IPAC2022 - List of Keywords (septum)

Paper	Title	Other Keywords	Page
MOPOPT022	Beam Dynamics of the Transparent Injection for the MAX IV 1.5 GeV Ring	injection, kicker, 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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MOPOPT051	Optical Fiber Based Beam Loss Monitor for SPS Machine	radiation, beam-losses, injection, operation	374
	T. Pulampong, W. Phacheerak, P. Sudmuang, N. Suradet SLRI, Nakhon Ratchasima, Thailand
	At the Siam Photon Source (SPS) beam loss monitors based on PIN diode have been used. The existing system allow beam loss detection very locally at the monitor position close to the vacuum chamber. For optical fiber, Cherenkov radiation can be detected when a lost particle travel in the fiber. Thus optical fiber based loss monitor with sufficient length can cover parts of the machine conveniently. Fast beam loss event can be detected with more accurate position. In this paper, the design and result of the optical fiber based beam loss monitor system at SPS machine are discussed. The system will be a prototype for the new 3 GeV machine SPS-II.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT051
About •	Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 08 July 2022
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MOPOTK060	An Induction-Type Septum Magnet for the EIC Complex	injection, induction, electron, extraction	603
	N. Tsoupas, D. Holmes, C. Liu, I. Marneris, C. Montag, V. Ptitsyn, V.H. Ranjbar, J.E. Tuozzolo 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). Part of the eIC accelerator complex and more specifically the Rapid Cycling Syncrotron (RCS) which accelerates the electron beam up to 18 GeV and the electron Storage Ring (eSR) which stores the electron beam bunces for collisions with the hadrons, will be built inside the tunnel of the Relativistic Heavy Ion Collider (RHIC). This paper provides information on the electromagnetic design of the septa magnets which will be employed to inject and extract the beam to and from the two synchrotrons used for the acceleration and storage of the electron beam bunches. The type of the septum is of induction type made o laminated iron and it is similar to the one described in ref.[3] The electromagnetic study is performed by the use of the transient module of the OPERA computer code. https://ww.bnl.gov/eic/ A. Zhuravlev, et al. PIPAC2013, Shanghai, China * https://www.3ds.com/products-services/simulia/products/opera/
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK060
About •	Received ※ 05 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 21 June 2022
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MOPOMS041	Concrete Shielding Activation for Proton Therapy Systems Using BDSIM and FISPACT-II	proton, shielding, neutron, simulation	728
	E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde ULB, Bruxelles, Belgium C. Hernalsteens CERN, Meyrin, Switzerland F. Stichelbaut IBA, Louvain-la-Neuve, Belgium
	Proton therapy systems are used worldwide for patient treatment and fundamental research. The generation of secondary particles when the beam interacts with the beamline elements is a well-known issue. In particular, the energy degrader is the dominant source of secondary radiation. This poses new challenges for the concrete shielding of compact systems and beamline elements activation computation. We use a novel methodology to seamlessly simulate all the processes relevant to the activation evaluation. A realistic model of the system is developed using Beam Delivery Simulation (BDSIM), a Geant4-based particle tracking code that allows a single model to simulate primary and secondary particle tracking and all particle-matter interactions. The secondary particle fluxes extracted from the simulations are provided as input to FISPACT-II to compute the activation by solving the rate equations. This approach is applied to the Ion Beam Applications (IBA) Proteus®ONE (P1) system and the shielding of the proton therapy research centre of Charleroi, Belgium. Proton loss distributions are used to model the production of secondary neutrals inside the accelerator structure. Two models for the distribution of proton losses are compared for the computation of the clearance index at specific locations of the design. Results show that the variation in the accelerator loss models can be characterised as a systematic error.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS041
About •	Received ※ 19 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 22 June 2022
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TUPOMS036	Commissioning of the Lower Emittance Lattice at SPEAR3	lattice, emittance, operation, simulation	1502
	K. Tian, W.J. Corbett, S.M. Gierman, X. Huang, J. Kim, J.B. Langton, NL. Parry, J.A. Safranek, J.J. Sebek, M. Song, Z. Zhang SLAC, Menlo Park, California, USA
	SPEAR3, commissioned in 2004, is a third generation light source at the SLAC National Accelerator Laboratory. The low emittance lattice with an emittance of 10 nm had been operated for over a decade until the recent commission of the new lower emittance lattice with 7 nm emittance. The new lattice, based on the same double-bend achromat lattice, has pushed toward the design limit of such type of lattice in SPEAR3. In this paper, we will elaborate our commissioning experience for the new lattice in SPEAR3.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS036
