- For cold (neutronless) fission we consider an analytical model of quantum tunneling with dissipation through a barrier U(q) evaluated with a M3Y nucleon-nucleon force. We calculate the tunneling spectrum, i.e., the fission rate as a function of the total kinetic energy of the fragments. The theoretical results are compared with the experimental data obtained for the fine structure of two cold fission modes of 252Cf: 148Ba+104Mo and 146Ba+106Mo. Taking into account the dissipative coupling of the potential function U(q) and of the momentum p with all the other neglected coordinates, we obtain a remarkable agreement with the experimental data. We conclude that the cold fission process is a spontaneous decay with a spectrum determined by the shape of the barrier and an amplitude depending on the strength of the dissipative coupling.
