Level sructure in 206At
X.C. Feng1 - Y.X. Guo1 - X.H. Zhou1 - X.F. Sun1 - X.G. Lei1 - W.X. Huang1 - J.J. He1 - Z. Liu1 - Y.H. Zhang1 - S.F. Zhu1 - Y.X. Luo1 - S.X. Wen2 - G.J. Yuan2 - X.G. Wu2
1 Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73000, P.R.
2 China Insitute of Atomic Energy, Beijing 102413, P.R. China
Receieved: 13 September 1999 Communicated by B. Povh
The high-spin states of 206At have been studied in the reaction 197 Au (12C, 3n) 206At at 12C energies from 60 to 80 MeV. In-beam measurements of -ray excitation functions, --t coincidences, and -ray angular distributions were carried out with seven BGO(AC)HPGe detectors and one intrinsic Ge planar detector. A level scheme for 206At with 25 rays was established for the first time, including a 10- isomer with a measured half-life of 410 80 ns. The level scheme of 206At consists of two disconnected cascades, probably corresponding to the proton excitations and the neutron-hole excitations, respectively.
23.20.Lv Gamma transition and level energies - 27.80.+w