Inelastic Collisions between Heavy Particles V: Electron Loss for Fast He+Ions passing through Atomic Hydrogen, and Ionization of Hydrogen Atoms by Fast He+Ions

Born's approximation is used to calculate the cross sections for the processes He+(1s) + H(1s) → He2+ + e + H (1s, 2, 3 or C), where C represents the continuum. The effect of double transitions is found to be important for impact energies greater than about 300 keV. The agreement between the calculated electron loss cross section and the experimental data of Allison, Cuevas and Murphy for energies of the incident He+ ion lying between 100 and 450 keV is quite good except at the limits of the experimental energy range. The ratio of the electron loss cross section to the electron capture cross section is also computed and compared with experiment. Again, the agreement is quite good. In addition, Born's approximation is employed to calculate the cross section for the process He+(1s) + H(1s) → He+(1s) + H+ + e, which provides the dominant contribution to the total ionization cross section.