IPAC2011 - List of Authors (Koseki, T.)

Paper	Title	Page
MOPS005	Beam Dynamics Simulations of J-PARC Main Ring for Upgrade Plan of Fast Extraction Operation	598
	Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori, M. Tomizawa KEK, Ibaraki, Japan H. Hotchi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Beam loss simulations under space charge effects are necessary to seek higher intensity proton beams. This paper presents simulations for fast extraction operation of Japan Proton Accelerator Research Complex (J-PARC) Main Ring. For upgrade plan, increasing protons per bunch and making higher repetition pattern are considered. Their optimal balance is discussed to minimize beam losses for aimed beam power considering space charge effects. We found that to optimize RF voltage pattern is a strong key to reduce beam losses for higher repetition. As benchmark works, we compare our simulations with the measured beam loss in our past operation.

WEPS008	Operation Status and Future Plan of J-PARC Main Ring	2499
	T. Koseki KEK, Ibaraki, Japan
	The J-PARC Main Ring (MR) has started users operation since 2009. The MR has two beam extraction systems. One is a fast extraction (FX) system for beam delivery to the neutrino beam line of the Tokai-to-Kamioka (T2K) experiment, and the other is a slow extraction (SX) system for beam delivery to the hadron experimental hall. For the T2K experiment, the maximum beam power of 145 kW is delivered continuously. For users of the hadron experimental hall, the beam power of 3 kW is delivered with extraction efficiency of 99.5%. In this paper, status of the high power beam operation of the MR is presented. Future prospect for increasing beam intensity is also discussed.

WEPS095	Status of J-PARC Accelerator Facilities after the Great East Japan Earthquake	2727
	K. Hasegawa, M. Kinsho, H. Oguri JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Koseki KEK, Tokai, Ibaraki, Japan
	J-PARC was heavily affected by the March 11 Great East Japan Earthquake. When the earthquake struck, we had a beam study operation of the linac and the machine immediately stopped. Fortunately, we had no effects of tsunami that happened nearby and no one was injured. We can see subsidence at many places; about 1.5m over the wide area at the entrance of the linac building, about 50cm over the area of 1m x 10m at the main ring building, etc. Underground water is coming into the linac and the main ring tunnels. The water level at the linac reached a depth of 10 cm, but pumping with a diesel generator successfully saved from further flooding. At the RCS, the circulating road went wavy and the yard area for electricity and water devices was heavily distorted. Therefore, a high voltage power is not available on the date of abstract submission. We are investigating damages of each facility and also we are trying to estimate the beam restoration. The current status of the J-PARC accelerator facilities after the earthquake will be presented.

Paper

Title

Page

Beam Dynamics Simulations of J-PARC Main Ring for Upgrade Plan of Fast Extraction Operation

598

Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori, M. Tomizawa
KEK, Ibaraki, Japan
H. Hotchi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Beam loss simulations under space charge effects are necessary to seek higher intensity proton beams. This paper presents simulations for fast extraction operation of Japan Proton Accelerator Research Complex (J-PARC) Main Ring. For upgrade plan, increasing protons per bunch and making higher repetition pattern are considered. Their optimal balance is discussed to minimize beam losses for aimed beam power considering space charge effects. We found that to optimize RF voltage pattern is a strong key to reduce beam losses for higher repetition. As benchmark works, we compare our simulations with the measured beam loss in our past operation.

WEPS008

Operation Status and Future Plan of J-PARC Main Ring

2499

T. Koseki
KEK, Ibaraki, Japan

The J-PARC Main Ring (MR) has started users operation since 2009. The MR has two beam extraction systems. One is a fast extraction (FX) system for beam delivery to the neutrino beam line of the Tokai-to-Kamioka (T2K) experiment, and the other is a slow extraction (SX) system for beam delivery to the hadron experimental hall. For the T2K experiment, the maximum beam power of 145 kW is delivered continuously. For users of the hadron experimental hall, the beam power of 3 kW is delivered with extraction efficiency of 99.5%. In this paper, status of the high power beam operation of the MR is presented. Future prospect for increasing beam intensity is also discussed.

WEPS095

Status of J-PARC Accelerator Facilities after the Great East Japan Earthquake

2727

K. Hasegawa, M. Kinsho, H. Oguri
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Koseki
KEK, Tokai, Ibaraki, Japan

J-PARC was heavily affected by the March 11 Great East Japan Earthquake. When the earthquake struck, we had a beam study operation of the linac and the machine immediately stopped. Fortunately, we had no effects of tsunami that happened nearby and no one was injured. We can see subsidence at many places; about 1.5m over the wide area at the entrance of the linac building, about 50cm over the area of 1m x 10m at the main ring building, etc. Underground water is coming into the linac and the main ring tunnels. The water level at the linac reached a depth of 10 cm, but pumping with a diesel generator successfully saved from further flooding. At the RCS, the circulating road went wavy and the yard area for electricity and water devices was heavily distorted. Therefore, a high voltage power is not available on the date of abstract submission. We are investigating damages of each facility and also we are trying to estimate the beam restoration. The current status of the J-PARC accelerator facilities after the earthquake will be presented.