Hyperfine Structure and Nuclear Moments of RaE (Bi210)

The magnetic-dipole interaction constant, $a$, and the electric-quadrupole interaction constant, $b$, have been measured for 5-day ${\mathrm{Bi}}^{210}$ ($I=1\mathrm{}$) in an atomic-beam experiment. The results are $\mathrm{}\left|a\right|=21.78\mathrm{}\pm 0.03$ Mc/sec and $\mathrm{}\left|b\right|=112.38\mathrm{}\pm 0.03$ Mc/sec, with $\frac{b}{a}=+5.160\mathrm{}\pm 0.007$. The nuclear magnetic-dipole and electric-quadrupole moments obtained from the interaction constants are $\left|\mu \right|=0.0442\mathrm{}\pm 0.0001$ nm and $\mathrm{}\left|Q\right|=0.13\mathrm{}\pm 0.01$ barn, respectively. The signs of these moments are not determined by the experiment. The ordering of the hyperfine levels is $F=\frac{1}{2}, \frac{5}{2}, \mathrm{and} \frac{3}{2}$. The values of the hyperfine level separations are $\Delta \nu (F=\frac{5}{2}\leftrightarrow F=\frac{3}{2})=194.93\mathrm{}\pm 0.09$ Mc/sec, $\Delta \nu (F=\frac{3}{2}\leftrightarrow F=\frac{1}{2})=220.19\mathrm{}\pm 0.08$ Mc/sec.