Nuclear moments ofLi9

The ground-state magnetic dipole and electric quadrupole moments of the $\beta$ emitter ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$ ($J^{\pi }={\frac{3}{2}}^{-}$, $T_{\frac{1}{2}}=0.176\mathrm{}$ s) have been measured for the first time. Polarized ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$ nuclei were produced in the ${}_{}{}^7{}_{}{}^{}\mathrm{Li}(\overrightarrow{\mathrm{t}}, \mathrm{p})$ reaction, using 5-6 MeV polarized tritons. The recoiling ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$ nuclei were stopped either in Au foils or in LiNb${\mathrm{O}}_3$ single crystals, and their polarization was detected by measuring the $\beta$-decay asymmetry. Nuclear magnetic resonance techniques were used to depolarize the nuclei, and the resonant frequencies were deduced from changes in the asymmetry. The ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$ dipole moment was deduced from the measured Larmor frequency in Au; the result, including corrections for diamagnetic shielding and the Knight shift, is $\left|\mu \mathrm{}\right|=3.4391\left(6\mathrm{}\right)\mathrm{}$ ${\mathrm{\mu }}_{\mathrm{N}}$. The ratio of the ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$ quadrupole moment to that of ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ was derived from their respective quadrupole couplings in LiNb${\mathrm{O}}_3$; the value is $\left|\frac{Q\left({}_{}{}^9{}_{}{}^{}\mathrm{Li}\right)}{Q\left({}_{}{}^7{}_{}{}^{}\mathrm{Li}\right)}\right|=0.88\mathrm{}\pm 0.18$. Both results are in agreement with shell model predictions.