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Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.
Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09
Times Cited Count：5 Percentile：87.42(Nuclear Science & Technology)In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.
Okabe, Kota; Yamamoto, Kazami; Kamiya, Junichiro; Takayanagi, Tomohiro; Yamamoto, Masanobu; Yoshimoto, Masahiro; Takeda, Osamu*; Horino, Koki*; Ueno, Tomoaki*; Yanagibashi, Toru*; et al.
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.853 - 857, 2017/12
The most important issue is to reduce the uncontrolled beam loss in the high intensity hadron accelerator such as J-PARC proton accelerators. The J-PARC 3 GeV Synchrotron (RCS) has a collimator system which narrows a high intensity beam in the RCS. After startup of RCS in 2007, the collimator system of the RCS worked well. However, in April 2016, vacuum leakage at the collimator system occurred during the maintenance operation. To investigate a cause of the failure, we took apart iron shields of the collimator reducing exposed dose of operators. As a result of inspection, we succeeded to identify the cause of the vacuum leakage failure. In this presentation, we report the failure investigation of the beam collimator system in the RCS.
Kato, Shinichi; Takayanagi, Tomohiro; Harada, Hiroyuki; Horino, Koki; Tobita, Norimitsu; Ueno, Tomoaki*; Kinsho, Michikazu
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1180 - 1184, 2015/09
For the high intensity proton accelerator, the mitigation of the space charge force is most important because it causes the beam loss. For mitigation, the painting injection method which arranges the injection beam on the wide phase-space area during the multi-turn injection has been performed to expand the circulating beam in the J-PARC RCS. In the horizontal plane, the position and angle of the injection beam are fixed and these of the circulating beam are changed during the painting injection. Specifically, the time variation of the bump orbit height at the injection point is generated by the 4 paint bump magnet whose power supply are separate. Hence, the accuracy of the painting injection depend on the power conditioning precision of the magnet power supply. Therefore, the output characteristics of the power supply was examined for the precise power conditioning. In addition, the automatic conditioning tool has been developed based on that results.
Murata, Mikio; Noguchi, Hiroshi; Kato, Shohei; Kokubun, Morinobu; *
JAERI-M 89-045, 65 Pages, 1989/04
no abstracts in English
Noguchi, Hiroshi; Murata, Mikio; Kato, Shohei; Kokubun, Morinobu; *
JAERI-M 88-061, 97 Pages, 1988/03
no abstracts in English
Kato, Shohei; Noguchi, Hiroshi; Murata, Mikio; Kokubun, Morinobu; *
JAERI-M 87-191, 82 Pages, 1987/11
no abstracts in English
Kato, Shohei; ; ; Kokubun, Morinobu
Hoken Butsuri, 22, p.453 - 465, 1987/00
no abstracts in English
Kato, Shinichi; Harada, Hiroyuki; Takayanagi, Tomohiro; Horino, Koki; Tobita, Norimitsu; Ueno, Tomoaki*; Kinsho, Michikazu
no journal, ,
In the J-PARC RCS, the multi-turn charge-exchange injection scheme is adopted. In addition, the painting injection method which arranges the injection beam on the wide phase-space area during the multi-turn injection has been performed to expand the circulating beam. This method is essential to mitigate the beam loss caused by the particles scattered at the charge-exchange foil and the space charge force. This method is performed by the 4 horizontal and 2 vertical deflection magnets. Hence, the accuracy of the painting injection depends on the power adjustment precision of the magnet power supply. Therefore, the output power adjustment application was developed in order to achieve the high precise painting injection. This application was developed based on the examination results of the output characteristics of the power supply. As a result, the adjustment time was reduced and the adjustment precision was improved to twice of the original design value. After that, the painting injection adjustment was performed using the application. As a result, it was confirmed that the high precise painting injection was achieved.
Kato, Shinichi; Harada, Hiroyuki; Hotchi, Hideaki; Saha, P. K.; Okabe, Kota; Takayanagi, Tomohiro; Horino, Koki; Ueno, Tomoaki; Tobita, Norimitsu*; Kinsho, Michikazu
no journal, ,
In the J-PARC 3GeV RCS, the injection painting is essential method for the reduction of the space charge force. In this method, the H
beam from Linac is arranged on the large phase space area of the ring orbit during multiple turns. To implement this method, painting magnets form the time variable beam orbit. Therefore, the precise output current control of the magnet power supply is required. Because the power supply controlled by mainly feedforward signal is operated, we developed the iterative tuning method for the optimum feedforward parameter determination. As a result, we could reduce the tracking error of the current compared to before. Furthermore, to improve the accuracy of the painting area size, we applied the output readjustment additionally. Because the current monitor value of the power supply was different from the actual magnetic field due to the delay in the circuit and the leakage field, we corrected the tracking of the current based on the measured painting area size determined by the analysis of the measured COD. As a result, we achieved the precise injection painting. This talk presents these improvement results of the injection painting in the RCS.
Kato, Rino*; Hida, Takenori*; Tsutsumi, Hideaki*; Takada, Tsuyoshi
no journal, ,
With the aim of constructing a more realistic earthquake response analysis model of a nuclear facility, we constructed a model using the system identification method developed by the authors making maximum use of the strong motion observation records in the past earthquakes, and discussed its validity.
