Hyperfine structure of the X 2Σ+ ground state of Ca 35Cl and Ca 37Cl by molecular-beam, laser-rf double resonance

Abstract
The hyperfine structure of the X 2Σ+ state of Ca 35Cl and Ca 37Cl, unresolved in previous studies, has been investigated in detail by the molecular‐beam, laser‐rf, double‐resonance technique. Results for the spin‐rotation interaction and the dipole and quadrupole hfs constants are given in the form of Dunham coefficients so that the N\ and v\ dependence of each constant can be explicitly exhibited. The results, after dividing out the purely nuclear effects, fall between the corresponding values for CaF and CaBr, as expected.