IPAC2011 - List of Authors (Yamazaki, Y.)

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.

WEPS096	Injection Energy Recovery of J-PARC RCS	2730
	N. Hayashi, H. Hotchi, J. Kamiya, P.K. Saha, T. Takayanagi, K. Yamamoto, M. Yamamoto, Y. Yamazaki JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The J-PARC RCS is a high beam power Rapid-Cycling Synchrotron (RCS). The original designed injection energy is 400MeV, although presently it is 181MeV, and its beam power is limited to 0.6MW. Works to recover the Linac energy are ongoing and injection magnets power supplies upgrade are required in the RCS. In order to achieve 1MW designed beam power, new instrumentation is also planned simultaneously. Activities related injection energy recovery in the J-PARC RCS is presented.

THPS037	Performance Characteristics of HBC-foils by 650 KeV H⁻ and DC High Intensity Ion Beam Irradiation	3502
	I. Sugai, Y. Irie, H. Kawakami, M. Oyaizu, A. Takagi, Y. Takeda KEK, Ibaraki, Japan M. Kinsho, Y. Yamazaki, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Newly developed Hybrid type Boron mixed Carbon stripper foils (HBC-stripper foil) are extensively used for not only J-PARC, for but also LANL-PSR since September of 2007. In order to know further characteristics of the HBC-stripper foils, we measured following parameters; foil lifetimes, thickness reduction, uniformity before and after beam irradiation and foil shrinkage, using 3.2 MeV Ne⁺ DC beam from TIT-Van de Grraff and 650 keV DC proton beam at KEK Cock-Croft accelerators, which are almost the same energy deposition as well as the J-PARC. We also investigated sputtering yield by hydrogen ion beam, thermal conductivity, weight change in heating and density of the HBC-stripper foils. We compared these values with other tested carbon stripper foils such as commercially available carbon foils (CM-foil), synthetic diamond (DM-foil) and nano-tube carbon foils (NTC-foil). Through these experiments, the　HBC-stripper foils showed superior performance characteristics, in especially, on the lifetime at temperature higher than 1800K compared with other tested CM-, DM- and NTC-foils.

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.

WEPS096

Injection Energy Recovery of J-PARC RCS

2730

N. Hayashi, H. Hotchi, J. Kamiya, P.K. Saha, T. Takayanagi, K. Yamamoto, M. Yamamoto, Y. Yamazaki
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The J-PARC RCS is a high beam power Rapid-Cycling Synchrotron (RCS). The original designed injection energy is 400MeV, although presently it is 181MeV, and its beam power is limited to 0.6MW. Works to recover the Linac energy are ongoing and injection magnets power supplies upgrade are required in the RCS. In order to achieve 1MW designed beam power, new instrumentation is also planned simultaneously. Activities related injection energy recovery in the J-PARC RCS is presented.

THPS037

Performance Characteristics of HBC-foils by 650 KeV H⁻ and DC High Intensity Ion Beam Irradiation

3502

I. Sugai, Y. Irie, H. Kawakami, M. Oyaizu, A. Takagi, Y. Takeda
KEK, Ibaraki, Japan
M. Kinsho, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Newly developed Hybrid type Boron mixed Carbon stripper foils (HBC-stripper foil) are extensively used for not only J-PARC, for but also LANL-PSR since September of 2007. In order to know further characteristics of the HBC-stripper foils, we measured following parameters; foil lifetimes, thickness reduction, uniformity before and after beam irradiation and foil shrinkage, using 3.2 MeV Ne⁺ DC beam from TIT-Van de Grraff and 650 keV DC proton beam at KEK Cock-Croft accelerators, which are almost the same energy deposition as well as the J-PARC. We also investigated sputtering yield by hydrogen ion beam, thermal conductivity, weight change in heating and density of the HBC-stripper foils. We compared these values with other tested carbon stripper foils such as commercially available carbon foils (CM-foil), synthetic diamond (DM-foil) and nano-tube carbon foils (NTC-foil). Through these experiments, the　HBC-stripper foils showed superior performance characteristics, in especially, on the lifetime at temperature higher than 1800K compared with other tested CM-, DM- and NTC-foils.

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.