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Okabe, Kota; Yamamoto, Kazami; Yoshimoto, Masahiro; Kinsho, Michikazu
Journal of the Korean Physical Society, 63(7), p.1379 - 1384, 2013/10
Times Cited Count：1 Percentile：11.42(Physics, Multidisciplinary)In the J-PARC 3-GeV Rapid Cycle Synchrotron (RCS), transverse beam halo diagnostic and scraping are required to increase the output beam power. Wire scanners and halo scrapers were used for measurement of projected beam distributions to determine the extent of beam halo formation at Linac-3GeV Beam Transport line (L3BT). In order to determine more detail of halo formation, Vibration Wire Monitor (VWM) was installed in L3BT for the beam halo measurement. The high sensitivity of the VWM makes it a prospective one for investigation of beam halo and weak beam scanning. In this paper, we will report a preliminary result of beam halo measurement by VWM and halo scraper at L3BT, and discuss about potential of the VWM for beam halo diagnostic.
Maruta, Tomofumi; Miura, Akihiko; Sako, Hiroyuki; Tamura, Jun; Ikegami, Masanori*; Futatsukawa, Kenta*; Fang, Z.*; Miyao, Tomoaki*; Liu, Y.*
Journal of the Korean Physical Society, 63(7), p.1274 - 1279, 2013/10
Times Cited Count：0 Percentile：0(Physics, Multidisciplinary)Ito, Takashi
Journal of the Korean Physical Society, 63(7), p.1243 - 1248, 2013/10
Times Cited Count：1 Percentile：11.42(Physics, Multidisciplinary)The Japan Proton Accelerator Research Complex (J-PARC) facilities were extensively damaged by the March 2011 earthquake. At the linac facility, a large amount of groundwater leaked into the tunnel. Therefore, the accelerator components were exposed to high-humidity air for several weeks. Vacuum leaks occurred in ion source, MEBT1 and SDTL sections by destruction of vacuum port, beam monitors and bellows. An alignment of the linac was also damaged. There had been observed about 0.2 mm misalignment of the DT bore center in the DTL and the displacement more than 40 mm of the alignment of the cavity. After recovery efforts, we resumed the beam operation in December 2011 and user operation in January 2012. The beam power from the linac reached at 13.3 kW in March 2012, which is the same power as just before the earthquake. In this report, we will present the recovery works from the earthquake and the present operating status of the J-PARC linac.
