IPAC2011 - List of Authors (Harada, H.)

Paper	Title	Page
TUPS033	Foil Scattering Loss Mitigation by the Additional Collimation System of J-PARC RCS	1605
	K. Yamamoto, H. Harada, J. Kamiya, Y. Yamazaki, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the RCS, the significant losses were observed at the branch of H0 dump line and the Beam Position Monitor which was put at the downstream of the H0 dump branch duct. From the beam study, we were certain that these losses were caused by the scattering of the injection and circulating beam at the charge exchange injection foil. In order to mitigate these losses, we started to develop a new collimation system in the H0 branch duct. We presents a overview of this new collimation system.

TUPS057	Displacement of J-PARC Caused by Megaquake	1662
	M.J. Shirakata, Y. Fujii, T. Ishii, Y. Shirakabe KEK, Tsukuba, Japan H. Harada, S. Harjo, T. Iwahashi, S.I. Meigo, T. Morishita, N. Tani JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Accelerators, beam lines, and experimental halls located in the J-PARC site were displaced by the 2011 off the Pacific coast of Tohoku Earthquake happened on 11th March, whose magnitude was nine, and its following many aftershocks. Site-wide network of measurement points distributed on grounds, buildings, and magnets was surveyed by using GPS survey system, precise digital levels, and laser trackers. The effect from the megaquake was reported for each J-PARC components, such as LINAC, Rapid Cycling Synchrotron (RCS), Main Ring (MR), neutrino and hadron beam lines, and experimental halls.

WEPO006	Suppression of Leakage Fields from DC Magnets in J-PARC 3 GeV RCS	2412
	M. Yoshimoto, H. Harada, N. Hayashi, H. Hotchi, M. Kinsho, P.K. Saha, K. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the J-PARC 3 GeV RCS, we found that DC leakage fields from the extraction beam line significantly affected the beam. For this issue, we installed additional shields and got the 40% reduction of the DC leakage field. Thus the circulating beam loss was successfully reduced. In this presentation, we report the detail of the shield structure and the results of the beam studies.

THPS040	Measurement of the Stripping Efficiency for HBC Stripper Foil in the 3-GeV RCS of J-PARC	3511
	P.K. Saha, H. Harada, S. Hatakeyama, H. Hotchi, M. Kinsho, Y. Yamazaki, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan Y. Irie, I. Sugai KEK, Ibaraki, Japan
	We have carried out experimental measurement of the stripping efficiency for the newly developed HBC (Hybrid type Boron doped Carbon) stripper foils. The HBC foil is used for charge-exchange injection in the RCS (Rapid Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex) and plays an important role for the RCS operation. We have developed a rather simple but very precise method using which stripping efficiencies for several HBC foils were determined accurately. Importance of knowing an accurate stripping efficiency so as to determine a realistic stripper foil for the RCS operation will be discussed.

Paper

Title

Page

Foil Scattering Loss Mitigation by the Additional Collimation System of J-PARC RCS

1605

K. Yamamoto, H. Harada, J. Kamiya, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the RCS, the significant losses were observed at the branch of H0 dump line and the Beam Position Monitor which was put at the downstream of the H0 dump branch duct. From the beam study, we were certain that these losses were caused by the scattering of the injection and circulating beam at the charge exchange injection foil. In order to mitigate these losses, we started to develop a new collimation system in the H0 branch duct. We presents a overview of this new collimation system.

TUPS057

Displacement of J-PARC Caused by Megaquake

1662

M.J. Shirakata, Y. Fujii, T. Ishii, Y. Shirakabe
KEK, Tsukuba, Japan
H. Harada, S. Harjo, T. Iwahashi, S.I. Meigo, T. Morishita, N. Tani
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Accelerators, beam lines, and experimental halls located in the J-PARC site were displaced by the 2011 off the Pacific coast of Tohoku Earthquake happened on 11th March, whose magnitude was nine, and its following many aftershocks. Site-wide network of measurement points distributed on grounds, buildings, and magnets was surveyed by using GPS survey system, precise digital levels, and laser trackers. The effect from the megaquake was reported for each J-PARC components, such as LINAC, Rapid Cycling Synchrotron (RCS), Main Ring (MR), neutrino and hadron beam lines, and experimental halls.

WEPO006

Suppression of Leakage Fields from DC Magnets in J-PARC 3 GeV RCS

2412

M. Yoshimoto, H. Harada, N. Hayashi, H. Hotchi, M. Kinsho, P.K. Saha, K. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the J-PARC 3 GeV RCS, we found that DC leakage fields from the extraction beam line significantly affected the beam. For this issue, we installed additional shields and got the 40% reduction of the DC leakage field. Thus the circulating beam loss was successfully reduced. In this presentation, we report the detail of the shield structure and the results of the beam studies.

THPS040

Measurement of the Stripping Efficiency for HBC Stripper Foil in the 3-GeV RCS of J-PARC

3511

P.K. Saha, H. Harada, S. Hatakeyama, H. Hotchi, M. Kinsho, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y. Irie, I. Sugai
KEK, Ibaraki, Japan

We have carried out experimental measurement of the stripping efficiency for the newly developed HBC (Hybrid type Boron doped Carbon) stripper foils. The HBC foil is used for charge-exchange injection in the RCS (Rapid Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex) and plays an important role for the RCS operation. We have developed a rather simple but very precise method using which stripping efficiencies for several HBC foils were determined accurately. Importance of knowing an accurate stripping efficiency so as to determine a realistic stripper foil for the RCS operation will be discussed.