Numerical analysis of the hydrogen atom density in a negative ion source

Takato, Naoyuki; Hanatani, Junji*; Mizuno, Takatoshi*; Hatayama, Akiyoshi*; Tobari, Hiroyuki; Hanada, Masaya; Inoue, Takashi; Taniguchi, Masaki; Dairaku, Masayuki; Kashiwagi, Mieko; Watanabe, Kazuhiro; Sakamoto, Keishi

The production and transport processes of the H atom are numerically simulated to obtain the H atom density. The three dimensional transport code using the Monte Carlo method has been applied to H atoms in the large "JAEA 10 ampere negative ion source" under the Cs-seeded condition. In this study, the production rate of H atoms through the dissociation process of H molecules is estimated from single probe characteristics of the Langmuir probe measurement. In addition, the energy relaxation process of H atoms is also considered. The results show that the existence of high-energy electrons and the energy relaxation process of H atoms affect the H atom density.