Neutron emission in fission and quasi-fission of Hs

Mass and energy distributions of fission-like fragments obtained in the reactions 26Mg + 248Cm, 36S+ 238U and 58Fe + 208Pb leading to the formation of 266,274Hs are reported. From the analysis of TKE distributions for symmetric fragment it was found that at energies below the Coulomb barrier the bimodal fission of 274Hs, formed in the reaction 26Mg+ 248Cm, is observed, while in the reaction 36S+ 238U at these energies the main part of the symmetric fragments arises from the quasi-fission process. At energies above the Coulomb barrier the fusion-fission is a main process leading to the formation of symmetric fragment for the both reactions. In the case of 58Fe+ 208Pb reaction the quasi-fission process is the main reaction mechanism at all measured energies. The pre- and post-scission neutron multiplicities as a function of the fragment mass have been obtained for all studied reactions. © 2010 American Institute of Physics.SCOPUS: cp.p