A classical analysis of the ionization threshold vicinity

Abstract

The classical trajectory method has been used for investigating electron-hydrogen-atom excitation and ionization regions close to the ionization threshold. Final energy and angular momentum distribution functions have been computed with the total angular momentum equal to zero, both below and above the ionization threshold. Combining the analytical result of Vinkalns and Gailitis (1967) with the computed energy distribution function, the threshold behaviour of the high n excitation function has been derived, which is subsequently confirmed by ab initio numerical calculations. The results show that the Wannier theory (1953) is applicable below the threshold, too. The numerical results show that each electron acquires large angular momentum in the threshold vicinity, as predicted by Fano (1974).