The Zeeman and hyperfine structure of the $\mathrm{}\left(5s5p\right)\mathrm{}{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ state of 6.7-h ${\mathrm{Cd}}^{107}$ has been determined by optical double resonance. Positive identification of the isotope was obtained through the observation of the decay of the Zeeman resonance signals. The nuclear spin ($I$), magnetic hyperfine-structure coupling constant ($A$), and the quadrupole coupling constant ($B$), are $I=\frac{5}{2}$, $A\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)=-854.2\mathrm{}\pm 1.0$ Mc/sec, and $B\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)=-166\mathrm{}\pm 3$ Mc/sec. Neglecting possible hyperfine structure anomalies and quadrupole shielding effects, the corresponding nuclear moments are ${\mu }_{107}=-0.6162\mathrm{}\left(8\right)\mathrm{}$ ${\mathrm{\mu }}_{\mathit{N}}$ and $Q_{107}=+0.77\mathrm{}\left(10\right)\mathrm{}$ b. These moments are compared with the predictions of the configuration mixing model of Noya, Arima, and Horie. The ratio of the ${\mathrm{Cd}}^{107}$ and ${\mathrm{Cd}}^{109}$ quadrupole moments is $\frac{Q_{107}}{Q_{109}}=0.993\mathrm{}\left(20\right)\mathrm{}$; this result is independent of the shielding corrections.

• Received 17 June 1963

DOI:https://doi.org/10.1103/PhysRev.132.1181