Structure ofBi209deduced from thePb208(t, 2nγ)reaction

Abstract
States in Bi209 were populated with the Pb208(t, 2n) reaction. Incident triton energies between 11 and 16 MeV were used. Gamma-ray excitation functions, angular distributions, and γγ-time coincidence spectra were measured. Approximately 50 newly-observed γ rays have been assigned to transitions in Bi209. Previously-unresolved doublets at Ex=2600, 3135, and 3154 keV have been identified. A new level at 3270 keV is reported, and the 3197-keV level is verified. Bi209 level energies are reported with an accuracy of 600 eV or less. A level scheme for Ex<4.14 MeV is presented, including spin-parity assignments. A new M1 transition between the 52+ and 32+ members of the πh923 septuplet is reported. The 19 levels belonging to the νg92p121, πh92 are identified.