New β-delayed proton precursor 142Ho was produced via heavy ion induced reaction 106Cd(40Ca, p3n), and identified for the first time by using a He-jet fast tape transport system in combination with 'p-γ' coi...New β-delayed proton precursor 142Ho was produced via heavy ion induced reaction 106Cd(40Ca, p3n), and identified for the first time by using a He-jet fast tape transport system in combination with 'p-γ' coincidence measurements. The β-delayed proton decay of 142Ho was observed and its half life was determined to be (0.4±0.1) s. By fitting the experimental relative branching ratios to final states in the proton daughter nucleus 141Tb and the energy spectrum of β-delayed protons with a statistical model calculation, the ground-state spin of 142Ho was assigned as 5, 6 or 7. Nuclear energy-potential-surface (EPS) calculations were performed using the Woods-Saxon Strutinsky method. The calculated results favored the assignments of 7- to 142Ho. AS the by-products, some γ-transitions in the proton daughter nuclei following the β-delayed proton decays of precursors 139Gd, 140Tb, 142Tb, and 143Dy were reported here for the first time.展开更多
基金the National Natural Science Foundation of China(Grant Nos.19975057 and 10005011)the Chinese Academy of Sciences,and the Major State Basic Research Development Program(Grant No.G2000077402).
文摘New β-delayed proton precursor 142Ho was produced via heavy ion induced reaction 106Cd(40Ca, p3n), and identified for the first time by using a He-jet fast tape transport system in combination with 'p-γ' coincidence measurements. The β-delayed proton decay of 142Ho was observed and its half life was determined to be (0.4±0.1) s. By fitting the experimental relative branching ratios to final states in the proton daughter nucleus 141Tb and the energy spectrum of β-delayed protons with a statistical model calculation, the ground-state spin of 142Ho was assigned as 5, 6 or 7. Nuclear energy-potential-surface (EPS) calculations were performed using the Woods-Saxon Strutinsky method. The calculated results favored the assignments of 7- to 142Ho. AS the by-products, some γ-transitions in the proton daughter nuclei following the β-delayed proton decays of precursors 139Gd, 140Tb, 142Tb, and 143Dy were reported here for the first time.
