Keyword: kicker
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MOPOST026 Influences of the Energy Jitter to the Performance of the Coherent Electron Cooling electron, simulation, experiment, emittance 115
 
  • G. Wang, V. Litvinenko, J. Ma
    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.
The bandwidth of a coherent electron cooling (CeC) system is typically two to three orders of magnitude higher than the traditional RF based stochastic cooling system, which make it possible to cool the ion bunches with high energy and high intensity. However, for such broad bandwidth, jitters in the energy of the cooling electron bunches present a serious challenge to the performance of the cooling system. In this work, we present analytical as well as simulation studies about the influences of the energy jitter to a CeC system with parameters relevant to the on-going CeC experiment at RHIC. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST026  
About • Received ※ 09 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 29 June 2022
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MOPOST037 Characterisation of Bunch-by-Bunch Tune Shift Effects in the CERN SPS simulation, impedance, injection, electron 148
 
  • I. Mases Solé, H. Bartosik, V. Kain, K. Paraschou, M. Schenk, C. Zannini
    CERN, Meyrin, Switzerland
  
  After the implementation of major upgrades as part of the LHC Injector Upgrade Project (LIU), the Super Proton Synchrotron (SPS) delivers high intensity bunch trains with 25 ns bunch spacing to the Large Hadron Collider (LHC) at CERN. These beams are exposed to several collective effects in the SPS, such as beam coupling impedance, space charge and electron cloud, leading to relatively large bunch-by-bunch coherent and incoherent tune shifts. Tune correction to the nominal values at injection is crucial to ensure beam stability and good beam transmission. During the beam commissioning of the SPS, measurements of the bunch-by-bunch coherent tune shifts have been conducted under different beam conditions, together with appropriate corrections of the average tunes at each injection. In this paper, we describe the methodology that has been developed to acquire bunch-by-bunch position data and to perform online computations of the coherent tune spectra of each bunch using refined Fourier transform analysis. The experimental data are compared to multiparticle tracking simulations using the SPS impedance model, in view of developing an accurate model for tune correction in the SPS.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST037  
About • Received ※ 03 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 19 June 2022
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MOPOST053 Transverse Resonance Islands Buckets at SPEAR3 lattice, resonance, experiment, feedback 203
 
  • J. Kim, J.A. Safranek, K. Tian
    SLAC, Menlo Park, California, USA
  
  We present populating bunches into the transverse resonance islands buckets (TRIBs) on SPEAR3. As one of operation modes for the timing-mode or providing separated bunches in transverse direction, we are exploring TRIBs on SPEAR3. Experience and analysis on applying kicks multiple times using the bunch-by-bunch feedback kicker to move bunches into the TRIBs is described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST053  
About • Received ※ 06 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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MOPOPT022 Beam Dynamics of the Transparent Injection for the MAX IV 1.5 GeV Ring injection, septum, storage-ring, multipole 284
 
  • M. Apollonio, Å. Andersson, M. Brosi, D.K. Olsson, P.F. Tavares, A.S. Vorozhtsov
    MAX IV Laboratory, Lund University, Lund, Sweden
  
  Following the successful operation of the Multipole Injection Kicker (MIK) in the MAX IV 3 GeV storage ring, we plan to introduce a similar device in the MAX IV 1.5 GeV ring. In order to assess the effectiveness of such device and to define its working parameters, we performed a series of studies aimed at understanding the beam dynamics related to the injection process. In this paper we describe the optimization of the MIK working parameters, we study the resilience to tune shifts for a chosen injection scheme and illustrate some tests conducted to evaluate the ring acceptance. We conclude with remarks about the effects of magnet errors on key performance parameters such as the injection efficiency and perturbations to the size and divergence of the stored beam and a brief discussion on future work.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT022  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 29 June 2022 — Issue date ※ 07 July 2022
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MOPOPT032 Improvement of Matching Circuit for J-PARC Main Ring Injection Kicker Magnet operation, injection, simulation, impedance 316
 
  • T. Sugimoto, K. Ishii, S. Iwata, H. Matsumoto, T. Shibata
    KEK, Ibaraki, Japan
  
  In this paper, present status of improvements of the impedance matching circuit for the J-PARC main ring injection kicker magnet to achieve 1.3MW beam operation planed after 2022 is described. In order to reduce the temperature-rise of resistors under the higher repetition rate pulse excitation, number of paralleled resistors was doubled and volume of each resistor was enlarged 2.6 times. Ceramic-made beads with diameter of 3 mm were filled in the cylinder of the resistor to increase the heat conductivity. An aluminum-made water-cooled heat sink was attached to the resistors directly and an air-cooling fan was mounted to the side of the box containing the resistors. All resistors and their support structure have been replaced in March 2022. Temperature-rise of resistors during continuous pulse excitation was measured by commercial thermo camera and compared with numerical calculations. In addition, predictions about the beam induced heating of the resistors are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT032  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 26 June 2022
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MOPOTK041 Magnetic Field Noise Search Using Turn-by-Turn Data at CESR power-supply, simulation, electron, synchrotron 553
 
  • V. Khachatryan, J. Barley, M.H. Berry, A.T. Chapelain, D.L. Rubin, J.P. Shanks, S. Wang
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Funding: The authors thank NSF PHYS-1416318 and DMR-1829070.
A method for searching for magnetic field noise has been developed using the CESR beam turn-by-turn data. The technique is tested using Monte-Carlo samples and turn-by-turn real data with induced noise in one of the CESR magnets. We estimate the analysis sensitivity for the noise sources slower than 4 kHz (or 100 CESR-turns) with the current CESR BPM system on the level of 1 microradian or 0.2 Gs×m field integral. In this work we report the observed noise sources and the improvements achieved by applying this technique. Long-term, several hours, beam stability analysis is also performed using the same method. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK041  
About • Received ※ 07 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 27 June 2022  
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MOPOMS032 Compact-Two-Octave-Spanning Perpendicular Kicker of MeV Electrons Based on a Cubic Magnet Dipole Array electron, dipole, radiation, laser 706
 
