Determination of thePo190α reduced width

The isotope ${}_{}{}^{190}{}_{}{}^{}\mathrm{Po}$ was produced in the ${}_{}{}^{144}{}_{}{}^{}\mathrm{Sm}$ ${(}^{48}$Ti,2n) reaction and its α-decay energy and half-life were measured to be 7.49(4) MeV and 2.$0_{\mathrm{-}1.0}^{+0.5\mathrm{}}$ ms, respectively. These data compare as follows with preliminary values reported by Quint et al.: ${\mathit{E}}_{\mathrm{\alpha }}$=7482(20) keV and a ${\mathit{T}}_{1/2}$=9.$6_{\mathrm{-}4.4}^{+47\mathrm{}}$ ms. While the two energies agree, the half-lives differ by a factor of almost 5. The earlier data yield an α reduced width which is much smaller than those of neighboring nuclides; our ${}_{}{}^{190}{}_{}{}^{}\mathrm{Po}$ energy and half-life result in a width that fits the overall α-decay-rate systematics in the mass region above the Z=82 closed shell. © 1996 The American Physical Society.