June 2021 issue date ※ 22 August 2021

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TUPAB179

Design of an MBEC Cooler for the EIC

electron, proton, hadron, simulation

1819

W.F. Bergan, P. Baxevanis, M. Blaskiewicz, E. Wang
BNL, Upton, New York, USA
G. Stupakov
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.
Reaching maximal luminosity for the planned electron-ion collider (EIC) calls for some form of strong hadron cooling to counteract beam emittance increase from IBS. We discuss plans to use microbunched electron cooling (MBEC) to achieve this. The principle of this method is that the hadron beam will copropogate with a beam of electrons, imprinting its own density modulation on the electron beam. These electron phase space perturbations are amplified before copropogating with the hadrons again in a kicker section. By making the hadron transit time between modulator and kicker dependent on hadron energy and transverse offset, the energy kicks which they receive from the electrons will tend to reduce their longitudinal and transverse emittances. We discuss details of the analytic theory and searches for optimal realistic parameter settings to achieve a maximal cooling rate while limiting the effects of diffusion and electron beam saturation. We also place limits on the necessary electron beam quality. These results are corroborated by simulations.

Poster TUPAB179 [4.006 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB179

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

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TUPAB180

Plasma Simulations for an MBEC Cooler for the EIC

electron, hadron, simulation, proton

1823

W.F. Bergan
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.
In order to reach its maximum luminosity, the electron-ion collider (EIC) is being designed to use microbunched electron cooling (MBEC) to cool the hadron beam. This involves having the hadron beam imprint on a beam of electrons, enhancing the perturbations in the electron beam using the microbunching instability, and feeding back on the original hadron beam to correct deviations in hadron energy, and, through the use of dispersion, the transverse emittances. This process has been modelled analytically in the linear regime*. However, in order to maximize the cooling rate, we wish to know how much saturation in the electron beam is acceptable before the effects of nonlinearity cause significant deviations from the analytic results. To understand this, we have developed a code to do fast one-dimensional plasma simulations of hadrons and electrons as they move through the MBEC section of the EIC. In addition to permitting us to understand the effects of saturation, other effects are included which do not fit easily in the analytic formalism.
* G. Stupakov and P. Baxevanis, PRAB 22, 034401 (2019).

Poster TUPAB180 [1.955 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB180

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 18 August 2021

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TUPAB287

Application of Artificial Neural Network in the APS Linac Bunch Charge Transmission Efficiency

linac, operation, controls, photon

2155

H. Shang, R. Maulik, Y. Sun
ANL, Lemont, Illinois, USA
T. Xu
Northern Illinois University, DeKalb, Illinois, USA

Funding: * Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
In recent years there has been a rapid growth in machine learning (ML) and artificial intelligence (AI) applications in accelerators. As the scale of complexity and sophistication of modern accelerators grows, the difficulties in modeling the machine increase greatly in order to include all the interacting subsystems and to consider the limitation of various diagnostics to benchmark against measurements. Tools based on ML can help substantially in revealing correlations of machine condition and beam parameters that are not easily discovered using traditional physics model-based simulations, reducing machine tuning up time etc among the many possible applications. While at APS we have many excellent tools for the optimization, diagnostics, and controls of the accelerators, we do not yet have ML-based tools established. It is our desire to test ML in our machine operation, optimization, and controls. In this paper, we introduce the application of neural networks to the APS linac bunch charge transmission efficiency.

Poster TUPAB287 [0.781 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB287

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paper received ※ 12 May 2021 paper accepted ※ 16 June 2021 issue date ※ 29 August 2021

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TUPAB299

Tuned Delay Unit for a Stochastic Cooling System at NICA Collider

pick-up, FPGA, controls, collider

2186

S.V. Barabin, T. Kulevoy, D.A. Liakin, A.Y. Orlov
ITEP, Moscow, Russia
I.V. Gorelyshev, K.G. Osipov, V.V. Peshkov, A.O. Sidorin
JINR/VBLHEP, Dubna, Moscow region, Russia

Stochastic cooling is one of the crucial NICA (Nuclotron-based Ion Collider fAcility) subsystems. This system requires fine tuning of the response delay to the kicker, for both longitudinal and transverse stochastic cooling systems. The use of a digital delay line allows to add additional features such as a frequency dependent group velocity correction. To analyse the capabilities of the digital delay unit, a prototype of the device was created and tested. The article presents the characteristics of the prototype, its architecture and principle of operation, test results and estimations for the future developments.

Poster TUPAB299 [0.493 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB299

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paper received ※ 17 May 2021 paper accepted ※ 10 June 2021 issue date ※ 16 August 2021

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TUPAB359

Magnetic Field Measurement and Beam Performance Test of Ceramics Chamber with Integrated Pulsed Magnet at KEK-PF

vacuum, experiment, survey, dipole

2352

Y. Lu
Sokendai, Ibaraki, Japan
K. Harada, Y. Kobayashi, C. Mitsuda, S. Nagahashi, T. Nogami, T. Obina, R. Takai, H. Takaki, T. Uchiyama, A. Ueda
KEK, Ibaraki, Japan

An air-core magnet named Ceramics Chamber with integrated Pulsed Magnet(CCiPM) is being developed at the photon factory of KEK(KEK-PF), which will have several applications for the future light source. One prototype has been developed as a dipole kicker, whose bore is only 30mm. Due to the type and structure, it’s expected to have strong magnetic field and high repetition rate. After finishing the offline measurement of magnetic field and evaluation of vacuum tightness, the CCiPM was installed in the beam transport-dump line of PF to have an online beam performance and durability test. The results of the magnetic field measurement and beam performance test will be reviewed.