  • T. Rohwer, R. Bazrafshan, F.X. Kärtner, N.H. Matlis
    Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany
  • R. Bazrafshan
    University of Hamburg, Hamburg, Germany
  • F.X. Kärtner
    The Hamburg Center for Ultrafast Imaging, University of Hamburg, Hamburg, Germany
  • F.X. Kärtner
    CFEL, Hamburg, Germany
  • P. Vagin
    DESY, Hamburg, Germany
  
  Funding: This work has been supported by the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) through the Synergy Grant AXSIS (609920).
New compact particle acceleration structures, including but not limited to plasma, THz and direct laser driven accelerators, have in common that they cover a wide energy range of potential final energies and often show a large energy spread. Moreover, they may initially have a rather large emittance. To analyze the energy range of a single shot and/or to deflect the beam to safely dump the electrons away from an end-station requires an electron kicker covering a large energy range. Here, we present a magnetic dipole structure based on a 2D Halbach array. For the current experimental test accelerator in AXSIS, an electron beam in the energy range from 4 to 20 MeV is deflected by 90 degree and energetically dispersed. In direct contrast to a simple magnetic dipole, an array of cubic magnet blocks with tailored magnetization directions allows a focusing of the beam for both longitudinal and transverse directions at 90 degree bend. A generic algorithm optimizes the magnetic field array to the predefined deflection angle and divergence. The modular array structure, in combination with the algorithm enables a simple exchange of magnets to adapt for different beam parameters. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS032  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 14 June 2022
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MOPOMS048 Fast Trigger System for Beam Abort System in SuperKEKB hardware, detector, power-supply, MMI 754
 
  • H. Ikeda, T. Mimashi, S. Nakamura, T. Oki, S. Sasaki
    KEK, Ibaraki, Japan
  
  In order to protect the hardware components of the de-tector and accelerator from sudden beam loss of high beam currents, the fast beam abort system is developed in the SuperKEKB. The previous abort system was not fast enough for sudden beam loss that caused QCS quench, and it gave a damage to the collimator and the Belle-II detector. A fast abort system is required to pre-venting such damage. The abort system consists of sev-eral sensors that generate interlock signal (the loss moni-tor, dose in the Bell-II detector, and the magnet failure etc.), optical cable system to transfer the interlock signal to central control room (CCR), the abort trigger signal generation system and the abort kicker. To reduce total time, we reduce transmission time from local control room to CCR by changing signal cable route. Since the interlock signal produced by magnet power supply was slow, we modified the magnet power supply. For more quick generation of abort trigger signal, we increased number of the abort gap. By these improvements, an average abort time is reduced from 31µsec to 25µsec. This improvement looks small, but it brought preventing the serious radiation damage to many hardware compo-nents. Detail of the system and result is presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS048  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
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TUPOST044 Fortune Telling or Physics Prediction? Deep Learning for On-Line Kicker Temperature Forecasting operation, simulation, injection, network 957
 
  • F.M. Velotti, M.J. Barnes, B. Goddard, I. Revuelta
    CERN, Meyrin, Switzerland
  
  The injection kicker system MKP of the Super Proton Synchrotron SPS at CERN is composed of 4 kicker tanks. The MKP-L tank provides additional kick needed to inject 26 GeV Large Hadron Collider LHC 25 ns type beams. This device has been a limiting factor for operation with high intensity, due to the magnet’s broadband beam coupling impedance and consequent beam induced heating. To optimise the usage of the SPS and avoid idle (kicker cooling) time, studies were conducted to develop a recurrent deep learning model that could predict the measured temperature evolution of the MKP-L, using the beam conditions and temperature history as input. In a second stage, the ferrite temperature is also estimated putting together the external temperature predictions from accurate thermo-mechanical simulations of the kicker magnet. In this paper, the methodology is described and details of the neural network architecture used, together with the implementation of an ad-hoc loss function, are given. The results applied to the SPS 2021 operational data are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST044  
About • Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 18 June 2022
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TUPOST045 Overview of the Machine Learning and Numerical Optimiser Applications on Beam Transfer Systems for LHC and Its Injectors proton, extraction, experiment, alignment 961
 
  • F.M. Velotti, M.J. Barnes, E. Carlier, Y. Dutheil, M.A. Fraser, B. Goddard, N. Magnin, R.L. Ramjiawan, E. Renner, P. Van Trappen
    CERN, Meyrin, Switzerland
  • E. Waagaard
    Uppsala University, Uppsala, Sweden
  
  Machine learning and numerical optimisation algorithms are getting more and more popular in the accelerator physics community and, thanks to the computing power available, their application in daily operation more likely. In the CERN accelerator complex, and specifically on the beam transfer systems, many promising exploitation of these numerical tools have been put in place in the last years. Some of the state-of-the-art machine learning models have been explored and used to solve problems that were never fully addressed in the past. In this paper, the most recent results of application of machine learning and numerical optimisation for injection, extraction and transfer of beam from machine and to experimental areas are presented. An overview of the possible next steps and shortcomings is finally discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST045  
About • Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022
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TUPOPT037 LCLS Multi-Bunch Improvement Plan: First Results FEL, linac, experiment, undulator 1092
 
  • A. Halavanau, A.L. Benwell, T.G. Beukers, L.B. Borzenets, F.-J. Decker, J. Hugyik, A. Ibrahimov, E.N. Jongewaard, A.K. Krasnykh, A.L. Le, K. Luchini, A.A. Lutman, A. Marinelli, M. Petree, A. Romero, A.V. Sy
    SLAC, Menlo Park, California, USA
  
