Excitation coefficients and cross-sections for electron swarms in methane

Abstract

We have measured electron excitation coefficients for production of excited fragments H(n = 3), H(n = 4), CH(A 2 Δ) and CH(B 2 Σ - ) from the ground-state methane molecules by an electron swarm in a drift tube type experiment (parallel plate Townsend discharge at very low currents). H α and H β lines as well as CH(A 2 Δ-X 2 Π) and CH(B 2 Σ - -X 2 Π) bands were used. Cross-sections from binary collision experiments were renormalized by fitting the measured data with the results of Boltzmann equation and Monte Carlo calculations for electron transport.