Absolute and relative emission cross sections for electron impact on CH 3 F, CH 2 F 2 and CHF 3

Abstract

Emission spectra following electron impact on CH3F, CH2F2 and CHF3 at various energies have been investigated in the spectral region from 200 nm to 700 nm. Emission thresholds and excitation functions for atomic and molecular fragments have been determined. Absolute emission cross sections were obtained for two band systems, A2 Δ → X2 Π, C2 Σ+ → X2 Π, observed in the emission spectrum of CH3F and for the H-Balmer radiation, Hα − Hγ, in the spectra of all compounds. The continuous emission between 200 nm and 400 nm in the spectra of CH2F2 and CHF3 has been examined systematically. It was found that CF2(A) is the main precursor in both spectra.