Quadrupole Coupling in the Hyperfine Structure of the Spectra of Ta I and Os I

Abstract

The shielding correction Δ defined by Q =(1+ Δ ) Q ' ( Q =true quadrupole moment; Q '=apparent quadrupole moment obtained by spectroscopic means neglecting the shielding effect) was investigated in the cases of the state 5 d 4 6 s of Ta I and 5 d 6 6 s 6 p of Os 189 I. In these cases the correction Δ for the group 5 d 4 6 s or 5 d 6 6 s was found to be of the order of 9±5; namely the shielding effect predominates over the antishielding effect. It is highly probable that Δ is around zero in the state 5 d 6 of Os I. The quadrupole moment of Os 189 is 0.8±0.2 barn. The hyperfine structure due to Os 187 was also studied, and µ(187)=+0.0656±0.0006 nm, was obtained.