Development and design of the negative-ion-based NBI for JT-60 Super Advanced

Hanada, Masaya; Akino, Noboru; Endo, Yasuei; Inoue, Takashi; Kawai, Mikito; Kazawa, Minoru; Kikuchi, Katsumi; Komata, Masao; Kojima, Atsushi; Mogaki, Kazuhiko; et al.

Journal of Plasma and Fusion Research SERIES, Vol.9, p.208 - 213, 2010/08

http://www.jspf.or.jp/JPFRS/PDF/Vol9/jpfrs2010_09-207.pdf

A large negative ion source with an ion extraction area of 110 cm 45 cm has been developed to produce 500 keV, 22 A D ion beams required for JT-60 Super Advanced. To realize the JT-60SA negative ion source, the JT-60 negative ion source has been modified and tested on the negative-ion-based neutral beam injector on JT-60U. A 500 keV H ion beam has been produced at 3 A without a significant degradation of beam optics. This is the first demonstration of a high energy negative ion acceleration of more than one-ampere to 500 keV in the world. The beam current density of 90 A/m is being increased to meet 130 A/m of the design value for JT-60SA by tuning the operation parameters. A long pulse injection of 30 s has been achieved at a injection D power of 3 MW. The injection energy, defined as the product of the injection time and power, reaches 80 MJ by neutralizing a 340 keV, 27 A D ion beam produced with two negative ion sources.

Technical design of NBI system for JT-60SA

Ikeda, Yoshitaka; Akino, Noboru; Ebisawa, Noboru; Hanada, Masaya; Inoue, Takashi; Honda, Atsushi; Kamada, Masaki; Kawai, Mikito; Kazawa, Minoru; Kikuchi, Katsumi; et al.

Fusion Engineering and Design, 82(5-14), p.791 - 797, 2007/10

https://doi.org/10.1016/j.fusengdes.2007.05.077

Modification of JT-60U to a superconducting device (so called JT-60SA) has been planned to contribute to ITER and DEMO. The NBI system is required to inject 34 MW for 100 s. The upgraded NBI system consists of twelve positive ion based NBI (P-NBI) units and one negative ion based NBI (N-NBI) unit. The injection power of the P-NBI units are 2 MW each at 85 keV, and the N-NBI unit will be 10 MW at 500 keV, respectively. On JT-60U, the long pulse operation of 30 s at 2 MW (85 keV) and 20 s at 3.2 MW (320 keV) have been achieved on P-NBI and N-NBI units, respectively. Since the temperature increase of the cooling water in both ion sources is saturated within 20 s, further pulse extension up to 100 s is expected to mainly modify the power supply systems in addition to modification of the N-NBI ion source for high acceleration voltage. The detailed technical design of the NBI system for JT-60SA is presented.

Present status of the negative ion based NBI system for long pulse operation on JT-60U

Ikeda, Yoshitaka; Umeda, Naotaka; Akino, Noboru; Ebisawa, Noboru; Grisham, L. R.*; Hanada, Masaya; Honda, Atsushi; Inoue, Takashi; Kawai, Mikito; Kazawa, Minoru; et al.

Nuclear Fusion, 46(6), p.S211 - S219, 2006/06

https://doi.org/10.1088/0029-5515/46/6/S02

Recently, the extension of the pulse duration up to 30 sec has been intended to study quasi-steady state plasma on JT-60U N-NBI system. The most serious issue is to reduce the heat load on the grids for long pulse operation. Two modifications have been proposed to reduce the heat load. One is to suppress the beam spread which may be caused by beamlet-beamlet interaction in the multi-aperture grid due to the space charge force. Thin plates were attached on the extraction grid to modify the local electric field. The plate thickness was optimized to steer the beamlet deflection. The other is to reduce the stripping loss, where the electron of the negative ion beam is stripped and accelerated in the ion source and then collides with the grids. The ion source was modified to reduce the pressure in the accelerator column to suppress the beam-ion stripping loss. Up to now, long pulse injection of 17 sec for 1.6 MW and 25 sec for 1 MW has been obtained by one ion source with these modifications.

Progress of negative ion source improvement in N-NBI for JT-60U

Kawai, Mikito; Akino, Noboru; Ebisawa, Noboru; Grisham, L. R.*; Hanada, Masaya; Honda, Atsushi; Inoue, Takashi; Kazawa, Minoru; Kikuchi, Katsumi*; Kuriyama, Masaaki; et al.

Fusion Science and Technology, 44(2), p.508 - 512, 2003/09

https://doi.org/10.13182/FST03-A387

The negative ion source for negative ion based neutral beam injector(N-NBI) of JT-60U aims at generating a negative ion beam with 500 keV and 22A for 10s. The N-NBI system was completed in 1996, followed by starting the efforts to increase beam power and energy. (1)Spatial non-uniformity of the source plasma causes position-dependent divergence of a beamlet due to mis-matching of local beam perveance. A part of the divergent energetic beams is intercepted by the grids and resultantly produce the excessive heat load of the grids and/or induce the high voltage breakdown. So several techniques to take measures against and to correct the non-uniformity in these sources were implemented. (2)Correction of beamlet deflection by adjusting the electric field at the extraction grids. It improved the beam divergence and then decreased an excessive heat load of a beam limiter by more than 50 %. As a result, the maximum injection power 6.2MW and beam pulse duration 10 seconds were obtaind.

The Development of a long life control rod in the fast reactor, 5; Dimensional measurement results of shroud tube of sodium bonded type control rod irradiated in Joyo

Donomae, Takako; Katsuyama, Kozo; Tachi, Yoshiaki; Maeda, Koji; Inoue, Takayuki*; Fukasaku, Hironobu*

no journal, , 

no abstracts in English

Construction of a BNCT facility using an 8MeV high power proton linac in Ibaraki

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

破損・溶融燃料含有物質中の核物質量の計測装置及び計測方法

堀 啓一郎; 井上 尚子; 中村 博文; 勝山 幸三; 石見 明洋

深澤 哲生*; 星野 国義*; 佐藤 記徳*; 矢澤 紀子*; 中村 友隆*

JP, 2015-090369  Patent licensing information  Patent publication (In Japanese)

【課題】燃料デブリを対象としたX線CT装置の利用により核物質量を計測することを可能とする破損・溶融燃料含有物質中の核物質量の計測装置及び計測方法を提供する。 【解決手段】燃料デブリを収納した燃料デブリ収納容器に対してX線を回転走査しながら照射して前記燃料デブリ収納容器を透過したX線を検知し、燃料デブリの密度の情報を得る第1の測定部と、燃料デブリ収納容器からの放射線を測定する第2の測定部と、第2の測定部で測定した放射線を第1の測定部で測定した燃料デブリの密度により補正し、補正後の放射線から燃料デブリの核物質量を定める処理部により構成されたことを特徴とする。