Redetermination of cross sections for charge transfer and ionisation in H+-He+collisions

The cross sections sigma c for charge transfer in H + -He + collisions previously measured in this laboratory have been found to be subject to an arithmetical error of 25%. The error has now been confirmed by remeasurements of sigma c in the CM energy range 49-141 keV. The revised values of sigma c and the cross sections for ionisation sigma i = sigma (He 2+ )- sigma c derived from the previous measurements (Angel et al., 1978) of the total cross sections sigma (He 2+ ) for He 2+ formation are in good accord with other measurements. The experimental data now permit a useful assessment of the range of validity of a number of theoretical predictions.