IPAC2012 - List of Authors (Shirakata, M.J.)

Paper	Title	Page
WEPPR052	Octupole Magnets for the Instability Damping at the J-PARC Main Ring	3045
	S. Igarashi, T. Koseki, K. Ohmi, M.J. Shirakata, H. Someya, T. Toyama KEK, Ibaraki, Japan A. Ando J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Octupole magnets have been installed for the instability damping at the J-PARC main ring. The transverse instability was observed during the injection and acceleration periods and caused the beam losses. The chromaticity tuning and bunch-by-bunch feedback system have been applied to suppress the instability. Octupole magnets were considered to create a larger amplitude dependent betatron tune shift and to supply additional option for the instability damping. The side effects of the dynamic aperture reduction and the resonances have been studied.

THPPP080	Beam Halo Reduction in the J-PARC 3-GeV RCS	3918
	H. Hotchi, H. Harada, P.K. Saha, Y. Shobuda, F. Tamura, K. Yamamoto, M. Yamamoto, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan Y. Irie, T. Koseki, Y. Sato, M.J. Shirakata KEK, Ibaraki, Japan K. Satou J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The J-PARC RCS (3-GeV rapid cycling synchrotron) has two functions as a proton driver to the MLF (Materials and life science facility) and an injector to the MR (50-GeV main ring synchrotron). One of important issues in the current RCS bam tuning is to suppress the beam halo formation, which is essential especially to reduce the beam loss at the MR. In this paper, we present beam study results on the formation mechanism and reduction of the beam halo in the RCS.

Paper

Title

Page

Octupole Magnets for the Instability Damping at the J-PARC Main Ring

3045

S. Igarashi, T. Koseki, K. Ohmi, M.J. Shirakata, H. Someya, T. Toyama
KEK, Ibaraki, Japan
A. Ando
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Octupole magnets have been installed for the instability damping at the J-PARC main ring. The transverse instability was observed during the injection and acceleration periods and caused the beam losses. The chromaticity tuning and bunch-by-bunch feedback system have been applied to suppress the instability. Octupole magnets were considered to create a larger amplitude dependent betatron tune shift and to supply additional option for the instability damping. The side effects of the dynamic aperture reduction and the resonances have been studied.

THPPP080

Beam Halo Reduction in the J-PARC 3-GeV RCS

3918

H. Hotchi, H. Harada, P.K. Saha, Y. Shobuda, F. Tamura, K. Yamamoto, M. Yamamoto, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y. Irie, T. Koseki, Y. Sato, M.J. Shirakata
KEK, Ibaraki, Japan
K. Satou
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The J-PARC RCS (3-GeV rapid cycling synchrotron) has two functions as a proton driver to the MLF (Materials and life science facility) and an injector to the MR (50-GeV main ring synchrotron). One of important issues in the current RCS bam tuning is to suppress the beam halo formation, which is essential especially to reduce the beam loss at the MR. In this paper, we present beam study results on the formation mechanism and reduction of the beam halo in the RCS.