Effect of non-uniform electron energy distribution function on plasma production in large arc driven negative ion source

Shibata, Takanori; Koga, Shojiro*; Terasaki, Ryo*; Inoue, Takashi; Dairaku, Masayuki; Kashiwagi, Mieko; Taniguchi, Masaki; Tobari, Hiroyuki; Tsuchida, Kazuki; Umeda, Naotaka; et al.

Review of Scientific Instruments, 83(2), p.02A719_1 - 02A719_3, 2012/02

https://doi.org/10.1063/1.3673485

In the NBI for large fusion devices, production of uniform negative ion beam is one of important issues. A physical model is proposed to understand the non-uniformity. It has been qualitatively shown that the non-uniform beam intensity is due to the following process; (1) formation of non-uniform EEDF, (2) localized production of hydrogen atoms/ions (H/H) due to (1), (3) non-uniform flux of H/H to the PG and (4) localized surface production of negative ions. However, in the past studies, the EEDF was assumed as two temperature Maxwellian distribution from measurements. Thus effects of high energy electrons are not taken into account precisely. In the present research, local EEDF is calculated by the 3D Monte-Carlo kinetic model which takes into account the spatial and magnetic configurations of the real negative ion source. The numerical result show that high energy component of the EEDF enhances the spatial non-uniformity in the production rate of H/H.

Measurements of Prompt Gamma-Ray Emission Probabilities for Determinations of Neutron Capture Cross Sections of Long Life Nuclides

Miyazaki, Itaru*; Shimizu, Toshiaki*; Shibata, Michihiro*; Kawade, Kiyoshi*; Taniguchi, Akihiro*; Furutaka, Kazuyoshi; Nakamura, Shoji; Sakane, Hitoshi; Harada, Hideo

JNC TY8400 2005-002, 40 Pages, 2005/06

JNC-TY8400-2005-002.pdf:2.69MB

Accurate cross section data for the neutron capture of long-lived fission products (LLFP) are needed for developing a nuclear transmutation technology which reduces radioactive wastes by transmuting nuclides that have half-lives of as long as a few million years to other nuclides that have much shorter half-lives. There are some nuclides, whose cross sections cannot be measured in activation method. Utilization of prompt gamma-rays is expected to solve this problem. The aim of present study was twofold: (i) to measure emission probabilities of the high energy gamma-ray, up to 10MeV, emitted from N()N reaction, which are usually used as standards, in order to improve their accuracies and (ii) to develop a measurement method for neutron capture cross sections by using prompt gamma-rays. Emission probabilities of principal prompt gamma-rays from N()N reaction were determined with 0.2-0.9% errors. For ten nuclides, Na, Al, V, Mn, Co, Ni, Cu, Pr, W, and Au capture cross sections were measured by using prompt gamma-rays and gamma-rays following b-decay. By comparing both cross section values, it was found that emission probabilities of prompt gamma-rays reported in the literatures were systematically larger than those inferred from the cross sections that were determined in activation methods. The cross section of a Pd()Pd reaction at thermal energy was measured. Considering transmutation of the nuclide, the cross section of Pd(), which is an isotope of palladium, is also necessary. A lower limit of the cross section was determined with 6% accuracy. Additionally, a method of estimating an upper limit was examined by noting similarity of nuclear structures to the neighboring nuclides. It was estimated that the observed lower limit of emission probabilities correspond to 79% of the cross section.

The First loading fuel elements and power-up for JRR-2

JRR-2 Control Office; Kambara, Toyozo; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Kohayakawa, Toru; Morozumi, Minoru; Kambayashi, Yuichiro; Shitomi, Hajimu; Kokanezawa, Takashi; et al.

JAERI 1027, 57 Pages, 1962/09

JAERI-1027.pdf:4.76MB

no abstracts in English

Treatment and analysis of the water and gas in JRR-2

JRR-2 Operations Office; Kambara, Toyozo; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Haginoya, Kinichi; Kohayakawa, Toru; Yamaki, Jikei; Yokota, Mitsuo; Horiki, Oichiro; et al.

JAERI 1024, 79 Pages, 1962/08

JAERI-1024.pdf:5.66MB

no abstracts in English

The Development of radioactive waste volume reduction treatment system by ultra-high frequency induction furnace

Aoyama, Yoshio; Sakakibara, Tetsuro; Yamaguchi, Hiromi; Sasaki, Naoto*; Taniguchi, Shoji*; Fujita, Michiru*; Suzuki, Hiroshi*

no journal, , 

no abstracts in English

Development of the volume reduction treatment system of radioactive waste by the ultra-high frequency induction furnace, 4; Outline of the demonstration system

Yamaguchi, Hiromi; Miyamoto, Yasuaki; Sakakibara, Tetsuro; Hanamoto, Yukio; Aoyama, Yoshio; Sasaki, Nao*; Nishikawa, Tsutomu*; Murata, Minoru*; Muroi, Masayuki*; Park, J.*; et al.

no journal, , 

no abstracts in English

Development of the volume reduction treatment system of radioactive waste by the ultra-high frequency induction furnace,6; Demonstration experiment, Non-radioactive tracer experiment

Aoyama, Yoshio; Yamaguchi, Hiromi; Miyamoto, Yasuaki; Sakakibara, Tetsuro; Hanamoto, Yukio; Sasaki, Nao*; Nishikawa, Tsutomu*; Murata, Minoru*; Muroi, Masayuki*; Park, J.*; et al.

no journal, , 

no abstracts in English

The Development of radioactive waste volume reduction treatment system by ultra-high frequency induction furnace, 8; Demonstration experiment, Characterization of solidified products

Aoyama, Yoshio; Yamaguchi, Hiromi; Sakakibara, Tetsuro; Hanamoto, Yukio; Murata, Minoru*; Sasaki, Nao*; Nishikawa, Tsutomu*; Taniguchi, Shoji*; Shimazaki, Shinichi*; Park, J.*; et al.

no journal, , 

no abstracts in English

The Development of radioactive waste volume reduction treatment system by ultra-high frequency induction furnace, 9; Design of the practical large scale system

Aoyama, Yoshio; Yamaguchi, Hiromi; Sakakibara, Tetsuro; Hanamoto, Yukio; Murata, Minoru*; Sasaki, Nao*; Nishikawa, Tsutomu*; Taniguchi, Shoji*; Shimazaki, Shinichi*; Park, J.*; et al.

no journal, , 

no abstracts in English