@article{oai:repo.qst.go.jp:00078941,
 author = {Ichikawa, Masahiro and Kojima, Atsushi and Hiratsuka, Junichi and Yoshida, Masafumi and Umeda, Naotaka and mae quinones Saquilayan, Glynnis and Watanabe, Kazuhiro and Tobari, Hiroyuki and Kashiwagi, Mieko and Masahiro, Ichikawa and Atsushi, Kojima and Junichi, Hiratsuka and Naotaka, Umeda and mae quinones Saquilayan, Glynnis and Kazuhiro, Watanabe and Hiroyuki, Tobari and Mieko, Kashiwagi},
 journal = {Review of Scientific Instruments},
 month = {Feb},
 note = {Long pulse negative ion beams of 500 keV and 154 A/m2 for 118 s have been achieved for the first time, which exceeds the requirement of the JT-60SA negative ion source. In order to solve the issues of such long pulse beams, the fast cutoff system of the power supply aims to reduce the surge current and to extend the lifetime of filaments and the suppression method of excess cesium (Cs) accumulation on the plasma grid
(PG) to achieve stable negative ion production. By developing the fast cutoff system using a field programmable gate array unit for the arc
power supply, the cutoff time has been reduced to 1/10 that of the original system and the lifetime of the filament was extended by three times.
In order to achieve stable negative ion production, incoming Cs on the PG surface has been reduced by keeping the chamber wall temperature
below 40 ○C. As a result, a stable beam current drift of <6% has been achieved for the 118 s duration.},
 title = {Achievement of stable negative ion production with Cs-seeded for long pulse beam operation in the prototype of Cs-seeded negative ion source for JT-60SA},
 volume = {91},
 year = {2020}
}