Nuclear moments ofTa179from optical measurement of hyperfine structure

We have made high-resolution laser spectroscopy of the hyperfine structure of a radioactive isotope $^{179}\mathrm{Ta}$ (${T}_{\frac{1}{2}}=1.8$ y) using an argon-ion sputtering atomic-beam source. From hyperfine constants $A$ and $B$ of the atomic ground state ($^{4}F_{\frac{3}{2}}5{d}^{3}6{s}^{2}$), the magnetic dipole and electric quadrupole moments of the nuclear ground state of $^{179}\mathrm{Ta}(I=\frac{7}{2})$ have been determined for the first time: ${\ensuremath{\mu}}_{I}^{179}=2.289(9){\ensuremath{\mu}}_{N}$ and ${Q}_{s}^{179}=3.37(4)$ b. It is pointed out that magnetic moments of the ground and isomeric states in the region $N=102\ensuremath{-}112$ can be systematically described in terms of the presently available theory while the revealed systematic behavior of electric quadrupole moments is hardly reproduced by the theory.