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Yako, Tomoki*; Iwashita, Yoshihisa*; Abe, Masashi*; Kurihara, Toshikazu*; Fukuda, Masafumi*; Sato, Masaharu*; Sugimura, Takashi*; Fuwa, Yasuhiro; Takamiya, Koichi*; Iinuma, Yuto*
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1003 - 1005, 2019/10
Permanent magnets are used as materials for beam optics elements, but it is known that radiation demagnetization occurs in neodymium magnets and samarium cobalt magnets. However, there is not enough information on the radiation demagnetization of ferrite magnets which is weak in strength but inexpensive. In order to verify the suitability of the ferrite magnet as a beam optics element, radiation demagnetization experiments by neutron irradiation of the ferrite magnet were carried out at the Kyoto University Research Reactor (KUR). In the experiment, neutron fluence up to 
cm
was irradiated, and no significant demagnetization was detected on the fluence.
filament arc-driven multi-cusp ion source for iBNCTShibata, Takanori*; Takagi, Akira*; Ikegami, Kiyoshi*; Sugimura, Takashi*; Nammo, Kesao*; Naito, Fujio*; Kobayashi, Hitoshi*; Kurihara, Toshikazu*; Honda, Yosuke*; Sato, Masaharu*; et al.
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.385 - 387, 2018/10
Hirano, Koichiro; Sugimura, Takashi*; Kurihara, Toshikazu*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.324 - 328, 2018/08
We could use a 3 MeV beam scraper without a problem for five months when the scraper received to 1.3 times as high as a normal average beam current of the scraper in 1MW beam operation. The peak temperature on the scraper surface was 1800
C. Irradiation damage caused by the 3 MeV beam with particle number of 3E22 was 700 
m depth. We study scraper materials which can withstand the current density higher than carbon composite used in the scraper because almost all beams can be irradiated to the scraper in 1 MW beam operation. Beam irradiation tests have been performed about graphene and tungsten as scraper materials with high heat conductivity. This paper describes beam irradiation test of the 3 MeV beam scraper and scraper materials.
Hirano, Koichiro; Ishiyama, Tatsuya; Kurihara, Toshikazu*; Sugimura, Takashi*; Maruta, Tomofumi*
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.847 - 852, 2017/12
Beam scrapers made of carbon composite have been used in the MEBT1 between a 324 MHz RFQ and a 50-MeV DTL of the J-PARC Linac. We have conducted the scraper irradiation test with the 3 MeV linac. The test piece of the scraper was irradiated by the H
beam up to particle number of 1.2E20. We measured the surface temperature of more than 3000C using a high-speed radiation thermometer and observed the irradiation damage on the scraper by using the laser microscope. When the surface temperature exceeded 2900C, the ionic current of carbon and the irradiation damage on the surface of the test piece rapidly increased. This paper describes beam irradiation test results of the scraper.
Hirano, Koichiro; Asano, Hiroyuki; Ishiyama, Tatsuya; Ito, Takashi; Okoshi, Kiyonori; Oguri, Hidetomo; Kondo, Yasuhiro; Kawane, Yusuke; Kikuzawa, Nobuhiro; Sato, Yoshikatsu; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.310 - 313, 2016/11
We have used a beam scraper with the incident angle of 65deg to reduce the beam power deposition density in the MEBT between a 324 MHz RFQ and a 50-MeV DTL of the J-PARC linac. The 65 scraper was irradiated by the H beam up to particle number of 1.47E22. We observed a lot of surface projections with several hundred micrometers high in the beam irradiation damage on the scraper by using the laser microscope. In order to study the limits of scrapers, we constructed a new 3 MeV linac at J-PARC. We will conduct the scraper irradiation test at the end of this year.
Naito, Fujio*; Anami, Shozo*; Ikegami, Kiyoshi*; Uota, Masahiko*; Ouchi, Toshikatsu*; Onishi, Takahiro*; Oba, Toshiyuki*; Obina, Takashi*; Kawamura, Masato*; Kumada, Hiroaki*; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1244 - 1246, 2016/11
The proton linac installed in the Ibaraki Neutron Medical Research Center is used for production of the intense neutron flux for the Boron Neutron Capture Therapy (BNCT). The linac consists of the 3-MeV RFQ and the 8-MeV DTL. Design average beam current is 10mA. Target is made of Beryllium. First neutron production from the Beryllium target was observed at the end of 2015 with the low intensity beam as a demonstration. After the observation of neutron production, a lot of improvement s was carried out in order to increase the proton beam intensity for the real beam commissioning. The beam commissioning has been started on May 2016. The status of the commissioning is summarized in this report.