Poster TUPAB359 [1.164 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB359

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paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 16 August 2021

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TUPAB400

Manufacturing of Ceramic Vacuum Chambers for Sirius On-Axis Kicker

vacuum, HOM, niobium, target

2457

R. Defavari, O.R. Bagnato, M.W.A. Feitosa, F.R. Francisco, D.Y. Kakizaki, R.L. Parise, R.D. Ribeiro
LNLS, Campinas, Brazil

Ceramic vacuum chambers were produced by LNLS for the Sirius kickers. Alumina tubes with an elliptical inner shape of 9.5 mm (V) x 29 mm (H) and 500 mm long were successfully manufactured by a Brazilian company. Metallic F136 titanium flanges were brazed to Nb inserts using Ag-58.5Cu-31.5Pd wt% alloy, these inserts were brazed to the ceramic using Ag-26.7Cu-4.5Ti wt% active filler metal. A titanium film was coated inside the chamber using argon plasma by RF Magnetron Sputtering technique. Samples have been investigated by Scanning Electron Microscopy (SEM) to measure film thickness along the inner section of the tube, coating morphology, chemical composition and homogeneity. The total electrical resistance of the tube was also monitored during the sputtering process to achieve the desired value (0.2 ohms/square). In this contribution, we present the results of an On-Axis kicker manufacturing process developed by LNLS.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB400

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paper received ※ 18 May 2021 paper accepted ※ 31 May 2021 issue date ※ 29 August 2021

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WEXB07

Transverse Beam Profile Measurements from Extraction Losses in the PS

extraction, septum, emittance, proton

2548

J.R. Hunt, F. Cerutti, L.S. Esposito, M. Giovannozzi, A. Huschauer, G. Russo
CERN, Geneva, Switzerland
G. Russo
Goethe Universität Frankfurt, Frankfurt am Main, Germany

During Multi-Turn Extraction (MTE) of continuous beams in the Proton Synchrotron (PS) at CERN, losses are generated on the blade of both the active and non-active septum during the rise time of the extraction kickers. Utilising pCVD Diamond detectors, secondary signal generated from these losses is measured. The high time resolution of these devices allows for insight into the detail of the horizontal beam distribution during extraction, and hence useful information such as the horizontal beam emittance may be computed. In this contribution, FLUKA simulations to relate the detector response to the beam impact conditions on the blades of the two septa are presented. The dependence on the beam angle, magnetic fringe field, and positioning of the detector is explored. Finally, realistic beam distributions are used to determine expected signal profiles at each septum.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXB07

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paper received ※ 18 May 2021 paper accepted ※ 20 July 2021 issue date ※ 27 August 2021

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WEPAB019

RF Harmonic Kicker R&D Demonstration and Its Application to the RCS Injection of the EIC

injection, cavity, electron, operation

2632

G.-T. Park, M.W. Bruker, J.M. Grames, J. Guo, R.A. Rimmer, S.O. Solomon, H. Wang
JLab, Newport News, Virginia, USA

The Rapid Cycling Synchrotron (RCS) of the Electron-Ion Collider (EIC) at Brookhaven National Laboratory (BNL) * is an accelerating component of the electron injection complex, which provides polarized electrons in electron-ion collisions in the main Electron Storage Ring (ESR). We present the injection scheme into the RCS based on an ultra-fast harmonic kicker, whose "five odd-harmonic modes" prototype was developed in the context of the Jefferson Lab EIC (JLEIC) conceptual design **. In its early stage of R&D, the sharp (~3 ns width) waveform construction, beam dynamics, and pulsed power operation with short ramping time (~10 us) will be discussed together with the fabrication work of the JLEIC prototype ***.
* BNL, "Electron Ion Collider Conceptual Design Report", 2020
** G. Park et. al, JLAB-TN-044
*** G. Park et. al., JLAB-TN-046

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB019

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paper received ※ 17 May 2021 paper accepted ※ 22 June 2021 issue date ※ 11 August 2021

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WEPAB113

Stripline Kickers for Injection Into PETRA IV

impedance, injection, electron, electronics

2863

G. Loisch, I.V. Agapov, S.A. Antipov, J. Keil, F. Obier
DESY, Hamburg, Germany
M.A. Jebramcik
CERN, Meyrin, Switzerland

PETRA IV is the planned ultralow-emittance upgrade of the PETRA III synchrotron light source at DESY, Hamburg. The current design includes an on-axis beam injection scheme using fast stripline kickers. These kickers have to fulfill the requirements on kick-strength, field quality, pulse rise-rate and a matched beam impedance. 3D finite element simulations in conjunction with Bayesian optimisation are used to meet these requirements simultaneously. Here, we will discuss the requirements on the PETRA IV injection kickers and the current design status.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB113

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paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 15 August 2021

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WEPAB117

Injection Feedback for a Storage Ring

injection, HOM, feedback, simulation

2870

A. Moutardier, C. Bruni, I. Chaikovska, S. Chancé, N. Delerue, E.E. Ergenlik, V. Kubytskyi, H. Monard
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France

Funding: Research Agency under the Equipex convention ANR-10-EQPX-0051.
We report on an injection feedback scheme for the ThomX storage ring project. ThomX is a 50-MeV-electron accelerator prototype which will use Compton backscattering in a storage ring to generate a high flux of hard X-rays. Given the slow beam damping (in the ring), the injection must be performed with high accuracy to avoid large betatron oscillations. A homemade analytic code is used to compute the corrections that need to be applied before the beam injection to achieve a beam position accuracy of a few hundred micrometers in the first beam position monitors (BPMs). In order to do so the code needs the information provided by the ring’s diagnostic devices. The iterative feedback system has been tested using MadX simulations. Our simulations show that a performance that matches the BPMs’ accuracy can be achieved in less than 50 iterations in all cases. Details of this feedback algorithm, its efficiency and the simulations are discussed.