  LCLS copper linac primarily operates in a single bunch mode with a repetition rate of 120 Hz. Presently, several in-house projects and LCLS user experiments require double- and multi-pulse trains of X-rays, with inter-pulse delay spanning between 0.35 and 220 ns. We discuss beam control improvements to the copper linac using ultra-fast stripline kicker, as well as additional photon diagnostics. We especially focus on a case of double-pulse mode, with 218 ns separation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT037  
About • Received ※ 12 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 10 July 2022
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TUPOPT064 Online Optimization of NSLS-II Dynamic Aperture and Injection Transient injection, timing, sextupole, lattice 1159
 
  • X. Yang, B. Bacha, S. Buda, C. Danneil, A.A. Derbenev, D.J. Durfee, K. Ha, Y. Hidaka, Y. Hu, Y. Li, D. Padrazo Jr, F. Plassard, T.V. Shaftan, V.V. Smaluk, Y. Tian, G.M. Wang, L.H. Yu
    BNL, Upton, New York, USA
  
  The goal of the NSLS-II online optimization project is to improve the beam quality for the user experiments. To increase the beam lifetime and injection efficiency, we have developed a model-independent online optimization of nonlinear beam dynamics using advanced algorithms, such as Robust Conjugate-Gradient Algorithm (RCDS). The optimization objective is the injection efficiency and optimization variables are the sextupole magnet strengths. Using the online optimization technique, we increased the NSLS-II dynamic aperture and reduced the amplitude-dependent tune shift. Recently, the sextupole optimization was successfully applied to double the injection efficiency up to above 90% for the high-chromaticity lattice being developed to improve the beam stability and to in-crease the single-bunch beam intensity. Minimizing the beam perturbation during injection is the second objective in this project, realized by online optimization of the injection kickers. To optimize the full set of kicker parameters, including the trigger timing, amplitude, and pulse width, we upgraded all kicker power supplies with the capability of tunable waveform width. As a result, we have reduced the injection transient by a factor of 29, down to the limit of 60 um.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT064  
About • Received ※ 18 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 16 June 2022
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TUPOMS019 Collimation Strategy for the Low-Emittance PETRA IV Storage Ring collimation, injection, undulator, emittance 1445
 
  • M.A. Jebramcik, I.V. Agapov, S.A. Antipov, R. Bartolini, R. Brinkmann, D. Einfeld, T. Hellert, J. Keil
    DESY, Hamburg, Germany
  
  The beam-intensity losses in the proposed PETRA IV electron storage ring that will replace DESY’s synchrotron light source PETRA III will be dominated by the Touschek effect due to the high bunch density. The beam lifetime will only be in the range of 5 h in the timing mode (80 high-intensity bunches) leading to a maximum power loss of ~170 mW along the storage ring (excluding injection losses). To avoid the demagnetization of the permanent-magnet undulators and combined-function magnets, this radiation-sensitive hardware has to be shielded against losses as well as possible. Such shielding elongates the lifetime of the hardware and consequently reduces the time and the resources that are spent on maintenance once PETRA IV is operational. This contribution presents options for collimator locations, e.g., at the dispersion bump in the achromat cell, to reduce the exposure to losses from the Touschek effect and the injection process. This contribution also quantifies the risk of damaging the installed collimation system in case of hardware failure, e.g., RF cavity or quadrupole failure, since the beam with an emittance of 20 pm could damage collimators if there is no emittance blow-up.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS019  
About • Received ※ 08 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 28 June 2022  
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TUPOMS037 RCDS-S: An Optimization Method to Compensate Accelerator Performance Drifts experiment, simulation, operation, storage-ring 1506
 
  • Z. Zhang, X. Huang, M. Song
    SLAC, Menlo Park, California, USA
  
  We propose an optimization algorithm, Safe Robust Conjugate Direction Search (RCDS-S), which can perform accelerator tuning while keeping the machine performance within a designated safe envelope. The algorithm builds probability models of the objective function using Lipschitz continuity of the function as well as characteristics of the drifts and applies to the selection of trial solutions to ensure the machine operates safely during tuning. The algorithm can run during normal user operation constantly, or periodically, to compensate for the performance drifts. Simulation and online tests have been done to validate the performance of the algorithm.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS037  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 30 June 2022 — Issue date ※ 30 June 2022
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WEIYGD1 Achievements and Performance Prospects of the Upgraded LHC Injectors MMI, injection, brightness, proton 1610
 
  • V. Kain, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, F. Antoniou, T. Argyropoulos, F. Asvesta, B. Balhan, M.J. Barnes, D. Barrientos, H. Bartosik, P. Baudrenghien, G. Bellodi, N. Biancacci, A. Boccardi, J.C.C.M. Borburgh, C. Bracco, E. Carlier, D.G. Cotte, J. Coupard, H. Damerau, G.P. Di Giovanni, A. Findlay, M.A. Fraser, A. Funken, B. Goddard, G. Hagmann, K. Hanke, A. Huschauer, M. Jaussi, I. Karpov, T. Koevener, D. Küchler, J.-B. Lallement, A. Lasheen, T.E. Levens, K.S.B. Li, A.M. Lombardi, N. Madysa, E. Mahner, M. Meddahi, L. Mether, B. Mikulec, J.C. Molendijk, E. Montesinos, D. Nisbet, F.-X. Nuiry, G. Papotti, K. Paraschou, F. Pedrosa, T. Prebibaj, S. Prodon, D. Quartullo, E. Renner, F. Roncarolo, G. Rumolo, B. Salvant, M. Schenk, R. Scrivens, E.N. Shaposhnikova, P.K. Skowroński, A. Spierer, F. Tecker, D. Valuch, F.M. Velotti, R. Wegner, C. Zannini
    CERN, Meyrin, Switzerland
  
