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In this paper we investigate the rotational band built upon a two-quasiparticle 8− isomeric state of 252No up to spin I π = 22−. The excited states of the band were populated with the 206Pb(48Ca, 2n) fusion-evaporation reaction. An unambiguous assignment of the structure of the 8− isomer as a 7/2+[624]ν ⊗ 9/2−[734]ν configuration has been made on the basis of purely experimental data. Comparisons with triaxial self-consistent Hartree-FockBogoliubov calculations using the D1S force and breaking time-reversal as well as z-signature symmetries are performed. These predictions are in agreement with present measurements. Mean-field calculations extended to similar states in 250Fm support the interpretation of the same two-neutron quasiparticle structure as the bandhead in both N = 150 isotones. peerReviewed

Mass, energy and folding angle distributions of the fission fragments as well as multiplicities of neutron and gamma‐quanta emissions accompanying the fission process were measured for fission of 226Th, 227Pa and 234Pu compound nuclei produced in reactions with 18O and 26Mg projectiles over a wide energy range. Data were analyzed with respect to the presence of fission modes. Asymmetric fission was observed even at very high initial excitation for all the measured systems. The so‐called fission mode S1 (caused by the proton shell Z∼50 and neutron shell N∼82 in heavy fragment) was found to be dominant in asymmetric fission of 234Pu. Reactions with not full linear momentum transfer were observed in the folding spectra for all the measured systems.

It has been proposed to associate the narrow (\Gamma=170 keV) and high spin ($J\pi$=36^+) resonance in the 24Mg + 24Mg reaction at E_c.m= 45.7 MeV with a hyperdeformed molecular state in 48Cr. Such a description has important consequences for the resonance decay into the favoured inelastic channels. Through fragment- coincidence measurements performed ON and OFF resonance using the PRISMA-CLARA array, we have established that the 24Mg states selectively populated are the 2^+ and 4^+ members of the ground state band.

The present work takes advantage of the multinucleon transfer mechanism between heavy reaction partners to study the population pattern of excited nuclear states in near spherical Zirconium isotopes following the 90Zr + 208Pb reaction at an energy closed to the Coulomb barrier. Both the projectile and the target are well known closed shell nuclei offering an optimum situation for clean experimental and theoretical conditions. Total kinetic energy loss (TKEL) distributions were compared with calculations performed with the GRAZING code. The ability to use the TKEL as a selection tool for the states at different excitation energies was shown.

The interest in the study of the fission process of superheavy nuclei mainly deals with the opportunity to obtain information about the cross-section of the compound nucleus (CN) formation at excitation energies E*\approx 15–30 MeV. It allows one to estimate the survival probability of the superheavy composite system after evaporation of 1–3 neutrons, i.e. in "cold" or "warm" fusion reactions. However, in order to solve this problem deeper understanding of the coalescence processes between colliding nuclei, the competition between fusion-fission and quasi-fission processes is needed. The characteristics of both processes, their manifestation in the experimental observables and the relative contribution to the capture cross-section in dependence on the excitation energies, reaction entrance channel etc were investigated for a wide range of target-projectile combinations. Results of the experiments devoted to the study of the fusion-fission and quasi-fission processes in the reactions of the formation of the superheavy nuclei with Z = 102–122 are presented. The heavy ions 26Mg, 48Ca, 50Ti, 58Fe and 64Ni were used as projectiles. The choice of the reactions with 48Ca and actinide-targets was inspired by the experiments on the production of the isotopes 283112, 289114 and 283116 in Dubna using the same reactions. The 50Ti, 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) and the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy) using the time-of-flight spectrometer of fission fragments CORSET. The role of the shell effects, the influence of the entrance channel asymmetry and the deformations of colliding nuclei on the mechanism of the fusion-fission and the competitive process of quasi-fission are discussed. The recent results on synthesis of superheavy nuclei and the perspectives of the "hot" fusion reaction for the production of superheavy nuclei are considered.

Since the discovery of the breakdown of shell effects in very neutron-rich N=20 and 28 nuclei, studies of the properties of nuclei far from stability have been of intense interest since they provide a unique opportunity to increase our understanding of nuclear interactions in extreme conditions and often challenge our theoretical models. Deep-inelastic processes can be used to populated high spin states of neutron-rich nuclei. In the deep-inelastic processes, an equilibration in N/Z between the target and projectile nuclei is achieved. For most heavy neutron-rich target nuclei, the N/Z ratio is 1.5 - 1.6, while for the possible neutron-rich sdf-shell projectile it is about 1.2. Thus by using deep-inelastic processes one can populate neutron-rich nuclei around N=20 and N=28. New results for the spectroscopy of neutron-rich N=22 ^36Si and ^37P are presented here.