https://doi.org/10.1051/epjconf/201612201009
Inversion of the Odd-Even Effect in Cold Fission from the Time-Dependent Pairing Equations
Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O. Box MG-G, Bucharest, Romania
a e-mail: mirea@ifin.nipne.ro
Published online: 21 June 2016
A peculiar phenomenon was observed experimentally in cold fission: the odd partition yields are favored over the even ones for excitations energies of the fragments smaller than 4 MeV. In this contribution, a microscopic model is proposed for the explanation of this odd-even effect in cold fission. This explanation is based on a mixing configuration mechanism that is produced during the fission process. This configuration mixing mechanism is obtained dynamically by solving a the generalized system of time-dependent pairing equations, which include a pair-breaking effect. The time dependent equations of motion for the pair breaking effect were corroborated with a condition that fixes dynamically the number of particles on the two fission fragment. The single particle level scheme was calculated with the Woods-Saxon superasymmetric two center shell model, providing a continuous variation of the single particle energies and of the wave functions from one nucleus up to two separated fragments. A first rule can be extracted from this model. The even-even fission products cannot be obtained at zero excitation energies because of the existence of dynamical excitations produced in the avoided- level-crossing regions when the nuclear system deforms slowly.
© The Authors, published by EDP Sciences, 2016
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