Poster WEPAB117 [2.422 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB117

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paper received ※ 28 May 2021 paper accepted ※ 01 July 2021 issue date ※ 25 August 2021

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WEPAB121

Design and Simulation of Transparent Injection Upgrade for the CLS Storage Ring

injection, storage-ring, sextupole, simulation

2885

P.J. Hunchak, M.J. Boland
University of Saskatchewan, Saskatoon, Canada
D. Bertwistle, M.J. Boland
CLS, Saskatoon, Saskatchewan, Canada

The Canadian Light Source (CLS) synchrotron uses four fast kicker magnets to inject electrons into the storage ring from a 2.9 GeV booster ring. The injection occurs over several turns of the stored beam, which is also perturbed by the injection kickers. The resultant oscillations of the stored beam can negatively affect beamline experiments, so it is desirable to implement an injection scheme which does not disturb the stored beam. Injection schemes of this type allow for transparent injection and are beneficial for planned top-up operations of the CLS storage ring. Many alternative injection techniques were examined as they apply to the CLS storage ring. Pulsed multipole magnets and a non-linear kicker (NLK) are the most viable options for integration with the current ring. Non-linear kicker designs are also being considered for the proposed CLS2 and studying the NLK in the limitations of the current machine provides insight to guide the work on the new machine. Simulation with the accelerator code ELEGANT shows the viability of the non-linear kicker design as developed at BESSY, MAX IV and SOLEIL for transparent injection at the CLS.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB121

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paper received ※ 19 May 2021 paper accepted ※ 16 July 2021 issue date ※ 01 September 2021

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WEPAB122

Development of Fast and Super-Fast Kicker System for SLS 2.0 Injection

injection, impedance, electron, damping

2889

M. Paraliev, M. Aiba, S. Dordevic, C.H. Gough, A. Streun
PSI, Villigen PSI, Switzerland

Swiss Light Source plans a major upgrade to turn the existing Storage Ring (SR) into a modern diffraction-limited light source called SLS 2.0. As part of this project, the injection system has to be upgraded as well in order to ensure reliable and efficient injection in the reduced beam aperture. A 4 kicker bump and a new thin septum will ensure the conventional injection in the SR. To further minimize the perturbation of the stored beam during injection two new schemes are in development: "Fast" and "Super-fast" one. The "Fast" injection scheme should be able to ensure single-bunch off-axis top-up injection affecting only 10 to 20 SR bunches that are 2 ns apart. The "Super-fast" one should bring the perturbed bunches down to only one. In on-axis mode it should be able to inject a top-up bunch between two SR bunches with minimum disturbance of the adjacent ones. To do this a combination of special beam injection schemes and an extremely fast (ns) kicker system is required. We will discuss the status of the development, the problems, and the solutions for reaching such a challenging goal.

Poster WEPAB122 [1.371 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB122

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paper received ※ 18 May 2021 paper accepted ※ 09 June 2021 issue date ※ 28 August 2021

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WEPAB123

Multi-Bunch Resistive Wall Wake Field Tracking via Pseudomodes in the ALS-U Accumulator Ring

injection, damping, simulation, feedback

2893

M.P. Ehrlichman, S. De Santis, T. Hellert, S.C. Leemann, G. Penn, C. Steier, C. Sun, M. Venturini, D. Wang
LBNL, Berkeley, USA

For the ALS-U project, particles will be injected from the booster to the accumulator ring utilizing an injection scheme that leaves the stored and injected particles with a non-trivial transient. This transient requires that multibunch feedback be masked for those buckets into which charge is injected. The masking significantly diminishes the damping capability of the multibunch feedback system. This problem is exacerbated by the large injection transient. The higher order resistive wall wake fields in the accumulator ring exceed the radiation damping time. To study whether the beam will remain multibunch stable during an injection cycle, a multibunch tracking simulation is used that simulates the multibunch feedback system and also pseudomode representation of resistive wall wake fields.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB123

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paper received ※ 20 May 2021 paper accepted ※ 01 September 2021 issue date ※ 23 August 2021

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WEPAB124

The Three Dipole Kicker Injection Scheme for the ALS-U Accumulator Ring

injection, septum, storage-ring, booster

2896

M.P. Ehrlichman, T. Hellert, S.C. Leemann, G. Penn, C. Steier, C. Sun, M. Venturini, D. Wang
LBNL, Berkeley, California, USA

The ALS-U light source will implement on-axis swap-out injection of individual trains employing an accumulator between the booster and storage rings. The accumulator ring design is a twelve period triple-bend achromat that will be installed along the inner circumference of the storage-ring tunnel. A non-conventional injection scheme will be utilized for top-off off-axis injection from the booster into the accumulator ring meant to accommodate a relatively narrow vacuum-chamber aperture while maximizing injection efficiency. The scheme incorporates three dipole kickers distributed over three sectors, with two kickers perturbing the stored beam and the third affecting both the stored and the injected beam trajectories. This paper describes this ‘‘3DK’’ injection scheme, how it was chosen, designed and optimized, and how we evaluated its fitness as a solution for booster-to-accumulator ring injection against alternate injection schemes.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB124

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paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 13 August 2021

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WEPAB125

Acceptance Analysis Method for the Scheme Design of Multipole Kicker Injection

injection, multipole, storage-ring, simulation

2900

P.N. Wang, W. Li, G. Liu, L. Wang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

A pulsed multipole kicker has zero magnetic field at the center, consequently, this injection scheme can be transparent to the stored beam and users. In general, multipole kicker injection schemes are derived from the method of phase space analysis. In this paper, a new method of acceptance analysis based on multi-particles tracking is proposed. Using this method, we can quickly obtain multiple kicker injection schemes and easily make adjustments to them. The details of this method are presented and we apply it to the HALF storage ring as an example. A series of tracking simulations are carried out and results are also discussed.

