Low-energy singly and doubly excited resonances in neon: behaviour of the complex photoionisation amplitudes at the resonances

Abstract

The shapes of three low-energy resonance features in the photoionisation of neutral neon are calculated along with the total cross section in the low-energy region. The lowest singly excited resonance is in particularly good agreement with experiment. The complex amplitudes in the vicinity of the lines are plotted and discussed as an aid to understanding aspects of these resonance features. The experimental absence of the 1s22s22p43s4p line, in particular, seems to be the result of the two open-channel amplitudes' fluctuating out of phase so that the sum of the resulting partial cross sections is not measurably disturbed.