  To provide HL-LHC performance, the CERN LHC injector chain underwent a major upgrade during an almost 2-year-long shutdown. In the first half of 2021 the injectors were gradually re-started with the aim to reach at least pre-shutdown parameters for LHC as well as for fixed target beams. The strategy of the commissioning across the complex, a summary of the many challenges and finally the achievements will be presented. Several lessons were learned and have been integrated to define the strategy for the performance ramp-up over the coming years. Remaining limitations and prospects for LHC beam parameters at the exit of the LHC injector chain in the years to come will be discussed. Finally, the emerging need for improved operability of the CERN complex will be addressed, with a description of the first efforts to meet the availability and flexibility requirements of the HL-LHC era while at the same time maximizing fixed target physics output.  
slides icon Slides WEIYGD1 [5.905 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEIYGD1  
About • Received ※ 08 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 09 July 2022  
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WEPOST011 Studies on Top-Up Injection into the FCC-ee Collider Ring injection, optics, collider, lattice 1699
 
  • P.J. Hunchak, M.J. Boland
    CLS, Saskatoon, Saskatchewan, Canada
  • M. Aiba
    PSI, Villigen PSI, Switzerland
  • W. Bartmann, Y. Dutheil, M. Hofer, R.L. Ramjiawan, F. Zimmermann
    CERN, Meyrin, Switzerland
  • M.J. Boland
    University of Saskatchewan, Saskatoon, Canada
  
  In order to maximize the luminosity production time in the FCC-ee, top-up injection will be employed. The positron and electron beams will be accelerated to the collision energy in the booster ring before being injected with either a small transverse or longitudinal separation to the stored beam. Using this scheme essentially keeps the beam current constant and, apart from a brief period during the injection process, collision data can be continuously acquired. Two top-up injection schemes, each with on- and off-momentum sub-schemes, viable for FCC-ee have been identified in the past and are studied in further detail to find a suitable design for each of the four operation modes of the FCC-ee. In this paper, injection straight optics, initial injection tracking studies and the effect on the stored beam are presented. Additionally, a basic proxy error lattice is introduced as a first step to studying injection into an imperfect machine.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST011  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 19 June 2022
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WEPOST025 A High Power Prototype of a Harmonic Kicker Cavity cavity, operation, MMI, electron 1749
 
  • G.-T. Park, G.A. Grose, J. Guo, A. OBrien, R.A. Rimmer, H. Wang, R.S. Williams
    JLab, Newport News, Virginia, USA
  • S.A. Overstreet
    ODU, Norfolk, Virginia, USA
  
  A harmonic kicker, a beam exchange device that can deflect the beam at an ultra-fast time scale (a few ns), has been developed in Jefferson Lab *, **. The high power prototype that can deliver more than a 100 kV kick at 7 kW was fabricated. The RF performance of cavity such as the harmonic resonant frequencies, kick profiles, it’s stability, and electric center is tested at bench. The cavity will eventually be tested with a beam at Upgraded Injector Test Facility (UITF) in Jefferson Lab. In this paper, we report some features of fabrication and bench test results. We also briefly describe our beam test plan in the future.
* G.Park, H.Wang, R.A.Rimmer, S. Wang, and J.Guo, THP092, Proceedings of IPAC2018, Vancouver, Canada (2018).
** G.Park, et al, WEPRBO99, Proceedings of IPAC2019, Melbourne, Australia (2019). 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST025  
About • Received ※ 11 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
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WEPOPT028 Design Update on the HSR Injection Kicker for the EIC impedance, injection, simulation, coupling 1904
 
  • M.P. Sangroula, C.J. Liaw, C. Liu, J. Sandberg, N. Tsoupas, B.P. Xiao
    BNL, Upton, New York, USA
  • X. Sun
    ANL, Lemont, Illinois, 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), the next-generation nuclear science facility, is under the design at the Brookhaven National Laboratory. The present RHIC rings will be reconfigured as the Hadron Storage Ring (HSR) for the EIC. Design of a stripline injection kicker for the HSR for beams with the rigidity of  ∼  81   T-m poses some technical challenges due to the expected shorter bunch spacing, heating due to higher peak current and the larger number of bunches, and the required higher pulsed voltage. Recently, we updated its mechanical design to optimize the characteristic and beam coupling impedances. In addition, we incorporated the impedance tuning capability by introducing the kicker aperture adjustment mechanism. Finally, we incorporated high voltage FID feedthroughs (FC26) to this kicker. This paper reports the design and optimization updates of the HSR injection kicker including the impedance tuning capability, optimization of both the characteristic and the beam coupling impedances, and finally the incorporation of a high voltage feedthrough design. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT028  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 26 June 2022
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WEPOPT034 Reconfiguration of RHIC Straight Sections for the EIC electron, hadron, focusing, quadrupole 1916
 