Poster WEPAB125 [0.930 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB125

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paper received ※ 18 May 2021 paper accepted ※ 09 June 2021 issue date ※ 13 August 2021

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WEPAB178

Non-Adiabatic Longitudinal Bunch Manipulation at Flattop of the J-PARC MR

bunching, extraction, experiment, flattop

3023

F. Tamura
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
C. Ohmori, Y. Sugiyama, M. Yoshii
KEK, Tokai, Ibaraki, Japan

The J-PARC MR delivers the high-intensity proton beams for the neutrino experiment. Eight bunches of high peak current are extracted by the extraction kickers, therefore the neutrino beam has a similar time structure. The new Intermediate Water Cherenkov Detector (IWCD) will be constructed for the future neutrino experiment and a low peak time structure is desired by the IWCD. Thus, we consider bunch manipulation at flattop of the MR for reducing the peak current. The manipulation requires a longer repetition period to extend the flattop. This reduces the output beam power. The manipulation should be quickly done to minimize the loss of the beam power. Also, the beam gap must be kept for the rise time of the extraction kicker. We propose a non-adiabatic bunch manipulation using the multiharmonic rf voltage. By using the neighbor harmonic of the accelerating harmonic, the first and eighth bunches can be decelerated and accelerated, respectively. After a certain period, the rf phase is flipped to pi for debunching. Thanks to the initial deceleration and acceleration, the beam gap for the kickers is kept. We present the concept and the longitudinal simulation result.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB178

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paper received ※ 17 May 2021 paper accepted ※ 25 June 2021 issue date ※ 28 August 2021

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WEPAB193

Optimization of the Hadron Ring Stripline Injection Kicker for the EIC

impedance, simulation, injection, wakefield

3073

M.P. Sangroula, C.J. Liaw, C. Liu, N. Tsoupas, B.P. Xiao, W. Zhang
BNL, Upton, New York, USA
X. Sun
ANL, Lemont, Illinois, USA
S. Verdú-Andrés
Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
The Electron-Ion Collider (EIC) at Brookhaven National Laboratory is a high luminosity, ( ∼ 10³⁴ \textrm{cm}^-2 \textrm{s}^-1 ) accelerator facility colliding polarized electron beam with different ion species ranging from lighter nuclei (proton, deuterium) to heavier nuclei (gold, uranium). Design of a stripline injection kicker for the Hadron Storage Ring (HSR) of EIC for beams with the rigidity of ∼ 81 T-m poses some technical challenges due to expected shorter bunch spacing and higher peak current of EIC. This paper focuses on the optimization of the EIC hadron ring injection kicker. Starting from the 2D cross-section design which includes the selection of electrodes shape, we describe the optimization of the kicker’s cross-section. Then we discuss converting this 2D geometry to 3D by adding essential components for the stripline kicker and the 3D optimization techniques that we employed. Finally, we show simulation results for the optimized geometry including wakefields and Time Domain Reflection (TDR) from one feedthrough to another.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB193

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paper received ※ 21 May 2021 paper accepted ※ 28 June 2021 issue date ※ 14 August 2021

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WEPAB208

Energy Sweeping Beam Extraction by the Septum Magnet Assisted with Charge Exchange for a Hadron Therapy

extraction, septum, power-supply, acceleration

3109

T.S. Dixit, A. Shaikh
SAMEER, Mumbai, India
T. Adachi, T. Kawakubo, K. Takayama
KEK, Ibaraki, Japan

An energy sweeping compact rapid cycling hadron therapy based on a fast cycling induction synchrotron has been proposed by KEK and SAMEER as the next generation of hadron therapy machine *. For energy sweep extraction, a C+5 beam is injected, captured and trapped in the barrier bucket. A fraction of the beam is continuously released from the barrier bucket by controlling the timing of barrier pulse generation. Released C+5 ions merge into the coasting beam and moves inwards with ramping of the guiding main magnets. Ions in the coasting beam eventually hit the carbon foil placed inside the beam chamber wall. As a result, C+5 is converted to C+6 and beam orbit is largely changed as it traverses through the downstream bending magnet. This notably facilitates C+6 beam extraction, resulting in a relatively small kick angle of the septum magnet. When the septum is excited in the same way as that of the main magnets, the extracted C+6 beam always places on the center of the irradiation beam line. LISE++ simulations demonstrated the charge exchange efficiency of almost 100 % for expected beam energy. The feasibility of the switching power supply for the septum magnet has been studied.
* PRAB 24, 011601 (2021)

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB208

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paper received ※ 14 May 2021 paper accepted ※ 22 June 2021 issue date ※ 16 August 2021

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WEPAB221

H⁰ Stark Stripping and Component Irradiation in Fermilab Booster

site, proton, booster, radiation

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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WEPAB265

Simulations of Cooling Rate for Coherent Electron Cooling with Plasma Cascade Amplifier

electron, simulation, plasma, hadron

3261

J. Ma, V. Litvinenko, G. Wang
BNL, Upton, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Coherent electron cooling (CeC) is a novel technique for rapidly cooling high-energy, high-intensity hadron beams. A plasma cascade amplifier (PCA) has been proposed for the CeC experiment in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). The cooling rate of CeC experiment with PCA has been predicted in 3D start-to-end CeC simulations using code SPACE.

