Isotope shifts of perturbed 6sns 1 S 0 and3 S 1 Rydberg states of odd barium isotopes

Abstract

Isotope shifts of the pairs Ba 135-138 and 137-138 have been measured for the 6sns 1S o (11-<n<23) and 6sns 3S 1 (14<n<23) Rydberg states. A quantitative analysis of the data in terms of hyperfine-induced singlet-triplet mixing was carried out. Admixtures of local perturbers belonging to the 5d 7d configuration were easily identified and admixture coefficients were derived.

Estimation of the specific mass effect in the isotope shifts of energy levels in the optical spectrum of Ba I and Ba II

“…The first row of Table 1 lists the ground state 6s 2 ~S o of Ba I level shift with respect to 6s~ Ba II published in [7]. The Berlin group's data agree within error Amsterdam, 1982), is in agreement with the value in [6], and lies consistent with the other data on a King plot (see below). The level shifts of all states below n= 10 connected by measured optical transitions to the atomic ground state are also listed in Table 1.…”

“…Data shown in King plots in [6] were later confirmed in [7] as implying that these Rydberg states had zero residual level shift with respect to 6s~ of BaII. Level shifts in Ca and Sr had been obtained earlier by Lorenzen et al [8].…”

“…Independent measurements by Rinneberg et al [6] and Hogervorst and ElM [7] of transition isotope shifts in neutral barium, including the high Rydberg states 6sns 1So, showed that the residual transition shifts were constant in the region 20_<n_<30, after the hyperfine shift induced by singlet-triplet mixing in the odd isotopes 135 and 137 had been subtracted. Data shown in King plots in [6] were later confirmed in [7] as implying that these Rydberg states had zero residual level shift with respect to 6s~ of BaII.…”

“…A graphical method for estimating mass and volume shifts from purely optical shift data is presented and compared with King's "bunching" method [5]. Recent laser spectroscopic measurements of Rydberg states of Ba I [6,7] have enabled level isotope shifts with respect to BaII to be found. In this article these shifts are parameterised with a linear model, including both neutral and ionic states and the effects of configuration mixing and relativity.…”

Zeeman effect in the perturbed 6s n d 1,3 D 2 sequences of Ba-I: test of MQDT wavefunctions

“…The configuration interaction can also be probed using hyperfine interactions and isotope shifts as illustrated, e.g. for Sr [9] and Ba [10][11][12]. For Sr, Wynne et al have performed an investigation of the Zeeman effect in the 5snd 1, 3D2 states around n = 16 [13], where the singlet-triplet character is interchanged.…”