Dissociation efficiency for molecular hydrogen and deuterium in a beam-driven discharge in Ar:H2(D2):CO and Ar:H2(D2):CH4 mixtures

An externally maintained discharge controlled by an electron beam in H2(D2) + Ar mixtures and by admixtures of carbon-containing CO and CH4 are studied experimentally and theoretically. It is shown experimentally that the addition of <5% CO and CH4 has little effect on the energetic properties of the discharge. Numerical calculations reveal that the quantity of atomic hydrogen that forms in a discharge due to dissociative attachment of electrons to vibrationally excited hydrogen and subsequent destruction of the negative ion H- is of order 2 · 1015 cm-3. The combined results imply that such a discharge in steady state with gas pumping can be used to create diamond films. 8 refs., 6 figs