Electron Loss from Fast Negative Ions of Atomic Hydrogen passing through Atomic Hydrogen

Born's approximation is used to calculate the cross sections of the processes H(1s) + H - (1s 2 ) → H(1s or 2p) + H(1s or 2p) + e at impact energies between 2.5 keV and 10 MeV. The sensitivity of the cross section of the process H(1s) + H - (1s 2 ) → H(1s) + H(2p) + e to the choice of bound and free H - wave function is examined, as is that of the process H(1s) + H - (1s 2 ) → H(2p) + H(1s) + e to the choice of free H - wave function. The electron loss cross section σ -1,0 is approximated by a sum rule, for the simplest choice of wave function. The results are compared with those of Allison for H - electron loss in H 2 . The energy distribution of ejected electrons at high impact energies is also given.