HB2023 - List of Keywords (extraction)

Paper	Title	Other Keywords	Page
MOA4I1	Design of a Fixed-Field Accelerating Ring for High Power Applications	injection, synchrotron, resonance, lattice	38
	S. Machida STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	A fixed field accelerating ring (FFA) has some advantage to achieve high beam power over conventional ring accelerators. It would be also a sustainable option as future proton drivers. We will discuss the design of an FFA taking a future upgrade plan of ISIS (ISIS-II) as an example.
	Slides MOA4I1 [14.313 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA4I1
About •	Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 15 October 2023 — Issued ※ 21 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUC4I1	A Kicker Impedance Reduction Scheme with Diode Stack and Resistor at the RCS in J-PARC	kicker, impedance, simulation, emittance	162
	Y. Shobuda, H. Harada, P.K. Saha, T. Takayanagi, F. Tamura, T. Togashi, Y. Watanabe, K. Yamamoto, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	At the 3-GeV Rapid Cycling Synchrotron (RCS) within the Japan Proton Accelerator Research Complex (J-PARC), kicker impedance causes beam instability. A 1-MW beam with a large emittance can be delivered to the Material and Life Science Experimental Facility (MLF) by suppressing beam instabilities without the need for a transverse feedback system¿simply by turning off the sextuple magnets. However, we require other high-intensity and high-quality beams with smaller emittances for the Main Ring (MR). To address this, we proposed a scheme for suppressing the kicker impedance using a diode stack and resistors, which effectively reduces beam instability. Importantly, these devices have a negligible effect on the extracted beam from the RCS.
	Slides TUC4I1 [2.713 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4I1
About •	Received ※ 26 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUC4C1	Beam Coupling Impedance of the Main Extraction Kickers in the CERN PS	impedance, kicker, coupling, simulation	178
	M. Neroni, M.J. Barnes, A. Lasheen, C. Vollinger CERN, Meyrin, Switzerland A. Mostacci Sapienza University of Rome, Rome, Italy B.K. Popovic ANL, Lemont, Illinois, USA
	In view of the High Luminosity (HL) upgrade of the LHC, the beam intensity must be doubled in the injector chain. To perform reliable beam dynamics simulations, the beam coupling impedance in the injectors, such as the Proton Synchrotron (PS), must be followed closely by including all contributing elements into the impedance model. The existing kicker magnets of the PS had been optimized for large kick strength and short rise/fall times, but not necessarily to minimise beam coupling impedance. Hence, unwanted beam induced voltage can build up in their electrical circuits, with an impact on the beam. The beam coupling impedances of the two main kicker magnets used for the fast extraction from PS, the KFA71 and KFA79, are extensively characterized in this study. In particular, electromagnetic simulation results for the longitudinal and transverse coupling impedance are shown. The critical impedance contributions are identified, and their effect on beam stability is discussed. Moreover, the impact of the cable terminations on the electromagnetic field pattern and possible mitigation techniques are presented, providing a complete impedance evaluation of the entire kicker installation.
	Slides TUC4C1 [2.715 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4C1
About •	Received ※ 30 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 15 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP02	Resonance Extraction Research Based on China Spallation Neutron Source	sextupole, resonance, kicker, lattice	397
	Y.W. An, L. Huang, Z.P. Li, S.Y. Xu, Y.S. Yuan IHEP, Beijing, People’s Republic of China
	Resonance extraction based on the RCS ring is an important aspect of beam applications. This article proposes a new design of resonance extraction based on the CSNS-RCS ring. By adjusting parameters such as the skew sextupole magnet, beam working point, RF-Kicker, etc., the simulation results from PyOrbit demonstrate the ability to rapidly extract a large number of protons within a few turns.
	Slides THAFP02 [1.497 MB]
	Poster THAFP02 [0.960 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP02
About •	Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 01 November 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP08	Performance of the Ion Chain at the CERN Injector Complex and Transmission Studies During the 2023 Slip Stacking Commissioning	injection, emittance, linac, MMI	418
	M. Slupecki, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, T. Argyropoulos, H. Bartosik, P. Baudrenghien, G. Bellodi, M. Bozzolan, R. Bruce, C. Carli, J. Cenede, H. Damerau, A. Frassier, D. Gamba, G. Hagmann, A. Huschauer, V. Kain, G. Khatri, D. Küchler, A. Lasheen, K.S.B. Li, E. Mahner, G. Papotti, G. Piccinini, A. Rey, M. Schenk, R. Scrivens, A. Spierer, G. Tranquille, D. Valuch, F.M. Velotti, R. Wegner CERN, Meyrin, Switzerland E. Waagaard EPFL, Lausanne, Switzerland
	The 2023 run has been decisive for the LHC Ion Injector Complex. It demonstrated the capability of producing full trains of momentum slip stacked lead ions in the SPS. Slip stacking is a technique of interleaving particle trains, reducing the bunch spacing in SPS from 100 ns to 50 ns. It is needed to reach the total ion intensity requested by the HL-LHC project, as defined by updated common LIU/HL-LHC target beam parameters. This paper reviews the lead beam characteristics across the Ion Injector Complex, including transmission efficiencies up to the SPS extraction. It also documents the difficulties found during the commissioning and the solutions put in place.
	Slides THAFP08 [1.114 MB]
