ANALYSIS OF THE OPTICAL-EMISSION FOLLOWING ELECTRON-IMPACT ON CF3I

An experimental study of the visible and ultraviolet emission features following pulsed electron impact on CF3I molecules is presented. The spectra in the 200-600 nm region, for electron-impact energies of 100 eV, show a number of narrow lines superimposed on two very broad bands centred at 300 and 470 nm thought to originate from the CF3 and IF* ion-pair emissions. The atomic lines arise from II'' and III fragment s and the lifetimes of the 14 more intense fragments have beer, measur ed to be in the 10-30 ns range. Atomic and molecular electronically ex cited emission thresholds and relative cross sections have been studie d for electron energies of up to 500 eV. Application of the Bethe-Born theory under Fano's characteristic parameters analysis shows that for mation of most II and III* species originates via optically allowed t ransitions.