Assignment of levels in ²⁰⁸Fr and 10⁻ isomers in the odd-odd isotones ²⁰⁶At and ²⁰⁸Fr

Abstract

Excited states in ²⁰⁸Fr have been identified using the ¹⁹⁷Au(16O, 5n)²⁰⁸Fr reaction and a variety of time-correlated γγ -ray and conversion electron spectroscopic techniques. Transitions above and below a ττ = 623(16) ns 10- isomer are placed in the level scheme. This isomer is analogous to that observed in the odd-odd isotone ²⁰⁶At for which additional spectroscopic information is also obtained, including a precise lifetime of ττ = 1173(30) ns. The γγ -rays assigned to ²⁰⁸Fr are the same as the main transitions erroneously assigned to ²⁰⁹Fr in previous work. Show more