IPAC2021 - Classification: MC2: Photon Sources and Electron Accelerators / T12 Beam Injection/Extraction and Transport

Paper	Title	Page
MOPAB082	Implementation of Using IGBT Switch Based Pulser for TPS Booster Extraction Kicker	315
	C.-S. Fann, H.-P. Chang, C.L. Chen, Y.-S. Cheng, K.T. Hsu, S.Y. Hsu, K.-K. Lin, K.L. Tsai, C.Y. Wu NSRRC, Hsinchu, Taiwan
	A pair of thyratron-switch-based pulse-forming-network (PFN) pulser has been operating successfully in the past 5 years for TPS booster extraction kickers. In order to improve the flattop of drive-current pulse and to extend possible electron bunch train adjusting knob required, an IGBT-switch-based pulser has been designed, fabricated, and installed onto the TPS booster for its characteristics verification. In this report, the overall technical considerations for the pulser upgrade is described and its beam commissioning results is given for illustration purpose.
	Poster MOPAB082 [0.621 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB082
About •	paper received ※ 20 May 2021 paper accepted ※ 27 May 2021 issue date ※ 13 August 2021
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MOPAB115	ATS/STA Transfer Line Design for the ALS Upgrade Project (ALS-U)	417
	C. Sun, M.P. Ehrlichman, T. Hellert, M. Juchno, J.-Y. Jung, M. Mardenfeld, J.R. Osborn, G. Penn, C. Steier, C.A. Swenson, M. Venturini LBNL, Berkeley, California, USA
	At the Advanced Light Source Upgrade (ALS-U), an on-axis swap-out injection will be used to replenish depleted bunches in the storage ring with refreshed bunches from the full energy accumulator ring. To implement this scheme, two transfer lines are required between the storage ring and the accumulator ring: the accumulator-to-storage-ring (ATS) transfer line and the storage-ring-to-accumulator (STA) transfer line. The design of the ATS/STA transfer lines is a challenging task as they must fit within a tight injection region while also accommodating the storage and accumulator rings at different elevations. Moreover, the ATS/STA design needs to meet both the boundary conditions and optics requirements. In this paper, we will present a design option for these ATS/STA transfer lines.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB115
About •	paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 15 August 2021
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MOPAB128	Operational Use of Pinger Magnets to Counter Stored Beam Oscillations During Injection at Diamond Light Source	459
	R.T. Fielder, M. Apollonio, I.P.S. Martin DLS, Oxfordshire, United Kingdom
	Diamond uses a four kicker bump injection scheme. Due to a variety of factors it has become more difficult to perfectly match the four kicks while maintaining injection efficiency, resulting in some disturbance to the stored beam during top-up. This has consequences for beamlines which may see degraded beam quality during injections. A gating signal is provided, but this is not appropriate for all experiments, and in any case ideally would not be required. The disturbance to the stored beam can be partly controlled using the existing diagnostic pinger magnets installed in the storage ring. We present here a comparison of different compensation schemes and tests with beamlines, along with initial experiences operating during user beam time. Use of these magnet also provides proof of principle for any future, purpose-built compensation kickers.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB128
About •	paper received ※ 18 May 2021 paper accepted ※ 20 May 2021 issue date ※ 01 September 2021
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WEPAB113	Stripline Kickers for Injection Into PETRA IV	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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WEPAB115	Beam Preparation with Temporally Modulated Photocathode Laser Pulses for a Seeded THz FEL	2866
	G.Z. Georgiev, N. Aftab, P. Boonpornprasert, J. Good, M. Groß, C. Koschitzki, M. Krasilnikov, X. Li, O. Lishilin, A. Lueangaramwong, D. Melkumyan, S.K. Mohanty, R. Niemczyk, A. Oppelt, H.J. Qian, H. Shaker, G. Shu, F. Stephan, G. Vashchenko, T. Weilbach DESY Zeuthen, Zeuthen, Germany N. Chaisueb Chiang Mai University, Chiang Mai, Thailand W. Hillert University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
