Pressure and electron temperature dependence of H− density in a hydrogen plasma

Abstract
The density of negative ions in a low‐pressure hydrogen plasma has been investigated as a function of neutral gas pressure, plasma density, and electron temperature. The comparison of the experimental data, obtained by the photodetachment technique, with theoretical results derived from computed reaction rates, seems to indicate that hydrogen negative‐ion production occurs mainly through the process of electron attachment on vibrationally excited hydrogen molecules.