Evidences for Causal Decoupling between StatisticalProbability and Time Scale of Fission

摘要

Fission of highly excited nuclei is affected by the viscose character of the system motion in deformation coordinates as is reported for very heavy nuclei with Z ≥ 90. The long-time-scale fission was proved for such systems formed in heavy-ion induced reactions. The overdamped diabatic motion may influence also fission of the spallation-residue products in reactions with protons at intermediate energy. In the present work, the experimental results on blocking lifetime experiments are analyzed together with the independent data on fission-to-spallation ratios for medium-mass targets. Cross examination of the fission probability, time-scale, and pre-fission neutron multiplicity allows a new conclusion on fission mechanism. The novel approach is specified for estimate of the characteristic fission time and for the consistent interpretation of whole set of experimental results. The standard statistical approach fails for understanding of them without contradictions, though some partial data at restricted range of the encounter parameters could be described, as known from previous publications.