IBIC2012 - List of Authors (Hatakeyama, S.)

Paper	Title	Page
MOPA26	Performance and Upgrade of BPMs at the J-PARC MR	107
	T. Toyama, Y. Hashimoto J-PARC, KEK & JAEA, Ibaraki-ken, Japan K. Hanamura Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan S. Hatakeyama JAEA/J-PARC, Tokai-mura, Japan M. Okada, M. Tejima KEK, Ibaraki, Japan
	Since recovery from the great earthquake 2011.3.11, proton beam, more than 10¹⁴ ppp, is accelerated up to 30 GeV at the J-PARC MR. The BPMs were originally designed with the external capacitors. The aim was to improve the position response in wider frequencies and to get an adequate output voltage at the design intensity, 4x10¹³ ppb. It was modified, however, not to have the capacitors. Therefore we have sufficient signal intensity from low intensity beams of the initial beam commissioning, but too large from the design intensity beam. The processing circuits (BPMC) have to accommodate those output signals from high intensity beams. We are adding the attenuator-LPFs just before the BPMC. This paper will describe these additional attenuator-LPFs. In connection with the MR collimator upgrade, some BPMs are re-allocated. This process is also reported.

Paper

Title

Page

Performance and Upgrade of BPMs at the J-PARC MR

107

T. Toyama, Y. Hashimoto
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
K. Hanamura
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
S. Hatakeyama
JAEA/J-PARC, Tokai-mura, Japan
M. Okada, M. Tejima
KEK, Ibaraki, Japan

Since recovery from the great earthquake 2011.3.11, proton beam, more than 10¹⁴ ppp, is accelerated up to 30 GeV at the J-PARC MR. The BPMs were originally designed with the external capacitors. The aim was to improve the position response in wider frequencies and to get an adequate output voltage at the design intensity, 4x10¹³ ppb. It was modified, however, not to have the capacitors. Therefore we have sufficient signal intensity from low intensity beams of the initial beam commissioning, but too large from the design intensity beam. The processing circuits (BPMC) have to accommodate those output signals from high intensity beams. We are adding the attenuator-LPFs just before the BPMC. This paper will describe these additional attenuator-LPFs. In connection with the MR collimator upgrade, some BPMs are re-allocated. This process is also reported.