According to the scission-point model, the probability for a particular fission event can be expressed in terms of the collective potential and the collective kinetic energy at the scission point. Two additional assumptions make the scission-point model an easily calculable model: the assumption of equal collective kinetic energies for constant distances d between the tips of the fragments, and the assumption that one is able to characterize the excitation energy of the fragments with a nuclear temperature T, independent of both the mass ratio and the charge ratio, and of the deformations of the fragments. It is pointed out that the latter assumption violates energy conservation. A modified, recursive procedure is proposed, resulting in an "energy conservation consistent" scission-point method. Mass and charge distributions for the fission of 235U and 252Cf compound systems have been calculated and compared with distributions following the "standard" scission-point method of Wilkins, Steinberg, and Chasman.
NUCLEAR REACTIONS Scission-point model. Collective potential and intrinsic excitation energy. Nuclear temperature T. Mass and charge distributions. Fission of 235U and 252C.