## Recent progress on Los Alamos nuclear structure, reaction and fission models

### NS2018 East Lansing, MI

Invited presentation on 08/2018

Atomic nuclei are one of the most multifaceted systems in the universe. The approach of studying these complex systems through the use of global nuclear models has been a cornerstone of LANL and proven insightful to a wide variety of applications. We report on recent progress made by combining nuclear structure calculations, e.g. from Quasi-particle Random Phase Approximation (QRPA), using the Finite-Range Droplet Model (FRDM) with statistical Hauser-Feshbach (HF). The QRPA+HF approach allows for the description of gamma-ray competition at each stage of particle emission. We apply this model to neutron-rich nuclei which yields branching ratios for beta-delayed neutron emission and beta-delayed fission. We further explore a low energy M1 scissors mode correlated to nuclear deformation and show how this improves the match between theoretical calculations and evaluated data. Finally, we report on fission model advances and comment on the potential impact to astrophysical applications.

LA-UR-18-27612

### Related Publications

Year Authors Title (Click for more details) Journal (PDF)
2019 M. Mumpower, T. Kawano, P. Möller $\beta^{-}$-delayed fission in the coupled Quasi-particle Random Phase Approximation plus Hauser-Feshbach approach to be submitted
2018 M. Mumpower, T. Kawano, T. M. Sprouse, N. Vassh, et al. $\beta$-delayed fission in $r$-process nucleosynthesis ApJ 869 1
2017 M. Mumpower, T. Kawano, J. L. Ullmann, M. Krticka, et al. Estimation of M1 scissors mode strength for deformed nuclei in the medium to heavy mass region by statistical Hauser-Feshbach model calculations PRC 96 024612
2016 M. Mumpower, T. Kawano, P. Möller Neutron-gamma competition for $\beta$-delayed neutron emission PRC 94 064317

## Mail

Matthew Mumpower
Los Alamos National Lab
MS B283
TA-3 Bldg 123
Los Alamos, NM 87544