Poster WEPAB265 [1.507 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB265

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paper received ※ 13 May 2021 paper accepted ※ 10 June 2021 issue date ※ 18 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, radiation, experiment, simulation

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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WEPAB273

Cooling and Diffusion Rates in Coherent Electron Cooling Concepts

electron, proton, plasma, hadron

3281

S. Nagaitsev, V.A. Lebedev
Fermilab, Batavia, Illinois, USA
W.F. Bergan, E. Wang
BNL, Upton, New York, USA
G. Stupakov
SLAC, Menlo Park, California, USA

Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
We present analytic cooling and diffusion rates for a simplified model of coherent electron cooling (CEC), based on a proton energy kick at each turn. This model also allows to estimate analytically the rms value of electron beam density fluctuations in the "kicker" section. Having such analytic expressions should allow for better understanding of the CEC mechanism, and for a quicker analysis and optimization of main system parameters. Our analysis is applicable to any CEC amplification mechanism, as long as the wake (kick) function is available.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB273

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paper received ※ 10 May 2021 paper accepted ※ 28 July 2021 issue date ※ 29 August 2021

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WEPAB317

Online Model Developments for BESSY II and MLS

controls, EPICS, MMI, synchrotron

3413

P. Schnizer, J. Bengtsson, T. Birke, J. Li, T. Mertens, M. Ries, A. Schälicke, L. Vera Ramirez
HZB, Berlin, Germany

Digital models have been developed over a long time for preparing accelerator commissioning next to benchmarking theory predictions to machine measurements. These digital models are nowadays being realized as digital shadows or digital twins. Accelerator commissioning requires periodic setup and review of the machine status. Furthermore, different measurements are only practical by comparison to the machine model (e.g. beam based alignment). In this paper we describe the architecture chosen for our models, describe the framework Bluesky for measurement orchestration and report on our experience exemplifying on dynamic aperture scans. Furthermore we describe our plans to extend the models applied to BESSY~II and MLS to the currently planned machines BESSY~III and MLS~II.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB317

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paper received ※ 19 May 2021 paper accepted ※ 28 July 2021 issue date ※ 21 August 2021

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WEPAB341

Injection and Extraction Kickers for the Advanced Light Source Upgrade Project (ALS-U)

storage-ring, impedance, extraction, injection

3487

W.L. Waldron, D.A. Dawson, S. De Santis, T. Oliver, C. Steier
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Advanced Light Source upgrade project (ALS-U) at Lawrence Berkeley National Laboratory includes the construction of a new accumulator ring and the replacement of the existing storage ring. Both ferrite-loaded kickers and stripline kickers are used in the ALS-U design for injection, extraction, and decohering the beam before storage ring extraction. In the accumulator ring, the rise and fall time requirements are based on the single bunch revolution time of 608 ns which allows the use of ferrite-loaded kickers. The 10 ns spacing between bunch trains in the storage ring requires stripline kickers to meet the rise and fall time requirements. Both types of kickers are driven by solid-state inductive voltage adders using MOSFETs. Modeling and prototyping efforts have characterized the kicker impedance and beam-induced heating, and explored the effects of beam strike on electrodes.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB341

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paper received ※ 20 May 2021 paper accepted ※ 27 July 2021 issue date ※ 24 August 2021

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WEPAB342

Beam Induced Power Deposition in CERN SPS Injection Kickers

impedance, simulation, HOM, coupling

3490

M.J. Barnes, O. Bjorkqvist
CERN, Geneva 23, Switzerland
K. Kodama
KEK, Ibaraki, Japan

The SPS injection kicker magnets (MKP) were developed in the 1970’s, before beam power deposition was considered an issue and before any advanced tools for analysing beam coupling impedance were available in their current form. These magnets are very lossy from a beam impedance perspective, and the beam induced power deposition is highly non-uniform. This is expected to be an issue during SPS operation with the higher intensity beams needed in the future for HL-LHC. There is an existing design, with serigraphy, that will mitigate the heating issues, which is presently being implemented on a prototype for test and measurement. Models have been developed to aid in predicting the safe operating regions until the upgraded MKPs are installed in the SPS: these are reported herein. A novel measurement technique is also presented to confirm the non-uniform power deposition in the ferrite yoke. Beam coupling impedance, power deposition, field rise time and field uniformity data are also presented for an upgraded, prototype, MKP.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB342

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paper received ※ 16 May 2021 paper accepted ※ 02 July 2021 issue date ※ 25 August 2021

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WEPAB343

Inductive Adder Prototype for FCC-hh Injection Kicker System

injection, flattop, simulation, collider

3494

D. Woog, M.J. Barnes, T. Kramer
CERN, Geneva, Switzerland
H. De Gersem
TEMF, TU Darmstadt, Darmstadt, Germany

The future circular collider (FCC) requires a highly reliable injection kicker system. Present day kicker systems often rely on thyratron-based pulse generators and a pulse forming network or line: the thyratron is susceptible to self-triggering. Hence, an alternative pulse generator topology, based on fast semiconductor switches, is considered for the FCC. One possibility is an inductive adder (IA). A prototype IA has been designed and built: the main challenges are the fast rise time, high output current, low system impedance and a 2.3 us pulse duration combined with low droop. This paper presents the results of measurements on the prototype IA where the rated output current and output voltage were achieved separately. Suggested improvements to the IA hardware are identified and proposals are presented that could help improve the kicker system performance.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB343

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paper received ※ 16 May 2021 paper accepted ※ 01 July 2021 issue date ※ 17 August 2021

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WEPAB344

Studies for Mitigating Flashover of CERN-LHC Dilution Kicker Magnets

electron, simulation, vacuum, high-voltage

3498

A.M. Loebner, M.J. Barnes, W. Bartmann, C. Bracco, L. Ducimetière, V. Namora, V. Senaj
CERN, Geneva 23, Switzerland