About •	Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 29 June 2022
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WEPOST013	Exploitation of Crystal Shadowing via Multi-Crystal Array, Optimisers and Reinforcement Learning	operation, extraction, simulation, proton	1707
	F.M. Velotti, M. Di Castro, L.S. Esposito, M.A. Fraser, S.S. Gilardoni, B. Goddard, V. Kain, E. Matheson CERN, Meyrin, Switzerland
	The CERN Super Proton Synchrotron (SPS) routinely delivers proton and heavy ion beams to the North experimental Area (NA) in the form of 4.8 s spills. To produce such a long flux of particles, resonant third integer slow extraction is used, which, by design, foresees primary beam lost on the electrostatic septum wires to separate circulating from extracted beam. Shadowing with thin bent crystal has been proposed and successfully tested in the SPS, as detailed in . In 2021, a thin crystal was used for physics production showing results compatible with what measured during early testing. In this paper, the results from the 2021 physics run are presented also comparing particle losses at extraction with previous operational years. The setting up of the crystal using numerical optimisers is detailed, with possible implementation of reinforcement learning (RL) agents to improve the setting up time. Finally, the full exploitation of crystal shadowing via multi-array crystals is discussed, together with the performance reach in the SPS. F.Velotti, et. al, "Septum shadowing by means of a bent crystal to reduce slow extraction beam loss", Phys. Rev. Accel. Beams 22, 093502 - Published 27 September 2019*
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST013
About •	Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 02 July 2022
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WEPOTK014	Hadron Storage Ring 4 O’clock Injection Design and Optics for the Electron-Ion Collider	injection, optics, electron, dipole	2068
	H. Lovelace III, J.S. Berg, D. Bruno, C. Cullen, K.A. Drees, W. Fischer, X. Gu, R.C. Gupta, D. Holmes, R.F. Lambiase, C. Liu, C. Montag, S. Peggs, V. Ptitsyn, G. Robert-Demolaize, R. Than, J.E. Tuozzolo, M. Valette, D. Weiss BNL, Upton, New York, USA B. Bhandari, F. Micolon, N. Tsoupas, S. Verdú-Andrés Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA B.R. Gamage, T. Satogata, W. Wittmer JLab, Newport News, Virginia, USA
	The Hadron Storage Ring (HSR) of the Electron-Ion Collider (EIC) will accelerate protons and heavy ions up to a proton energy of 275 GeV and an Au⁺⁷⁹ 110 GeV/u to collide with electrons of energies up to 18 GeV. To accomplish the acceleration process, the hadrons are pre-accelerated in the Alternating Gradient Synchrotron (AGS), extracted, and transferred to HSR for injection. The planned area for injection is the current Relativistic Heavy Ion Collider (RHIC) 4 o’clock straight section. To inject hadrons, a series of modifications must be made to the existing RHIC 4 o’clock straight section to accommodate for the 20 new ~18 ns injection kickers and a new injection septum, while providing sufficient space and proper beam conditions for polarimetry equipment. These modifications will be discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK014
About •	Received ※ 02 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 21 June 2022
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WEPOTK023	Simulation Study of Fast Extraction in the Absence of One Septum Magnet for J-Parc Main Ring	operation, extraction, kicker, 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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WEPOTK024	Upgrade of Septum Magnets for Fast Extraction in J-Parc Main Ring	operation, extraction, vacuum, power-supply	2103
	S. Iwata, K. Ishii, H. Matsumoto, N. Matsumoto, Y. Sato, T. Shibata, T. Sugimoto, M. Uota KEK, Tokai, Ibaraki, Japan
	We aim to supply a high-power proton beam of 1.3 MW to the neutrino facility from J-PARC Main Ring (MR) by shortening the repetition cycle to 1.16 s from 2.48 s and increasing the number of particles by 30%. The six sep-tum magnets for fast extraction (FX) need to be replaced to reduce the heat that is generated as a result of shorten-ing the repetition cycle. The replacement of the septum magnets began in July 2021 and was completed at the end of May 2022. The beam commissioning starts in June 2022. We report the details of the replacement work and operation test of the new septum magnets. We found a defect in the magnetic coil of the septum (SM32) in August 2021. We decided to postpone its installation to around August 2022 and produce new magnet coils for the SM32. The beam extraction in June 2022 will be per-formed using a temporary vacuum duct instead of the SM32 magnet, and the extraction beam orbit will be maintained by increasing the magnetic field of the other five septum magnets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK024
About •	Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022
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WEPOTK025	Concepts and Considerations for FCC-ee Top-Up Injection Strategies	injection, kicker, 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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THOYSP2	The New Eddy Current Type Septum Magnet for Upgrading of Fast Extraction in Main Ring of J-PARC	extraction, operation, power-supply, injection	2428
	T. Shibata, K. Ishii, S. Iwata, H. Matsumoto, T. Sugimoto KEK, Ibaraki, Japan K. Fan HUST, Wuhan, People’s Republic of China
	For our first goal of the beam power of Main Ring for Fast eXtraction (FX), 750 kW, we have been evaluating a new Low-Field FX Septum magnets which are induced eddy current type (Eddy-Septum) since 2014. The pending technical issues are disagreement in two current monitor systems and the long switching time of the Main-charger to Sub-charger at low charging voltage. We measured a gap field during measurement of current, and found no drift in time variation of gap field. Our conclusion was that the cause of the disagreement is electric and radiative noise which make the drift in the time variation. The long-term stability of the output pulsed current depends on the switching time and charging voltage. We investigated the correlation between the keeping time of flat-top charging voltage and long-time stability with various charging voltages. In June 2021, we have first conducted the 1 Hz operation and high-voltage test of the Eddy-Septum which is mounted in a vacuum chamber, and we found no problem. A new pure iron duct type magnetic shield for reducing the leakage field were produced in July 2021. The new LF FX-Septum will be installed in MR in early of 2022.
	Slides THOYSP2 [5.375 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THOYSP2
About •	Received ※ 20 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 21 June 2022
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THPOPT018	Aperture Sharing Injection for Diamond-II	injection, storage-ring, kicker, lattice	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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THPOPT043	Injection Design Options for the Low-Emittance PETRA IV Storage Ring	injection, kicker, 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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THPOTK004	The Reduction of the Leakage Field of the Injection Septum Magnet in Main Ring of J-PARC	operation, injection, proton, quadrupole	2774
	T. Shibata, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto KEK, Ibaraki, Japan
	A new injection septum magnet (InjSep) was installed in MR in 2016 for one of the upgrading of beam power of MR. We have measured the leakage field before installation, and it was found from the measurement results that the leakage field at the beam upstream region of the circulating duct was enough smaller than previous InjSep, however we tried to reduce the leakage field further by installation a new magnetic shield. First magnetic shield was produced in 2017, and we installed it in the InjSep. The leakage field was reduced, however the magnetic field of a quadrupole magnet at beam upstream of the InjSep was also reduced slightly. The decrease of the magnetic field of the one of main magnet was not permitted from the requirement of beam optics. In consequently, the first version was failed. The second one was produced in 2018, and we measured the leakage field was measured in Jan. 2019. The leakage field was reduced, while no reduction of the quadrupole magnet. We decided to use the second version for beam operation. The new additional shield was started to use in Nov. 2019.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK004
About •	Received ※ 20 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 13 June 2022
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THPOTK005	The New High Field Septum Magnet for Upgrading of Fast Extraction in Main Ring of J-PARC	operation, extraction, flattop, proton	2778
	T. Shibata, K. Ishii, S. Iwata, H. Matsumoto, N. Matsumoto, T. Sugimoto KEK, Ibaraki, Japan K. Fan HUST, Wuhan, People’s Republic of China
	Upgrading the beam-power of the J-PARC Main Ring to 750 kW is underway by reducing the cycle from 2.48 s to 1.3 s. Required upgrade of the four High Field (HF) Septa will be completed in 2022. The operation test of a new HF SM31 was conducted in 2020. First was 1 Hz operation test. The power supply had no problem in the operation, and the joule heating at the magnet coil was lower than limit. We found a good linearity between the current and the gap field which has no saturation. The field integral in the magnet gap was measured to calculate the appropriate current for beam operation, and we found it was 3,400 A. We compared the gap field of the neutrino side with that of the beam abort side. The magnitude of gap field had no significant discrepancy larger than its measurement accuracy. The end-fringe field was measured and the we found large leakage field still existed around the end-fringes. We are producing an additional magnetic shield which will be mounted in the circulating beam duct, and it will finished in Feb. 2022. In next March we will install the inner shield and measured the leakage field. After that we will install the new SM31 in MR.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK005
About •	Received ※ 20 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 28 June 2022
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Paper

