Status | Confirmed |
Seminar Series | NUC-THEO |
Subjects | nucl-th |
Date | Thursday 26 July 2018 |
Time | 11:30 |
Institute | IPN |
Seminar Room | Bâtiment 100, Salle A015 |
Speaker's Last Name | Dupuis |
Speaker's First Name | Marc |
Speaker's Email Address | |
Speaker's Institution | CEA, DAM, DIF |
Title | Advances in microscopic modeling of (n,$x$n$\gamma$) reactions for actinides |
Abstract | Recent developments in nuclear structure approaches offer a great mean to improve various aspects of nuclear reaction modeling and to further understand reaction mechanisms from a microscopic point of view. Recently, direct and pre-compound nucleon emission, for nucleon induced reaction on spherical and axially deformed nuclei, have been successfully modeled [1] using a description of target states provided by fully consistent axially-symmetric deformed quasi-particle random-phase approximation (QRPA) calculations [2]. Direct inelastic scattering to target excitations built from one-phonon QRPA states accounted simultaneously for direct inelastic scattering to discrete states, and pre-equilibrium emission as far as second order processes, that involve more complex excitations such as two-phonon states, and multiple emission remain negligible. The QRPA nuclear structure approach has also been applied recently to determine, for a large pannel of even-even nuclei, E1 and M1 photon strength functions [3], that play a key-role in the modeling of statistical reactions.\\ We will review the status on the ongoing work on direct/pre-compound neutron emission for neutron induced reaction below 20~MeV for even-even actinides. Target states are described as rotational bands built from each state in the target intrinsic frame, described as QRPA one-phonon excitation of the intrinsic correlated ground state. QRPA excitations which display a collective character can thus be viewed as vibrational band heads. Couplings between states of the GS band and states belonging to an excited band are accounted for within a coupled channel framework. Our approach in then applied to the modeling of (n,n'$\gamma$) reactions and for both intra- and inter-band gamma transitions [4]. For these reactions, the role played by the present microscopic approach for direct/pre-equilibrium emission is discussed. We finally focus on the impact on the determination of (n,n'$\gamma$) cross sections of newly calculated QRPA E1- and M1-photon strength functions, that enter the description of statistical decay from compound nucleus states in the continuum.\\ [1] M. Dupuis, E. Bauge, S. Hilaire, F. Lechaftois, S. P\'eru, N. Pillet and C. Robin, Eur. Phys. J. A, 51 12 (2015) 168.\\[.1cm] [2] S. P\'eru,G. Gosselin, M. Martini, M. Dupuis, S. Hilaire, and J.-C. Devaux, Phys. Rev. C 014314 (2011).\\[.1cm] [3] S. Goriely, S. Hilaire, S. P\'eru, M. Martini, I. Deloncle, and F. Lechaftois Phys. Rev. C 94, 044306 (2016); M. Martini, S. P\'eru, S. Hilaire, S. Goriely, and F. Lechaftois, Phys. Rev. C 94, 014304 (2016).\\[.1cm] [4] M. Dupuis, S. Hilaire, S. P\'eru, E. Bauge, M. Kerveno, P. Dessagne and G. Henning EPJ Web Conf., 146 (2017) 12002. |
arXiv Preprint Number | |
Comments | $ $ |
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