Predicted electron-transport coefficients at high E/N values. I. Hydrogen

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Abstract
Transport coefficients of electrons in hydrogen are calculated over the range 10−16⩽E/N⩽2.9×10−15 V cm2 by solving the Boltzmann equation using a two‐term spherical‐harmonic expansion which takes into account the effect of the source of new electrons produced by ionization. Recently reported electron cross‐section data, both experimental and theoretical, have been used in the calculation. It is shown that the release of new electrons in ionizing collisions has a noticeable effect on the electron distribution function starting from E/N≃1.2×10−15 V cm2. The predicted values of the first Townsend ionization coefficient are in excellent agreement with experimental results over the entire range of E/N values considered without using unrealistically large momentum‐transfer cross sections at high electron energies. The calculated values for the drift velocity vd are in good agreement with the measured values. For the characteristic energy DT/μ, the agreement is good up to E/N=2×10−15 V cm2, while for higher E/N it becomes less satisfactory. The electron excitation rates for the vibration, the excitation of the B 1Σ+u and C 1Πu electronic states, and the rate of H‐atom production are presented as a function of E/N. Results are also given for the fraction of the input power that is transfered to the various inelastic processes.