Differential cross sections in electron - hydrogen scattering at energies lying between then= 3 andn= 4 thresholds

Abstract

Two independent calculations have been carried out to obtain the differential cross sections (DCS) for the excitation of n = 2 and 3 states from the ground state of hydrogen at electron impact energies lying between the n = 3 and n = 4 thresholds. They are the 15-state R-matrix calculation of Fon et al and the algebraic variational method of Wang and Callaway. The cross sections show complicated and irregular structures associated with overlapping resonances in different partial waves. Resonance analysis has been carried out. In the absence of experiments and other theoretical calculations, the 15-state R-matrix calculation is used to describe the shape of the DCS while the absolute magnitude is estimated by the algebraic variational method.