  • C. Liu, J.S. Berg, D. Bruno, C. Cullen, K.A. Drees, W. Fischer, X. Gu, R.C. Gupta, D. Holmes, R.F. Lambiase, H. Lovelace III, C. Montag, S. Peggs, V. Ptitsyn, G. Robert-Demolaize, R. Than, J.E. Tuozzolo, M. Valette, S. Verdú-Andrés, D. Weiss, D. Xu
    BNL, Upton, New York, USA
  • B. Bhandari, F. Micolon, N. Tsoupas
    Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
  • B.R. Gamage, T. Satogata, W. Wittmer
    JLab, Newport News, Virginia, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 and Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177.
The Electron-Ion Collider (EIC) will be built in the existing Relativistic Heavy Ion Collider (RHIC) tunnel with the addition of electron acceleration and storage rings. The two RHIC rings will be reconfigured as a single Hadron Storage Ring (HSR) for accelerating and storing ion beams. The proton beam energy will be raised from 255 to 275 GeV to achieve the desired center-of-mass energy range: 20’140 GeV. It is also mandatory to operate the HSR with a constant revolution frequency over a large energy range (41’275 GeV for protons) to synchronize with the Electron Storage Ring (ESR). These and other requirements/challenges dictate modifications to RHIC accelerators. This report gives an overview of the modifications to the RHIC straight sections together with their individual challenges. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT034  
About • Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 06 July 2022
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WEPOPT035 Optics for Strong Hadron Cooling in EIC HSR-IR2 electron, hadron, optics, cavity 1920
 
  • S. Peggs, W.F. Bergan, D. Bruno, Y. Gao, D. Holmes, R.F. Lambiase, C. Liu, H. Lovelace III, G.J. Mahler, V. Ptitsyn, G. Robert-Demolaize, R. Than, J.E. Tuozzolo, E. Wang, D. Weiss, D. Xu
    BNL, Upton, New York, USA
  • S.V. Benson, T.J. Michalski
    JLab, Newport News, Virginia, USA
  • F. Micolon
    Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC001 2704, and by Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177.
Insertion Region 2 (IR2) of the Relativistic Heavy Ion Collider will be modified to accommodate a Strong Hadron Cooling facility in the Hadron Storage Ring (HSR) of the Electron-Ion Collider (EIC). This paper describes the current proof-of-principle design of HSR-IR2 - layout, optical performance, design methodology, and engineering requirements. It also describes the challenges and opportunities in the future development of the HSR-IR2 design, in order to further optimize Strong Hadron Cooling performance. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT035  
About • Received ※ 02 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 06 July 2022
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WEPOPT047 Beam Optics of the Injection/Extraction and Beam Transfer in the Electron Rings of the EIC Project injection, extraction, electron, optics 1964
 
  • N. Tsoupas, D. Holmes, C. Liu, C. Montag, V. Ptitsyn, V.H. Ranjbar, J. Skaritka, J.E. Tuozzolo, E. Wang, F.J. Willeke
    BNL, Upton, New York, USA
  • B. Bhandari
    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) project* has been approved by the Department of Energy to be built at the site of Brookhaven National Laboratory (BNL). The goal of the project is the collision of energetic (of many GeV/amu) ion species with electron bunches of energies up to 18 GeV. The EIC includes two electron rings, the Rapid Cycling Synchrotron (RCS) which accelerates the electron beam up to 18 GeV, and the Electron Storage Ring (ESR) which stores the electron beam for collisions with hadron beam, both to be installed in the same tunnel as the Hadron Storage Ring (HSR). This paper discusses the layout and the beam optics of the injection/extraction beam lines the electron rings and the beam optics of the transfer line from the RCS to the ESR ring.
* https://www.bnl.gov/eic/ 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT047  
About • Received ※ 05 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 23 June 2022
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WEPOTK023 Simulation Study of Fast Extraction in the Absence of One Septum Magnet for J-Parc Main Ring septum, operation, extraction, vacuum 2100
 
  • S. Iwata, S. Igarashi, K. Ishii, H. Matsumoto, N. Matsumoto, Y. Sato, T. Shibata, T. Sugimoto, T.Y. Yasui
    KEK, Tokai, Ibaraki, Japan
  
  At J-PARC main ring (MR), the two fast extracting beamlines to the neutrino facility and to the abort dump have a symmetrical layout of 6 septum magnets each, a total of 12. Since there are many magnets, it is necessary to be careful about failure. It is important to consider how to continue beam supply even if one of the septum mag-nets is missing. From July 2021, upgrade works of the FX septum magnets commenced with an aim of increasing the beam power of MR to 1.3 MW from 500 kW. We simulated the beam extraction without one of the septum magnets under the conditions of the new geometry of septum magnets and the new aperture. We found that the beam can be extracted by increasing the current of the surrounding septum magnets and compensating for the output.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK023  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022
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WEPOTK025 Concepts and Considerations for FCC-ee Top-Up Injection Strategies injection, septum, multipole, collider 2106
 
  • R.L. Ramjiawan, W. Bartmann, Y. Dutheil, M. Hofer
    CERN, Meyrin, Switzerland
  • M. Aiba
    PSI, Villigen PSI, Switzerland
  • P.J. Hunchak
    University of Saskatchewan, Saskatoon, Canada
  • P.J. Hunchak
    CLS, Saskatoon, Saskatchewan, Canada
  
  The Future Circular electron-positron Collider (FCC-ee) is proposed to operate in four modes, with beam energies from 45.6 GeV (Z-pole) to 182.5 GeV (tt-bar production) and luminosities up to 4.6×1036 cm2s-1. At the highest energies the beam lifetime would be less than one hour, meaning that top-up injection will be crucial to maximise the integrated luminosity. Two top-up injection strategies are considered here: conventional injection, employing a closed orbit bump and septum, and multipole-kicker injection, with a pulsed multipole magnet and septum. On-axis and off-axis injections are considered for both. We present a comparison of these injection strategies taking into account aspects such as spatial constraints, machine protection, disturbance to the stored beam and injection efficiency. We overview potential kicker and septum technologies for each.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK025  
About • Received ※ 03 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 14 June 2022
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WEPOMS004 Investigation of RF Heating for the Multipole Injection Kicker Installed at SOLEIL impedance, injection, simulation, operation 2233
 
  • A. Gamelin, P. Alexandre, R. Ben El Fekih, J. Da Silva Castro, M. El Ajjouri, A. Letresor, L.S. Nadolski, R. Ollier, T.S. Thoraud
    SOLEIL, Gif-sur-Yvette, France
  • M. Sacko, S. Taurines
    Avantis Concept, SAINT-CERE, France
  
