Numerical Study of the H0 Atomic Density and the Balmer Line Intensity Profiles in a Hydrogen Negative Ion Source with the Effect of Non-Equilibrium Electron Energy Distribution Function

Spatial profiles of the atomic (H0) density and the resultant Hα line intensity are investigated in a large negative ion source (the Japan Atomic Energy Agency (JAEA) 10 A negative ion source). The H0 density analysis has been done in the present study with the effects of production, transport, and ionization processes by taking into account the non-Maxwellian component of electron energy distribution function (EEDF). The H0 density profile shows a non-uniform spatial profile due to the local enhancement of the H0 production rate even with the flattening effects by the ionization and the transport processes. The Hα line intensity observed from the viewing ports in the spectrometry is compared with the line intensity in the calculation to validate the numerical results. The both results show a good agreement in the spatial profile. It has been shown that the non-Maxwellian component of the EEDF plays an important role to determine the profile of the Hα line intensity in the plasma production region.