Cross sections for electron impact ionisation of metastable rare-gas excimers (He2*, Kr2*, Xe2*)

Cross sections for electron impact ionisation of metastable rare-gas excimers (He2*, Kr2* and Xe2*) are evaluated using a binary encounter method with orbital speed distributions determined by the appropriate molecular orbital. Gaussian basis sets are calculated for He2* and Kr2* and potential energy curves are provided for Kr2*. The resulting ionisation cross sections are of order 1*10-15 cm2 and are about a factor of two higher for Kr2* and Xe2* than for He2*. The cross sections for Kr2* and Xe2* are between 50% and 40% higher than the corresponding metastable atom cross sections.