The LHC beam dump system is used for extracting beam from the LHC and, as such, is a safety critical system whose proper functionality must be assured. Dilution kicker magnets (MKBs) sweep the extracted beam over the cross-sectional area of a dump block as the energy density would otherwise be too high and damage the block. In 2018, a high voltage flashover occurred in a vertical MKB (MKBV) vacuum tank, during a beam dump, which resulted in non-ideal sweep of the beam over the block. The location of the flashover could not be identified during a subsequent inspection of the magnet. Hence, electrical field simulations have been carried out to identify potentially critical regions, to determine the most probable region of the flashover. One potentially critical region is a rectangular beam pipe (RBP) between the end of the tank and the MKBV magnet, whose purpose is to reduce plasma propagation to the adjacent tank in the event of a flashover. Mitigating measures were studied and are reported in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB344

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paper received ※ 16 May 2021 paper accepted ※ 06 July 2021 issue date ※ 22 August 2021

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WEPAB345

Impedance and Thermal Studies of the LHC Injection Kicker Magnet Upgrade

impedance, injection, simulation, coupling

3502

M.J. Barnes, O. Bjorkqvist, F. Motschmann
CERN, Geneva 23, Switzerland

The bunch intensities of High Luminosity (HL) LHC are predicted to lead to heating of the ferrite yokes of the LHC injection kicker magnets (MKI), in their current configuration, to their Curie temperature. Hence, the MKIs are being upgraded to meet the requirements of HL-LHC, which is planned to start in the mid-2020s. The upgraded design features an RF damping ferrite loaded structure at the upstream end of each magnet, which will absorb a large portion of the beam induced power deposition of the magnet. The ferrite damper is cooled via a copper sleeve, brazed to the ferrite, and a set of water pipes. The thermal contact conductance (TCC) between ferrite and copper is very important, as are the properties of the ferrite. In this paper, we present measurements of the TCC and ferrite properties. This data is used to predict temperatures during operation of the LHC. In addition, a measurement and prediction is shown for the longitudinal impedance of the magnet. The models developed in this study will be benchmarked during run III of the LHC.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB345

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paper received ※ 19 May 2021 paper accepted ※ 06 July 2021 issue date ※ 13 August 2021

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WEPAB346

Electromagnetic Modelling of Kicker Magnets to Derive Equivalent Circuits

coupling, simulation, impedance, extraction

3506

M.J. Barnes, O. Bjorkqvist
CERN, Geneva 23, Switzerland
L. Jensen, O.A. Nielsen
Aarhus University, Aarhus, Denmark

An equivalent circuit model of a kicker magnet system is an invaluable tool for predicting the performance, studying possible modifications and for helping to diagnose faults. The frequency content of pulses associated with a ferrite loaded transmission line kicker magnet generally extend up to a few tens of MHz: hence, it is feasible to accurately model such a kicker magnet using lumped elements. This modelling technique is powerful since it in general has a run time several orders of magnitude shorter than a full wave electromagnetic simulation. In this paper, we determine values, including those of parasitic components, using modern simulation tools, for use in the lumped equivalent circuit models. In addition, the paper describes a method to simulate coupling between beam and the electrical circuit of a kicker magnet at relatively low frequencies: this allows one to use circuit analysis tools to study means of mitigating beam induced resonances.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB346

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paper received ※ 16 May 2021 paper accepted ※ 02 July 2021 issue date ※ 14 August 2021

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WEPAB347

Design, Construction and Testing of a Magnetic Probe for Fast Kicker Magnets

vacuum, impedance, injection, operation

3510

N. Ayala, A. Ferrero Colomo, T. Kramer
CERN, Geneva, Switzerland

The CERN PS injection kicker has been modified in the framework of the LHC Injector Upgrade (LIU) project to allow injecting proton beams with an energy of 2 GeV. One of the most important items of the system parameter validation is the measurement and analysis of the magnetic field in the magnet aperture. To meet the required measurement precision without compromising the magnet vacuum performance, a dedicated magnetic probe has been designed, constructed and tested. The results are presented in this paper highlighting the mitigations of electrical, mechanical and vacuum complications. The paper concludes with an analysis of the probe performance during the first magnetic field measurements in the laboratory.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB347

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paper received ※ 19 May 2021 paper accepted ※ 07 July 2021 issue date ※ 02 September 2021

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WEPAB348

Injection and Extraction Systems of the SIS100 Heavy Ion Synchrotron at FAIR

extraction, injection, vacuum, septum

3514

I.J. Petzenhauser, U. Blell, S. Heberer
GSI, Darmstadt, Germany

The "Facility for Antiproton and Ion Research" (FAIR) is a new international accelerator complex, which is currently built in Darmstadt, Germany. Part of this complex is the SIS100 heavy ion synchrotron with a circumference of ~1086 m. To inject ions into the SIS100, an injection kicker system will we required. For fast extraction of the particle beam from the SIS100, an extraction kicker is used. This extraction kicker will be a bipolar system, this way it works as an emergency kicker at the same time. The fast kicker systems have to produce a current pulse >6 kA. To achieve this, energy storages are charged up to voltages >70 kV and are quickly discharged. The pulse durations vary from 0.5 us to 7 us, depending on the kicker type and the operation mode. Slow extraction of the ion beam will include an electrostatic septum, operating with voltages up to 160 kV. The requirements of these injection/extraction devices will be described in detail and the status of the projects will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB348

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paper received ※ 17 May 2021 paper accepted ※ 11 June 2021 issue date ※ 20 August 2021