  During the commissioning of the new Multipole Injection Kicker (MIK) pulsed magnet at SOLEIL synchrotron, an anomalously high heating of the MIK chamber and flanges was found. To better manage the heat load, fans directed toward the MIK were added to improve the air-cooling flow. This allowed the nominal current to be reached in all operation modes while keeping reasonable temperatures on the MIK. Post-installation investigations subsequently showed that the initial estimate of the maximal heat load was in agreement with the measured temperature in several operation modes both with and without the additional fans. In this article, we present the complete study, starting from the impedance calculation to thermal simulations, and comparison with the measured data with beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS004  
About • Received ※ 18 May 2022 — Accepted ※ 16 June 2022 — Issue date ※ 24 June 2022  
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WEPOMS029 Modeling of the Optical Stochastic Cooling at the IOTA Storage Ring Using ELEGANT radiation, experiment, coupling, undulator 2307
 
  • A.J. Dick, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • J.D. Jarvis
    Fermilab, Batavia, Illinois, USA
  • P. Piot
    ANL, Lemont, Illinois, USA
  
  In support of the Optical Stochastic Cooling (OSC) experiment at IOTA, we implemented a high-fidelity model of OSC in ELEGANT. The element is generalizable to any OSC experiment and captures three main behaviors; (i) the longitudinal time of flight OSC, (ii) the effects between the transverse motion of particles in the beam and the transverse distribution of undulator radiation, and (iii) the incoherent contributions of neighboring particles. Together these produce a highly accurate model of OSC and were benchmarked using the results from the IOTA OSC experiment.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS029  
About • Received ※ 14 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 05 July 2022 — Issue date ※ 06 July 2022
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WEPOMS032 Simulations of Coherent Electron Cooling with Orbit Deviation electron, simulation, plasma, hadron 2319
 
  • 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 beam. Plasma cascade amplifier (PCA) has been proposed for the CeC experiment in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Cooling performance of PCA based CeC has been predicted in 3D start-to-end CeC simulations using code SPACE. The dependence of the PCA gain and the cooling rate on the electron beam’s orbit deviation has been explored in the simulation studies. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS032  
About • Received ※ 16 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 29 June 2022
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THPOST017 Physical Design of a 10 MeV High Scanning Frequency Irradiation Electron Linear Accelerator electron, radiation, gun, simulation 2476
 
  • S. Zhang, Z.D. Zhang
    UCAS, Beijing, People’s Republic of China
  • Y.L. Chi, M. Iqbal, J.R. Zhang, S. Zhang, Z.D. Zhang, Z.S. Zhou
    IHEP, Beijing, People’s Republic of China
  
  A compact 10 MeV irradiation S-band electron linear accelerator has been proposed to carry out the electron radiation effect test of materials and devices. The Linac includes a standing wave pre-buncher, a traveling wave bunching accelerating structure. The traveling wave accelerating structure uses a 5MW klystron as RF source and provides electron beam energy 3.5-10MeV and average current 0.01-1mA. The required irradiation scanning frequency is very high, up to 100Hz and irradiation area is large (200mm×200mm). To meet the requirements, a novel beam scanning system, including one kicker for horizontal scanning and one magnet for vertical scanning, have been proposed. This paper presents the physical design of the 10MeV electron Linac and beam dynamics simulation results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST017  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 14 June 2022
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THPOST039 SPS Beam Dump System (SBDS) Commissioning After Relocation and Upgrade MMI, controls, vacuum, hardware 2530
 
  • P. Van Trappen, E. Carlier, L. Ducimetière, V. Namora, V. Senaj, F.M. Velotti, N. Voumard
    CERN, Meyrin, Switzerland
  
  In order to overcome several machine limitations, the SBDS has been relocated from LSS1 (Long Straight Section 1) to LSS5 during LS2 (Long Shutdown 2) with an important upgrade of the extraction kicker installation. An additional vertical deflection kicker magnet (MKDV) was produced and installed while the high voltage (HV) pulse generators have been upgraded by changing gas-discharge switches (thyratrons and ignitrons) to semiconductor stacks operating in oil. Furthermore the horizontal sweep generators have been upgraded to allow for a lower kick strengths. The controls, previously consolidated during LS1, went through an additional light consolidation phase with among others the upgrade of the trigger & retrigger distribution system and the installation of a new fast-interlocks detection system. This paper describes the commissioning without and with beam and elaborates on the measured improvements and encountered problems with corrective mitigations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST039  
About • Received ※ 07 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 15 June 2022  
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THPOST048 RHIC Machine Protection System Upgrades detector, power-supply, operation, monitoring 2548
 
  • M. Valette, D. Bruno, K.A. Drees, P.S. Dyer, R.L. Hulsart, J.S. Laster, J. Morris, G. Robert-Demolaize, J. Sandberg, C. Schultheiss, T.C. Shrey, G.M. Tustin
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
’In order to protect the future sPHENIX detector from spontaneous and asynchronous firing of one of the five RHIC abort kickers, mechanical relays were added to the triggering channel for each of them. The mechanical relays add several milliseconds to the delay between the detection of a failure or beam loss and the beam being safely disposed of. In order to account for this delay new inputs were included into the RHIC Machine Protection System to ensure detection of abnormal conditions as early as possible. These inputs include system diagnostics and beam measurements such as Beam Position Monitor signals. In this paper we detail the upgrades that will allow reliable operations with high intensity and high energy ion beams and the new detector as well as related operational challenges and how they were addressed. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST048  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022
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THPOPT018 Aperture Sharing Injection for Diamond-II injection, storage-ring, lattice, septum 2606
 
