The hyperfine structures of the ${}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ state of 55-min ${\mathrm{Cd}}^{105}$ and 49-min ${\mathrm{Cd}}^{111m}$ have been determined by the optical double-resonance technique. For ${\mathrm{Cd}}^{105}$, the measurements yield a nuclear spin $I=\frac{5}{2}$, a dipole interaction constant $A_{105}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)=-1025.9\mathrm{}\left(2\right)\mathrm{}$ MHz, and a quadrupole interaction constant $B_{105}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)=-103.9\mathrm{}\left(3\right)\mathrm{}$ MHz. For ${\mathrm{Cd}}^{111m}$, $I=\frac{5}{2}$, $A_{111m}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)=-697.1\mathrm{}\left(2\right)\mathrm{}$ MHz, and $B_{111m}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)=+202.3\mathrm{}\left(5\right)\mathrm{}$ MHz. If the hfs anomaly and quadrupole shielding effects are neglected, the nuclear magnetic dipole moments with diamagnetic correction are ${\mu }_{105}=-0.7385\mathrm{}\left(2\right)\mathrm{}{\mu }_N$ and ${\mu }_{111m}=-1.1040\mathrm{}\left(4\right)\mathrm{}{\mu }_N$, and the nuclear quadrupole moments are $Q_{105}=+0.43\mathrm{}\left(4\right)\mathrm{}$ b and $Q_{111m}=-0.85\mathrm{}\left(9\right)\mathrm{}$ b.

• Received 23 September 1968

DOI:https://doi.org/10.1103/PhysRev.177.1615