Excited states in Yb-168 from electron-capture decay of Lu-168(m) (T-1/2=6.7 min) - art. no. 024304

The electron-capture decay of the Lu-168(m) (T-1/2=6.7 min, J(pi)=3(+)) iso mer was studied with high purity sources, obtained by using a new radiochem ical method consisting of fast continous on-line separation of reaction pro ducts. A complex spectrum composed of about 200 gamma rays was observed. Fr om these, 162 transitions were assigned to a level scheme of 39 excited lev els of Yb-168, primarily by gamma-gamma coincidence spectroscopic measureme nts. About 60 transitions were placed for the first time and >90% of the de cay intensity was clearly identified. The structure of the levels directly fed by the electron-capture decay was reviewed as particle-hole excitations of the core. [S0556-2813(99)01308-4].