IPAC2012 - List of Authors (Kamiya, J.)

Paper	Title	Page
MOPPD053	Reduction of Outgassing from the Ferrite Cores in the Kicker Magnet of J-PARC RCS	487
	N. Ogiwara, Y. Hikichi, J. Kamiya, M. Kinsho, M. Nishikawa, K. Suganuma, T. Yanagibashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Kicker magnets are used to kick out the accelerated beam to the beam transport lines in the RCS of the J-PARC. A high voltage is applied to kickers for a short period, so they must be installed in a vacuum to prevent discharge. Therefore, it is important to reduce the outgassing of water vapor from the ferrite cores. After bake-out at 200°C for 300 hours, the outgassing rate decreased to less than 1×10^-7 Pam/s. However, the small amount of water vapor and carbon monoxide were emitted from the ferrite cores at charging voltage of 80 kV. This time, we have decided to construct the reserve magnets with very low outgassing at high-voltage discharge. First of all, the thermal desorption behavior of the ferrite was investigated. Water vapor has two peaks: at ~ 100°C and 350°C. Carbon monoxide is rather largely emitted until 300°C. From these results, the ferrite cores were vacuum-fired at 450°C for 10 h. Then the good properties for the magnetic cores were confirmed. And now the assembling of the kicker magnet is undertaken. The performance of the kicker magnet made of the vacuum-fired ferrite will be shown in this meeting.

MOPPD074	Localization of Large Angle Foil Scattering Beam Loss Caused by Multi-Turn Charge-Exchange Injection	535
	S. Kato Tohoku University, Graduate School of Science, Sendai, Japan H. Harada, S. Hatakeyama, J. Kamiya, M. Kinsho, K. Yamamoto, Y. Yamazaki, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the J-PARC 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. These losses were caused by the large angle scattering of the injection and circulating beam at the charge exchange foil. To realize high power operation, we have to mitigate these losses. So, we started to develop a new collimation system in the H⁰ branch duct and installed in October 2011. In order to optimize this system efficiently, we primarily focused on the relative angle of collimator block from scattering particles. We simulated behavior of particles scattered by foil and produced by collimator block and researched most optimized position and angle of the collimator block. In this process, we devised the method of angular regulation of collimator block. We present the method of angular regulation and performance of this new collimation system.

WEPPD013	Status of the Vacuum System in J-PARC RCS	2522
	J. Kamiya, Y. Hikichi, M. Kinsho, M. Nishikawa, N. Ogiwara, T. Yanagibashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the vacuum system of J-PARC Rapid cycling synchrotron (RCS), we use beam pipes and bellows whose materials are vacuum fired at 700~850 oC in order to eliminate atoms in their bulk who are origin of outgassing. Until now, beam power has been increased up to 300 kW. Pressure in synchrotron beam line increased when the high power beam was accelerated. However, increment of pressure has reduced during the continuous beam operation. It is because the molecules, which adsorb on surface of the wall of the vacuum chambers, desorb by an ion bombardment and a heat generation due to an eddy current. Because the atoms in the bulk is eliminated, desorption of the molecules, which adsorb on the surface, means the reduction of the outgassing from the wall. In this presentation, we will report the past situation of the vacuum system during the beam operation. In addition, we also show the status after the Great East Japan Earthquake.

THPPP081	Status of Injection Energy Upgrade for J-PARC RCS	3921
	N. Hayashi, H. Harada, H. Hotchi, J. Kamiya, P.K. Saha, Y. Shobuda, T. Takayanagi, N. Tani, M. Watanabe, Y. Watanabe, K. Yamamoto, M. Yamamoto, Y. Yamazaki, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The injection energy upgrade for J-PARC RCS is planed in 2013. This includes the power supplies upgrade of injection pulsed magnet system, suppression for leakage field, quadrupole correction magnets, reduction of kicker impedance effect and improvements of beam diagnostic instrumentation. The paper reports the present status.

Paper

Title

Page

Reduction of Outgassing from the Ferrite Cores in the Kicker Magnet of J-PARC RCS

487

N. Ogiwara, Y. Hikichi, J. Kamiya, M. Kinsho, M. Nishikawa, K. Suganuma, T. Yanagibashi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Kicker magnets are used to kick out the accelerated beam to the beam transport lines in the RCS of the J-PARC. A high voltage is applied to kickers for a short period, so they must be installed in a vacuum to prevent discharge. Therefore, it is important to reduce the outgassing of water vapor from the ferrite cores. After bake-out at 200°C for 300 hours, the outgassing rate decreased to less than 1×10^-7 Pam/s. However, the small amount of water vapor and carbon monoxide were emitted from the ferrite cores at charging voltage of 80 kV. This time, we have decided to construct the reserve magnets with very low outgassing at high-voltage discharge. First of all, the thermal desorption behavior of the ferrite was investigated. Water vapor has two peaks: at ~ 100°C and 350°C. Carbon monoxide is rather largely emitted until 300°C. From these results, the ferrite cores were vacuum-fired at 450°C for 10 h. Then the good properties for the magnetic cores were confirmed. And now the assembling of the kicker magnet is undertaken. The performance of the kicker magnet made of the vacuum-fired ferrite will be shown in this meeting.

MOPPD074

Localization of Large Angle Foil Scattering Beam Loss Caused by Multi-Turn Charge-Exchange Injection

535

S. Kato
Tohoku University, Graduate School of Science, Sendai, Japan
H. Harada, S. Hatakeyama, J. Kamiya, M. Kinsho, K. Yamamoto, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the J-PARC 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. These losses were caused by the large angle scattering of the injection and circulating beam at the charge exchange foil. To realize high power operation, we have to mitigate these losses. So, we started to develop a new collimation system in the H⁰ branch duct and installed in October 2011. In order to optimize this system efficiently, we primarily focused on the relative angle of collimator block from scattering particles. We simulated behavior of particles scattered by foil and produced by collimator block and researched most optimized position and angle of the collimator block. In this process, we devised the method of angular regulation of collimator block. We present the method of angular regulation and performance of this new collimation system.

WEPPD013

Status of the Vacuum System in J-PARC RCS

2522

J. Kamiya, Y. Hikichi, M. Kinsho, M. Nishikawa, N. Ogiwara, T. Yanagibashi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the vacuum system of J-PARC Rapid cycling synchrotron (RCS), we use beam pipes and bellows whose materials are vacuum fired at 700~850 oC in order to eliminate atoms in their bulk who are origin of outgassing. Until now, beam power has been increased up to 300 kW. Pressure in synchrotron beam line increased when the high power beam was accelerated. However, increment of pressure has reduced during the continuous beam operation. It is because the molecules, which adsorb on surface of the wall of the vacuum chambers, desorb by an ion bombardment and a heat generation due to an eddy current. Because the atoms in the bulk is eliminated, desorption of the molecules, which adsorb on the surface, means the reduction of the outgassing from the wall. In this presentation, we will report the past situation of the vacuum system during the beam operation. In addition, we also show the status after the Great East Japan Earthquake.

THPPP081

Status of Injection Energy Upgrade for J-PARC RCS

3921

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

The injection energy upgrade for J-PARC RCS is planed in 2013. This includes the power supplies upgrade of injection pulsed magnet system, suppression for leakage field, quadrupole correction magnets, reduction of kicker impedance effect and improvements of beam diagnostic instrumentation. The paper reports the present status.