Synthesis of heavy and superheavy elements is severely hindered by fission and fission-like processes. The probability of these fission-like, non-equilibrium processes strongly depends on the entrance channel parameters. This article attempts to summarize the recent experimental findings and classify the signatures of these non-equilibrium processes based on macroscopic variables. The importance of the sticking time of the dinuclear complex with respect to the equilibration times of various degrees of freedom is emphasized.

An overview of the experimental result on simultaneous measurement of pre-scission neutron, proton, 𝛼-particle and GDR 𝛾-ray multiplicities for the reaction ²⁸Si+¹⁷⁵Lu at 159 MeV using the BARC–TIFR Pelletron–LINAC accelerator facility is given. The data were analysed using deformation-dependent particle transmission coefficients, binding energies and level densities which are incorporated in the code JOANNE2 to extract fission time-scales and mean deformation of the saddle-to-scission emitter. The neutron, light charged particle and GDR 𝛾-ray multiplicity data could be explained consistently. The emission of neutrons seems to be favoured towards larger deformation as compared to charged particles. The pre-saddle time-scale is deduced as (0–2) × 10⁻²¹ s whereas the saddle-to-scission time-scale is (36–39) × 10⁻²¹ s. The total fission time-scale is deduced as (36–41) × 10⁻²¹ s.