Hyperfine Structure of the Level 5²P_1/2of Potassium 39

Abstract

The hyperfine structure of the level 52P1/2 of potassium 39 has been measured by the techniques of optical-radio-frequency double resonance. The magnetic interaction constant a1/2 was found to be 8.99±0.15 Mc/s, which leads to the value 4.56±0.3 for the ratio a1/2/a3/2. This is significantly lower than the value 5.08 which the Goudsmit-Fermi-Segrè theory would predict. The measured value of the Landé g-factor is 0.665±0.003.