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t—The mass–energy distributions of fission fragments of excited 180,190Hg nuclei formed in 36Ar + 144,154Sm reactions are measured at incident 36Ar energies of 158, 181, and 222 MeV using the double-arm time-of-flight spectrometer CORSET. The asymmetric fission of 180,190Hg with the most probable masses of light and heavy fragments of 79 and 101 amu, and 84 and 106 amu, respectively, is observed in mass distributions of 180,190Hg at energies of excitation of up to 75 MeV. Two components manifesting the symmetric and asymmetric fission modes are observed in the kinetic energy distributions.

Charge equilibration is analyzed in the context of the dynamic approach based on the Langevin equations. The time and energy dependences of this process are discussed. Analysis of the isotopic distributions of the final products obtained in the 40Ca, 58Ni and 64Ni + 208Pb shows that charge equilibration process strongly affects the multinucleon transfer in them. Yields of the most neutron-rich heavy nuclides obtained in the 58Ni and 64Ni + 208Pb reactions are discussed.

The production of very neutron-rich nuclides heavier than fission fragments is an ongoing experimental challenge. Multi-nucleon transfer reactions (MNT) have been suggested as a method to produce these nuclides. By thermalizing the reaction products in gas-filled stopping cells, we can deliver them as cooled high-quality beams to decay, laser and mass spectrometry experiments. High precision mass spectrometry will allow for the first time to universally and unambiguously identify the atomic and proton numbers of the ions produced in MNT reactions. In this way their ground and isomeric state properties can be studied in high-precision measurements. In experiments at IGISOL, Finland and at FRS Ion Catcher, Germany, we have done and will perform broadband measurements of the reaction products, with the aim to improve the understanding of the reaction mechanism and to determine the properties of the ground and isomeric states of the produced nuclides. First results and preparations for upcoming experiments are presented.

The use of multi-nucleon transfer (MNT) reactions to produce neutron-rich nuclei in the heavy region has received an increased attention in the last decade. The feasibility of employing such reactions at the FRS Ion Catcher facility at GSI and the IGISOL facility at JYFL is studied using a combination of theoretical calculations and experiment simulations. The reactions are computed within a Langevin-type model, and the Geant program is used to simulate the transport of the resulting products within the experimental setups of the above-mentioned facilities. The angular distribution of ion release, possible target choices and target-to-beam-dump distances are discussed. peerReviewed

The formation of new isotopes of heavy and superheavy elements in the fusion of neutron-enriched projectiles with actinide targets is discussed. Cross sections for the formation of evaporation residues in fusion reactions is predicted for several combinations of colliding nuclei.

Energy, angle, and charge distributions of binary products of the deep inelastic collisions of heavy ions are studied in the framework of a multidimensional dynamical model of nucleus-nucleus collisions based on the Langevin equations. The model is verified on the example of the 136Xe + 209Bi system at several above barrier energies.

The paper describes the principles of organization and operation of the NRV web knowledge base on low-energy nuclear physics ( http://nrv.jinr.ru/ ) which integrates a large amount of digitized experimental data on the properties of nuclei and nuclear reaction cross sections with a wide range of computational programs for modeling of nuclear properties and various processes of nuclear dynamics which work directly in the browser of a remote user. The paper also gives an overview of the current situation in the field of application of network information technologies in nuclear physics. The features of the NRV knowledge base are illustrated in detail on the example of the analysis of nucleon transfer reactions within the distorted wave Born approximation.

An increasing interest in multinucleon transfer processes in low-energy deep inelastic (damped) collisions of heavy ions appeared in recent years is due, in part, to by the possibility of using them as a method of production of heavy neutron-enriched nuclei. Possible promising projectile-target combinations include nuclei deformed in the ground state (e.g., actinides). Mutual orientations of such the nuclei in the entrance channel of the reaction may significantly influence the reaction dynamics. Available experimental data on multinucleon transfer reactions with statically deformed as well as spherical heavy nuclei 144Sm + 144Sm, 154Sm + 154Sm, 160Gd + 186W, and 208Pb + 208Pb/238U have been analyzed within the developed model. A good agreement of the calculated quantities with the corresponding experimental data is reached. Special attention in the paper is paid to analysis of production possibility of the neutron-enriched isotopes of heavy and superheavy elements in multinucleon transfer processes in the 238U + 238U/248Cm/254Es collisions., 13 pages, 10 figures

Principles underlying the organization and operation of the NRV web knowledge base on low-energy nuclear physics (http://nrv.jinr.ru) are described. This base includes a vast body of digitized experimental data on the properties of nuclei and on cross sections for nuclear reactions that is combined with a wide set of interconnected computer programs for simulating complex nuclear dynamics, which work directly in the browser of a remote user. Also, the current situation in the realms of application of network information technologies in nuclear physics is surveyed. The potential of the NRV knowledge base is illustrated in detail by applying it to the example of an analysis of the fusion of nuclei that is followed by the decay of the excited compound nucleus formed.

Background: Low-energy multinucleon transfer reactions may be used for production of new neutron-enriched heavy nuclei.Purpose: Our aim is to investigate the influence of proton ($Z=82$) and neutron ($N=82$, 126) shells as well as orientation effects on the formation of reaction products in the inverse quasifission process in the reactions $^{156,160}\mathrm{Gd}+^{186}\mathrm{W}$.Methods: Mass, energy, and angular distributions of primary binary fragments formed in the reactions $^{156}\mathrm{Gd}+^{186}\mathrm{W}$ at an energy of 878 MeV, and $^{160}\mathrm{Gd}+^{186}\mathrm{W}$ at 860 and 935 MeV, have been measured using the double-arm time-of-flight spectrometer CORSET at the U400 cyclotron of the Flerov Laboratory of Nuclear Reactions (FLNR) at the Joint Institute for Nuclear Research (JINR), Dubna.Results: Enhancement in the yield of products with masses 200--215 u has been found for both reactions. The cross sections of the formation of trans-target fragments with masses around 208 u are found to be about 10 \ensuremath{\mu}b at the Coulomb barrier energy and reach the level of 0.5 mb at the energy above the barrier for side-to-side collision.Conclusions: The enhanced yield of products with masses heavier than the target mass confirms the important role of the closed shells at $Z=82$ and $N=82$, 126 in the inverse quasifission process in low-energy damped collisions. The orientation effect caused by the strong deformation of colliding nuclei can result in a gain in the yield of heavy target-like fragments.