Current status of the cesiated RF-driven negative hydrogen ion source and its R&D activities for future facility projects at J-PARC

J-PARCでのセシウム添加型高周波駆動負水素イオン源の現状と高度化に向けたイオン源の開発

神藤 勝啓   ; 大越 清紀 ; 柴田 崇統*; 南茂 今朝雄*; 飛田 健太郎*; 池上 清*; 上野 彰  

Shinto, Katsuhiro; Okoshi, Kiyonori; Shibata, Takanori*; Nammo, Kesao*; Tobita, Kentaro*; Ikegami, Kiyoshi*; Ueno, Akira

It is important to note that more than a decade has elapsed since the radiofrequency (RF)-driven negative hydrogen (H) ion source initiated operation in the autumn of 2014 at J-PARC. Since the 2022/2023 campaign, H beams with a beam current of 60 mA have been generated by a single RF-driven H ion source during a campaign. The continuous operation time of the ion source reached 4,962 hours during the 2023/2024 campaign. In the 2024/2025 campaign, a single RF-driven H ion source functioned continuously for 4,289 hours to produce H beams with a beam current of 62.5 mA for the J-PARC users and 75 mA for the accelerator beam studies. The objective of these studies is to prepare for higher beam delivery of a proton beam to the experimental facilities in future. Concurrently, we are engaged in R&D activities of the ion source toward advancement.