Heat loading of MeV accelerator grids during long pulse beam operation

Umeda, Naotaka; Mizuno, Takatoshi; Taniguchi, Masaki; Kashiwagi, Mieko; Ezato, Koichiro; Tobari, Hiroyuki; Dairaku, Masayuki; Watanabe, Kazuhiro; Sakamoto, Keishi; Inoue, Takashi

Journal of Plasma and Fusion Research SERIES, Vol.9, p.259 - 263, 2010/08

Long pulse acceleration of ITER class H ion beam has carried out at MeV accelerator. Melts of the acceleration grids were found around grid apertures. To accelerate higher power beam, compensation of the beam deflection and design of a new grid which has high cooling performance is required. In this study, 3D thermal transport analysis was carried out and a new acceleration grid was designed. From the analysis, it was found that the grid temperature exceeded the melting point in a few seconds. To overcome this problem, a new acceleration grid was designed whose cooling channel was drilled near upper surface. This countermeasure is effective not only to reduce the temperature rise but to enlarge the aperture size from 14 mm to 16 mm. From the result of heat analysis, temperature rise of the new grid is greatly reduced than that of the previous grid. It is expected that higher power and longer pulse beam would be accelerated at next test campaign.

Role of metals loaded on a TiO Surface in the oxidation of xylene in air using an electron beam irradiation/catalytic process

Hakoda, Teruyuki; Matsumoto, Kanae*; Mizuno, Akira*; Hirota, Koichi

Applied Catalysis A; General, 357(2), p.244 - 249, 2009/04

https://doi.org/10.1016/j.apcata.2009.01.030

Catalytic oxidation of xylene in air was performed under electron beam (EB) irradiation using pure TiO as well as TiO loaded with Ag, Pt, Au, and Mn to clarify the role of loaded metal in the enhancement of oxidation of xylene and its irradiation byproducts to CO in EB-induced non-thermal plasma. EB irradiation experiments were performed with the catalyst bed placed in both irradiated and non-irradiated spaces. The highest conversion percentage of decomposed xylene to CO was obtained by irradiation/catalytic oxidation using an Ag/TiO bed placed in a non-irradiated space. The greater enhancement of CO production on an Ag/TiO pellet surface compared to that on other metal-loaded TiO pellet surfaces was due to the synergetic effect of strong adsorption of the byproducts on the Ag loaded on TiO and production of active oxygen from decomposition of O in the presence of Ag.

Oxidation of xylene and its irradiation byproducts using an electron-beam irradiating a -AlO bed

Hakoda, Teruyuki; Matsumoto, Kanae*; Mizuno, Akira*; Hirota, Koichi

Journal of Physics D; Applied Physics, 41(15), p.155202_1 - 155202_7, 2008/08

https://doi.org/10.1088/0022-3727/41/15/155202

The oxidation of xylene and its irradiation byproducts in air using a -AlO bed was studied under electron-beam irradiation to enhance the decomposition of volatile organic compounds in ventilation gases emitted from paint factories. The use of the -AlO bed enhanced the oxidation of the irradiation byproducts to CO. Furthermore, the oxidation of the byproducts was accelerated by the placement of the -AlO bed in an irradiation space, because of the interaction of primary electrons with the surface of -AlO pellets. This combined oxidation process enabled a reduction in the energy consumption for non-toxic CO formation, and improved the selectivity of CO production.

International Conference on JNC Underground Research Laboratory Projects in Mizunami and Horonobe, Japan (2004) Part 1: International Conference on Geoscientific Study in Mizunami '04 (ICGM'04) -Record-

Hanamuro, Takahiro; Saito, Hiroshi; Asamori, Koichi; Iyatomi, Yosuke; Tsuruta, Tadahiko; Yabuuchi, Satoshi; Mizuno, Takashi; Sato, Toshinori; Nakatsuka, Noboru; Shigeta, Naotaka; et al.

JNC TN7400 2004-010, 173 Pages, 2004/12

JNC-TN7400-2004-010.pdf:41.03MB

Japan Nuclear Cycle Development Institute. (JNC) is developing two underground research laboratory projects; the Mizunami Underground Research Laboratory(MIU) Project for crystalline rock,.at Tono Geoscience Center (TGC) and the Horonobe Underground Research Laboratory ・Project for・ sedimentary rock at the Horonobe Underground Research Center. Both projects are intended for research and development of geological disposal technology for high-level radioactive wastes. At this time, these two underground research laboratory projects are advancing to the Construction Phase (Phase II) from the Surface-based Investigation Phase (Phase I). Therefore it was considered appropriate for JNC to hold an international conference to introduce the two underground research laboratory projects and R&D results from Phase I, to have presentations on overseas URLs, to exchange opinions by researchers in each field of research and to reflect the conference outcome in a future R&D plan. The Conference was held in two parts. Part 1, the "International Conference on Geoscientific Study in Mizunami '04 (ICGM '04)" featured the MIU Project and the Regional Hydrogeological Study Project performed by TGC. It was held in Mizunami City at the Sogo Bunka Center from October 21st to 22nd. In Part 2, the "International Workshop on Horonobe Underground Research Laboratory Project", featured the Horonobe Underground Research Laboratory Project performed by the Horonobe Underground Research Center. It was held at Horonobe Town Hall from, October 25th to 26th 2004. This Technical Report documents the ICGM'04 program, abstracts of presentations and slides and transcription of "Panel Discussions II and "Summary of the Conference"

On-line support of the FUGEN plant using MARS

Iguchi, Yukihiro; Sotsu, Masutake; Mizuno, Koichi

Proceedings of 7th International Conference on Nuclear Engineering (ICONE-7), 0 Pages, 1999/00

None

Decomposition of xylene in air by electron beam irradiation using -AlO

Hakoda, Teruyuki; Matsumoto, Kanae; Mizuno, Akira*; Hirota, Koichi

no journal, , 

no abstracts in English

Decomposition of xylene in air by electron beam irradiation using -AlO

Hakoda, Teruyuki; Matsumoto, Kanae; Mizuno, Akira*; Hirota, Koichi

no journal, , 

no abstracts in English

Role of metals loaded on a TiO in the oxidation of VOC in air using an electron beam irradiation/catalytic process

Hakoda, Teruyuki; Mizuno, Akira*; Hirota, Koichi

no journal, , 

no abstracts in English

In-situ environmental radioactivity measurement in high dose rate areas using a CdZnTe semiconductor detector

Kowatari, Munehiko; Kubota, Takumi*; Shibahara, Yuji*; Fujii, Toshiyuki*; Takamiya, Koichi*; Mizuno, Satoshi*; Yamana, Hajimu*

no journal, , 

For the purpose of determining a surface deposition density on soil for radio-cesiums, a CdZnTe (CZT) semiconductor detector whose crystal has dimensions of 1 cm cubic was applied to the in situ environmental radio-activity measurement in deeply contaminated areas in Fukushima region. Even in high dose rate areas where pulse height spectra weren't able to be properly obtained by the conventional high purity Ge semiconductor detector, proper pulse height spectra were obtained by the CZT detector with certain accuracy. Results of deposition density on soil for Cs and Cs derived from net peak areas by the CZT detector seemed consistent, comparing with those measured by the Japanese government. Air kerma rates were estimated by the same pulse height spectra for determining surface deposition density on soil for radio-cesiums and found to be almost the same values as obtained by the NaI(Tl) scintillation survey-meter.