Proton emission from the odd-odd nuclei ${}^{146}\mathrm{Tm}$ and ${}^{150}\mathrm{Lu}$ has been reinvestigated by means of the recoil mass spectrometer. In the ${}^{146}\mathrm{Tm}$ study, the strongest proton transitions at 1.12 MeV and at 1.19 MeV have been assigned to the decay of ${}^{146m}\mathrm{Tm}$ ${(T}_{1/2}=200\mathrm{}\pm 10\mathrm{ms})$ and to the ${}^{146gs}\mathrm{Tm}$ decay ${(T}_{1/2}=80\mathrm{}\pm 10\mathrm{ms}),$ respectively. Three new proton lines were identified at 0.89 MeV, 0.94 MeV, and 1.01 MeV. The observed decay pattern has been interpreted by using spherical estimates of emission probabilities. The decays of ${}^{146m,gs}\mathrm{Tm}$ to the $\nu s_{1/2}$ ${}^{145}\mathrm{Er}$ ground state and to excited neutron states originating from the $\nu h_{11/2}$ orbital are reported. This work represents the first observation of fine structure in proton emission from an odd-odd nucleus. In the ${}^{150}\mathrm{Lu}$ study, the proton energy and half-life values of $E_p=1277\mathrm{}\pm 8\mathrm{keV}$ and $T_{1/2}{=39\mathrm{}}_{-6}^{+8\mathrm{}}\mu \mathrm{s}$ for the decay of ${}^{150m}\mathrm{Lu}$ were obtained with better precision, but no evidence for fine structure in the proton emission was found.

• Received 27 May 2003

DOI:https://doi.org/10.1103/PhysRevC.68.034330