The ~(130)Nd → ~(130)Pr → ~(130)Ce decay chain revisited

摘要

An investigation of low-lying energy levels of ~(130)Pr and ~(130)Ce has been made via β-decay. The radioactive parent nuclei were produced via ~(94,96)Mo + ~(40)Ca reactions at 6.8 MeVucleon and transported by a He-jet system. Gamma-γ-t, γ-X-t, γ-e~--t coincidence measurements were performed. Internal conversion coefficients have been measured with a magnetic spectrometer. The new β-decay half-life of ~(130)Nd has been determined to be 21(3) s. A partial level scheme of ~(130)Pr at low-spin has been constructed. The β-decay of ~(130)Pr to ~(130)Ce suggests the existence of three β-instable isomeric states in ~(130)Pr, while only one half-life T_(1/2) = 40(4) s has been measured. Based on the present work and low-lying excited sates in neighbouring odd-mass nuclei, the spins and parities of isomeric states in ~(130)Pr are proposed to be 2~+, (4,5)~+ and (7,8~+). The ground state in ~(130)Pr is still undetermined.