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Mass and energy distributions of binary reaction products obtained in the reactions 22Ne+249Cf,26Mg+248Cm,36S+238U and 58Fe+208Pb leading to Hs isotopes have been measured. At energies below the Coulomb barrier the bimodal fission of Hs*, formed in the reaction 26Mg+248Cm, is observed. In the reaction 36S+238U the considerable part of the symmetric fragments arises from the quasifission process. At energies above the Coulomb barrier the symmetric fragments originate mainly from fusion-fission process for both reactions with Mg and S ions. In the case of the 58Fe+208Pb reaction the quasifission process dominates at all measured energies. The pre- and post-scission neutron multiplicities as a function of the fragment mass have been obtained for the reactions studied.

Mass-energy distributions, as well as capture cross-section of fission-like fragments for the reactions {sup 64}Ni+{sup 238}U and {sup 58}Fe+{sup 244}Pu leading to the formation of superheavy compound system with Z = 120 and N 182 at energies near the Coulomb barrier have been measured. Fusion-fission cross sections were estimated from the analysis of mass and total kinetic energy distributions. It was found that the fusion probability is about one order of magnitude higher for the reaction {sup 58}Fe+{sup 244}Pu than that for the reaction with {sup 64}Ni-ions.

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.

We are carrying out a research program with the 8πLP apparatus at the Laboratori Nazionali di Legnaro (Italy), aimed at studying fission dynamics in systems of intermediate fissility. These systems, compared to the heavier ones, are characterized by larger pre‐scission charged particle multiplicities as well as by comparable fission and evaporation residue cross sections. Therefore, the measurement of observables in both channels allows putting severe constraints on the models, in order to obtain more reliable information on the dynamics of the process. We present the results for the composite system 122Ce, produced at Ex = 122 MeV in 200 MeV 32S+100Mo reaction. The comparison of the data with the predictions of a dynamical model, based on 3‐D Langevin equations, indicates that full one‐body dissipation plays a dominant role in the fission process, with a viscosity parameter independent from the temperature and a fission delay of ∼25*10−21 s.

Systems of intermediate fissility are characterized by an evaporation residues cross section comparable or larger than the fission cross section, and by a relatively higher probability for charged particle emission in the pre‐scission channel. In a theoretical framework in which time scale estimates of the fission process rely on statistical model calculations, the analysis of particle emission in the evaporation residues channel is the source of additional constraints on the statistical and dynamical models. This contribution will focus on our statistical and dynamical analysis of a more complete set of data from the system 32S+100Mo at ELab = 200 MeV. Statistical model fails in reproducing the whole set of data and no convincing estimate is possible of the fission time scale. In particular, while pre‐scission multiplicities can be reproduced without delay, the model strongly overestimates proton and alpha particle multiplicities in the evaporation residues channel irrespective of the statistical model input parameters and prescriptions used for the level density and the transmission coefficients. The analysis of the same set of data with a three‐dimensional Langevin dynamical model produces a very good agreement with the full set of data and indicates that one‐body dissipation plays a dominant role in the fission process, implying a fission delay 23–25×10−21 s.

Mass and energy distributions of fission and quasifission fragments in the reactions 22Ne+249Cf, 26Mg+248Cm, 36S+238U and 58Fe+208Pb leading to the formation of the Z = 108 composite nucleus are reported. In this series of experiments it is shown for the first time that the quasifission process leads to the formation of not only asymmetric fragments but also gives a contribution to the symmetric mass region of fission fragments, most probably caused by the influence of nuclear shells with Z = 50 and N = 82.

Mass and energy distributions of fission fragments for spontaneous and low energy fission of nuclei with Z = 98–112 are discussed. The dependence of fragment characteristics (symmetric and asymmetric mass, low and high kinetic energy, bimodal) on nucleon composition of the compound nucleus and on the structure of fission fragments is investigated.

The CLARA-PRISMA setup is a powerful tool for spectroscopic studies of neutron-rich nuclei produced in multi-nucleon transfer and deep-inelastic reactions. It combines the large acceptance spectrometer PRISMA with the gamma-ray array CLARA. At present, the ancillary heavy-ion detector DANTE, based on Micro-Channel Plates to be installed at the CLARA-PRISMA setup, is being constructed at LNL. DANTE will open the possibility of measuring gamma-gamma-Doppler-corrected coincidences for the events outside the acceptance of PRISMA. In this presentation, it is described the heavy-ion detector DANTE, as well as the performances of the first prototype.

Results of the experiments aimed at the study of fission and quasi‐fission processes in the reactions 12C+204Pb, 48Ca+144,154Sm, 168Er, 208Pb, 238U, 244Pu, 248Cm; 58Fe+208Pb, 244Pu, 248Cm, and 64Ni+186W, 242Pu are presented. The choice of the above‐mentioned reactions was inspired by the experiments on the production of the isotopes 283112, 289114 and 283116 at Dubna using the same reactions. The 58Fe and 64Ni projectiles were chosen since the corresponding projectile‐target combinations lead to the synthesis of even heavier elements. The experiments were carried out at the U‐400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Russia), the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy) and the Accelerator of the Laboratory of University of Jyvaskyla (JYFL, Finland) using the time‐of‐flight spectrometer of fission fragments CORSET and the neutron multi‐detector DEMON. The role of shell effects and the influence of the entrance channel asymmetry and the deformatio...

The fusion-fission reactions {sup 22}Ne + {sup 248}Cm and {sup 22}Ne + {sup 249}Cf were investigated at projectile energies equal to 102 and 127 MeV. Mass-energy distributions and yields are shown. Two-dimensional plots of TKE vs fragment mass are also shown for {sup 48}Ca reactions at 230 MeV with {sup 208}Pb and {sup 238}U, leading to {sup 256}No and {sup 286}112.

The cross section and angular distributions of fission fragments have been measured for the compound nucleus {sup 224}Th produced in the reaction {sup 16}O+{sup 208}Pb at four energy values in the range from 5 to 15 MeV below the fusion barrier calculated in terms of the Bass model. The performed measurements allowed one for the first time to obtain data for the region of interaction of heavy ions with nuclei characterized by the cross section being by 8 orders of magnitude lower than the geometric cross section. It can be seen that at the energy of oxygen ions of up to E{sub lab}{