Fission Fragment Properties from a Microscopic Approach

Abstract

We calculate potential energy surfaces in the elongation-asymmetry plane, up to very large deformations, with the Hartree-Fock-Bogoliubov method and the Gogny nucleon-nucleon effective interaction DIS, for the ^^^Th and 256,258,260pj^ fissioning systems. We then define a criterion based on the nuclear density, in order to discriminate between pre-and postscission configurations. Using this criterion, many scission configurations are identified, and are used for the calculation of several fragment properties, like fragment deformations, deformation energies, energy partitioning, neutron binding energies at scission, charge polarization, total fragment kinetic energies and neutron multiplicities.

Shell effects in fission and quasi-fission reactions

“…The system may return to symmetric shapes (Q 30 = 0) for little additional cost in energy (dashed line), leading to symmetric elongated fragments. These results are in good agreement with theoretical predictions using other EDF (see, e.g., [25][26][27]), as well as with experimental observations indicating similar yields for both modes at low excitation energy [4; 5].…”

Pre-neutron-emission mass distributions for reaction 238 U(n, f) up to 60 MeV

“…Several important theories and models [2,[5][6][7][8][9][10][11][12][13][14][15][16][17] have been developed for understanding the fission mechanism or quantitatively calculating the fragment mass distributions or fission product yields. These models are mainly focused on the dynamical processes.…”