Alpha- and EC-decay measurements of $^{257}$Rf
Résumé
Alpha- and Electron capture (EC) decay properties of 257Rf were investigated by measuring α-γ coincidences and correlations between conversion electrons (CE) emitted during the process of EC decay of 257Rf and α decays of the daughter isotope 257Lr. So far, previously unobserved α (8296 keV)-γ (557 keV) coincidences were measured and interpreted as decays of 257mRf (11/2 −[725]) into the 7/2−[743] level in 253No. A search of delayed coincidences between α particles and signals at E ≤ 1000 keV, which are interpreted as being due to CE emission, revealed a clear correlation between CE and α particles from the decay of 257Lr, which is regarded as a direct proof of the EC decay of 257gRf and 257mRf.
