Vacuum ultraviolet emission and H^- production in a low pressure hydrogen plasma

The vacuum ultraviolet emission from a low pressure hydrogen plasma has been used to study the production mechanism for vibrationally excited ground state molecules thought to be important in negative hydrogen ion production. The present results are in agreement with theoretical calculations by Hiskes (1980). The rate of production of molecules with v>or=5 has been estimated and is sufficient to allow H^- production in such plasmas to be via these molecules.