Decay of 175Hf and 181Hf

Nuclear-physical properties of 175Hf and 181Hf produced by neutron irradiation of natural hafnium in the SM-3 nuclear reactor were studied. The X-ray and γ-ray spectra were measured with high-energy-resolution HPGe and Ge(Li) detectors. The half-lives T1/2 (days) were determined: 175Hf 71.9±1.3 and 181Hf 42.12±0.25. The relative intensities (rel. units) of the γ-ray lines (keV) of 181Hf are as follows: 133.03, 54.0±1.6; (136.28 + 136.86), 8.9±0.3; 345.919, 20.4±0.6; and 482.193, 100. The ratios of the intensities in the X-ray spectrum were measured: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$^{{175}} {Lu}K_{{\beta }_{1,3} } /^{175} {Lu}K_{{\beta }_{2} } = 3.96(12)$$ \end{document}, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$^{181} {Ta}K_{{\beta }_{{1,3}} } /^{181} {Ta}K_{{\beta }_{2} } = 3.72(11)$$ \end{document}, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$^{{175}} {Lu}K_{{\alpha }_1 } /^{175} {Lu}K_{{\alpha }_{2} } = 1.74(5)$$ \end{document}, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$^{181} {Ta}K_{{\alpha }_{1} } /^{181} {Ta}K_{{\alpha }_{2} } = 1.70(5)$$ \end{document}.