The decay chain162Yb (19·0 min) →162Tm (21·8 min) →162Er and the decay of160Tm (9·2 min) TO160Er

The decay of¹⁶²Yb,¹⁶²Tm and¹⁶⁰Tm has been investigated with Ge(Li) and Si(Li) detectors using isotopically separated samples produced by the YASNAPP facility at Dubna. The singles γ-ray spectrum, β-γ and γ-γ coincidences were measured. Strong ytterbium and thulium activities were used for conversion electron measurements with high resolution magnetic β-spectrographs. 3, 134 and 39 new γ-rays were attributed to the decays of¹⁶²Yb,¹⁶²Tm and¹⁶⁰Tm, respectively. Decay schemes of these isotopes are proposed. Three and 12 new levels were found in¹⁶²Er and¹⁶⁰Er, respectively. TheQ-values of¹⁶²Yb,¹⁶²Tm and¹⁶⁰Tm were determined to be ≦2·2, MeV, 4·6±0·3 MeV and 4·9±0·5 MeV, respectively.