2006/01/01 by E. Ruchowska, W. Płóciennik, J. Ż̷ylicz +27 · 4 citations
Physics and Astronomy · #Astronomical and nuclear sciences #Atomic and Molecular Physics #Nuclear physics research studies #Radioactive Decay and Measurement Techniques #Scientific Research and Discoveries
paper · pdf · doi:10.1103/physrevc.73.044326
openalex publication_date 2006/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/15
Lifetimes of excited states in 229Th, populated in the \β-decay of 229Ac, have been measured using the advanced time-delayed \β\γ\γ(t)-method. Half-lives of 14 states have been determined including 11 of them for the first time. Twenty-seven new \γ-lines have been introduced into the \β-decay scheme of 229Ac based on results of \γ\γ-coincidence measurements. Reduced transition probabilities have been determined for more than 70 \γ-transitions in 229Th. Average ∣D0∣ values of 0.029(1), 0.077(3) and 0.024(5) e fm have been deduced for the lowest K\π=1/2\± , 3/2\± and 5/2\± parity partner bands, respectively. Excited states in 229Th and experimental transition rates have been interpreted within the quasiparticle-plus-phonon model. The half-life of the 3.5 eV , 3/2+ isomeric state is predicted to be about 10 h. Potential energy surfaces on the (\β2 ,, ,\β3) plane for the lowest single quasiparticle configurations in 229Th have been calculated using the Strutinsky method.