A 3 MeV linac for development of accelerator components at J-PARC

Kondo, Yasuhiro; Asano, Hiroyuki*; Chishiro, Etsuji; Hirano, Koichiro; Ishiyama, Tatsuya; Ito, Takashi; Kawane, Yusuke; Kikuzawa, Nobuhiro; Meigo, Shinichiro; Miura, Akihiko; et al.

Proceedings of 28th International Linear Accelerator Conference (LINAC 2016) (Internet), p.298 - 300, 2017/05

https://doi.org/10.18429/JACoW-LINAC2016-MOPLR071

We have constructed a linac for development of various accelerator components at J-PARC. The ion source is same as the J-PARC linac's, and the RFQ is a used one in the J-PARC linac. The beam energy is 3 MeV and nominal beam current is 30 mA. The accelerator has been already commissioned, and the first development program, laser-charge-exchange experiment for the transmutation experimental facility, has been started. In this paper, present status of this 3-MeV linac is presented.

Development of beam scrapers using a 3-Mev linac at J-PARC

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

http://www.pasj.jp/web_publish/pasj2016/proceedings/PDF/MOP0/MOP005.pdf

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.

Radiation monitoring using an unmanned helicopter in the evacuation zone around the Fukushima Daiichi Nuclear Power Plant

Sanada, Yukihisa; Kondo, Atsuya*; Sugita, Takeshi*; Nishizawa, Yukiyasu; Yuki, Yoichi*; Ikeda, Kazutaka*; Shoji, Yasunori*; Torii, Tatsuo

Exploration Geophysics, 45(1), p.3 - 7, 2014/11

https://doi.org/10.1071/EG13004

The Great East Japan Earthquake on March 11, 2011 generated a series of large tsunami waves that resulted serious damage to the Fukushima Daiichi Nuclear Power Plant (NPP) and a large amount of radioactive materials were discharged from the NPP to the environment. In recent years, technologies for an unmanned helicopter have been developed and applied to various fields. In expectation of the application of the unmanned helicopter to airborne radiation monitoring, we had developed a radiation monitoring system. Then, we measured the radiation level by using unmanned helicopter in soil contaminated areas by radioactive cesium emitted from the NPP to evaluate ambient dose-rate distribution around the areas. Here, we reports on the measurement technique and the result.

The Aerial radiation monitoring in Japan after the Fukushima Daiichi Nuclear Power Plant accident

Sanada, Yukihisa; Sugita, Takeshi; Nishizawa, Yukiyasu; Kondo, Atsuya*; Torii, Tatsuo

Progress in Nuclear Science and Technology (Internet), 4, p.76 - 80, 2014/04

http://www.aesj.or.jp/publication/pnst004/data/076_080.pdf

The ambient dose-rate and the deposition concentration of radioactive cesium was measured by using helicopters in the whole area of Japan to investigate the influence of the radioactivity that released in the atmosphere due to the disaster of the Fukushima Daiichi NPP (Nuclear Power Plant), Tokyo Electric Power Company (TEPCO), occurred by the East Japan earthquake and tsunami on March 11, 2011. As a result, the deposition of radioactive cesium on the ground discharged from the Fukushima Daiichi NPP was obtained, and it was clarified that the scattered range of the cesium had been almost limited from the southern part of Tohoku to Kanto areas. The variation distribution of the dose-rate of Japan was also revealed in this measurement.

Investigation of radionuclide distribution using aircraft for surrounding environmental survey from Fukushima Dai-ichi Nuclear Power Plant

Torii, Tatsuo; Sanada, Yukihisa; Sugita, Takeshi; Kondo, Atsuya*; Shikaze, Yoshiaki; Takahashi, Masaki; Ishida, Mutsushi; Nishizawa, Yukiyasu; Urabe, Yoshimi

JAEA-Technology 2012-036, 182 Pages, 2012/12

JAEA-Technology-2012-036.pdf:41.89MB

We carried out aerial radiation monitoring (ARM) of all Japan area in order to investigate the influence of the radio cesium which was emitted into the atmosphere by disaster of the Fukushima Dai-ichi Nuclear Power Plant of Tokyo Electric Power Co., Inc.. AMS can measure a ray quickly by flight from 300 m height above the ground. Moreover, ARM has an advantage which can grasp self-possessed quantity distribution of an air dose rate and radioactive cesium in "field", and is visually intelligible. Although there were apparatus and the technique of ARM in our country, sufficient preparations for wide area monitoring were not made. Therefore, it fixed based on the method of the U.S. Department of Energy (DOE) about the method of the conversion to all radiation dose, and the conversion method to radiocesium deposition and the method of mapping. It is possible to discriminate from a background (cosmic-ray, self-contamination and natural nuclides) at the time of western-part-of-Japan measurement by improving of the method in parallel to data acquisition. By this monitoring, it was able to check about the distribution situation of the air dose rate of the Japanese whole region, or the radioactive cesium deposition. Here, the measurement technique and a result are described.

RBPO(R=Ca, Sr)-based storage phosphors for neutron detection

Sakasai, Kaoru; Katagiri, Masaki; Matsubayashi, Masahito; Nakamura, Tatsuya; Kondo, Yasuhiro*

IEEE Transactions on Nuclear Science, 52(5), p.1856 - 1859, 2005/10

https://doi.org/10.1109/TNS.2005.856617

Storage characteristics of RBPO(R=Ca, Sr) based phosphors have been investigated for neutron detection. To increase the photostimulated luminescence (PSL) yields of CaBPO:Ce and SrBPO:Ce phosphors, fluorine atoms were introduced and the molar ratio of the fluorine atoms was optimized for the PSL yields. In addition, the authors found that the PSL yields of SrBPO:Eu phosphors were significantly increased by adding LiBO, though introducing fluorine and brome atoms in the phosphor was not effective for the PSL yields. These phosphors will be usable as new neutron storage phosphors with low -ray sensitivity because they consist of light materials.

Characteristics of SrBPO:Ce based materials as a neutron storage phosphor

Sakasai, Kaoru; Katagiri, Masaki; Matsubayashi, Masahito; Nakamura, Tatsuya; Kondo, Yasuhiro*

Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.378 - 383, 2004/08

https://doi.org/10.1016/j.nima.2004.05.015

no abstracts in English

New photostimulable phosphors for neutron imaging

Sakasai, Kaoru; Katagiri, Masaki; Matsubayashi, Masahito; Nakamura, Tatsuya; Kondo, Yasuhiro*

Hoshasen, 29(4), p.189 - 197, 2003/10

http://ci.nii.ac.jp/naid/10012127833

no abstracts in English

Report on the 18th International Conference on High Pressure Science and Technology (AIRAPT-18)

Shimizu, Hiroyasu*; Utsumi, Wataru; Kume, Tetsuji*; Kondo, Tadashi*; Shimizu, Katsuya*; Sotani, Tomohiro*; Taniguchi, Takashi*; Nakamura, Kazutaka*

Koatsuryoku No Kagaku To Gijutsu, 11(4), p.334 - 338, 2001/12

https://ci.nii.ac.jp/naid/10007402307

no abstracts in English

Radiation measurement to research the contamination of radioactive materials in the environment

Ito, Chikara; Sanada, Yukihisa; Ito, Keisuke; Kondo, Atsuya; Ishikawa, Takashi; Nakano, Hironobu; Nozaki, Tatsuo; Torii, Tatsuo; Notomi, Akihiro*

no journal, , 

no abstracts in English