Correlation between the pairing gap at scission and the fission-fragment mass yield
Résumé
The pairing correlations of neutrons in 236U deformed at maximum was studied as function of the mass asymmetry of the fission fragments. The renormalized BCS equations were used. The nuclear shapes involved were described by modified Cassini ovals. A strong dependence of the pairing gap Delta on the fission-fragment mass ratio AH/AL was found with a pronounced minimum at 1.5. This is in agreement with the most probable mass division measured in 235U(nth,f). Since the lowest value of Delta corresponds to the most stable configuration, we offer a simple explanation of mass asymmetry in low-energy nuclear fission.