Excited States ofTc94Studied Through the Enhancement of Neutron and Gamma-Ray Yields from theMo94(p, n)Tc94Reaction at Isobaric Analog Resonances

A revised and extended level scheme for ${}_{}{}^{94}{}_{}{}^{}\mathrm{Tc}$ results from the combined study of neutron and $\gamma$-ray spectra emitted at proton energies near isobaric analog resonances. The cross sections for the ${}_{}{}^{94}{}_{}{}^{}\mathrm{Mo}(p, n){}_{}{}^{94}{}_{}{}^{}\mathrm{Tc}$ reactions and relative yields of $\gamma$ rays from the decay of the states of ${}_{}{}^{94}{}_{}{}^{}\mathrm{Tc}$ have been measured on the energy interval between 5.35 to 6.1 MeV in the vicinity of three analog resonances. The energies of neutrons emitted were measured by the time-of-flight technique. Excitation energies of levels in ${}_{}{}^{94}{}_{}{}^{}\mathrm{Tc}$ were determined from the neutron spectra and the energies of the $\gamma$ rays observed. The enhancement of the neutron and $\gamma$ ray yields with measurements of neutron angular distributions has been compared with statistical model calculations. The results provide spin-parity assignments to two levels and suggest others. Of particular interest is the location of the $2^{-}$ and $3^{-}$ states separated by an energy of 142 keV. The results illustrate the use of the statistical analysis at isobaric analog resonances according to the method of Robson for the extraction of spectroscopic information about nuclei. Comparison with shell-model calculations is given.