Nalazite se na CroRIS probnoj okolini. Ovdje evidentirani podaci neće biti pohranjeni u Informacijskom sustavu znanosti RH. Ako je ovo greška, CroRIS produkcijskoj okolini moguće je pristupi putem poveznice www.croris.hr
izvor podataka: crosbi !

Constraints on the dipole photon strength for the odd uranium isotopes (CROSBI ID 306451)

Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija

(n_TOF Collaboration) Moreno-Soto, J. ; ... ; Bosnar, Damir ; ... ; Žugec, Petar Constraints on the dipole photon strength for the odd uranium isotopes // Physical review. C, 105 (2022), 024618, 14. doi: 10.1103/PhysRevC.105.024618

Podaci o odgovornosti

Moreno-Soto, J. ; ... ; Bosnar, Damir ; ... ; Žugec, Petar

n_TOF Collaboration

engleski

Constraints on the dipole photon strength for the odd uranium isotopes

Background: The photon strength functions (PSFs) and nuclear level density (NLD) are key ingredients for calculation of the photon interaction with nuclei, in particular the reaction cross sections. These cross sections are important especially in nuclear astrophysics and in the development of advanced nuclear technologies. Purpose: The role of the scissors mode in the M1 PSF of (well-deformed) actinides was investigated by several experimental techniques. The analyses of different experiments result in significant differences, especially on the strength of the mode. The shape of the low-energy tail of the giant electric dipole resonance is uncertain as well. In particular, some works proposed a presence of the E1 pygmy resonance just above 7 MeV. Because of these inconsistencies additional information on PSFs in this region is of great interest. Methods: The γ-ray spectra from neutron-capture reactions on the 234U, 236U, and 238U nuclei have been measured with the total absorption calorimeter of the n_TOF facility at CERN. The background-corrected sum-energy and multi-step-cascade spectra were extracted for several isolated s-wave resonances up to about 140 eV. Results: The experimental spectra were compared to statistical model predictions coming from a large selection of models of photon strength functions and nuclear level density. No combination of PSF and NLD models from literature is able to globally describe our spectra. After extensive search we were able to find model combinations with modified generalized Lorentzian (MGLO) E1 PSF, which match the experimental spectra as well as the total radiative widths. Conclusions: The constant temperature energy dependence is favored for a NLD. The tail of giant electric dipole resonance is well described by the MGLO model of the E1 PSF with no hint of pygmy resonance. The M1 PSF must contain a very strong, relatively wide, and likely double-resonance scissors mode. The mode is responsible for about a half of the total radiative width of neutron resonances and significantly affects the radiative cross section.

uranium isotopes, dipole photon strength, n_TOF

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

Podaci o izdanju

105

2022.

024618

14

objavljeno

2469-9985

2469-9993

10.1103/PhysRevC.105.024618

Povezanost rada

Fizika

Poveznice
Indeksiranost