Comparison of binary-encounter and Born approximation for incident neutral systems

A comparison is made between 'Born' and 'binary-encounter' generalized oscillator strengths of the continuum states of hydrogen for hydrogen atom impact. The results of this comparison show that resonance excitations are less important for ionization by hydrogen atom impact than for ionization by proton impact and that, consequently, the Born and binary-encounter approximations will be in closer agreement in the former case than in the latter case.