@article{oai:repo.qst.go.jp:00078979,
 author = {Hiratsuka, Junichi and Kashiwagi, Mieko and Ichikawa, Masahiro and Umeda, Naotaka and mae quinones Saquilayan, Glynnis and Tobari, Hiroyuki and Watanabe, Kazuhiro and Kojima, Atsushi and Yoshida, Masafumi and Junichi, Hiratsuka and Mieko, Kashiwagi and Masahiro, Ichikawa and Naotaka, Umeda and mae quinones Saquilayan, Glynnis and Hiroyuki, Tobari and Kazuhiro, Watanabe and Atsushi, Kojima},
 issue = {023506},
 journal = {Review of Scientific Instruments},
 month = {Feb},
 note = {Long pulse acceleration of hydrogen negative ion beams with the power density over 70 MW/m2 and the pulse length over 100 s has been demonstrated for the first time by using a multi-aperture 3-stage accelerator. Such long pulse acceleration was achieved by integrating the design of beam optics and voltage holding capability to meet the requirements of JT-60SA. By using the newly designed accelerator for JT60SA, voltage holding at 500 kV with beam acceleration was stably sustained even after 5 g of cesium was seeded, and heat load on each acceleration grid was reduced below the allowable level for long pulse, less than 5% of total acceleration power. As a result, 500 keV, 154 A/m2 for 118 s beam acceleration was achieved, which satisfies the requirement of the negative ion source for JT-60SA. This pulse length of such high-power density beams is longest in the world. In addition, the result contributes to the long pulse acceleration of multi-stage electrostatic accelerators, such as 1 MeV negative ion accelerator for ITER.},
 pages = {1--6},
 title = {Achievement of high power and long pulse negative ion beam acceleration for JT-60SA NBI},
 volume = {91},
 year = {2020}
}