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Hayashi, Naoki; Saha, P. K.; Yoshimoto, Masahiro; Hatakeyama, Shuichiro
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1055 - 1059, 2018/08
The J-PARC Rapid-Cycling Synchrotron (RCS) is designed as an 1-MW high power accelerator. It has been operated since 2007, and its injection energy and beam current are upgraded in 2014. Its operation is very smooth and provides the high intensity beam to the Material and Life science experimental facility (MLF) and the Main Ring (MR). The beam is injected with multi-turn mode. It is possible because the negative hydrogen ion beam from the Linac, H
, and the circulating proton beam H
are different state. The H is converted to H at the injection point, where a charge stripper foil is set. A small fraction of the injected beam, which is not fully stripped, are transferred to the injection beam dump through H0 dump line to prevent un-necessary activation. Since the limit of beam dump is only 4 kW, which is about 3% of designed injection beam power 133 kW, the beam has to be stopped immediately in case of stripper foil break up incident.
Hayashi, Naoki; Saha, P. K.; Yoshimoto, Masahiro; Miura, Akihiko
Proceedings of 8th International Particle Accelerator Conference (IPAC '17) (Internet), p.277 - 280, 2017/06
Multi-turn painting injection scheme is important for high intensity proton accelerators. At the J-PARC RCS, a transverse painting scheme was adapted by adding vertical painting magnets to the beam transport line before the injection point, with horizontal painting being performed by a set of dedicated pulse magnets in the ring. To establish a transverse painting condition, it is usual to base on the pulse magnet current pattern. However, it is more desirable to directly measure the beam orbit time variation for evaluation. A linac beam was chopped to match the ring RF bucket. We thought that it would be difficult to measure the position for each pulse; however, the average position could be extracted by introducing a particular device. For the beam injected into the ring, because the linac RF frequency component was diminished due to debunching quickly, one could determine its position in the beginning of the injection period. However, due to rebunching effect the position determination becomes difficult. This problem needs to be resolved.
Tone, Tatsuzo; *; ; *
Journal of Nuclear Science and Technology, 18(9), p.684 - 696, 1981/00
Times Cited Count：2 Percentile：36.87(Nuclear Science & Technology)no abstracts in English
