Electron impact dissociation cross sections for C2F6

Absolute total dissociation cross sections for electron impact, sigma(t,diss), from 8 to 700 eV are reported for C2F6. A dense set of data was obtained in the technologically important 8-30 eV energy range relevant to modelling the type of plasmas used in both fundamental and applied scientific investigations. The threshold for dissociation was found to be 12.0 +/- 0.2 eV and appears to be associated with a Rydberg state. Estimated values for the total neutral dissociation cross section, sneut, diss, were obtained by subtracting the ionization cross sections ( all ionizing events cause dissociation) from the total dissociation cross section. It is shown that a calibration error in a paper by one of us (HFW) caused a distortion of several previous investigations. When the data from the present work are used to recalibrate data from swarm experiments, agreement becomes quite reasonable. There is now a consistent set of data obtained from several investigators which describe the dissociation of C2F6. Neutral dissociation cross sections are obtained from electron-impact excitation calculations and found to be in reasonable agreement with measurements over most of the energy range.