  • J. Kallestrup, H. Ghasem, I.P.S. Martin
    DLS, Oxfordshire, United Kingdom
  
  The planned Diamond-II storage ring will provide users with an increase in brightness of up to two orders of magnitude compared with the existing Diamond facility. The aim is to maintain excellent photon beam stability in top-up mode, which requires frequent injections. This paper introduces the aperture sharing injection scheme designed for Diamond-II. The scheme promises, through the use of short striplines equipped with high-voltage nano-second pulsers, a quasi-transparent injection while maintaining an approximately 100% injection efficiency.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT018  
About • Received ※ 31 May 2022 — Accepted ※ 30 June 2022 — Issue date ※ 01 July 2022  
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THPOPT039 Performance Report of the SOLEIL Multipole Injection Kicker injection, storage-ring, MMI, synchrotron 2675
 
  • R. Ollier, P. Alexandre, R. Ben El Fekih, A. Gamelin, N. Hubert, M. Labat, A. Nadji, L.S. Nadolski, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette, France
  
  A Multipole Injection Kicker (MIK) was installed in a short straight section of the SOLEIL storage ring and successfully commissioned in 2021. A small horizontal orbit distortion in the micrometer range was achieved outperforming the standard bump-based injection scheme installed in a 12-m long straight section. Refined studies have been conducted to fully understand and further improve the performance of the device. Indeed, a novel generation of the MIK will be the key element for the injection scheme of the SOLEIL Upgrade. We report simulation studies and the latest MIK experimental performance. Both injected and stored beam-based measurements were performed using new types of diagnostics with turn-by-turn capability (Libera Brillance+ BPM, KALYPSO: 2x1D imaging). The residual perturbations on the beam positions and sizes were measured; the magnetic field of the MIK device was reconstructed. An unexpected kick was detected in the vertical plane and an active correction implemented to cancel the resulting perturbation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT039  
About • Received ※ 09 June 2022 — Accepted ※ 29 June 2022 — Issue date ※ 06 July 2022  
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THPOPT040 Injection Using a Non-Linear Kicker at the ESRF injection, SRF, simulation, emittance 2679
 
  • S.M. White, T.P. Perron
    ESRF, Grenoble, France
  
  The ESRF injection consists in a standard four kickers bump off-axis injection. Although this scheme is very robust and reliable it is known to disturb users during injections and may represent a severe limitation in case frequent injections are required. The non-linear kicker injection scheme provides a possible solution to this problem by acting only on the injected beam. This paper reports on the potential integration of a non-linear kicker injection scheme at the ESRF. A layout and specifications for the kicker are proposed and simulations are provided to evaluate the performance and limitations of such scheme.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT040  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOPT041 Commissioning of New Kicker Power Supplies to Improve Injection Perturbations at the ESRF injection, power-supply, SRF, storage-ring 2683
 
  • S.M. White, N. Carmignani, L.R. Carver, M. Dubrulle, L. Hoummi, M. Morati, T.P. Perron, B. Roche
    ESRF, Grenoble, France
  
  The ESRF-EBS storage ring resumed operation in 2020. Due to the reduced lifetime, top-up injection is required for all operation modes. Perturbations on the stored beam introduced by the pulsed injection elements represent a significant disturbance to the beam lines that need to run experiments across injection. In order to reduce these perturbation, new kicker power supplies with slower ramping times and better shot-to-shot reproducibility were developed at ESRF to improve the efficiency of the feed-forward compensation scheme. This paper reports on the design, commissioning and first experimental validation of these new power supplies.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT041  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOPT043 Injection Design Options for the Low-Emittance PETRA IV Storage Ring septum, injection, emittance, lattice 2689
 
  • M.A. Jebramcik, I.V. Agapov, S.A. Antipov, R. Bartolini, R. Brinkmann, D. Einfeld, T. Hellert, J. Keil, G. Loisch, F. Obier
    DESY, Hamburg, Germany
  
  The proposed PETRA IV electron storage ring that will replace DESY’s flagship synchrotron light source PETRA III will feature a horizontal emittance as low as 20 pm based on a hybrid six-bend achromat lattice. Such a lattice design leads to the difficulty of injecting the incoming beam into an acceptance that is as small as 2.6 um. In contrast to earlier lattice iterations based on a seven-bend achromat lattice, the latest version allows accumulation, i.e., the off-axis injection of the incoming beam. In this contribution, the effects of deploying different septum types, namely a pulsed or a Lambertson septum, on the injection process as well as the injection efficiency are presented. This analysis includes the effects of common manipulations to the injected beam, e.g., beam rotation and aperture sharing, on the injection efficiency. Furthermore, the option of a nonlinear kicker and its optimization (wire positions, wire current, optics functions) are presented since a nonlinear kicker could provide an alternative to the rather large number of strip-line kickers that are necessary to generate the orbit bump at the septum.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT043  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022
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THPOPT047 A Double Dipole Kicker for Off and On-Axis Injection for ALBA-II injection, dipole, vacuum, storage-ring 2701
 
  • G. Benedetti, M. Carlà, M. Pont
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  
  Injection into the ALBA-II storage ring will be performed off-axis in a 4 meters straight section with a single multipole kicker. We present a novel topology for the coils of the injection kicker, named double dipole kicker (DDK). The resulting magnetic field is the superposition of two opposite dipoles, generated by four inner and four outer conductor rods. When the eight rods are powered, the dipole term cancels and the remaining multipole field is used for off-axis injection. Alternatively, when the four inner rods are switched off, an almost pure dipole is produced, that is useful for on-axis injection during the commissioning. A prototype of DDK is presently under design to be installed and tested in the existing ALBA storage ring. The positioning of the rods is calculated in order to maximise the kick efficiency in mrad/kA and minimise the disturbance to the orbit and the emittance of the stored beam. A metallic coating with optimised thickness along the inner ceramic vacuum chamber should provide compensation for the eddy currents induced field in order to minimize the disturbance to the stored beam while ensuring sufficiently low heat dissipation by the beam image currents.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT047  
About • Received ※ 16 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 20 June 2022
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THPOTK040 Few-Nanosecond Stripline Kickers for Top-Up Injection into PETRA IV injection, feedback, vacuum, synchrotron 2858
 
