Measurement of the hyperfine structure splitting for the 4 and 5^(2)P_(1/2) states of sodium using radio-frequency spectroscopy

The hyperfine-structure splitting for the 4 and 52P1/2 states of sodium was measured using step-wise laser excitation combined with rf-resonance techniques. The magnetic dipole interaction constants were found to be a(42P1/2)=30.4(5) MHz and a(52P1/2) =13.3(2) MHz. The results are compared with a theoretical calculation, taking polarization effects into account