	Poster THAFP08 [1.995 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP08
About •	Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP11	MKP-L Impedance Mitigation and Expectations for MKP-S in the CERN-SPS	impedance, kicker, coupling, shielding	466
	C. Zannini, M.J. Barnes, M.S. Beck, M. Díaz Zumel, L. Ducimetière, G. Rumolo, D. Standen, P. Trubacova CERN, Meyrin, Switzerland
	Beam coupling impedance mitigation is key in preventing intensity limitations due to beam stability issues, heating and sparking. In this framework, a very good example is the optimization of the SPS kickers beam-coupling impedance for beam-induced heating mitigation. After the optimization of the SPS extraction kickers, the SPS injection kickers became the next bottleneck for high intensity operation. This system is composed of three MKP-S tanks and one MKP-L. To accommodate LIU beam intensities, it was necessary to mitigate the beam induced heating of the MKP-L, using a shielding concept briefly reviewed in this paper. Moreover, temperature data from the 2023 run are analyzed to qualify the accuracy of the models and assess the effectiveness of the impedance mitigation. Finally, the expected limitations from the MKP-S, expected to become the new bottleneck in terms of beam induced heating, are discussed.
	Poster THBP11 [1.655 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP11
About •	Received ※ 29 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 24 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP34	PSI Injector II and the 72 MeV Transfer Line: MinT-Simulation vs. Measurements	cyclotron, emittance, space-charge, simulation	547
	C. Baumgarten, H. Zhang PSI, Villigen PSI, Switzerland
	PSI’s Injector II cyclotron is the only cyclotron worldwide that makes use of the so-called "Vortex effect", in which strong space charge forces generate the counter-intuitive effect to "roll up" bunches thus keeping them longitudinally compact. The effect has been verified by bunch shape measurements and the PIC-code OPAL. However, PSI’s new fast matrix code MinT allows to reproduce the Vortex effect by a linear matrix model which is computational much cheaper than PIC simulations, and is suitable for "online use" in Control rooms. Furthermore it provides the second moments of matched distributions.
	Poster THBP34 [0.840 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP34
About •	Received ※ 30 September 2023 — Revised ※ 03 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 31 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP59	Tomographic Longitudinal Phase Space Reconstruction of Bunch Compression at ISIS	synchrotron, proton, simulation, operation	625
	B.S. Kyle, H.V. Cavanagh, A. Seville, R.E. Williamson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	ISIS is an 800 MeV, high intensity, rapid-cycling synchrotron (RCS) used as a driver for a spallation neutron and muon spectroscopy (¿SR) facility. The intensity-limited beam and RCS operation at ISIS poses significant challenges, with non-adiabatic acceleration and space charge forces resulting in distortions to the Hamiltonian longitudinal dynamics. Effective modelling of the machine and benchmarking of models with beam measurements is essential both to improving machine performance, and to the development of the proposed ISIS II facility. The tomographic principle is a well-established tool for the reconstruction of the longitudinal phase space (LPS) of synchrotron beams. Is it operationally desirable for the ISIS accelerator to provide longitudinally compressed proton beams for ¿SR instrumentation. A new bunch compression scheme has been developed and validated using tomography. A reconstruction of the LPS of the ISIS high-intensity proton beam is presented, along with accompanying benchmarking measurements and beam physics simulations.
	Poster THBP59 [0.907 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP59
About •	Received ※ 01 October 2023 — Revised ※ 09 October 2023 — Accepted ※ 20 October 2023 — Issued ※ 25 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRC1I3	Devices for High-Efficiency Slow Extraction at J-PARC Main Ring	septum, proton, betatron, cathode	656
	R. Muto, T. Kimura, S. Murasugi, K. Numai, K. Okamura, Y. Shirakabe, M. Tomizawa, E. Yanaoka KEK, Ibaraki, Japan A. Matsumura Nihon Advanced Technology Co., Ltd, Ibaraki, Nakagun, Tokaimura, Japan
	J-PARC Main Ring (MR) is a synchrotron that accelerates protons up to 30 GeV and supplies them to the Neutrino Experimental Facility and the Hadron Experimental Facility (HEF). Beam extraction from MR to HEF is performed by slow extraction using third-order resonance. In the slow extraction a device called an electrostatic septum (ESS) is used to scrape out the beam, and it is important to reduce the beam loss at the septum electrode of the ESS in order to supply a high-intensity beam. So far, we have achieved a slow extraction efficiency of 99.5% by developing an ESS with a thin septum electrode and tuning the bump orbit to reduce the width of the angular distribution of protons at the ESS. In addition, a collimator is installed downstream of the ESS to absorb particles scattered by the septum electrode, thereby reducing activation of the components downstream. In order to achieve further reduction of the beam loss, we are currently considering to install beam diffusers and/or bent silicon crystals at the upstream of the ESS. In this talk, we will present the current status of the slow extraction devices and future plans to further improve the extraction efficiency.
	Slides FRC1I3 [3.167 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-FRC1I3
About •	Received ※ 18 October 2023 — Revised ※ 19 October 2023 — Accepted ※ 23 October 2023 — Issued ※ 01 November 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOA4I1

