SPECTROSCOPY OF I-123

The level scheme of I-123 has been studied by in-beam gamma-ray spectroscopy in the fusion evaporation reaction Sb-121(alpha,2ngamma)I-123. Gamma-gamma coincidences and gamma-ray angular distributions have been measured with large-volume high-resolution germanium detectors. The multipolarities and multipole mixing ratios have been determined for some of the transitions. Several new levels and transitions are observed and assigned to I-123. A revised decay scheme is presented showing new levels and transitions associated with various bands in I-123. The band structure of I-123 is discussed and interpreted in the light of theoretical predictions and evidence is presented for possible coexistence of different shapes in this nucleus.