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WEPAB351

Requirements for an Inductive Voltage Adder as Driver for a Kicker Magnet with Short Circuit Termination

impedance, simulation, timing, flattop

3521

J. Ruf, M.J. Barnes, T. Kramer
CERN, Geneva 23, Switzerland
M. Sack
KIT, Karlsruhe, Germany

At CERN pulse generators based on Thyratron switches and SF6 gas filled pulse forming lines, used for driving kicker magnets, are to be replaced with semiconductor technology. Preliminary investigations show the inductive voltage adder is suitable as a pulse generator for this application. To increase the magnetic field without raising the system voltage, a short-circuit termination is often applied to a kicker magnet. Because of the electrical length of a transmission line magnet, wave propagation needs to be considered. To allow for the wavefront reflected from the short-circuit termination back to the generator, a novel approach for an inductive adder architecture has been investigated. It is based on a modified generator interface, circulating the current back into the load, until the stored energy is absorbed at the end of the pulse. This approach allows for a smaller magnetic core size compared to a conventional design with a matched load. Moreover, it enables more energy-efficient operation involving smaller storage capacitors. This paper summarizes the conceptual design features and furthermore gives an overview of the parameter space for possible applications at CERN.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB351

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

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WEPAB353

Design and Commissioning of a Multipole Injection Kicker for the SOLEIL Storage Ring

injection, synchrotron, storage-ring, operation

3525

R. Ollier, P. Alexandre, R. Ben El Fekih, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France

In third-generation synchrotron light sources, achieving an orbit distortion below 10% of the stored beam size is very challenging. The standard injection scheme of SOLEIL is made of 2 septa and 4 kicker magnets installed in a 12 m long straight section. Tuning the 4 kickers, to reduce perturbations, revealed to be almost impossible since it requires having 4 identical magnets, electronics, and Ti coated ceramic chambers. To reach the position stability requirement of the stored beam, a single pulsed magnet with no field on the stored beam path can replace the 4 kickers. Such a device, called MIK (Multipole Injection Kicker), was developed by SOLEIL and successfully commissioned in the MAX-IV 3-GeV ring as the key device used in the standard injection scheme for user operation, reducing the beam orbit distortion below 1 micron in peak value in both planes. A copy of the MIK has been installed in a short straight section of the SOLEIL storage ring, in January 2021. We report MIK positioning studies, the constraints of the project, sapphire chamber coating challenges and the first commissioning results. The R&D MIK is a demonstrator for the injection scheme of SOLEIL upgrade as well.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB353

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paper received ※ 21 May 2021 paper accepted ※ 23 July 2021 issue date ※ 31 August 2021

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THPAB031

Dump Line Layout and Beam Dilution Pattern Optimization of the Future Circular Collider

quadrupole, target, extraction, hardware

3815

B. Facskó, D. Barna
Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary
A. Lechner, E. Renner
CERN, Geneva, Switzerland

To avoid any damage to the beam dump target in the Future Circular Collider, the beam will be swept over its surface using oscillating kickers in the x/y planes with a 90-degree phase difference, and an amplitude changing in time, creating a spiral pattern. The ideal pattern must have an increasing spiral pitch towards smaller radii to produce an even energy deposition density. We recommend the realization of the optimal pattern using two beating frequencies. This method enables a flat energy deposition density while only using simple independent damped oscillators. In this poster, we also present the study of the beamline optics and hardware that can realize the needed pattern. Two different possible hardware layouts were examined and optimized as well.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB031

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paper received ※ 19 May 2021 paper accepted ※ 28 July 2021 issue date ※ 18 August 2021

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THPAB168

Optics Measurement by Excitation of Betatron Oscillations in the CERN PSB

injection, optics, dipole, MMI

4078

E.H. Maclean, F. Antoniou, F. Asvesta, H. Bartosik, C. Bracco, J. Dilly, E. Fol, H. Garcia Morales, M. Hofer, J. Keintzel, M. Le Garrec, T.E. Levens, L. Malina, T.H.B. Persson, T. Prebibaj, E. Renner, P.K. Skowroński, F. Soubelet, R. Tomás García, A. Wegscheider, L. van Riesen-Haupt
CERN, Geneva, Switzerland

Optics measurement from analysis of turn-by-turn BPM data of betatron oscillations excited with a kicker magnet has been employed very successfully in many machines but faces particular challenges in the CERN PSB where BPM to BPM phase advances are sub-optimal for optics reconstruction. Experience using turn-by-turn oscillation data for linear optics measurements during PSB commissioning in2021 is presented, with implications for the prospect of such techniques in the PSB more generally.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB168

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paper received ※ 19 May 2021 paper accepted ※ 14 July 2021 issue date ※ 27 August 2021

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THPAB178

The SIS100 Extraction and Emergency Kicker Magnet System

vacuum, extraction, high-voltage, HOM

4115

J.H. Hottenbacher, K. Dunkel, M. Eisengruber, M. Osemann, A. Padvi, C. Piel
RI Research Instruments GmbH, Bergisch Gladbach, Germany
S. Heberer, I.J. Petzenhauser
GSI, Darmstadt, Germany

The extraction and emergency kicker system for SIS100 is a bipolar kicker system that allows for an in-situ choice between two directions: extraction to the experiments or to the beam dump. For that, both magnet ends are connected to a PFN each which are being charged simultaneously up to 80kV continuously. Due to the static HV operation, different to usually in other pulsed kicker systems, not only displacement current is flowing in the ferrite material. After less than 1s, the ferrite material is nearly field-free and the E-field is concentrated in the surrounding ceramic magnet clamp mechanism. As the field is further concentrated in gaps between ceramic and metallic parts, the HV layout of the magnet is a critical design task. As a magnetic field homogeneity of ±1% is required, special shaping of the coil is required as found during iterative 3D field simulations. The kicker chamber is designed to operate at a pressure level of 3·10^-11 mBar. As one 3 meter-chamber contains 3.5 m² ferrite surface, careful vacuum heat treatment of the ferrite is required to reach this pressure level. The paper will describe design principles for HV and UHV and effects found by 3D modeling.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB178

