Isomers and high-spin states in 205At

Abstract

The properties of high-spin states in 205At have been investigated to J ⩾ 37 2 and an excitation energy of > 4.0 MeV. The properties of the 29 2 + isomer at 2340 keV have been established and those of the 25 2 + isomer at 2063 keV have been further investigated. In the present study the mean lives of these isomers have been determined as 11.2±0.2μs and 98±2 ns respectively. The M2 branch of the 13 2 + state at 970 keV to the 9 2 + ground state has been measured. This decay is attributed to a proton single-particle i 13 2 → h 9 2 transition. The trend of excitation energies of a number of proton excitations in the odd-mass nuclei from 211At to 201At has been compared to the corepolarization model and the average ν f 5 2 −1 π f 7 2 interaction energy has been deduced. Comments are made upon probable configurations for many of the levels.