Title

Other Keywords

Page

MOPOPT022

Beam Dynamics of the Transparent Injection for the MAX IV 1.5 GeV Ring

injection, kicker, 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

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Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 29 June 2022 — Issue date ※ 07 July 2022

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MOPOPT051

Optical Fiber Based Beam Loss Monitor for SPS Machine

radiation, beam-losses, injection, operation

374

T. Pulampong, W. Phacheerak, P. Sudmuang, N. Suradet
SLRI, Nakhon Ratchasima, Thailand

At the Siam Photon Source (SPS) beam loss monitors based on PIN diode have been used. The existing system allow beam loss detection very locally at the monitor position close to the vacuum chamber. For optical fiber, Cherenkov radiation can be detected when a lost particle travel in the fiber. Thus optical fiber based loss monitor with sufficient length can cover parts of the machine conveniently. Fast beam loss event can be detected with more accurate position. In this paper, the design and result of the optical fiber based beam loss monitor system at SPS machine are discussed. The system will be a prototype for the new 3 GeV machine SPS-II.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT051

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Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 08 July 2022

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MOPOTK060

An Induction-Type Septum Magnet for the EIC Complex

injection, induction, electron, extraction

603

N. Tsoupas, D. Holmes, C. Liu, I. Marneris, C. Montag, V. Ptitsyn, V.H. Ranjbar, J.E. Tuozzolo
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). Part of the eIC accelerator complex and more specifically the Rapid Cycling Syncrotron (RCS) which accelerates the electron beam up to 18 GeV and the electron Storage Ring (eSR) which stores the electron beam bunces for collisions with the hadrons, will be built inside the tunnel of the Relativistic Heavy Ion Collider (RHIC)**. This paper provides information on the electromagnetic design of the septa magnets which will be employed to inject and extract the beam to and from the two synchrotrons used for the acceleration and storage of the electron beam bunches. The type of the septum is of induction type made o laminated iron and it is similar to the one described in ref.[3] The electromagnetic study is performed by the use of the transient module of the OPERA computer code***.
* https://ww.bnl.gov/eic/
** A. Zhuravlev, et al. PIPAC2013, Shanghai, China
*** https://www.3ds.com/products-services/simulia/products/opera/

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK060

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Received ※ 05 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 21 June 2022

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MOPOMS041

Concrete Shielding Activation for Proton Therapy Systems Using BDSIM and FISPACT-II

proton, shielding, neutron, simulation

728

E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde
ULB, Bruxelles, Belgium
C. Hernalsteens
CERN, Meyrin, Switzerland
F. Stichelbaut
IBA, Louvain-la-Neuve, Belgium

Proton therapy systems are used worldwide for patient treatment and fundamental research. The generation of secondary particles when the beam interacts with the beamline elements is a well-known issue. In particular, the energy degrader is the dominant source of secondary radiation. This poses new challenges for the concrete shielding of compact systems and beamline elements activation computation. We use a novel methodology to seamlessly simulate all the processes relevant to the activation evaluation. A realistic model of the system is developed using Beam Delivery Simulation (BDSIM), a Geant4-based particle tracking code that allows a single model to simulate primary and secondary particle tracking and all particle-matter interactions. The secondary particle fluxes extracted from the simulations are provided as input to FISPACT-II to compute the activation by solving the rate equations. This approach is applied to the Ion Beam Applications (IBA) Proteus®ONE (P1) system and the shielding of the proton therapy research centre of Charleroi, Belgium. Proton loss distributions are used to model the production of secondary neutrals inside the accelerator structure. Two models for the distribution of proton losses are compared for the computation of the clearance index at specific locations of the design. Results show that the variation in the accelerator loss models can be characterised as a systematic error.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS041

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Received ※ 19 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 22 June 2022

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TUPOMS036

Commissioning of the Lower Emittance Lattice at SPEAR3

lattice, emittance, operation, simulation

1502

K. Tian, W.J. Corbett, S.M. Gierman, X. Huang, J. Kim, J.B. Langton, NL. Parry, J.A. Safranek, J.J. Sebek, M. Song, Z. Zhang
SLAC, Menlo Park, California, USA

