FIRST BORN APPROXIMATION CROSS SECTIONS FOR ELECTRON LOSS FROM FAST HYDROGEN ATOMS PASSING THROUGH ATOMIC HELIUM AND FAST HELIUM ATOMS PASSING THROUGH ATOMIC HYDROGEN AND HELIUM

The first Born approximation is used to calculate cross sections for one-electron loss from fast atoms A passing through atomic targets B for the following colliding partners (A, B): (H, He), (He, H) and (He, He). Full account is taken of double transitions and the calculations are performed using length and velocity formulation values of the helium matrix elements. Comparison is made with available experimental data, and for the case (H, He) excellent agreement is obtained at high impact energies. Further experimental measurements are desirable for (He, H) and (He, He).