IPAC2018 - List of Authors (Hayashi, N.)

Paper	Title	Page
TUXGBF4	ORBIT Simulation, Measurement and Mitigation of Transverse Beam Instability in the Presence of Strong Space Charge in the 3-GeV RCS of J-PARC	620
	P.K. Saha, H. Harada, N. Hayashi, H. Hotchi, Y. Shobuda, F. Tamura JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The transverse impedance of eight extraction pulse kicker magnets (KM) is extremely strong source of transverse beam instability in the 3-GeV RCS (Rapid Cycling Synchrotron) at J-PARC. To realize the designed 1 MW beam power, collective beam dynamics with including the space charge effect for the coupled bunch instabilities excited by the KM impedance and associated measures were studied by incorporating all realistic time-dependent machine parameters in the ORBIT 3-D particle tracking code. The simulation results were all reproduced by measurements and, as a consequence, an acceleration of 1 MW beam power has been successfully demonstrated. In order to maintain variation of the RCS parameters required for multi-user operation, realistic measures for beam instability mitigation were proposed and also been successfully implemented in reality. To further increase the RCS beam power, beam stability issues and possible measures beyond 1 MW beam power are also considered.
	Slides TUXGBF4 [2.241 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUXGBF4
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TUPAL017	Performance and Status of the J-PARC Accelerators	1038
	K. Hasegawa, N. Hayashi, M. Kinsho, H. Oguri, K. Yamamoto, Y. Yamazaki JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Koseki, F. Naito, M. Yoshii KEK, Tokai, Ibaraki, Japan N. Yamamoto J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The J-PARC is a high intensity proton facility and the accelerator consists of a 400 MeV linac, a 3 GeV Rapid Cycling Synchrotron (RCS) and a 30 GeV Main Ring Synchrotron (MR). Regarding 3 GeV beam from the RCS, we delivered it at 150 kW to the materials and life science experimental facility (MLF), for the neutron and muon users. The beam powers for the neutrino experiment at 30 GeV was 420 kW in May 2016, but increased to 470 kW in February 2017 thanks to the change and optimization of operation parameters. For the hadron experimental facility which uses a slow beam extraction mode at 30 GeV, we delivered beam at a power of 37 kW, after the recovery from a trouble at an electro static septum. We have experienced many failures and troubles to impede full potential and high availability. In this report, operational performance and status of the J-PARC accelerators are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

ORBIT Simulation, Measurement and Mitigation of Transverse Beam Instability in the Presence of Strong Space Charge in the 3-GeV RCS of J-PARC

620

P.K. Saha, H. Harada, N. Hayashi, H. Hotchi, Y. Shobuda, F. Tamura
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The transverse impedance of eight extraction pulse kicker magnets (KM) is extremely strong source of transverse beam instability in the 3-GeV RCS (Rapid Cycling Synchrotron) at J-PARC. To realize the designed 1 MW beam power, collective beam dynamics with including the space charge effect for the coupled bunch instabilities excited by the KM impedance and associated measures were studied by incorporating all realistic time-dependent machine parameters in the ORBIT 3-D particle tracking code. The simulation results were all reproduced by measurements and, as a consequence, an acceleration of 1 MW beam power has been successfully demonstrated. In order to maintain variation of the RCS parameters required for multi-user operation, realistic measures for beam instability mitigation were proposed and also been successfully implemented in reality. To further increase the RCS beam power, beam stability issues and possible measures beyond 1 MW beam power are also considered.

Slides TUXGBF4 [2.241 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUXGBF4

Export •

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

TUPAL017

Performance and Status of the J-PARC Accelerators

1038

K. Hasegawa, N. Hayashi, M. Kinsho, H. Oguri, K. Yamamoto, Y. Yamazaki
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Koseki, F. Naito, M. Yoshii
KEK, Tokai, Ibaraki, Japan
N. Yamamoto
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The J-PARC is a high intensity proton facility and the accelerator consists of a 400 MeV linac, a 3 GeV Rapid Cycling Synchrotron (RCS) and a 30 GeV Main Ring Synchrotron (MR). Regarding 3 GeV beam from the RCS, we delivered it at 150 kW to the materials and life science experimental facility (MLF), for the neutron and muon users. The beam powers for the neutrino experiment at 30 GeV was 420 kW in May 2016, but increased to 470 kW in February 2017 thanks to the change and optimization of operation parameters. For the hadron experimental facility which uses a slow beam extraction mode at 30 GeV, we delivered beam at a power of 37 kW, after the recovery from a trouble at an electro static septum. We have experienced many failures and troubles to impede full potential and high availability. In this report, operational performance and status of the J-PARC accelerators are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL017

Export •

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