Level Crossings in the(5s5p)P13State of RadioactiveCd107andCd109

Four level crossings, which obey the selection rule $\Delta m_F=2\mathrm{}$, have been detected for hyperfine levels in the $\mathrm{}\left(5s5p\right)\mathrm{}{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ state of both 6.7-h ${\mathrm{Cd}}^{107}$ and 470-day ${\mathrm{Cd}}^{109}$ by observing the change in intensity at 90° of the resonance fluorescence of the 3261 Å intercombination line. The hyperfine interaction constants found from an analysis of the crossing point fields, and corrected for interaction with the adjacent fine structure states of the $5s5p$ multiplet, are $A_{107}=-853.543\mathrm{}\left(6\right)\mathrm{}$ Mc/sec, $B_{107}=-163.279\mathrm{}\left(5\right)\mathrm{}$ Mc/sec, $A_{109}=-1148.784\mathrm{}\left(7\right)\mathrm{}$ Mc/sec, $B_{109}=-165.143\mathrm{}\left(5\right)\mathrm{}$ Mc/sec. The ratios of the magnetic-dipole moments, and the electricquadrupole moments, to within the effect of hyperfine anomalies, are $\frac{{\mu }_{107}}{{\mu }_{109}}=0.742997\mathrm{}\left(8\right)\mathrm{}$; $\frac{Q_{107}}{Q_{109}}=0.98871\mathrm{}\left(4\right)\mathrm{}$.