Observation and theoretical analysis of the odd J=3 autoionising spectrum of Sr up to the 4d threshold

Abstract

The odd J=3 autoionising spectrum of Sr between the 5s and the 4d thresholds has been observed. In a Sr atomic beam, the ionised atoms produced by a two-step excitation scheme have been analysed via a time-of-flight spectrometer. A theoretical approach based on the R-matrix method combined with multichannel quantum defect theory calculations provided a good description of the position of the observed lines. Analysis of the observed profiles gave qualitatively good results although the intermediate 5p2 1D2 level is not perfectly described in the model.