XXXIV. The excitation of the hydrogen molecule by electron impact

Abstract

Calculations have been made on the inelastic scattering of electrons in molecular hydrogen, using the Born approximation. The differential cross-section for the aggregate of inelastically scattered electrons and also the cross-sections corresponding to the excitation of individual states are found to decrease steadily with increasing angle and voltage, showing no evidence of diffraction maxima or minima. The B and C states give very similar scattering curves, and a finite cross-section is obtained for the ¹X state even at high voltages, indicating that the optically forbidden A→¹X transition can occur under electron excitation. The scattering curves ior the different states strongly resemble the curves for the corresponding states of helium. It is found that the use of two different types of wave function for the B state leads to two very similar results for the scattering. The Frank-Condon Principle fails to give correct values for the relative probabilities of excitation of the vibrational levels.