Kurihara, Toshikazu*; Kobayashi, Hitoshi*; Sugimura, Takashi*; Hirano, Koichiro
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.814 - 816, 2016/11
A problem of irradiation damage is the one observed in each part of a component of particle accelerators; accelerating tubs, scrapers, monitors and neutron targets. In-situ observation by an actual proton accelerator is made our last target. We observed the radiation damage of the various materials used by particle accelerators. From the distant place the target which is in the high radiation area, we propose the method to get information from the catoptric light from the target using a laser as a light source. A principle of this observation method as well as generating process of blisterings and limitation of this method will be reported.
Uesaka, Mitsuru*; Kobayashi, Hitoshi*; Kureta, Masatoshi; Nakatsuka, Shigehiro*; Nishimura, Kazuya*; Igashira, Masayuki*; Hori, Junichi*; Kiyanagi, Yoshiaki*; Tagi, Kazuhiro*; Seki, Toshichika*; et al.
Reviews of Accelerator Science and Technology, 8, p.181 - 207, 2015/00
We choose nuclear data and nuclear material inspection for energy application and nondestructive testing of explosive and hidden nuclear materials for security application. 90 keV electrostatic accelerators of deuterium are commercially available for nondestructive testing. For nuclear data measurement, electrostatic ion accelerators and L-band and S-band electron linear accelerators (linac) are used for the neutron source. Compact or mobile X-band electron linac neutron sources are under development. Compact proton linac neutron source is used for nondestructive testing especially water in solids. Several efforts for more neutron intensity using proton and deuteron accelerators are also introduced.
Sugimura, Takashi*; Hirano, Koichiro; Nammo, Kesao*; Kurihara, Toshikazu*
Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.862 - 866, 2014/06
By introducing a new ion source and a new RFQ, beam current will increase from 20 mA to 50 mA. According to an increase of the beam current, wasted beam that should not be accelerated in the following accelerator sections also increase. To stop wasted beam, there is a beam scraper in the MEBT region just after the RFQ at the beam energy of 3 MeV. An existing beam scraper is made of carbon composite material and it has a dent caused by merely small beam current of 20 mA in daily operation. A new scraper that endures upgraded beam current of 50 mA is the essential item for the beam power upgrade of J-PARC. Thermal simulations on several materials have been performed with the ANSYS code assuming the upgraded beam power. They revealed that maximum temperatures in a beam cycle are much higher than their melting points in some materials and consequently that lessening of heat load for a scraper by beam operation is an essential factor.
Yamazaki, Yoshio; Yoshimoto, Masahiro; Saha, P. K.; Takeda, Osamu; Kinsho, Michikazu; Taguchi, Tomitsugu; Yamamoto, Shunya; Kurihara, Toshikazu*; Sugai, Isao*
no journal, ,
no abstracts in English
Hirano, Koichiro; Sugimura, Takashi*; Kurihara, Toshikazu*
no journal, ,
Beam scrapers made of carbon composite have been used in the MEBT1 of the J-PARC Linac. We could use a beam scraper without a problem for five months when the scraper received to 1.3 times as high as a normal average beam current of the scraper in 1MW beam operation. In order to evaluate the limits of the beam scraper, we conducted the scraper irradiation test by using an off-line 3 MeV beam test-stand. We measured the surface temperature by a high-speed radiation thermometer which can be measured the maximum temperature of 3500C. As the result of the test, we observed the gasification of carbon became significant when the surface temperature exceeded 2900C. To avoid significant thermal decomposition of the scraper, we need to keep the maximum temperature less than 2900C. This paper describes present status of the 3 MeV beam scraper and results of the beam irradiation test. This paper describes beam irradiation test of the 3 MeV beam scraper and scraper materials.
Kobayashi, Hitoshi*; Kurihara, Toshikazu*; Matsumoto, Hiroshi*; Yoshioka, Masakazu*; Matsumoto, Noriyuki*; Kumada, Hiroaki*; Matsumura, Akira*; Sakurai, Hideyuki*; Hiraga, Fujio*; Kiyanagi, Yoshiaki*; et al.
no journal, ,
no abstracts in English
