Nuclear level densities and γ-ray strength functions of 56,57Fe 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 in 57Fe indicate its dipole nature, in agreement with findings for 56Fe. 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.
Low-energy enhancement and fluctuations of γ-ray strength functions in 56,57Fe : test of the Brink-Axel hypothesis / A.C. Larsen, M. Guttormsen, N. Blasi, A. Bracco, F. Camera, L.C. 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, T.G. Tornyi, G.M. Tveten, A.V. Voinov, M. Wiedeking, F. Zeiser. - In: JOURNAL OF PHYSICS. G, NUCLEAR AND PARTICLE PHYSICS. - ISSN 0954-3899. - 44:6(2017), pp. 064005.1-064005.28.
Low-energy enhancement and fluctuations of γ-ray strength functions in 56,57Fe : test of the Brink-Axel hypothesis
A. Bracco;F. Camera;S. Leoni;
2017
Abstract
Nuclear level densities and γ-ray strength functions of 56,57Fe 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 in 57Fe indicate its dipole nature, in agreement with findings for 56Fe. 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.
| File | Dimensione | Formato | |
|---|---|---|---|
|
JPG44-Larsen-2017-064005.pdf
accesso riservato
Tipologia:
Publisher's version/PDF
Dimensione
2.46 MB
Formato
Adobe PDF
|
2.46 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
