IPAC2012 - List of Authors (Igarashi, S.)

Paper	Title	Page
TUPPC019	Beam Dynamics Simulations of J-PARC Main Ring for Damage Recovery from the Tohoku Earthquake in Japan and Upgrade Plan of Fast Extraction Operation	1200
	Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori KEK, Ibaraki, Japan H. Hotchi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Magnets of Japan Proton Accelerator Research Complex (J-PARC) were shaken by the Tohoku Earthquake in Japan on March 11th, 2011. The alignment of J-PARC Main Ring (MR) received 20 mm displacement horizontally and 6 mm vertically. Beam dynamics simulations were performed to estimate the effect of the displacement on closed orbit distortions and beam loss in fast extraction (FX) operation of J-PARC MR. Based on the simulation results, we concluded that re-alignment of J-PARC MR was needed to achieve high-power beam. The re-alignment of MR was finished on October 28th, 2011. We also considered the effects of the earthquake on the upstream of MR to establish our upgrade plan, which was based on beam dynamics simulations optimizing collimator balance of injection beam transport (3-50BT) and MR, and RF patterns. J-PARC MR FX operation was resumed from December 2011.

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.

Paper

Title

Page

Beam Dynamics Simulations of J-PARC Main Ring for Damage Recovery from the Tohoku Earthquake in Japan and Upgrade Plan of Fast Extraction Operation

1200

Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori
KEK, Ibaraki, Japan
H. Hotchi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Magnets of Japan Proton Accelerator Research Complex (J-PARC) were shaken by the Tohoku Earthquake in Japan on March 11th, 2011. The alignment of J-PARC Main Ring (MR) received 20 mm displacement horizontally and 6 mm vertically. Beam dynamics simulations were performed to estimate the effect of the displacement on closed orbit distortions and beam loss in fast extraction (FX) operation of J-PARC MR. Based on the simulation results, we concluded that re-alignment of J-PARC MR was needed to achieve high-power beam. The re-alignment of MR was finished on October 28th, 2011. We also considered the effects of the earthquake on the upstream of MR to establish our upgrade plan, which was based on beam dynamics simulations optimizing collimator balance of injection beam transport (3-50BT) and MR, and RF patterns. J-PARC MR FX operation was resumed from December 2011.

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.