Structures of Po201 and Rn205 from EC/β+-decay studies

Abstract

Several low-lying excited states in 86205Rn119 and 84201Po117 were identified for the first time following EC/β+ decay of Fr205 and At201, respectively, using γ-ray and conversion electron spectroscopy at the CERN isotope separator on-line (ISOLDE) facility. The EC/β+ branch from Fr205 was measured to be 1.5(2)%. The excited states of the daughter nuclei are understood in terms of the odd nucleon coupling to the neighboring even-even core. The neutron single-particle energies of the p3/2 orbital relative to the f5/2 ground state in Rn205, and the f5/2 orbital relative to the p3/2 ground state in Po201, were determined to be 31.4(2) and 5.7(3) keV, respectively. We tentatively identify a 132+ isomeric level at 657.1(5) keV in Rn205. The systematic behavior of the 132+ and 32- levels is also discussed. © 2010 The American Physical Society.