  • G. Loisch, V. Belokurov, F. Obier
    DESY, Hamburg, Germany
  
  PETRA IV is the planned ultralow-emittance upgrade of the PETRA III synchrotron light source at DESY, Hamburg. The current baseline injection scheme is an off-axis, top-up injection with few-nanosecond stripline kickers, which would allow for accumulation and least disturbance of experiments during injection. Besides the requirements on kick-strength, field quality, pulse rise-rate, and heat management, two mechanical designs with different apertures are necessary, as the devices will be used for injection and the transverse multi-bunch feedback system. In this contribution we will present the current status of 3D finite element simulations of electromagnetic fields and heating as well as the mechanical design and first pulse electronics tests.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK040  
About • Received ※ 20 May 2022 — Revised ※ 17 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 29 June 2022
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THPOTK041 Development of Programmable Bipolar Multi kHz Kicker Drivers for Long Pulse Superconducting Electron Linacs FEL, electron, gun, laser 2862
 
  • J.L. Teichgräber, W. Decking, J. Kahl, F. Obier
    DESY, Hamburg, Germany
  
  Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany Superconducting cavities allow for long rf-pulses, which enable the acceleration of thousands of electron bunches within one rf-pulse. Due to transient effects, e.g. coupler kicks, eddy currents or wakefields, bunch properties like the beam trajectory can change along the pulse train. To compensate for this, kicker systems based on high-current operational amplifiers have been developed for the free electron lasers European XFEL and FLASH at DESY in Hamburg. Here, we present the layout of the kicker system, the setup of the pulse electronics, and operational results with beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK041  
About • Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 19 June 2022
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THPOTK043 Mitigation of High Voltage Breakdown of the Beam Screen of a CERN SPS Injection Kicker Magnet impedance, injection, simulation, coupling 2868
 
  • M.J. Barnes, W. Bartmann, M. Díaz Zumel, L. Ducimetière, L.M.C. Feliciano, T. Kramer, V. Namora, T. Stadlbauer, D. Standen, P. Trubacova, F.M. Velotti, C. Zannini
    CERN, Meyrin, Switzerland
  
  The SPS injection kicker magnets (MKP) were developed in the 1970’s, before beam induced power deposition was considered an issue. These magnets are very lossy from a beam impedance perspective: this is expected to be an issue during SPS operation with the higher intensity beams needed for HL-LHC. A design, with serigraphy applied to an alumina carrier, has been developed to significantly reduce the broadband beam coupling impedance and hence mitigate the heating issues. During high voltage pulse testing there were electrical discharges associated with the serigraphy. Detailed mathematical models have been developed to aid in understanding the transiently induced voltages and to reduce the magnitude and duration of electric field. In this paper, we discuss the solutions implemented to mitigate the electrical discharges while maintaining an adequately low beam-coupling impedance. In addition, the results of high voltage tests are reported. The alumina substrate has a high secondary electron yield and thus electron-cloud could be an issue, with SPS beam, if mitigating measures were not taken: this paper also discusses the measures implemented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK043  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022
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THPOTK045 Branch Module for an Inductive Voltage Adder for Driving Kicker Magnets with a Short Circuit Termination operation, injection, impedance, controls 2875
 
  • J. Ruf, M.J. Barnes, Y. Dutheil, T. Kramer
    CERN, Meyrin, Switzerland
  • M. Sack
    KIT, Karlsruhe, Germany
  
  For driving kicker magnets terminated in a short circuit, a branch module for an inductive voltage adder has been designed and assembled. The module has been designed for a maximum charging voltage of 1.2 kV and an output current of 200 A considering the current doubling due to the short circuit termination. It features three consecutive modes of operation: energy injection, freewheeling, and energy extraction. Therefore, the topology of the branch module consists of two independently controlled SiC MOSFET switches and one diode switch. In order not to extend the field rise time of the kicker magnet significantly beyond the magnet fill time, the pulse must have a fast rise time. Hence, the switch for energy injection is driven by a gate boosting driver featuring a half bridge of GaN HEMTs and a driving voltage of 80 V. Measurements of the drain source voltage of this switch showed a fall time of 2.7 ns at a voltage of 600 V resulting in a voltage rise time of 5.4 ns at the output terminated with a resistive load. To meet both the rise time and current requirements, a parallel configuration of four SiC MOSFETs was implemented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK045  
About • Received ※ 16 May 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022  
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FRIXGD1 Status and Prospects in Fast Beam-Based Feedbacks feedback, cavity, pick-up, hadron 3112
 
  • W. Höfle
    CERN, Meyrin, Switzerland
  
  Fast beam-based Feedback systems play an important role in circular accelerators to mitigate instabilities and reduce the impact of injection oscillations and perturbations on beam quality, both in the longitudinal and transverse planes. The status and prospects of such beam-based feedback systems for circular accelerators are reviewed. This includes progress towards the fundamental limits in noise and feedback gain and the possibilities of modern digital systems to extract large amounts of data that can be used to characterise beam properties. The talk concentrates on machines with hadrons and gives an outlook on possible developments for future accelerator projects under study.  
slides icon Slides FRIXGD1 [3.562 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-FRIXGD1  
About • Received ※ 08 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022  
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