Design of a Fixed-Field Accelerating Ring for High Power Applications

injection, synchrotron, resonance, lattice

38

S. Machida
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

A fixed field accelerating ring (FFA) has some advantage to achieve high beam power over conventional ring accelerators. It would be also a sustainable option as future proton drivers. We will discuss the design of an FFA taking a future upgrade plan of ISIS (ISIS-II) as an example.

Slides MOA4I1 [14.313 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA4I1

About •

Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 15 October 2023 — Issued ※ 21 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUC4I1

A Kicker Impedance Reduction Scheme with Diode Stack and Resistor at the RCS in J-PARC

kicker, impedance, simulation, emittance

162

Y. Shobuda, H. Harada, P.K. Saha, T. Takayanagi, F. Tamura, T. Togashi, Y. Watanabe, K. Yamamoto, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

At the 3-GeV Rapid Cycling Synchrotron (RCS) within the Japan Proton Accelerator Research Complex (J-PARC), kicker impedance causes beam instability. A 1-MW beam with a large emittance can be delivered to the Material and Life Science Experimental Facility (MLF) by suppressing beam instabilities without the need for a transverse feedback system¿simply by turning off the sextuple magnets. However, we require other high-intensity and high-quality beams with smaller emittances for the Main Ring (MR). To address this, we proposed a scheme for suppressing the kicker impedance using a diode stack and resistors, which effectively reduces beam instability. Importantly, these devices have a negligible effect on the extracted beam from the RCS.

