@misc{oai:repo.qst.go.jp:00066258,
 author = {平塚, 淳一 and 小島, 有志 and 梅田, 尚孝 and 花田, 磨砂也 and 柏木, 美恵子 and 吉田, 雅史 and 錦織, 良 and 市川, 雅浩 and 渡邊, 和弘 and 戸張, 博之 and 大楽, 正幸 and 山中, 晴彦 and 阿部, 宏幸 and 川又, 亮一 and 柴田, 直樹 and 前島, 哲也 and 照沼, 勇人 and 小田, 勇樹 and 秋野, 昇 and 藻垣, 和彦 and 佐々木, 駿一 and 関, 則和 and 根本, 修司 and 清水, 達夫 and 遠藤, 安栄 and 宮本, 賢治 and 山納, 康 and R., Grisham L. and 平塚 淳一 and 小島 有志 and 梅田 尚孝 and 花田 磨砂也 and 柏木 美恵子 and 吉田 雅史 and 錦織 良 and 市川 雅浩 and 渡邊 和弘 and 戸張 博之 and 大楽 正幸 and 山中 晴彦 and 阿部 宏幸 and 川又 亮一 and 柴田 直樹 and 前島 哲也 and 小田 勇樹 and 秋野 昇 and 藻垣 和彦 and 佐々木 駿一 and 関 則和 and 根本 修司 and 清水 達夫 and 遠藤 安栄},
 month = {Oct},
 note = {Pulse duration of the ITER-relevant high power density hydrogen negative ion beams at 1 MeV has been successfully extended from 0.4 s to 60 s by using a prototype Multi-Aperture and Multi-Grid accelerator for the ITER and JT-60SA neutral beam systems. This significant progress was achieved based on developments of technology for the design of a voltage holding capability and improvement of a beam optics, which are directly applicable to ITER and JT-60SA. In the design of the voltage holding capability, one of critical remaining issues was a multi-grid effect. This was experimentally investigated by using a multi-grid configuration. This result was also applied to improve the beam optics by tuning the acceleration gap. In addition, the extractor configuration was optimized. These tunings significantly contributed to reduce the grid power load and to increase the current density. As the result, 0.97 MeV, 190 A/m2 negative ion beams were generated stably without any breakdowns and any thermal damages on the acceleration grids. This pulse length of the beams with the ITER-relevant energy and current density is the longest one in the world and contributes to assure the 1 MeV accelerator for the ITER NB system., 26th IAEA Fusion Energy Conference},
 title = {Long-pulse acceleration of 1MeV negative ion beams toward ITER and JT-60SA neutral beam injectors},
 year = {2016}
}