THRESHOLD ELECTRON-IMPACT EXCITATION AND NEGATIVE-ION FORMATION IN XEF6 AND XEF4

Electronic excitation and dissociative electron attachment in XeF 6 and XeF4 were investigated by studying the products of low-energy electron-molecule collisions in the gas phase. The relative abundances of the major negative ions produced were recorded as a function of the electron-beam energy. Both molecules attached electrons at ∼0 and ∼5 eV and dissociated into a number of negative-ion products. The similar energy dependence of the various ion currents suggested that the fragment ions were competing for the electron attached to XeF6 or XeF4. The threshold electron-impact excitation spectra were determined by means of the SF6-electron-scavenger" technique. No evidence for low-lying electronic states was found."