Effects of the Fission Fragments on the Angular Distribution of Scission Particles

We investigate the angular distribution of scission particles taking account of the effects of fission fragments. The time evolution of the wave function of the scission particle is obtained by integrating the time-dependent Schrödinger equation. The effects of the fission fragments are taken into account by means of the optical potentials. The angular distribution is strongly modified by the presence of the fragments. The attractive nuclear potential enhances the yield along the fragment axis for both neutrons and protons. For scission protons, the focusing effect due to the repulsive Coulomb field of the fragments is demonstrated. In the case of asymmetric fission, it is found that the heavy fragment has stronger effects.