Atom and ion chemistry in low pressure hydrogen DC plasmas

The chemical composition of low-pressure hydrogen dc plasma produced in a hollow cathode discharge is measured and calculated. The concentrations of H atoms and of H(super +), H(sub 2)(super +) and H(sub 3)(super +) ions are determined with a combination of optical spectroscopic and mass spectroscopic methods and the results are rationalized with the help of a zero-order kinetic model.