IPAC2013 - List of Authors (Toyama, T.)

Paper

Title

Page

A Trial to Reduce the Kicker Impedance of 3-GeV RCS in J-PARC

1742

Y. Shobuda, N. Hayashi, T. Takayanagi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y. Irie
KEK, Ibaraki, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

At 3GeV RCS in J-PARC, the kicker impedance has been considered to be the dominant source to cause the beam instability. Recently, experimental studies demonstrate that the beam instability is suppressed by reducing the kicker impedance. In this report, a trial to reduce the kicker impedance is reported.

THXB101

High Power Operation and Beam Instrumentations in J-PARC Synchrotrons

3085

T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Beam monitors developed and utilized at MR and RCS of J-PARC will be presented with emphasis on special characteristics for high intensity proton accelerator. Achieved beam characteristics and approach to improve beam intensity will be described in connection with the beam monitors. Usage of a transverse RF field to improve a duty factor of the slow extracted beam will be presented.

Slides THXB101 [16.387 MB]

THPWO032

Progress of Injection Energy Upgrade Project for J-PARC RCS

3833

N. Hayashi, H. Harada, K. Horino, H. Hotchi, J. Kamiya, M. Kinsho, P.K. Saha, Y. Shobuda, T. Takayanagi, N. Tani, T. Togashi, T. Ueno, M. Watanabe, Y. Watanabe, K. Yamamoto, M. Yamamoto, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y. Irie
KEK, Ibaraki, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The injection energy of the J-PARC RCS will be upgraded in 2013. New power supplies for the shift bump magnet system will be installed. Some of other systems, upgrade of the painting bump power supplies and pulse steering systems, are already installed and tested or used for the nominal operation. The paper reports the progress of injection energy upgrade project.

TUPWA009

Bunch by Bunch Intra-Bunch Feedback System for Curing Transverse Beam Instabilities at the J-PARC MR

1739

O. A. Konstantinova, Y.H. Chin, Y. Kurimoto, T. Obina, M. Okada, K. Takata, M. Tobiyama, T. Toyama
KEK, Ibaraki, Japan
Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

At the J-PARC Main Ring (MR), transverse instabilities have been observed during the injection and at the onset of acceleration with large particle losses. The present bunch by bunch feedback system, operating in a narrowband mode, has been effectively suppressing these instabilities, allowing the beam power to reach 230kW with only 400W of particle losses. The observed beam signals show that bunches are still executing complicated intra-bunch oscillations even if the narrowband feedback system is on, though they are not imposing significant particle losses at present. The new and more advanced broadband feedback system has been developed for control of the intra-bunch oscillations and further reduction of particle losses. The elaborate analysis code has been also developed on the MATLAB platform to analyse effects of the broadband feedback system on intra-bunch oscillations. This paper describes the development of these advanced instruments and presents the analysis of the latest beam test results using the MATLAB code.

Paper	Title	Page
TUPWA010	A Trial to Reduce the Kicker Impedance of 3-GeV RCS in J-PARC	1742
	Y. Shobuda, N. Hayashi, T. Takayanagi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan Y. Irie KEK, Ibaraki, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	At 3GeV RCS in J-PARC, the kicker impedance has been considered to be the dominant source to cause the beam instability. Recently, experimental studies demonstrate that the beam instability is suppressed by reducing the kicker impedance. In this report, a trial to reduce the kicker impedance is reported.

THXB101	High Power Operation and Beam Instrumentations in J-PARC Synchrotrons	3085
	T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Beam monitors developed and utilized at MR and RCS of J-PARC will be presented with emphasis on special characteristics for high intensity proton accelerator. Achieved beam characteristics and approach to improve beam intensity will be described in connection with the beam monitors. Usage of a transverse RF field to improve a duty factor of the slow extracted beam will be presented.
	Slides THXB101 [16.387 MB]

THPWO032	Progress of Injection Energy Upgrade Project for J-PARC RCS	3833
	N. Hayashi, H. Harada, K. Horino, H. Hotchi, J. Kamiya, M. Kinsho, P.K. Saha, Y. Shobuda, T. Takayanagi, N. Tani, T. Togashi, T. Ueno, M. Watanabe, Y. Watanabe, K. Yamamoto, M. Yamamoto, Y. Yamazaki, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan Y. Irie KEK, Ibaraki, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The injection energy of the J-PARC RCS will be upgraded in 2013. New power supplies for the shift bump magnet system will be installed. Some of other systems, upgrade of the painting bump power supplies and pulse steering systems, are already installed and tested or used for the nominal operation. The paper reports the progress of injection energy upgrade project.

TUPWA009	Bunch by Bunch Intra-Bunch Feedback System for Curing Transverse Beam Instabilities at the J-PARC MR	1739
	O. A. Konstantinova, Y.H. Chin, Y. Kurimoto, T. Obina, M. Okada, K. Takata, M. Tobiyama, T. Toyama KEK, Ibaraki, Japan Y. Shobuda JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	At the J-PARC Main Ring (MR), transverse instabilities have been observed during the injection and at the onset of acceleration with large particle losses. The present bunch by bunch feedback system, operating in a narrowband mode, has been effectively suppressing these instabilities, allowing the beam power to reach 230kW with only 400W of particle losses. The observed beam signals show that bunches are still executing complicated intra-bunch oscillations even if the narrowband feedback system is on, though they are not imposing significant particle losses at present. The new and more advanced broadband feedback system has been developed for control of the intra-bunch oscillations and further reduction of particle losses. The elaborate analysis code has been also developed on the MATLAB platform to analyse effects of the broadband feedback system on intra-bunch oscillations. This paper describes the development of these advanced instruments and presents the analysis of the latest beam test results using the MATLAB code.