Ge73(n,γ)Ge74Gamma-Ray Spectrum and Energy Levels ofGe74

Abstract

The $\ensuremath{\gamma}$-ray spectra resulting from thermal-neutron capture in targets of natural germanium and enriched ${\mathrm{Ge}}^{73}$ were measured with a Ge(Li) germanium detector. The energies and intensities of 85 $\ensuremath{\gamma}$ rays in the energy range 0.20-3.00 MeV and 47 $\ensuremath{\gamma}$ rays in the range 6.1-9.6 MeV were identified with the reaction ${\mathrm{Ge}}^{73}(n,\ensuremath{\gamma}){\mathrm{Ge}}^{74}$. The $\ensuremath{\gamma}$-ray spectrum was used to suggest four new levels, and place limits on the spins and partities of three other levels. Errors in the $\ensuremath{\gamma}$-ray energy values were reduced to less than 3 keV in all cases, and to less than 1 keV for many. Based on this experiment and other information, the energy levels identified below 3 MeV were 0.0 (${0}^{+}$), 596.3 (${2}^{+}$), 1204.9 (${2}^{+}$), 1466.2 (${4}^{+}$), [1486 (${0}^{+}$)], [1697.7], 1699.9 (${3}^{\ifmmode\pm\else\textpm\fi{}}$, ${4}^{+}$, 2168.3 (${3}^{\ifmmode\pm\else\textpm\fi{}}$, ${4}^{+}$), 2200.2 (${2}^{+}$), 2539.3 (${3}^{\ensuremath{-}}$), 2574.1, 2672.4, [2695.8], 2699.1, 2833.2, 2929.2, 2939.7, and 2978.1 keV, where the levels in brackets were not fed directly from the capture state. The level energies were determined to with 1 keV. The energy of the capture state in the compound nucleus (${\mathrm{Ge}}^{73}+n$) was found to be 10 203.1\ifmmode\pm\else\textpm\fi{}0.9 keV.