Hyperfine structure constants of the CaII states 4 s S and 4 p P and the nuclear quadrupole moment ofCa.

The hyperfine structure splittings of the 4 s S → 4 p P transitions inCaII have been measured by fast ion beam collinear laser spectroscopy. The resonant laser interaction was observed using non-optical detection based on optical ground state depopulation pumping, state selective neutralization and charge state separated particle counting. The extracted magnetic dipole hyperfine structure constants forCa A( S)=−805(2) MHz, A( P)=−145.5(1.0) MHz and A( P)=−31.9(0.2) MHz are in excellent agreement with relativistic many body perturbation theory predictions available for this alkali-like ion. The combined results are used to evaluate the semi-empirical analysis method. From the electrical quadrupole hyperfine structure constant B( P)=−6.7(1.4) MHz and the calculated B/Q value for this one valence electron configuration, the nuclear quadrupole moment Q(Ca)=−0.043(9) b is derived. This result supports a previous evaluation based on the hyperfine structure of the two valence electron P configurations of CaI. [ABSTRACT FROM AUTHOR]