The Hyperfine Structure of the Stable Isotopes of Indium

The atomic beams magnetic resonance method has been applied to the study of the h.f.s. of the metastable ${}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$ state of both ${\mathrm{In}}^{113}$ and ${\mathrm{In}}^{115}$. It has been found that the separations of the energy levels at zero external magnetic field are completely described by the equation $W=\frac{\mathrm{haC}}{2}+hbC(C+1\mathrm{})\mathrm{}$, where $C=F(F+1\mathrm{})-I(I+1\mathrm{})-J(J+1\mathrm{})\mathrm{}$, and $a$ and $b$ are the magnetic dipole and electric quadrupole interaction constants, respectively. No evidence has been found to indicate the existence of a nuclear moment of higher order than the quadrupole moment. These are the heaviest atoms in which a critical search for such moments has been made.