Slides TUC4I1 [2.713 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4I1

About •

Received ※ 26 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUC4C1

Beam Coupling Impedance of the Main Extraction Kickers in the CERN PS

impedance, kicker, coupling, simulation

178

M. Neroni, M.J. Barnes, A. Lasheen, C. Vollinger
CERN, Meyrin, Switzerland
A. Mostacci
Sapienza University of Rome, Rome, Italy
B.K. Popovic
ANL, Lemont, Illinois, USA

In view of the High Luminosity (HL) upgrade of the LHC, the beam intensity must be doubled in the injector chain. To perform reliable beam dynamics simulations, the beam coupling impedance in the injectors, such as the Proton Synchrotron (PS), must be followed closely by including all contributing elements into the impedance model. The existing kicker magnets of the PS had been optimized for large kick strength and short rise/fall times, but not necessarily to minimise beam coupling impedance. Hence, unwanted beam induced voltage can build up in their electrical circuits, with an impact on the beam. The beam coupling impedances of the two main kicker magnets used for the fast extraction from PS, the KFA71 and KFA79, are extensively characterized in this study. In particular, electromagnetic simulation results for the longitudinal and transverse coupling impedance are shown. The critical impedance contributions are identified, and their effect on beam stability is discussed. Moreover, the impact of the cable terminations on the electromagnetic field pattern and possible mitigation techniques are presented, providing a complete impedance evaluation of the entire kicker installation.

Slides TUC4C1 [2.715 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4C1

About •

Received ※ 30 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 15 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP02

Resonance Extraction Research Based on China Spallation Neutron Source

sextupole, resonance, kicker, lattice

397

Y.W. An, L. Huang, Z.P. Li, S.Y. Xu, Y.S. Yuan
IHEP, Beijing, People’s Republic of China

Resonance extraction based on the RCS ring is an important aspect of beam applications. This article proposes a new design of resonance extraction based on the CSNS-RCS ring. By adjusting parameters such as the skew sextupole magnet, beam working point, RF-Kicker, etc., the simulation results from PyOrbit demonstrate the ability to rapidly extract a large number of protons within a few turns.

Slides THAFP02 [1.497 MB]

Poster THAFP02 [0.960 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP02

About •

Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 01 November 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP08

Performance of the Ion Chain at the CERN Injector Complex and Transmission Studies During the 2023 Slip Stacking Commissioning

injection, emittance, linac, MMI

418

M. Slupecki, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, T. Argyropoulos, H. Bartosik, P. Baudrenghien, G. Bellodi, M. Bozzolan, R. Bruce, C. Carli, J. Cenede, H. Damerau, A. Frassier, D. Gamba, G. Hagmann, A. Huschauer, V. Kain, G. Khatri, D. Küchler, A. Lasheen, K.S.B. Li, E. Mahner, G. Papotti, G. Piccinini, A. Rey, M. Schenk, R. Scrivens, A. Spierer, G. Tranquille, D. Valuch, F.M. Velotti, R. Wegner
CERN, Meyrin, Switzerland
E. Waagaard
EPFL, Lausanne, Switzerland

The 2023 run has been decisive for the LHC Ion Injector Complex. It demonstrated the capability of producing full trains of momentum slip stacked lead ions in the SPS. Slip stacking is a technique of interleaving particle trains, reducing the bunch spacing in SPS from 100 ns to 50 ns. It is needed to reach the total ion intensity requested by the HL-LHC project, as defined by updated common LIU/HL-LHC target beam parameters. This paper reviews the lead beam characteristics across the Ion Injector Complex, including transmission efficiencies up to the SPS extraction. It also documents the difficulties found during the commissioning and the solutions put in place.

Slides THAFP08 [1.114 MB]

Poster THAFP08 [1.995 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP08

About •

Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP11

MKP-L Impedance Mitigation and Expectations for MKP-S in the CERN-SPS

impedance, kicker, coupling, shielding

466

C. Zannini, M.J. Barnes, M.S. Beck, M. Díaz Zumel, L. Ducimetière, G. Rumolo, D. Standen, P. Trubacova
CERN, Meyrin, Switzerland

Beam coupling impedance mitigation is key in preventing intensity limitations due to beam stability issues, heating and sparking. In this framework, a very good example is the optimization of the SPS kickers beam-coupling impedance for beam-induced heating mitigation. After the optimization of the SPS extraction kickers, the SPS injection kickers became the next bottleneck for high intensity operation. This system is composed of three MKP-S tanks and one MKP-L. To accommodate LIU beam intensities, it was necessary to mitigate the beam induced heating of the MKP-L, using a shielding concept briefly reviewed in this paper. Moreover, temperature data from the 2023 run are analyzed to qualify the accuracy of the models and assess the effectiveness of the impedance mitigation. Finally, the expected limitations from the MKP-S, expected to become the new bottleneck in terms of beam induced heating, are discussed.

