Partition between the fission fragments of the excitation energy and of the neutron multiplicity at scission in low-energy fission

The partition between the light (L) and the heavy (H) fission fragments of the excitation energy available at scisssion is studied in the frame of the sudden approximation i.e., under the assumption that the neck rupture and the absorption of the neck pieces by the fragments happens infinitely fast. We are dealing with a sudden transition between two different nuclear configurations (a_i->a_f ) and we only need to know the two sets of neutron eigenstates involved. The accent in the present work is put on the dependence of this share of energy on the mass asymmetry AL/AH of the primary fission fragments during the low-energy fission of 236U. In particular, for every fragment mass A we estimate the scission neutron multiplicity nu_sc, the average energy cost for their release E_sci, the primary fragments’ excitation energy E_sc and the corresponding temperature Tsc. The results are analysed separately for each value of Omega (the projection of the angular momentum on the symmetry axis). As general trend, a decrease of E_sc (Tsc) and an increase of nu_sc (E_sci) with increasing A was observed.

CARJAN N.;  HAMBSCH Franz-Josef;  RIZEA M.;  SEROT Olivier; 

2012-07-19

AMER PHYSICAL SOC

JRC66255

0556-2813,   

http://link.aps.org/doi/10.1103/PhysRevC.85.044601,    https://publications.jrc.ec.europa.eu/repository/handle/JRC66255,   

10.1103/PhysRevC.85.044601,