Reaction studies with recoil separators at IUAC

Recoil separators have been very useful devices in the study of nuclear reactions and nuclear structure for decades. Trajectories of ions, produced in nuclear reactions, are manipulated by application of electric and magnetic fields. These devices are capable of separating reaction products of interest from dominant background events, which are then detected at the focal plane of the separator. Fusion between two massive nuclei is characterized by three stages, viz., capture of the system inside the barrier, formation of a compound nucleus (CN) and decay of the CN to a cold evaporation residue (ER). In very heavy systems, ER cross sections are severely inhibited because of separation of the reaction partners before formation of compound nuclei via fission-like processes and dominance of fission channels after formation of compound nuclei. In the light of synthesis of super-heavy elements, it is important to investigate the factors affecting ER formation probability. Such studies are quite challenging experimentally as the observables, originating from different stages of evolution of the di-nuclear system, have overlapping characteristics. A gas filled separator, like the HYRA, is suitable for measuring low ER cross sections. A systematic study of several heavy systems can shed light on the complex processes that follow collision between two heavy nuclei