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arXiv · 1402.6203

Level density and gamma-ray strength function in the odd-odd 238Np

Tamás Gábor Tornyi·Magne Guttormsen·Tomas Kvalheim Eriksen·Andreas Görgen·Francesca Giacoppo·Trine Wiborg Hagen·Attila Krasznahorkay·Ann-Cecilie Larsen·Therese Renstrøm·Sunniva Johanne Rose·Sunniva Siem·Gry Merete Tveten
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Abstract

The level density and gamma-ray strength function in the quasi-continuum of 238Np has been measured using the Oslo method. The level density function follows closely the constant-temperature level density formula and reaches 43 million levels per MeV at Sn = 5.488 MeV of excitation energy. The gamma-ray strength function displays a two-humped resonance at low-energy as also seen in previous investigations of Th, Pa and U isotopes. The structure is interpreted as the scissors resonance and has an average centroid of wSR = 2.26(5) MeV and a total strength of BSR = 10.8(12)m2N, which is in excellent agreement with sum-rule estimates. The scissors resonance is shown to have an impact on the 237Np(n; g)238Np cross section.

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Tamás Gábor Tornyi, Magne Guttormsen, Tomas Kvalheim Eriksen, Andreas Görgen, Francesca Giacoppo, Trine Wiborg Hagen, Attila Krasznahorkay, Ann-Cecilie Larsen, Therese Renstrøm, Sunniva Johanne Rose, Sunniva Siem, Gry Merete Tveten. 2014-02-25. Level density and gamma-ray strength function in the odd-odd 238Np. https://arxiv.org/abs/1402.6203

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