Studies on the decay of 160Tb to levels in 160Dy by Ge (Li)-Ge(Li)-coincidence system

This work concerned with the study of the energy levels and the properties of gamma-ray transitions in 160Dy resulting from the B-decay of the parent radioactive isotope 160Tb (72 d.). These studies have been done by means of, single and gamma-gamma coincidence measurements. Log(ft). Internal Conversion Coefficient (ICC) values and the branching ratios have been calculated. The construction and testes of the Ge(Li)-Ge(Li) gamma-gamma coincidence spectrometer are presented. In addition to the previously reported transitions in three new transitions of energies 203, 420 and 1048 keV have been observed for the first time. The energy level at 1288.60 keV is confirmed, due to the presence of the 246 keV and 1005 keV gamma-ray transitions in the singles and gamma-gamma coincidence spectra. Furthermore the B-intensity feeding this level was calculated for the first time to be 0.08%. The log(ft) values of the energy level at 1288.6 keV was calculated for the first time to be 10.79. The energy level diagram of 160Dy as summerised in the present work consists of 12 excited states, the levels at 581(6+) and 1391 keV reported by some authors were not encluded, since no transitions populated or depopulated these levels could be observed