SPEAR3, commissioned in 2004, is a third generation light source at the SLAC National Accelerator Laboratory. The low emittance lattice with an emittance of 10 nm had been operated for over a decade until the recent commission of the new lower emittance lattice with 7 nm emittance. The new lattice, based on the same double-bend achromat lattice, has pushed toward the design limit of such type of lattice in SPEAR3. In this paper, we will elaborate our commissioning experience for the new lattice in SPEAR3.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS036

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Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 29 June 2022

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WEPOST013

Exploitation of Crystal Shadowing via Multi-Crystal Array, Optimisers and Reinforcement Learning

operation, extraction, simulation, proton

1707

F.M. Velotti, M. Di Castro, L.S. Esposito, M.A. Fraser, S.S. Gilardoni, B. Goddard, V. Kain, E. Matheson
CERN, Meyrin, Switzerland

The CERN Super Proton Synchrotron (SPS) routinely delivers proton and heavy ion beams to the North experimental Area (NA) in the form of 4.8 s spills. To produce such a long flux of particles, resonant third integer slow extraction is used, which, by design, foresees primary beam lost on the electrostatic septum wires to separate circulating from extracted beam. Shadowing with thin bent crystal has been proposed and successfully tested in the SPS, as detailed in *. In 2021, a thin crystal was used for physics production showing results compatible with what measured during early testing. In this paper, the results from the 2021 physics run are presented also comparing particle losses at extraction with previous operational years. The setting up of the crystal using numerical optimisers is detailed, with possible implementation of reinforcement learning (RL) agents to improve the setting up time. Finally, the full exploitation of crystal shadowing via multi-array crystals is discussed, together with the performance reach in the SPS.
F.Velotti, et. al, "Septum shadowing by means of a bent crystal to reduce slow extraction beam loss", Phys. Rev. Accel. Beams 22, 093502 - Published 27 September 2019

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST013

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Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 02 July 2022

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WEPOTK014

Hadron Storage Ring 4 O’clock Injection Design and Optics for the Electron-Ion Collider

injection, optics, electron, dipole

2068

H. Lovelace III, J.S. Berg, D. Bruno, C. Cullen, K.A. Drees, W. Fischer, X. Gu, R.C. Gupta, D. Holmes, R.F. Lambiase, C. Liu, C. Montag, S. Peggs, V. Ptitsyn, G. Robert-Demolaize, R. Than, J.E. Tuozzolo, M. Valette, D. Weiss
BNL, Upton, New York, USA
B. Bhandari, F. Micolon, N. Tsoupas, S. Verdú-Andrés
Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
B.R. Gamage, T. Satogata, W. Wittmer
JLab, Newport News, Virginia, USA

The Hadron Storage Ring (HSR) of the Electron-Ion Collider (EIC) will accelerate protons and heavy ions up to a proton energy of 275 GeV and an Au⁺⁷⁹ 110 GeV/u to collide with electrons of energies up to 18 GeV. To accomplish the acceleration process, the hadrons are pre-accelerated in the Alternating Gradient Synchrotron (AGS), extracted, and transferred to HSR for injection. The planned area for injection is the current Relativistic Heavy Ion Collider (RHIC) 4 o’clock straight section. To inject hadrons, a series of modifications must be made to the existing RHIC 4 o’clock straight section to accommodate for the 20 new ~18 ns injection kickers and a new injection septum, while providing sufficient space and proper beam conditions for polarimetry equipment. These modifications will be discussed in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK014

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Received ※ 02 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 21 June 2022

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WEPOTK023

Simulation Study of Fast Extraction in the Absence of One Septum Magnet for J-Parc Main Ring

operation, extraction, kicker, 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.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK023

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Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022

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WEPOTK024

Upgrade of Septum Magnets for Fast Extraction in J-Parc Main Ring

operation, extraction, vacuum, power-supply

2103

S. Iwata, K. Ishii, H. Matsumoto, N. Matsumoto, Y. Sato, T. Shibata, T. Sugimoto, M. Uota
KEK, Tokai, Ibaraki, Japan

We aim to supply a high-power proton beam of 1.3 MW to the neutrino facility from J-PARC Main Ring (MR) by shortening the repetition cycle to 1.16 s from 2.48 s and increasing the number of particles by 30%. The six sep-tum magnets for fast extraction (FX) need to be replaced to reduce the heat that is generated as a result of shorten-ing the repetition cycle. The replacement of the septum magnets began in July 2021 and was completed at the end of May 2022. The beam commissioning starts in June 2022. We report the details of the replacement work and operation test of the new septum magnets. We found a defect in the magnetic coil of the septum (SM32) in August 2021. We decided to postpone its installation to around August 2022 and produce new magnet coils for the SM32. The beam extraction in June 2022 will be per-formed using a temporary vacuum duct instead of the SM32 magnet, and the extraction beam orbit will be maintained by increasing the magnetic field of the other five septum magnets.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK024

