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arXiv · 0806.4489

Evolution of the N=50 shell gap energy towards $^{78}$Ni

J. Hakala·S. Rahaman·V. -V. Elomaa·T. Eronen·U. Hager·A. Jokinen·A. Kankainen·I. D. Moore·H. Penttilä·S. Rinta-Antila·J. Rissanen·A. Saastamoinen·T. Sonoda·C. Weber·J. Äystö
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Abstract

Atomic masses of the neutron-rich isotopes $^{76-80}$Zn, $^{78-83}$Ga, $^{80-85}Ge, $^{81-87}$As and $^{84-89}$Se have been measured with high precision using the Penning trap mass spectrometer JYFLTRAP at the IGISOL facility. The masses of $^{82,83}$Ga, $^{83-85}$Ge, $^{84-87}$As and $^{89}$Se were measured for the first time. These new data represent a major improvement in the knowledge of the masses in this neutron-rich region. Two-neutron separation energies provide evidence for the reduction of the N=50 shell gap energy towards germanium Z=32 and a subsequent increase at gallium (Z=31). The data are compared with a number of theoretical models. An indication of the persistent rigidity of the shell gap towards nickel (Z=28) is obtained.

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J. Hakala, S. Rahaman, V. -V. Elomaa, T. Eronen, U. Hager, A. Jokinen, A. Kankainen, I. D. Moore, H. Penttilä, S. Rinta-Antila, J. Rissanen, A. Saastamoinen, T. Sonoda, C. Weber, J. Äystö. 2008-06-27. Evolution of the N=50 shell gap energy towards $^{78}$Ni. https://doi.org/10.1103/physrevlett.101.052502

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