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Yamamoto, Kazami
EPJ Web of Conferences, 153, p.07022_1 - 07022_6, 2017/09
Times Cited Count：1 Percentile：61.03(Nuclear Science & Technology)The J-PARC 3 GeV Rapid Cycling Synchrotron (RCS) delivers a 1-MW, high-intensity beam to the following facilities. In such high-intensity accelerator, the operational beam intensity is limited to keep the exposure to the workers by the residual dose within acceptable tolerances. Therefore we continue to commission the accelerator system to reduce the beam loss. In order to achieve further high-intensity operation, the J-PARC accelerator system was drastically upgraded (Increment of the injection energy of RCS and peak current of Linac) over the past two years. After the upgrade, the beam loss was decreased by the commissioning. The output power was increased; nevertheless the residual doses were kept same level or decreased. Since we replaced the broken collimator which was higher activated, we kept the exposure to the workers within acceptable level.
Kinsho, Michikazu
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.3382 - 3384, 2014/07
Big issue for the J-PARC rapid cycling synchrotron (RCS) was displacement of main magnets caused by last big earthquake because this made beam loss more than 400 kW beam power. Since realignment of main magnets and other components was essential to realize higher beam power and stable operation, this work has been done during maintenance period in 2013. To achieve the nominal performance 1MW beam power at the RCS and 0.75 MW at the MR, beam energy of linac was increased from 181 MeV to 400 MeV with a new accelerating structure ACS (Annular-ring Coupled Structure) linac from this January. It was successful 400 MeV beam injection and 3 GeV beam extraction at the RCS, and user operation has been performed with beam power of 300 kW. An equivalent beam power of 560 kW with a beam loss of only 0.3% could be achieved during short time for high intensity beam study.
