Decay of Hf172

The internal conversion spectrum of Hf¹⁷² was examined with an intermediate image magnetic spectrometer. The gamma-ray spectrum and gamma-gamma coincidence spectrum were studied by means of scintillation spectrometers. The half-life of the 65·9 keV excited level in Lu¹⁷² was found to beT _1/2 = (3·32±0·20) × 10^–7 sec. The proposed decay scheme is discussed.On the same apparatus the half-life of the 206·25 keV excited level in Re¹⁸⁷ was measured and the result isT _1/2 = (5·05±0·13) × 10^–7 sec.The authors wish to thank to Ing. Vobecký and Ing. Matalka for the separation of Hf and Z. Praáková for assistance in the numerical calculation.