Restricted spin-range correction in the Oslo Method: The example of nuclear level density and $\gamma$-ray strength function from $^{239}\mathrm{Pu}(\mathrm{d,p}\gamma)^{240}\mathrm{Pu}$
Nuclear Experiment2020-12-09v2Data Analysis, Statistics and Probability
The Oslo Method has been applied to particle-γ coincidences following the 239Pu(d,p) reaction to obtain the nuclear level density (NLD) and γ-ray strength function (γSF) of 240Pu. The experiment was conducted with a 12 MeV deuteron beam at the Oslo Cyclotron Laboratory. The low spin transfer of this reaction leads to a spin-parity mismatch between populated and intrinsic levels. This is a challenge for the Oslo Method as it can have a significant impact on the extracted NLD and γSF. We have developed an iterative approach to ensure consistent results even for cases with a large spin-parity mismatch, in which we couple Green's Function Transfer calculations of the spin-parity dependent population cross-section to the nuclear decay code RAINIER. The resulting γSF shows a pronounced enhancement between 2-4 MeV that is consistent with the location of the low-energy orbital M1 scissors mode.
Cite
@article{arxiv.1904.02932,
title = {Restricted spin-range correction in the Oslo Method: The example of nuclear level density and $\gamma$-ray strength function from $^{239}\mathrm{Pu}(\mathrm{d,p}\gamma)^{240}\mathrm{Pu}$},
author = {F. Zeiser and G. M. Tveten and G. Potel and A. C. Larsen and M. Guttormsen and T. A. Laplace and S. Siem and D. L. Bleuel and B. L. Goldblum and L. A. Bernstein and F. L. Bello Garrote and L. Crespo Campo and T. K. Eriksen and A. Görgen and K. Hadynska-Klek and V. W. Ingeberg and J. E. Midtbø and E. Sahin and T. Tornyi and A. Voinov and M. Wiedeking and J. Wilson},
journal= {arXiv preprint arXiv:1904.02932},
year = {2020}
}