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paper received ※ 18 May 2021 paper accepted ※ 28 July 2021 issue date ※ 26 August 2021

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THPAB324

PIP-II 800 MeV Proton Linac Beam Pattern Generator

booster, injection, linac, MEBT

4426

H. Maniar, B.E. Chase
Fermilab, Batavia, Illinois, USA
J.E. Dusatko
SLAC, Menlo Park, California, USA
S. Khole
BARC, Trombay, Mumbai, India
D. Sharma
RRCAT, Indore (M.P.), India

The PIP2 IT Beam Pattern Generator is the system that synchronizes beam injection and the RF systems between the PIP2 LINAC to the Booster. The RF frequencies of these two accelerator systems are not harmonically related. Synchronization is accomplished by controlling two MEBT Beam Choppers, which select 162.5MHz beam bunches from the LEBT and RFQ to produce an appropriate reduced beam bunch pattern that enables bucket-to-bucket transfer to the Booster RF at 46.46MHz (84th harmonic). This chopping pattern also reduces the beam current to an average of 2mA over the Booster injection, matching the Linac nominal beam current. The BPG also generates the RF frequency/phase reference which the Booster will phase lock to during injection. The BPG is fully programmable, allowing for arbitrary beam patterns with adjustable timing parameters, having a fine adjustment resolution of 38ps. The latter is accomplished using digital signal processing techniques. This paper discusses the design of the BPG, its construction, test results, and operational experience after being integrated into the PIP2 IT test accelerator and concludes with a discussion of the system’s performance and future plans.

Poster THPAB324 [0.676 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB324

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paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 13 August 2021

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THPAB340

Sub-Nanosecond Switching of HV SiC MOS Transistors for Impact Ionisation Triggering

plasma, electron, laser, high-voltage

4454

V. Senaj, T. Kramer, A.A. del Barrio Montañés
CERN, Geneva 23, Switzerland
M. Sack
KIT, Karlsruhe, Germany

Pulse generators with multi kV/kA pulses are necessary for the particle accelerator environment for beam transfer magnets. Traditionally these generators are using thyratrons - until recently the only switches capable of switching such pulses within tens of ns. There is a strong demand to replace thyratrons with semiconductor switches to avoid their future obsolescence. Very promising candidates are components from the family of fast ionization dynistors triggered by impact ionization. Their sub-nanosecond switching time and extreme current densities can provide performances superior to that of thyratrons. Recent investigations showed that impact ionization triggering is feasible also in cheap industrial thyristors. The main issue is the generation of triggering pulses with slew rates in the multi kV/ns region and with the required output current for charging the parasitic capacitance of the thyristor. We present an approach of generating > 1 kV/ns pulses by ultra-boosted gate driving of HV SiC MOS transistors. We found that the MOS lifetime under these extreme triggering conditions can still reach more than 10⁸ pulses, enough for kicker generator applications.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB340

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paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 27 August 2021

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THPAB354

Deployment and Commissioning of the CERN PS Injection Kicker System for Operation with 2 GeV Beams in Short Circuit Mode

injection, operation, MMI, controls

4489

T. Kramer, N. Ayala, J.C.C.M. Borburgh, P.A.H. Burkel, E. Carlier, L. Ducimetière, L.M.C. Feliciano, A. Ferrero Colomo, M.A. Fraser, L.A. Govertsen, R. Noulibos, S. Pavis, L. Sermeus
CERN, Geneva, Switzerland

Within the framework of the LHC Injector Upgrade (LIU) project, the feasibility and design of an upgrade of the existing CERN PS proton injection kicker system have been outlined in previous publications already. This paper describes the adjustments of final design choices, testing, and deployment as well as the validation and commissioning of the new 2 GeV injection kicker system. The upgrade pays particular attention to the reduction of pulse reflections unavoidably induced by a magnet in short circuit mode configuration whilst keeping a fast 10⁴ ns rise and fall time. An adapted thyratron triggering system to reduce jitter and enhance thyratron lifetime is outlined. Additionally, improvements to the magnet entry box and the elimination of SF6 gas in the magnet connection box and the associated pulse transmission lines are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB354

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

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FRXB04

Newly Development of Ceramics Chamber with Integrated Pulsed Magnet for Super-Narrow Bore in KEK-PF

injection, multipole, dipole, vacuum

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C. Mitsuda, K. Harada, Y. Kobayashi, S. Nagahashi, T. Nogami, T. Obina, R. Takai, H. Takaki, T. Uchiyama, A. Ueda
KEK, Ibaraki, Japan
K. Hamaji, K. Iwamoto, A. Sasagawa, A. Yokoyama
KYOCERA Corporation, Higashiomi-city, Shiga, Japan
Y. Lu
Sokendai, Ibaraki, Japan

Ceramics chamber with integrated pulsed magnet (CCiPM) is a new air-core type magnet that has a plan to be used as a multipole injection magnet, a dipole injection kicker, and a fast correction kicker in the next-generation light source. The magnet coils are implanted completely into the thickness of cylindrical ceramic and integrated with ceramic structurally. The first CCiPM was developed for an internal diameter of 60 mm as a magnet bore to establish the basic production techniques. The technique has been enhanced to realize narrower bore over 3 years, and finally, the achieved internal diameters were 40 and 30 mm in newly developed CCiPM. These super small bores have an expectation to conform to the size of the vacuum beam duct in the ring of a future light source. New CCiPMs are under the off-line test to confirm the vacuum durability, electrical characteristics, and magnetic performance, and the beam test for the CCiPM with 30 mm diameter has also proceeded in parallel. The points of production technique and the recent results of the off-line test will be presented in this conference.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-FRXB04

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

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