Collective effects on mass asymmetry in fission

The development of the mass asymmetry vibrations in the final stages of the fission process is studied with an approximate treatment of the coupling to relative motion. A parametrized friction is introduced and its effects are studied. Numerical results are presented for ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}$, together with estimates for the kinetic energy of the fragments.

RADIOACTIVITY, FISSION ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}$; calculated mass distribution, kinetic energy distribution. Collective dynamics, shell correction method, cranking model.