Unified set of atomic transition probabilities for neutral argon

Abstract

The atomic transition probabilities and radiative lifetimes of neutral argon have been the subject of numerous experiments and calculations, but the results exhibit many discrepancies and inconsistencies. We present a unified set of atomic transition probabilities, which is consistent with essentially all recent results, albeit sometimes only after critical reanalysis. The data consistency and scale confirmation has been achieved in two ways. (i) We have carried out some lifetime–branching-ratio measurements for a principal 5p level and the associated 4s-5p transitions. These measurements have very closely confirmed the accuracy of the results of recent independent emission experiments. (ii) We have critically reanalyzed and revised the literature data for the 4s-4p transitions, as well as utilized the results of a similar critical analysis for the 4s-5p transition array, to establish complete sets of absolute data for these arrays. We have found these data to be mutually consistent from cross-correlation checks between the two arrays, using recent literature data. Finally, we have proposed renormalization factors for other argon transitions based on this analysis.