Hyperfine structure ofSr87in theP23metastable state

Abstract
The atomic-beam magnetic-resonance technique has been used to measure the hyperfine structure of the P23 state of Sr87. This metastable state is populated in an electrical discharge located just in front of the oven orifice. The measured frequencies are Δν(F=132112)=1346.497(6) MHz and Δν(F=11292)=1170.208(6) MHz. Using these transition frequencies the hyperfine interaction constants, corrected for the perturbing interactions due to neighboring fine-structure levels, are A=212.765(1) MHz and B=67.215(15) MHz. The errors quoted are only those arising from the uncertainty in the experimental data. We have also used these data with the P13 hfs separations measured by zu Putlitz to calculate the quadrupole moment Q=0.335(20) b using the antishielding correction estimated by Sternheimer. The error quoted for Q includes the error in Sternheimer's estimate.