Poster THBP11 [1.655 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP11

About •

Received ※ 29 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 24 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP34

PSI Injector II and the 72 MeV Transfer Line: MinT-Simulation vs. Measurements

cyclotron, emittance, space-charge, simulation

547

C. Baumgarten, H. Zhang
PSI, Villigen PSI, Switzerland

PSI’s Injector II cyclotron is the only cyclotron worldwide that makes use of the so-called "Vortex effect", in which strong space charge forces generate the counter-intuitive effect to "roll up" bunches thus keeping them longitudinally compact. The effect has been verified by bunch shape measurements and the PIC-code OPAL. However, PSI’s new fast matrix code MinT allows to reproduce the Vortex effect by a linear matrix model which is computational much cheaper than PIC simulations, and is suitable for "online use" in Control rooms. Furthermore it provides the second moments of matched distributions.

Poster THBP34 [0.840 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP34

About •

Received ※ 30 September 2023 — Revised ※ 03 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 31 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP59

Tomographic Longitudinal Phase Space Reconstruction of Bunch Compression at ISIS

synchrotron, proton, simulation, operation

625

B.S. Kyle, H.V. Cavanagh, A. Seville, R.E. Williamson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

ISIS is an 800 MeV, high intensity, rapid-cycling synchrotron (RCS) used as a driver for a spallation neutron and muon spectroscopy (¿SR) facility. The intensity-limited beam and RCS operation at ISIS poses significant challenges, with non-adiabatic acceleration and space charge forces resulting in distortions to the Hamiltonian longitudinal dynamics. Effective modelling of the machine and benchmarking of models with beam measurements is essential both to improving machine performance, and to the development of the proposed ISIS II facility. The tomographic principle is a well-established tool for the reconstruction of the longitudinal phase space (LPS) of synchrotron beams. Is it operationally desirable for the ISIS accelerator to provide longitudinally compressed proton beams for ¿SR instrumentation. A new bunch compression scheme has been developed and validated using tomography. A reconstruction of the LPS of the ISIS high-intensity proton beam is presented, along with accompanying benchmarking measurements and beam physics simulations.

Poster THBP59 [0.907 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP59

About •

Received ※ 01 October 2023 — Revised ※ 09 October 2023 — Accepted ※ 20 October 2023 — Issued ※ 25 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRC1I3

Devices for High-Efficiency Slow Extraction at J-PARC Main Ring

septum, proton, betatron, cathode

656

R. Muto, T. Kimura, S. Murasugi, K. Numai, K. Okamura, Y. Shirakabe, M. Tomizawa, E. Yanaoka
KEK, Ibaraki, Japan
A. Matsumura
Nihon Advanced Technology Co., Ltd, Ibaraki, Nakagun, Tokaimura, Japan

J-PARC Main Ring (MR) is a synchrotron that accelerates protons up to 30 GeV and supplies them to the Neutrino Experimental Facility and the Hadron Experimental Facility (HEF). Beam extraction from MR to HEF is performed by slow extraction using third-order resonance. In the slow extraction a device called an electrostatic septum (ESS) is used to scrape out the beam, and it is important to reduce the beam loss at the septum electrode of the ESS in order to supply a high-intensity beam. So far, we have achieved a slow extraction efficiency of 99.5% by developing an ESS with a thin septum electrode and tuning the bump orbit to reduce the width of the angular distribution of protons at the ESS. In addition, a collimator is installed downstream of the ESS to absorb particles scattered by the septum electrode, thereby reducing activation of the components downstream. In order to achieve further reduction of the beam loss, we are currently considering to install beam diffusers and/or bent silicon crystals at the upstream of the ESS. In this talk, we will present the current status of the slow extraction devices and future plans to further improve the extraction efficiency.

Slides FRC1I3 [3.167 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-FRC1I3

About •

Received ※ 18 October 2023 — Revised ※ 19 October 2023 — Accepted ※ 23 October 2023 — Issued ※ 01 November 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)