Nuclear Energy Levels ofK37

Approximately 40 levels in ${}_{}{}^{37}{}_{}{}^{}\mathrm{K}$ have been established via the reactions ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}(p, \alpha ){}_{}{}^{37}{}_{}{}^{}\mathrm{K}$, ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}(p, p){}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}$, ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}(p, \gamma ){}_{}{}^{37}{}_{}{}^{}\mathrm{K}$, ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}(p, p^{\prime }\gamma ){}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}$, ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}(d, n){}_{}{}^{37}{}_{}{}^{}\mathrm{K}$, and ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}({}_{}{}^3{}_{}{}^{}\mathrm{He}, d){}_{}{}^{37}{}_{}{}^{}\mathrm{K}$. Measurements of capture $\gamma$-ray energies with Ge(Li) counters have made possible the determination of several level energies with precisions ranging from 1 to 5 keV. The analogs in ${}_{}{}^{37}{}_{}{}^{}\mathrm{K}$ of the first two excited levels in ${}_{}{}^{37}{}_{}{}^{}\mathrm{Ar}$ were found as a closely spaced doublet at 1368- and 1380-keV excitation energy. The half-life of the latter has been measured electronically to be 9.6±1.4 nsec. The energies (in keV), spins, and parities of the lowest eight levels are 0, ${\frac{3}{2}}^{+}$; 1368±3, (${\mathrm{½}}^{+}$); 1380±2, ${\frac{7}{2}}^{-}$; 2169±5, (${\frac{3}{2}}^{-}$); 2278±9, (?); 2750±1, ${\frac{5}{2}}^{+}$; 3083±4, (${\frac{5}{2}}^{-}$); and 3311±4,