Hyperfine structure of the A^2Π state of Ca^35Cl

Abstract
The hyperfine structure (hfs) of the A2Π excited state of Ca35Cl has been investigated by using the new rf-pumped, laser-rf double-resonance technique. The optically unresolved hfs components of the R2 (N″ = 101), AX (0,0) line were resolved by double resonance, and the measured splittings, when combined with the known X2+- state hfs spacings, show that the A2Π-state hfs splittings are not more than 1 MHz.