Theoretical investigations on the bound odd-parity spectrum of neutral krypton

Abstract

Extensive new data on the bound odd-parity spectrum of krypton have been provided recently by two-step laser spectroscopy experiments. Highly excited levels belonging to seven Rydberg series nd or ns converging to the ionisation limit have been observed, but some series are difficult to assign. Therefore, by means of multichannel quantum defect theory (MQDT) the authors have performed the analysis of all available energy data relevant to the J=0, 1, 2, 3 odd-parity bound spectra of krypton. These studies allow them to identify all the newly observed highly excited Rydberg series by connecting the new data with previous work relevant to the low-energy range. Perturbations of nd and ns principal Rydberg series by the lowest members ns' and nd' of Rydberg series converging to the second limit occur in the low-energy range; these perturbations are successfully interpreted. The energies of unknown levels are predicted and a new value for the ionisation limit is provided. Additional information on the fine structure of highly excited configurations is obtained by means of the Slater-Condon method. The Slater integrals of highly excited configurations are determined and the Jl coupling scheme of levels is discussed.