	The need for carrier-envelope-phase (CEP) stable THz pump pulses is recognized at many pump-probe experiments at the European XFEL. At the Photo Injector Test Facility at DESY in Zeuthen (PITZ), a proof-of-principle experiment of an accelerator-based THz FEL source is in preparation. Since the CEP stability of FEL pulses is not guaranteed in the SASE regime, a seeding scheme is needed. A common scheme for seeding is to drive the microbunching process with external laser pulses, which are power-limited in the THz range. Alternatively, a pre-bunched beam, generated for example by applying a temporally modulated photocathode laser pulse, can be used to drive the FEL. The beam dynamics with such a seeding method are studied with ASTRA tracking code simulations with space-charge forces as well as experimentally. The results of these studies are shown and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB115
About •	paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 26 August 2021
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WEPAB117	Injection Feedback for a Storage Ring	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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WEPAB118	Loss Maps Along the ThomX Transfer Line and the Ring First Turn	2874
	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 studies of the loss maps for particles travelling from the end of the ThomX’s linac along the transfer line to the end of the ring first turn in preparation of the machine commissioning. ThomX is a 50-MeV-electron accelerator prototype which will use Compton backscattering to generate a high flux of hard X-rays. The accelerator tracking code MadX is used to simulate electrons’ propagation and compute losses. These maps may be projected at any localisation along the bunch path or plotted along the bunch path. This information is particularly relevant at the locations of the monitoring devices (screens, position monitors,…) where loss predictions will be compared with measurements.
	Poster WEPAB118 [3.173 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB118
About •	paper received ※ 28 May 2021 paper accepted ※ 28 July 2021 issue date ※ 12 August 2021
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WEPAB119	Beam Injection with a Pulsed Nonlinear Magnet Into the HALF Storage Ring	2878
	G. Liu, W. Li, L. Wang, P.N. Wang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	The nonlinear optics of the HALF storage ring are well optimized to make it possible to inject the beam with the pulsed multipole injection scheme. In this paper, the injection scheme is studied with an innovatively designed pulsed nonlinear magnet. The layout and parameters of the injection system are well designed based on the acceptance analysis. The injection process is simulated with particle tracking is presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB119
About •	paper received ※ 20 May 2021 paper accepted ※ 29 July 2021 issue date ※ 13 August 2021
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WEPAB120	Upgrades to the Booster to Storage Ring Transfer Line at the Canadian Light Source	2881
	W.A. Wurtz, T. Batten, B.E. Bewer, M. Bree, S.R. Carriere, A.M. Duffy, B. Fogal, L.X. Lin, C.M. Randall, B.A. Schneider, J.M. Vogt, J. Willard, T. Wilson CLS, Saskatoon, Saskatchewan, Canada P. Kuske HZB, Berlin, Germany
	Investigations into the booster to storage ring transfer process identified non-linear fields in the booster extraction septum as the cause for the poor transfer efficiency. We found that by correcting the trajectory through the septum, the transfer efficiency improved substantially. This motivated an upgrade project to reliably control the trajectory through the septum and transfer line, to provide improved diagnostics and to implement a set of four horizontal scrapers to reduce the horizontal emittance of the beam before it reaches the storage ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB120
About •	paper received ※ 10 May 2021 paper accepted ※ 24 June 2021 issue date ※ 23 August 2021
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WEPAB121	Design and Simulation of Transparent Injection Upgrade for the CLS Storage Ring	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	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	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	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	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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Paper

