Level sructure in $^{206}$At

X.C. Feng; Y.X. Guo; X.H. Zhou; X.F. Sun; X.G. Lei; W.X. Huang; J.J. He; Z. Liu; Y.H. Zhang; S.F. Zhu; Y.X. Luo; S.X. Wen; G.J. Yuan; X.G. Wu

doi:doi:10.1007/s100500050339

EPJ

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. China
² China Insitute of Atomic Energy, Beijing 102413, P.R. China

Receieved: 13 September 1999 Communicated by B. Povh

Abstract
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 $\gamma$ -ray excitation functions, $\gamma$ - $\gamma$ -t coincidences, and $\gamma$ -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 $\gamma$ rays was established for the first time, including a 10^- isomer with a measured half-life of 410 $\pm$ 80 ns. The level scheme of ²⁰⁶At consists of two disconnected cascades, probably corresponding to the proton excitations and the neutron-hole excitations, respectively.

PACS
23.20.Lv Gamma transition and level energies - 27.80.+w $190 \leq A \leq 219$

Article contents