Experimental approach towards shell structure at 100Sn^{100}Sn and 78Ni^{78}Ni

The status of experimental approach to Sn-100 and Ni-78 is reviewed. Revised single particle energies for neutrons are deduced for the N=Z=50 shell closure and evidence for low lying I-pi=2(+) and 3(-) states is presented. Moderate E2 polarization charges of 0.1 e and 0.6 e are found to reproduce the experimental data when core excitation of Sn-100 is properly accounted for in the shell model. For the neutron rich Ni region no conclusive evidence for an N=40 subshell is found, whereas firm evidence for the persistence of the N=50 shell at Ni-78 is inferred from the existence of seniority isomers. The disappearance of this isomerism in the mid nug(9/2) shell is discussed

Beta decay of medium and high spin isomers in 94Ag^{94}Ag

Abstract The very neutron-deficient isotope 94 Ag was produced at the GSI on-line mass separator by using the reaction 58 Ni( 40 Ca, p3n). The β -decay properties of 94 Ag were studied by detecting for the first time β -delayed γ rays and β – γ – γ coincidences. Both the population of excited levels in the daughter nucleus 94 Pd and the β -decay half-life of 94 Ag were investigated. The major part of the feeding was assigned to the decay of an I π =(7 + ) isomer with a half-life of (0.36±0.03) s. A weak β -decay branch was found to populate high-spin levels in the 94 Pd daughter with I ⩾18. It is tentatively assigned to the decay of a high-spin parent state in 94 Ag with I ⩾17 and a half-life (0.3±0.2) s. The measured β -decay properties as well as the level structure of 94 Ag and 94 Pd are discussed in comparison with shell-model predictions

N = 40 Neutron Subshell Closure in the 68 Ni Nucleus

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Deep-inelastic reactions - A new tool for nuclear spectroscopy

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First measurement of β-decay properties of the proton drip-line nucleus 60Ga^{60}Ga

By using the fusion-evaporation reaction $^{28}$Si($^{36}$Ar,p3n) and spectroscopy of $\beta$-delayed $\gamma$-rays and charged particles on mass-separated sources, $\beta$-decay properties of the neutron-deficient isotope $^{60}$Ga were studied for the first time. The half-life of $^{60}$Ga was determined to be 70(15) ms, and, based on $\beta\gamma\gamma$ coincidences, the isobaric-analogue state in $^{60}$Zn was identified at 4851.9(7) keV. A semiempirical proton separation energy value of 40(70) keV was deduced for $^{60}$Ga. The experimental results on half-life, mass excess, proton separation energy, and structure of the $^{60}$Zn daughter states are discussed in comparison with various model predictions, including large-scale shell model calculations

Magnetic Rotation in the 105Sn nucleus

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