Title

Page

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

315

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

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

Poster MOPAB082 [0.621 MB]

DOI •

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

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

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MOPAB115

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

417

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

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

DOI •

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

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

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MOPAB128

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

459

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

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

DOI •

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

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

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WEPAB113

Stripline Kickers for Injection Into PETRA IV

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

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

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WEPAB115

Beam Preparation with Temporally Modulated Photocathode Laser Pulses for a Seeded THz FEL

2866

G.Z. Georgiev, N. Aftab, P. Boonpornprasert, J. Good, M. Groß, C. Koschitzki, M. Krasilnikov, X. Li, O. Lishilin, A. Lueangaramwong, D. Melkumyan, S.K. Mohanty, R. Niemczyk, A. Oppelt, H.J. Qian, H. Shaker, G. Shu, F. Stephan, G. Vashchenko, T. Weilbach
DESY Zeuthen, Zeuthen, Germany
N. Chaisueb
Chiang Mai University, Chiang Mai, Thailand
W. Hillert
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany

The need for carrier-envelope-phase (CEP) stable THz pump pulses is recognized at many pump-probe experiments at the European XFEL. At the Photo Injector Test Facility at DESY in Zeuthen (PITZ), a proof-of-principle experiment of an accelerator-based THz FEL source is in preparation. Since the CEP stability of FEL pulses is not guaranteed in the SASE regime, a seeding scheme is needed. A common scheme for seeding is to drive the microbunching process with external laser pulses, which are power-limited in the THz range. Alternatively, a pre-bunched beam, generated for example by applying a temporally modulated photocathode laser pulse, can be used to drive the FEL. The beam dynamics with such a seeding method are studied with ASTRA tracking code simulations with space-charge forces as well as experimentally. The results of these studies are shown and discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB115

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paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 26 August 2021

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WEPAB117

Injection Feedback for a Storage Ring

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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WEPAB118

Loss Maps Along the ThomX Transfer Line and the Ring First Turn

2874

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 studies of the loss maps for particles travelling from the end of the ThomX’s linac along the transfer line to the end of the ring first turn in preparation of the machine commissioning. ThomX is a 50-MeV-electron accelerator prototype which will use Compton backscattering to generate a high flux of hard X-rays. The accelerator tracking code MadX is used to simulate electrons’ propagation and compute losses. These maps may be projected at any localisation along the bunch path or plotted along the bunch path. This information is particularly relevant at the locations of the monitoring devices (screens, position monitors,…) where loss predictions will be compared with measurements.

Poster WEPAB118 [3.173 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB118

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

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WEPAB119

Beam Injection with a Pulsed Nonlinear Magnet Into the HALF Storage Ring

2878

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

The nonlinear optics of the HALF storage ring are well optimized to make it possible to inject the beam with the pulsed multipole injection scheme. In this paper, the injection scheme is studied with an innovatively designed pulsed nonlinear magnet. The layout and parameters of the injection system are well designed based on the acceptance analysis. The injection process is simulated with particle tracking is presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB119

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paper received ※ 20 May 2021 paper accepted ※ 29 July 2021 issue date ※ 13 August 2021

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WEPAB120

Upgrades to the Booster to Storage Ring Transfer Line at the Canadian Light Source

2881

W.A. Wurtz, T. Batten, B.E. Bewer, M. Bree, S.R. Carriere, A.M. Duffy, B. Fogal, L.X. Lin, C.M. Randall, B.A. Schneider, J.M. Vogt, J. Willard, T. Wilson
CLS, Saskatoon, Saskatchewan, Canada
P. Kuske
HZB, Berlin, Germany

Investigations into the booster to storage ring transfer process identified non-linear fields in the booster extraction septum as the cause for the poor transfer efficiency. We found that by correcting the trajectory through the septum, the transfer efficiency improved substantially. This motivated an upgrade project to reliably control the trajectory through the septum and transfer line, to provide improved diagnostics and to implement a set of four horizontal scrapers to reduce the horizontal emittance of the beam before it reaches the storage ring.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB120

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paper received ※ 10 May 2021 paper accepted ※ 24 June 2021 issue date ※ 23 August 2021

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WEPAB121

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

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

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

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

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

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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