Decay of 165m, gDy to Levels of 165Ho

Radio-active sources of 165 Dy and 165m Dy were produced by neutron irradiation and the decay was investigated. Forty gamma-rays were observed in the decay of 165 Dy with a Ge(Li) detector and a Ge(Li)-NaI(Tl) coincidence apparatus. New gamma-rays were detected at the energy of 178 and 339 keV in the coincidence spectra. Seven gamma-rays were seen in the decay of 165m Dy. A delayed and a prompt coincidence measurements with the 361.8 keV gamma-ray were performed to confirm cascade relations with this gamma-ray. Decay schemes of 165 Dy and 165m Dy were proposed on the basis of the present experimental results.