Molecular autoionisation width for He(3¹P)+Ne: Penning and associative ionisation cross sections

Associative and Penning ionisation cross sections sigma A 4dI and sigma PI and their sum sigma TI = sigma AI + sigma PI are calculated for collisions of Ne with radiative excited He * (3 1 P) in the energy range 0.025-0.21 eV, in the classical impact parameter formulation. It is shown that the energy dependence of the sigma Al cross section previously measured in a crossed-beam apparatus in the authors; laboratory and the velocity-average quenching cross sections sigma TI obtained in discharges can be explained in terms of an autoionisation width for (HeNe)* which includes simultaneous direct and exchange mechanisms and is saturated in the small-R region.