| Popis: |
The nuclear spin, the nuclear magnetic-dipole interaction constant $a$, and the nuclear electric-quadrupole interaction constant $b$, have been determined for 17-hr bromine-76 by an atomic-beam experiment. The results are: $I=1$, $|a|=345.422\ifmmode\pm\else\textpm\fi{}0.014$ Mc/sec, $|b|=314.329\ifmmode\pm\else\textpm\fi{}0.022$ Mc/sec, $\frac{b}{a}=0.9100\ifmmode\pm\else\textpm\fi{}0.0001$. The nuclear magnetic-dipole and electric-quadrupole moments are calculated to be, respectively, $\ensuremath{\mu}=\ifmmode\pm\else\textpm\fi{}0.5479\ifmmode\pm\else\textpm\fi{}0.0001$ nuclear magneton, and $Q=\ensuremath{\mp}0.27\ifmmode\pm\else\textpm\fi{}0.01$ barn. The sign of $\ensuremath{\mu}$, though not determined, is probably negative. The hyperfine structure separations are $\ensuremath{\Delta}\ensuremath{\nu}(\frac{5}{2}, \frac{3}{2})=1256.47\ifmmode\pm\else\textpm\fi{}0.05$ Mc/sec, and $\ensuremath{\Delta}\ensuremath{\nu}(\frac{1}{2}, \frac{3}{2})=189.11\ifmmode\pm\else\textpm\fi{}0.05$ Mc/sec. The hyperfine structure is of particular interest because the $F=\frac{1}{2} \mathrm{and} \frac{3}{2}$ levels are inverted and not in normal order. This inversion is the first case of its kind established in an atomic-beam experiment. |
