Structures of {sup 201}Po and {sup 205}Rn from EC/{beta}{sup +}-decay studies

Several low-lying excited states in {sub 86}{sup 205}Rn{sub 119} and {sub 84}{sup 201}Po{sub 117} were identified for the first time following EC/{beta}{sup +} decay of {sup 205}Fr and {sup 201}At, respectively, using {gamma}-ray and conversion electron spectroscopy at the CERN isotope separator on-line (ISOLDE) facility. The EC/{beta}{sup +} branch from {sup 205}Fr 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 p{sub 3/2} orbital relative to the f{sub 5/2} ground state in {sup 205}Rn, and the f{sub 5/2} orbital relative to the p{sub 3/2} ground state in {sup 201}Po, were determined to be 31.4(2) and 5.7(3) keV, respectively. We tentatively identify a (13/2){sup +} isomeric level at 657.1(5) keV in {sup 205}Rn. The systematic behavior of the (13/2){sup +} and (3/2){sup -} levels is also discussed.