${}_{}{}^{59}{}_{}{}^{}\mathrm{Mn}$ was produced using the ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}({}_{}{}^{13}{}_{}{}^{}\mathrm{C},pn){}_{}{}^{59}{}_{}{}^{}\mathrm{Mn}$ reaction at $E_{{13}_{\mathrm{C}}}=26\mathrm{}$ MeV. $\gamma$ rays from the decay of ${}_{}{}^{59}{}_{}{}^{}\mathrm{Mn}$ were observed in singles and coincidence experiments using large Ge(Li) detectors after the targets were transferred to a shielded counting area by a multiple-target pneumatic transfer system. Assignment of $\gamma$ rays to transitions in ${}_{}{}^{59}{}_{}{}^{}\mathrm{Mn}$ was confirmed by performing an ${}_{}{}^{58}{}_{}{}^{}\mathrm{Fe}(d,p\gamma ){}_{}{}^{59}{}_{}{}^{}\mathrm{Fe}$ experiment. The half-life of ${}_{}{}^{59}{}_{}{}^{}\mathrm{Mn}$ was determined to be 4.6 ± 0.1 s. The results of this work limit the ground-state spin of ${}_{}{}^{59}{}_{}{}^{}\mathrm{Mn}$ to ${5/2}^{-}$ or ${3/2}^{-}$. Theoretical and systematic considerations favor ${5/2}^{-}$. The total $\beta$-decay energy, $Q_{\beta }$, was measured to be 5.2 ± 0.1 MeV, which corresponds to a mass excess of -55.5 ± 0.1 MeV.

[RADIOACTIVITY ${}_{}{}^{59}{}_{}{}^{}\mathrm{Mn}$: measured $T_{\frac{1}{2}}$, $E_{\gamma }$, $I_{\gamma }$, $\gamma -\gamma$ coin, $E_{\beta }$, $\beta -\gamma$ coin; deduced decay scheme, $log\mathrm{ft}$ limits, $Q_{\beta }$, g.s. $J^{\pi }$ limit. Enriched targets, Ge(Li) detectors, plastic scintillator, multiple rabbit.]

• Received 25 February 1977

DOI:https://doi.org/10.1103/PhysRevC.16.370