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Sakai, I.

Paper Title Page
MOPEA039 Beam Study for FFAG Accelerator at KURRI 157
 
  • Y. Kuriyama, Y. Ishi, J.-B. Lagrange, Y. Mori, T. Planche, M. Takashima, T. Uesugi, E. Yamakawa
    KURRI, Osaka
  • H. Imazu, K. Okabe, I. Sakai, Y. Takahoko
    University of Fukui, Faculty of Engineering, Fukui
 
 

In Kyoto University Research Reactor Institute (KURRI), The FFAG accelerator complex for accelerator driven sub-critical reactor (ADSR) project has been already constructed and world first ADSR experiment has been done at May, 2009. In the main ring, proton beams of 11.5 MeV are injected and accelerated up to 100 MeV. During the acceleration, two different types of beam loss have been observed. To investigate these beam loss, betatron and synchrotron motion have been measured experimentally. The details of measurements will be described in this presentation.

 
TUOCRA03 Present Status and Future of FFAGs at KURRI and the First ADSR Experiment 1327
 
  • Y. Ishi, M. Inoue, Y. Kuriyama, J.-B. Lagrange, Y. Mori, T. Planche, M. Takashima, T. Uesugi, E. Yamakawa
    KURRI, Osaka
  • H. Imazu, K. Okabe, I. Sakai, Y. Takahoko
    University of Fukui, Faculty of Engineering, Fukui
 
 

World's first ADSR experiments which use spallation neutrons produced by high energy proton beams accelerated by the FFAG synchrotron has started since March 2009 at KURRI. In these experiments, the prompt and delayed neutrons which indicate neutron multiplication caused by external source have been detected. The accelerator complex for ADSR study in KURRI consists of three FFAG proton rings. It delivers the 100MeV proton beam to the W target located in front of the subcritical nuclear fuel system constructed in the reactor core of KUCA (Kyoto University Critical Assembly) at 30Hz repetition rate. Current status of the facility and the future plans of ADSR system and high intensity pulsed spallation neutron source which employ a newly added 700MeV FFAG synchrotron to the existing FFAG complex in KURRI will be presented.

 

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Slides

 
THPEB010 Electrostatic Septum for 50GeV Proton Synchrotron in J-PARC 3900
 
  • Y. Arakaki, S. Murasugi, R. Muto, K. Okamura, Y. Shirakabe, M. Tomizawa
    KEK, Ibaraki
  • D. Horikawa, I. Sakai
    University of Fukui, Faculty of Engineering, Fukui
  • M. Nishikawa
    Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture
 
 

The two electrostatic septa are one of the most important device for the slow extraction in 50GeV proton synchrotron. We have developed the thin ribbon type septum in order to reduce the beam loss. If alignment of ribbons is poor, the effective thickness seen from the beam become large, and it would increase the beam-hitting rate. The alignment of ribbon over 1.5m long septa was measured by a laser-focus displacement meter. The achieved effective thickness of septa is estimated to be 0.075mm and 0.080mm respectively. We will report a high voltage conditioning and a performance under beam commissioning.

 
THPEB009 Development of H- Injection of Proton-FFAG at KURRI 3897
 
  • K. Okabe, R. Nakano, Y. Niwa, I. Sakai
    University of Fukui, Faculty of Engineering, Fukui
  • Y. Arakida
    KEK, Ibaraki
  • M. Inoue, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, T. Planche, T. Uesugi, E. Yamakawa
    KURRI, Osaka
 
 

In Kyoto University Research Reactor Institute (KURRI), the FFAG accelerator for accelerator driven sub-critical reactor (ADSR) system has been constructed and world's first ADSR experiments have started in March 2009. In order to upgrade beam intensity, multiturn charge exchange injection system for scaling FFAG accelerator is being studied. The 11MeV H- beam is injected from linac and is accelerated up to 100MeV in FFAG main ring. In this presentation, the detail of injection system is described and feasibility of such a low energy H- injection system is discussed.

 
THPEB014 Status and Upgrade Plan of Slow Extraction from the J-PARC Main Ring 3912
 
  • M. Tomizawa, T. Adachi, Y. Arakaki, A. Kiyomichi, S. Murasugi, R. Muto, H. Nakagawa, K. Niki, K. Okamura, Y. Sato, S. Sawada, Y. Shirakabe, H. Someya, K.H. Tanaka, T. Toyama, E. Yanaoka
    KEK, Ibaraki
  • A. Ando, Y. Hashimoto, T. Koseki, J. Takano
    J-PARC, KEK & JAEA, Ibaraki-ken
  • D. Horikawa, I. Sakai
    University of Fukui, Faculty of Engineering, Fukui
  • K. Mochiki, S. Onuma
    Tokyo City University, Tokyo
  • H. Sato
    Tsukuba University, Ibaraki
  • A. Schnase
    JAEA/J-PARC, Tokai-mura
 
 

High power protons from the J-PARC main ring is slowly extracted using the third integer resonance and delivered to the experimental hall for various nuclear and particle physics experiments. The slow extraction device comprises two electro static septa (ESS),ten magnetic septa, four bump magnets, eight resonant sextupole magnets and their power supply. One of the critical issue of the slow extraction is radiation caused by the beam loss during the slow extraction. We have developed the electrostatic and magnetic septa with thin septum thickness. A unique scheme with large step size and small angular spread of the extracted beam enables hit rate on the ESS less than 1% level. In January 2009, first 30 GeV proton beam has been successfully delivered to the fixed target. Quadrupole magnets and a DSP feedback control system to obtain a uniform beam spill structure were implemented in 2009 summer shutdown period. We will report the extraction efficiency, extracted beam profiles and spill structure obtained by the beam commissioning so far. We will also mention a upgrade plan based on some new ideas to aim a higher performance.