Fast fission phenomena: A possible intermediate time scale between deep inelastic reactions and compound nucleus formation

The change of the FWHM of the mass distribution of the fission products as a function of angular momentum is interpreted as a signature for a mechanism which is intermediate between compound nucleus formation and deep inelastic reactions. An intermediate composite system is assumed to be formed during the reaction, which undergoes fission. This kind of mechanism can therefore be called fast fission phenomena. It is related to the existence of a long lifetime component in déep inelastic reactions. Within the framework of a simple statistical model a qualitative as well as a quantitative estimate is done for a particular system. The conditions under which such a mechanism can be observed are discussed.