IN-BEAM STUDY OF SN-109

In-beam spectroscopic investigations of Sn-109 have been performed using the reactions Mn-55(Ni-58, 3pn) and Cd-106(alpha, n) with E(58Ni) = 240 MeV and E(alpha) = 23 MeV, respectively. An extended level scheme of Sn-109 is presented showing high-spin states up to E(x) approximate to 8 MeV with J(pi) = (41/2(+)). The problem of the Sn-109 ground state has been solved identifying a 12.8 keV transition deexciting the 7/2(+) state to the 5/2(+) g.s. A half-life of T-1/2 = 7(1) ns has been measured for the 17/2(+) state at E(x) = 2114 keV. The experimental data are compared with the predictions of shell-model calculations.