Charge exchange in fast collisions of H⁺and He²⁺with helium

The continuum distorted-wave (CDW) approximation is used to calculate total cross sections for the charge-exchange process H + +He(1s 2 ) to H(1s, 2s, 2p, 3s, 3p, 3d, 4s)+He + (1s) in the impact energy range 25 keV-10.5 MeV. The results obtained are compared with experimental data and it is found that the CDW method is quite successful in the prediction of the electron capture into the s states of H. The CDW cross sections Q tot for the electron capture summed over all final projectile bound states in the reaction He 2+ +He(1s 2 ) to He + ( Sigma )+He + (1s) agree well with experimental data at impact energies 500 keV-7 MeV. In addition, several approximate good-state wavefunctions of He are used to establish the degree of sensitivity of the CDW cross sections to the choice of wavefunction.