Modeling of the discharge plasma in a back lighted thyratron during the conduction phase

Temperature, energy, and densities of two electron components, i.e., isoptropic "bulk" and anisotropic beam electrons, are evaluated for a Back Lighted Thyratron (BLT) hydrogen switch plasma. Measured plasma parameters are peak electron density of 1-3*I0/sup15/ cm/sup 3/ and peak current density of 10/sup 4/ A/cm/sup 2/. Estimates of a very small cathode fall width during the conduction phase and high electric field strengths lead to injection of an electron beam with energies /spl ges/100 eV and density of 10/sup 13/-10/sup 14/ cm/sup -3/ into a Maxwellian "bulk" plasma. Collisional and radiative processes of monoenergetic beam electrons, "bulk" plasma electrons and ions, and atomic hydrogen are modeled by a set of rate equations and line intensity ratios are compared with measurements. For an initial density n/sub H2/=10/sup 16/ cm/sup -3/ the evaluated "bulk" plasma parameters are electron density of 1-3*I0/sup 15/ cm/sup -3/ and electron temperature of 0.8-1 eV.