Ionisation in H+-He+collisions using an improved beam-pulsing technique for measuring the formation of He2+

An improved beam-pulsing technique has been developed for an experiment with two intersecting charged-particle beams. The total cross sections sigma 2+ for He 2+ formation from the combined processes H + He + to H 0 +He 2+ (charge transfer, cross section sigma c ) and H + +He + to H + +He 2+ +e (ionisation, cross section sigma i ) have been measured in the centre-of-mass energy range 17-100 keV. The cross sections sigma i for ionisation are determined by subtracting the authors' recently measured sigma c values from the cross sections sigma 2+ . The data are compared with previous experimental and theoretical results.