Improved half-life measurement of224Paand its209Bi(18O,3n)224Paproduction cross section

${}^{224}\mathrm{Pa}$ was produced via the ${}^{209}{\mathrm{B}\mathrm{i}(}^{18}\mathrm{O},3n)$ reaction at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron and the half-life was determined to be 850±20 ms by measuring its alpha decay using our rotating wheel system. Our value is consistent with a previously reported half-life of 950±150 ms for ${}^{224}\mathrm{Pa}$ produced via the ${}^{205}{\mathrm{T}\mathrm{l}(}^{22}\mathrm{N}\mathrm{e},3n)$ reaction, but its much more precise. The cross section for the ${}^{209}{\mathrm{B}\mathrm{i}(}^{18}\mathrm{O},{3n)}^{224}\mathrm{Pa}$ reaction was measured to be 0.5±0.1 mb for 87–89 MeV ${}^{18}{\mathrm{O}}^{5+}$ projectiles incident on the target.