1. Constraining the nuclear spin distribution using improved 197Au neutron resonance parameters.
- Author
-
Koehler, P. E., Ullmann, J. L., Couture, A. J., and Mosby, S. M.
- Subjects
- *
NUCLEAR spin , *NEUTRON resonance , *ENERGY level densities , *NUCLEAR models , *NUCLIDES , *NEUTRON capture , *RADIOISOTOPES - Abstract
New neutron transmission data at resonance energies using a 197 Au sample were measured using an early version of the Device for Indirect Capture Experiments on Radionuclides (DICER), which is under development at the Los Alamos Neutron Science Center (LANSCE). These data were combined with previous neutron transmission and capture data in a simultaneous R-matrix analysis to extract improved neutron resonance parameters for this nuclide. As a result, total radiation widths, Γ γ , were obtained for 33 J = 1 and 44 J = 2 197 Au+n resonances. Γ γ distributions for these two spins states were compared to distributions calculated according to the nuclear statistical model using published nuclear level density (NLD) and photon strength functions (PSF) measured using the Oslo technique. The calculated distributions were found to be narrower and the average values for the two spins states closer together than the data. The calculation can be brought into agreement with the data by substantial modifications to the spin distribution in 198 Au as a function of excitation energy. As far as we know, the spin distribution currently is otherwise poorly constrained. The modified spin distribution changes the shapes of the NLD and PSF extracted using the Oslo technique and so could have broad implications. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF