Excitation and ionisation processes in He+(1s)+H(1s) collisions

Abstract
Calculations are performed in the first Born approximation for the formation of He+(2s or 2p), the formation of H(2s or 2p) and the ionisation of He+(1s) in He+(1s)+H(1s) collisions. Close-coupling theory is also employed to examine the effect of coupling for the single-transition processes contributing to the formation of the n=2 states of He+ and H. For He2(2s or 2p) coupling is important for helium-ion impact energies less than 300 keV. For H(2s or 2p) coupling is important for hydrogen impact energies less than 1000 keV and 600 keV, respectively. Theory and experiment are good agreement for He+(2s) formation and for He+(1s) ionisation for impact energies greater than 300 keV and 150 keV, respectively.