Translational Energy Distribution Functions of H and H+ in H2 Volume Discharges

In these last years large attention has been devoted to the nonequilibrium plasma kinetics of H2 in multicusp magnetic plasmas, due to their wide use for the production of negative ions (H-,D-)1–3. The accepted mechanism for H- production is dissociative attachment from vibrationally excited H2 molecules (H2(v)). Therefore the theoretical effort has been addressed to the understanding of numerous microscopic processes affecting the vibrational distribution of H2 (NV). One of the open problems concerns the translational energy distribution function (TEDF) of atomic hydrogen and of protons, which can affect N. Usually it is assumed that the translational temperature ofV H and H+ are much higher that the corresponding one for H2.