IPAC2017 - List of Authors (Tamura, F.)

Paper	Title	Page
TUPVA091	Batch Compression Scheme for Multi-MW J-PARC	2294
	C. Ohmori, M. Furusawa, K. Hara, K. Hasegawa, Y. Sugiyama, M. Yoshii KEK, Tokai, Ibaraki, Japan M. Nomura, T. Shimada, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan
	Replacement of all J-PARC MR cavities has completed in this summer to increase the RF voltage. Nine sets of new high-gradient FT3L cavities will generate the required RF voltage for the 1.16 second cycle operation. Upgrade of magnet power supplies is planned and the cycle time becomes 1.3 seconds from the present 2.48 seconds in FY2018 to achieve the beam power of 750 kW-1 MW. For the further improvement of beam power, a new rapid-cycling booster is considered to increase the injection energy of the MR from 3 GeV to 6-8 GeV. By the reduction of the space charge effects, the injection time can be extended and a batch compression scheme becomes possible. It will increase the number of bunches from 8 to 11 or 12 during the beam injection. And, recent beam study of the 3 GeV RCS shows the potential capability of 6.6·10¹³ proton per bunch. Combining these improvements with the booster, the beam power of 3 MW will be manageable.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA091
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TUPVA092	An Upgrade Scenario of RF System to Achieve 1.6 MW Beam Acceleration in J-PARC RCS	2297
	M. Yamamoto, M. Nomura, T. Shimada, F. Tamura JAEA/J-PARC, Tokai-mura, Japan K. Hara, K. Hasegawa, C. Ohmori, Y. Sugiyama, M. Yoshii KEK, Tokai, Ibaraki, Japan
	The J-PARC RCS has successfully accelerated 1 MW equivalent proton beam. However, the beam commissioning results and the particle tracking simulation suggest that the RCS has possibility to accelerate up to 1.6 MW beam. Since the power supply of the rf system almost reaches the limit under the condition of 1 MW beam, we consider the possible upgrade scenario of the rf system to accelerate 1.6 MW beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA092
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WEOAA3	Realizing a High-Intensity Low-Emittance Beam in the J-PARC 3-GeV RCS	2470
	H. Hotchi, H. Harada, S. Kato, K. Okabe, P.K. Saha, Y. Shobuda, F. Tamura, N. Tani, Y. Watanabe, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The J-PARC 3-GeV rapid cycling synchrotron (RCS) has two functions; one as a proton driver to produce pulsed muons and neutrons, and the other as an injector to the following 50-GeV main ring (MR). RCS is now intensively developing a high-intensity beam test to realize a high-intensity low-emittance beam with less beam halo required from MR. This paper presents the recent experimental results, together with detailed discussions for the emittance growth and its mitigation mechanisms.
	Slides WEOAA3 [1.732 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOAA3
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WEPIK014	Coupled Bunch Instability and Its Cure at J-PARC RCS	2946
	Y. Shobuda, H. Harada, H. Hotchi, P.K. Saha, T. Takayanagi, F. Tamura, N. Tani, T. Togashi, Y. Watanabe, K. Yamamoto, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan Y.H. Chin, Y. Irie, T. Toyama KEK, Tokai, Ibaraki, Japan
	The RCS at J-PARC is a kicker-impedance dominant machine, which violates the impedance budget from a classical viewpoint. Nevertheless, we have recently succeeded to accelerate a 1-MW equivalent beam by making maximum use of the space charge effect on the beam instabilities. In this report, we explain the manipulation to suppress the beam instability, at first. Then, we discuss some issues to suppress the beam instabilities for beams with much smaller transverse emittance, as well as the present status of our efforts to reduce the kicker impedance toward the realization of the higher beam power at the RCS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK014
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Paper

Title

Page

Batch Compression Scheme for Multi-MW J-PARC

2294

C. Ohmori, M. Furusawa, K. Hara, K. Hasegawa, Y. Sugiyama, M. Yoshii
KEK, Tokai, Ibaraki, Japan
M. Nomura, T. Shimada, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

Replacement of all J-PARC MR cavities has completed in this summer to increase the RF voltage. Nine sets of new high-gradient FT3L cavities will generate the required RF voltage for the 1.16 second cycle operation. Upgrade of magnet power supplies is planned and the cycle time becomes 1.3 seconds from the present 2.48 seconds in FY2018 to achieve the beam power of 750 kW-1 MW. For the further improvement of beam power, a new rapid-cycling booster is considered to increase the injection energy of the MR from 3 GeV to 6-8 GeV. By the reduction of the space charge effects, the injection time can be extended and a batch compression scheme becomes possible. It will increase the number of bunches from 8 to 11 or 12 during the beam injection. And, recent beam study of the 3 GeV RCS shows the potential capability of 6.6·10¹³ proton per bunch. Combining these improvements with the booster, the beam power of 3 MW will be manageable.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA091

Export •

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

TUPVA092

An Upgrade Scenario of RF System to Achieve 1.6 MW Beam Acceleration in J-PARC RCS

2297

M. Yamamoto, M. Nomura, T. Shimada, F. Tamura
JAEA/J-PARC, Tokai-mura, Japan
K. Hara, K. Hasegawa, C. Ohmori, Y. Sugiyama, M. Yoshii
KEK, Tokai, Ibaraki, Japan

The J-PARC RCS has successfully accelerated 1 MW equivalent proton beam. However, the beam commissioning results and the particle tracking simulation suggest that the RCS has possibility to accelerate up to 1.6 MW beam. Since the power supply of the rf system almost reaches the limit under the condition of 1 MW beam, we consider the possible upgrade scenario of the rf system to accelerate 1.6 MW beam.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA092

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

WEOAA3

Realizing a High-Intensity Low-Emittance Beam in the J-PARC 3-GeV RCS

2470

H. Hotchi, H. Harada, S. Kato, K. Okabe, P.K. Saha, Y. Shobuda, F. Tamura, N. Tani, Y. Watanabe, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The J-PARC 3-GeV rapid cycling synchrotron (RCS) has two functions; one as a proton driver to produce pulsed muons and neutrons, and the other as an injector to the following 50-GeV main ring (MR). RCS is now intensively developing a high-intensity beam test to realize a high-intensity low-emittance beam with less beam halo required from MR. This paper presents the recent experimental results, together with detailed discussions for the emittance growth and its mitigation mechanisms.

Slides WEOAA3 [1.732 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOAA3

Export •

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

WEPIK014

Coupled Bunch Instability and Its Cure at J-PARC RCS

2946

Y. Shobuda, H. Harada, H. Hotchi, P.K. Saha, T. Takayanagi, F. Tamura, N. Tani, T. Togashi, Y. Watanabe, K. Yamamoto, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan
Y.H. Chin, Y. Irie, T. Toyama
KEK, Tokai, Ibaraki, Japan

The RCS at J-PARC is a kicker-impedance dominant machine, which violates the impedance budget from a classical viewpoint. Nevertheless, we have recently succeeded to accelerate a 1-MW equivalent beam by making maximum use of the space charge effect on the beam instabilities. In this report, we explain the manipulation to suppress the beam instability, at first. Then, we discuss some issues to suppress the beam instabilities for beams with much smaller transverse emittance, as well as the present status of our efforts to reduce the kicker impedance toward the realization of the higher beam power at the RCS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK014

Export •

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