Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Okabe, Kota; Yoshimoto, Masahiro; Kinsho, Michikazu
JPS Conference Proceedings (Internet), 8, p.012024_1 - 012024_7, 2015/09
In the high intensity proton accelerator as the J-PARC accelerators, serious radiation and residual dose is induced by a small beam loss such a beam halo. Therefore, diagnostics of the beam halo formation is one of most important issue to control the beam loss. For the beam halo monitor, the vibration wire monitor (VWM) has a potential for investigating the beam halo and weak beam scanning. The VWM has a wide dynamic range, high resolution and the VWM is not susceptible to secondary electrons and electric noises. We have studied the VWM futures as a new beam-halo monitor on the test stands with low energy electron gun. The frequency shift of the irradiated vibration wire was conformed about various wire materials and the electron beam profile measured by using the VWM was consistent with the results of the faraday cup measurement. Also we calculated a temperature distribution on the vibration wire which is irradiated by the electron beam with the numerical simulation. The simulations have been fairly successful in reproducing the transient of the irradiated vibration wire frequency measured by test stands experiments. In this presentation, we will report a result of performance evaluation study for the VWM on the test stands and discuss about the VWM for beam halo diagnostic.
Yoshimoto, Masahiro; Harada, Hiroyuki; Okabe, Kota; Kinsho, Michikazu
Proceedings of 54th ICFA Advanced Beam Dynamics Workshop on High-Intensity, High Brightness and High Power Hadron Beams (HB 2014) (Internet), p.143 - 147, 2015/03
Transverse beam halo is one of the most important beam parameters due to limit the performance of the high intensity beam accelerator. Therefore the transverse beam halo measurement is required to increase the beam power of the J-PARC 3-GeV RCS. In the beam profile, there are the beam core which is a high density area, the beam tail which is a low density area around the beam core, and the beam halo which is the area outside of the beam tail and in which few particles are straggling. Generally, the beam halo intensity is less than 1/100000 
1/1000000 of the beam core. Therefore, the dynamic range of the beam halo is required typically an order of 10
, but it is difficult to achieve this ultra wide dynamic range by any one diagnostics. Then, new beam halo monitor, which is combined a wire type beam scraper and some beam loss monitors, are developed and installed in the extraction beam transport line. Each beam loss monitor has not more than 10
order of the dynamic range. However, to use some beam loss monitors with a plurality of different sensitivity range, its ultra wide dynamic range can be achieved and beam profile including both of the beam core, beam tail, and beam halo can be obtained.
beam halo scraper system in the J-PARC L3BTOkabe, Kota; Yamamoto, Kazami; Yoshimoto, Masahiro; Kinsho, Michikazu
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.876 - 878, 2014/07
In the Japan Proton Accelerator Research Complex (J-PARC) 3-GeV rapid cycle synchrotron (RCS), transverse beam halo scraping for the injection beam is required to increase the output beam power. The transverse scraper system at the Linac-RCS beam transport line (L3BT) was utilized in a nominal beam operation because the area of the scraper section was contaminated when the scrapers were working. In the summer-autumn period of 2013, we installed the new beam-halo scrapers which had optimized scraper heads for mitigation of the radiation around the scraper system. In this paper, we report a preliminary result for a halo scraper at the L3BT.
Ikegami, Masanori
Nuclear Instruments and Methods in Physics Research A, 454(2-3), p.289 - 298, 2000/11
Times Cited Count：2 Percentile：26.88(Instruments & Instrumentation)no abstracts in English
Ikegami, Masanori*
Physical Review E, 59(2), p.2330 - 2338, 1999/02
Times Cited Count：26 Percentile：70.89(Physics, Fluids & Plasmas)no abstracts in English
Ikegami, Masanori*
Nuclear Instruments and Methods in Physics Research A, 435(3), p.284 - 296, 1999/00
Times Cited Count：10 Percentile：60.55(Instruments & Instrumentation)no abstracts in English
Machida, Shinji*; Ikegami, Masanori
Proceedings of 6th European Particle Accelerator Conference (EPAC98) (CD-ROM), p.282 - 284, 1998/01
no abstracts in English
Ikegami, Masanori*; Mizumoto, Motoharu
Proc. of XIX Int. Linac Conf. (LINAC98), 2, p.821 - 823, 1998/00
no abstracts in English
Ikegami, Masanori*
Proceedings of 23rd Linear Accelerator Meeting in Japan, p.390 - 392, 1998/00
no abstracts in English
Machida, Shinji*; Ikegami, Masanori*
Workshop on Space Charge Physics in High Intensity Hadron Rings, p.73 - 84, 1998/00
no abstracts in English
Okabe, Kota
no journal, ,
In the Japan Proton Accelerator Research Complex (J-PARC) 3-GeV rapid cycle synchrotron (RCS), supression of the transverse beam halo for the injected beam int the RCS is required to increase the output beam power. Transverse beam matching of the injection beam at the Linac-RCS beam transport line (L3BT) is one of the most useful method to reduce a beam loss in the RCS. Results of the beam commissioning for high intensity operation at the RCS, beam loss in the RCS and halo compornent of the extracted beam from the RCS ware supressed by the transverce matching methd. In this presentation, we will report the injection beam matching method at the L3BT and discuss the space charge phenomena about the high intensity beam.
