検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年

ITER NBI調達に向けた1MeV加速器・ブッシング開発

Development of 1 MeV accelerator for the procurement of ITER NBI

井上 多加志; 大楽 正幸; 柏木 美恵子; 水野 貴敏; 谷口 正樹; 戸張 博之; 梅田 尚孝; 渡邊 和弘; 山中 晴彦

Inoue, Takashi; Dairaku, Masayuki; Kashiwagi, Mieko; Mizuno, Takatoshi; Taniguchi, Masaki; Tobari, Hiroyuki; Umeda, Naotaka; Watanabe, Kazuhiro; Yamanaka, Haruhiko

原子力機構では、ITER中性粒子入射加熱装置(NBI)に向けて多孔5段静電加速器(MeV級加速器)と加速器に電力を供給するHVブッシングの開発を行っている。これまで、陰極三重点の電界緩和(約1kV/mm)によりFRP製絶縁管の真空側沿面での放電を抑制して、運転ガス圧条件(水素ガス圧0.1Pa程度)で1MV保持を達成していた。今回、電極-支持枠間の段差・ギャップ・角部や固定用ネジなどを起点とした放電痕に着目し、局所的な電界集中を低減するため、従来72-90mmであった加速器電極の真空ギャップを100mmに延長し、真空中(10$$^{-4}$$Pa)での1MV保持に成功した。この結果、従来記録(796keV, 320mA)を大きく更新する879keV, 360mA, 0.2s(0.32MW)の水素負イオン加速に成功した。

Multiaperture multigrid accelerators and a HV bushing that connects power supply and the accelerator have been developed at JAEA for the ITER neutral beam injector (NBI). So far, the accelerator held dc 1 MV high voltage at operation pressure range of 0.1 Pa by lowering electric stress at cathode triple junction. Recently many discharge traces were found from small gaps, steps, corners, edges and even on screw heads suggesting discharges initiated from such local concentration of electric stresses. In order to mitigate the local stress gap between the accelerator grids were expanded from original 72 - 90 m to 100 mm. This was effective to improve the voltage holding even without hydrogen gas, and as the consequence, 360 mA H$$^{-}$$ ions were accelerated up to 879 keV, which updated previous record of 796 keV, 320 mA.

Access

:

- Accesses

InCites™

:

Altmetrics

:

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.