Speaker
Description
A good understanding of neutron scattering mechanisms and prediction capacity of associated
cross sections is crucial to many nuclear technologies, among which all kinds of reactors based on
fission process. For deformed nuclei, the computation of scattering observables for the elastic
channel and the first, low-lying excited states requires coupled channel calculations. Local,
phenomenological optical and macroscopic transition potentials are the most commonly used in
coupled channel analyses, and various microscopic approaches are being developed in order to
improve prediction power and theoretical understanding, like the Nuclear Structure Method [1] or
nuclear matter approaches [2]. Potentials obtained microscopically are nonlocal, and while there
exists methods to localize a potential that yield good results for elastic scattering [3] recent studies
[4] [5] [6] have emphasized the importance of treating explicitly this nonlocality, especially for
inelastic channels.
We have developed a code that can solve coupled channel equations with nonlocal microscopic
optical potentials, while treating the nonlocality with no approximation. We lead our study on 208Pb, with potentials derived from the Melbourne G-matrix and ground state and transition densities stemming from the Random Phase Approximation nuclear structure model. We consider 1 and 2- phonons excitations within the coupled channel framework. Extensive experimental data for both elastic and inelastic scattering of neutrons is available on 208Pb, and we use this target to validate our approach and investigate effects of nonlocality in the coupled channel framework before focusing on deformed nuclei.
[1] G. Blanchon, M. Dupuis, H. F. Arellano and N. Vinh Mau, "Microscopic positive-energy
potential based on the Gogny interaction," Physical Review C, vol. 91, no. 014612, 2015.
[2] H. F. Arellano et W. G. Love, «In-medium full-folding model approach to quasielastic (p,n)
charge-exchange reactions,» Phys. Rev. C, vol. 76, p. 014617, 2007.
[3] F. G. Perey et B. Buck, «A non-local potential model for the scattering of neutrons by nuclei,»
Nuclear Physics, vol. 32, pp. 353-380, 1962.
[4] A. Ross, L. J. Titus, F. M. Nunes, M. H. Mahzoon, W. H. Dickhoff et R. J. Charity, «Effects of
nonlocal potentials on (p,d) transfer reactions,» Phys. Rev. C, vol. 92, p. 044607, 2015.
[5] N. Keeley et R. S. Mackintosh, «Dynamic polarization potential and dynamical nonlocality in
nuclear potentials : Nucleon-nucleus potential,» Phys. Rev. C, vol. 90, p. 044602, 2014.
[6] L. Titus, F. Nunes and G. Potel, "Explicit inclusion of nonlocality in (d,p) transfer reactions,"
Physical Review C, vol. 93, no. 014604, 2016.
