Decay studies of 215-217Th using ER-γ-α-γ coincidences

The decay of Th215-217 was investigated by ER-gamma-alpha-gamma coincidence measurements. The nuclei were produced by the reaction Er-170(Ti-50, xn)Th220-x. Evaporation residues recoiling out of the target were separated in flight by the velocity filter SHIP and stopped in a position-sensitive 16-strip PIPS-detector in order to study their subsequent decays. Associated gamma-rays were detected by a fourfold Ge-Clover detector. In the present work we extracted new and improved data for Th215-217 including isomeric decays. The results are discussed and compared to previously published data.