Hyperfine structure and isotope shift of high-lying metastable states of rhenium

Abstract

Fourteen transitions in ReI, starting from high-lying metastable states belonging to the configurations (5d+6s) 7, have been studied by laser-induced fluorescence in a collimated atomic beam, and accurate values for the isotope shifts in these transitions as well as for the hyperfine structure constants of 13 metastable and 9 excited states have been obtained. In addition, high precision measurements of the hyperfine structure of the states 5d 56S 2 ~DT/2 and 5d66s 6D1/2,3/2,5/2,9/2 have been performed using the atomic beam magnetic resonance technique coupled with laser-induced state-selective detection of metastable atoms. The analysis of the hyperfine structure data yields experimental evidence for far configuration mixing effects on the off-diagonal spin-dipole matrix elements. The phenomenological interpretation of the isotope shifts shows the significance of off-diagonal field-shift effects.

Isotope Shifts in Atomic Spectra

“…(1979) were able to deduce the large amounts of 5d 5 6s6p (and possibly 5d 6 6p) which are present in the upper levels of the lines with negative field shifts. Burger et al (1982) have made a parametric study of the isotope shifts that they measured in several optical transitions in Re I, and were able to show the presence of second-order (]-dependent) field shifts with parameter values in good agreement with those obtained for other 5d-shell atoms (see, for example, Grethen et al, 1980).…”

High precision hyperfine structure measurements in185Re and187Re

“…Because of the weak population, especially of the 4Gs/2 state, counting times up to 1,000s were necessary in order measurements of the hfs of these and other highlying states were performed using a laser detection system. These measurements will be described in a forthcoming paper [25].…”

Isotope shift and hyperfine structure in the iridium I spectrum

“…So far the IS parameters of six 5d-elements (Hf [4], W [4], Re [23], [24], [3], [18], Os [4], Ir (this work), Pt [25]) were determined with sufficient accuracy which now permit to look for possible systematic trends. Each IS parameter consists of an electronic and a nuclear part of which the latter can be expressed by the factor 2.…”