1. Low-energy enhancement and fluctuations of γ-ray strength functions in 56,57Fe: test of the Brink–Axel hypothesis.
- Author
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A C Larsen, M Guttormsen, N Blasi, A Bracco, F Camera, L Crespo Campo, T K Eriksen, A Görgen, T W Hagen, V W Ingeberg, B V Kheswa, S Leoni, J E Midtbø, B Million, H T Nyhus, T Renstrøm, S J Rose, I E Ruud, S Siem, and T G Tornyi
- Subjects
ENERGY level densities ,IRON isotopes ,FLUCTUATIONS (Physics) ,STRENGTH of materials ,PROTONS ,ANGULAR distribution (Nuclear physics) - Abstract
Nuclear level densities and γ-ray strength functions of
56,57 Fe have been extracted from proton-γ coincidences. A low-energy enhancement in the γ-ray strength functions up to a factor of 30 over common theoretical E1 models is confirmed. Angular distributions of the low-energy enhancement in57 Fe indicate its dipole nature, in agreement with findings for56 Fe. The high statistics and the excellent energy resolution of the large-volume LaBr3 (Ce) detectors allowed for a thorough analysis of γ strength as function of excitation energy. Taking into account the presence of strong Porter–Thomas fluctuations, there is no indication of any significant excitation energy dependence in the γ-ray strength function, in support of the generalized Brink–Axel hypothesis. [ABSTRACT FROM AUTHOR]- Published
- 2017
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