LASER-RF DOUBLE-RESONANCE STUDIES OF THE HYPERFINE-STRUCTURE OF V-51

The laser-rf double-resonance technique has been used to study the hyperfine structure (hfs) of the excited 3d44sD4 levels of V15 in a continuation of earlier atomic-beam magnetic-resonance studies of the lower levels. The new results make it possible for the first time to distinguish clearly between the contact hfs due to the 4s electron and that due to core polarization associated with the 3d electrons. The values found for the radial hfs integrals from a systematic analysis of both the new and earlier results are compared with the relativistic Hartree-Fock values of Lindgren and Rosén. The magnetic octopole hfs interaction is measured for one level. Hyperfine constants and lifetime information, deduced from laser-fluorescence studies, are presented for the levels 3d44pP52,32,12o4 at 25000 cm-1 exitation. © 1979 The American Physical Society.