Numerical analysis of atomic density distribution in arc driven negative ion sources

The purpose of this study is to calculate atomic (H⁰) density distribution in JAEA 10 ampere negative ion source. A collisional radiative model is developed for the calculation of the H⁰ density distribution. The non-equilibrium feature of the electron energy distribution function (EEDF), which mainly determines the H⁰ production rate, is included by substituting the EEDF calculated from 3D electron transport analysis. In this paper, the H⁰ production rate, the ionization rate, and the density distribution in the source chamber are calculated. In the region where high energy electrons exist, the H⁰ production and the ionization are enhanced. The calculated H⁰ density distribution without the effect of the H⁰ transport is relatively small in the upper region. In the next step, the effect should be taken into account to obtain more realistic H⁰ distribution.