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Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022

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WEPOTK025

Concepts and Considerations for FCC-ee Top-Up Injection Strategies

injection, kicker, 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.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK025

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Received ※ 03 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 14 June 2022

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THOYSP2

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

extraction, operation, power-supply, injection

2428

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

For our first goal of the beam power of Main Ring for Fast eXtraction (FX), 750 kW, we have been evaluating a new Low-Field FX Septum magnets which are induced eddy current type (Eddy-Septum) since 2014. The pending technical issues are disagreement in two current monitor systems and the long switching time of the Main-charger to Sub-charger at low charging voltage. We measured a gap field during measurement of current, and found no drift in time variation of gap field. Our conclusion was that the cause of the disagreement is electric and radiative noise which make the drift in the time variation. The long-term stability of the output pulsed current depends on the switching time and charging voltage. We investigated the correlation between the keeping time of flat-top charging voltage and long-time stability with various charging voltages. In June 2021, we have first conducted the 1 Hz operation and high-voltage test of the Eddy-Septum which is mounted in a vacuum chamber, and we found no problem. A new pure iron duct type magnetic shield for reducing the leakage field were produced in July 2021. The new LF FX-Septum will be installed in MR in early of 2022.

Slides THOYSP2 [5.375 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THOYSP2

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Received ※ 20 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 21 June 2022

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THPOPT018

Aperture Sharing Injection for Diamond-II

injection, storage-ring, kicker, lattice

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.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT018

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Received ※ 31 May 2022 — Accepted ※ 30 June 2022 — Issue date ※ 01 July 2022

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THPOPT043

Injection Design Options for the Low-Emittance PETRA IV Storage Ring

injection, kicker, 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.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT043

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Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022

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THPOTK004

The Reduction of the Leakage Field of the Injection Septum Magnet in Main Ring of J-PARC

operation, injection, proton, quadrupole

2774

T. Shibata, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto
KEK, Ibaraki, Japan

A new injection septum magnet (InjSep) was installed in MR in 2016 for one of the upgrading of beam power of MR. We have measured the leakage field before installation, and it was found from the measurement results that the leakage field at the beam upstream region of the circulating duct was enough smaller than previous InjSep, however we tried to reduce the leakage field further by installation a new magnetic shield. First magnetic shield was produced in 2017, and we installed it in the InjSep. The leakage field was reduced, however the magnetic field of a quadrupole magnet at beam upstream of the InjSep was also reduced slightly. The decrease of the magnetic field of the one of main magnet was not permitted from the requirement of beam optics. In consequently, the first version was failed. The second one was produced in 2018, and we measured the leakage field was measured in Jan. 2019. The leakage field was reduced, while no reduction of the quadrupole magnet. We decided to use the second version for beam operation. The new additional shield was started to use in Nov. 2019.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK004

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Received ※ 20 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 13 June 2022

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THPOTK005

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

operation, extraction, flattop, proton

2778

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

Upgrading the beam-power of the J-PARC Main Ring to 750 kW is underway by reducing the cycle from 2.48 s to 1.3 s. Required upgrade of the four High Field (HF) Septa will be completed in 2022. The operation test of a new HF SM31 was conducted in 2020. First was 1 Hz operation test. The power supply had no problem in the operation, and the joule heating at the magnet coil was lower than limit. We found a good linearity between the current and the gap field which has no saturation. The field integral in the magnet gap was measured to calculate the appropriate current for beam operation, and we found it was 3,400 A. We compared the gap field of the neutrino side with that of the beam abort side. The magnitude of gap field had no significant discrepancy larger than its measurement accuracy. The end-fringe field was measured and the we found large leakage field still existed around the end-fringes. We are producing an additional magnetic shield which will be mounted in the circulating beam duct, and it will finished in Feb. 2022. In next March we will install the inner shield and measured the leakage field. After that we will install the new SM31 in MR.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK005

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Received ※ 20 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 28 June 2022

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