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Yamamoto, Kazami; Takayanagi, Tomohiro; Togashi, Tomohito; Hatakeyama, Shuichiro
no journal, ,
The beam commissioning of the J-PARC 3-GeV rapid cycling synchrotron (RCS) was started in 2007, and the proton beams were delivered to the neutron target along with the Main Ring synchrotron in December 2008. At the beginning of the RCS operation, the operation stability was compromised by the discharge of a thyratron that was a part of the power supply system of the extraction kicker magnet. We investigated the operational statistics of the thyratron to improve its reliability and found an efficient method that fit the characteristics of an individual thyratron. As a result, the discharge rate was improved dramatically. During the operation, a radiation leak accident occurred in the Hadron Experimental Hall. In addition, two other water leak accidents occurred in the neutron target. From these accidents, we considered that it was necessary to not only monitor the status of the accelerator components but also to monitor the beam condition and radiation level to obtain rapid detection of any target defects. Therefore, we developed a new monitoring system. Also we developed a new interlock system to prevent an extraction of an unexpected beam, which might affect the components in the downstream facilities. These improvements have improved the stability of the RCS operation.
Yamamoto, Kazami; Hasegawa, Kazuo; Kinsho, Michikazu; Oguri, Hidetomo; Hayashi, Naoki; Yamazaki, Yoshio; Kikuchi, Kazuo; Naito, Fujio*; Koseki, Tadashi*; Yamamoto, Noboru*; et al.
no journal, ,
The Japan Proton Accelerator Research Complex (J-PARC) is a multipurpose facility for scientific experiments. The J-PARC facilities were constructed at the Tokai site of the Japan Atomic Energy Agency. The accelerator complex consists of a linac, a 3 GeV rapid-cycling synchrotron (RCS) and a main ring synchrotron (MR). The RCS delivers a proton beam to the neutron target and MR, and the MR delivers the beams to the neutrino target and the Hadron Experimental Facility. The first operation of the neutron experiments began in December 2008. In January 2009, we achieved a slow extraction of the hadron beam line at the MR. The regular neutrino experiments to obtain physical data began in January 2010. Following this, user operation has been continued with some accidental suspensions. In this report, the reliability of J-PARC and the major causes of suspension are summarized.
Yamazaki, Yoshio
no journal, ,
no abstracts in English