Ionic fragmentation of SF6 ionised in the sulphur 2p shell

The ionic fragmentation of SF6 following excitations between 160 and 230 eV has been studied by the electron-ion coincidence technique. The observed fragmentation has been separated into valence- and inner- (S 2p) shell components. A constant ionic fragmentation pattern for all of the sulphur 2p ionisation continuum, including the pronounced structures at 184 and 196 eV, is demonstrated. The significance of this result to various descriptions of these structures is discussed. The absorption oscillator strength of SF6 from 5 to 230 eV, derived from forward-scattering electron energy-loss measurements at small momentum transfer, is also reported and compared to earlier optical data. Finally, the ion autocorrelation spectrum indicates the relatively large contribution of double dissociative-ionisation processes ( approximately 2% of all ionisation events for 8 keV electron impact) to the decay of highly excited SF6.