Ionisation and charge transfer in fast H+-He+collisions: further measurements of improved accuracy

Total cross sections for He 2+ production from the combined processes of ionisation and charge transfer in H + -He + collisions have been measured in the centre-of-mass energy range 40-386 keV. Results were obtained using the authors' previous experimental approach (see ibid., vol.10, p.1897 (1977)) but improvements to the apparatus and measuring procedure have provided data of greatly increased statistical accuracy in an extended energy range. At the higher impact energies the cross sections obtained show a significant departure from theoretical cross sections for ionisation based on the Born approximation.