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A new algorithm for the analog spectrometer of the DGFRS-2 setup installed at DC-280 cyclotron is presented. The main goal of application of this algorithm is to search an optimal time correlation recoilalpha parameter directly during the acquisition C++ code execution. A new real-time flexible algorithm in addition to the conventional ER − a algorithm, which has been used for a several years at the DGFRS-1 setup installed at the U-400 FLNR cyclotron, is presented. The main parts of the spectrometer are a 48×128 strip DSSD detector (Double Side Strip Detector) and a low-pressure gaseous detector. They are presented schematically. Nuclear reactions for synthesis of element Z=119 at the DGFRS-2 are under consideration. Some attention is paid to computer simulation of the heavy recoil spectra, taking into account its pulse height defect in silicon. First beam test results are also presented. A new formula for half-life time using recent data for superheavy nuclei is obtained.

The fascination with superheavy elements (SHE) spans the nuclear physics, astrophysics, and theoretical chemistry communities. Extreme relativistic effects govern these elements’ chemistry and challenge the traditional notion of the periodic law. The experimental quest for SHE critically depends on theoretical predictions of these elements’ properties, especially chemical homology, which allows for successful prototypical experiments with more readily available lighter homologues of SHE. This work is a comprehensive quantum-chemical investigation into astatine (At) as a non-intuitive homologue of element 113, nihonium (Nh). Combining relativistic coupled-cluster and density functional theory approaches, we model the behaviour of At and AtOH in thermochromatographic experiments on a pristine gold surface. Insights into the electronic structure of AtOH and NhOH and accurate estimates of At–gold and AtOH–gold adsorption energies rationalise recent experimental findings and justify the use of At as a chemical homologue of Nh for the successful design of future experiments on Nh detection and chemical characterisation. [ABSTRACT FROM AUTHOR]

The GRAND universal gas-filled separator, located at the Factory of Super-Heavy Elements in the Flerov Laboratory of Nuclear Reactions (FLNR), Joint Institute for Nuclear Research, has been created and put into operation. The separator can be used both in experiments on α, β, and γ spectroscopy of isotopes of heavy and superheavy elements and in experiments on the chemical properties of superheavy elements as a preseparator. The results of the first experimental tests of the GRAND separator are presented. The possibility of effectively carrying out experiments both on a "physical" detection system and on a "chemical" installation has been demonstrated. [ABSTRACT FROM AUTHOR]

An Erratum to this paper has been published: https://doi.org/10.1134/S1062873824010015 [ABSTRACT FROM AUTHOR]

The 20th century started with the realization that working together and collaborating expedites new discoveries. The Solvay Conference in 1911 brought together scientists to try to understand the real nature of matter, the new elements, and their properties. Through global conflicts, the scientists stayed in communication and organized IUPAC and IUPAP to stay current in advances internationally in chemistry and physics, respectively. The outcomes include the discovery and naming of the elements that complete the periodic table of elements and the chart of nuclides with the heavy atoms and all of their isotopes. Mary Lowe Good forged new directions in developing tools in the field of radiochemistry. She exemplified cooperation and collaboration nationally and internationally. Now the advances in the heavy elements by Yuri Ts. Oganessian and colleagues staying close to the principles of international cooperation and sharing the new information about the connection of the production of super heavy elements to the main part of the chart of nuclides. The future lies in determining whether there are more elements to be discovered and what are their chemical properties. [ABSTRACT FROM AUTHOR]

For further study of the physical and chemical properties of superheavy elements (SHE), the SHE Factory was created based on the DC-280 cyclotron. The first facility of the factory is a gas-filled separator DGFRS-2. The principle of operation, the main characteristics of the separator and the results of test experiments are presented and discussed. The simulation model of the separator based on the GEANT4 software package is described. Methods for determining the optimal settings of the separator are presented. [ABSTRACT FROM AUTHOR]

Experiments on the synthesis of isotopes of element 114 in the 242Pu + 48Ca reaction were carried out at a new gas-filled separator DGFRS-2 online to the DC-280 cyclotron of the Superheavy Element Factory at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research. The decay properties of 286Fl and 287Fl, as well as their α-decay products, were refined. The possibility of the existence of isomeric states in successive α-decays of 287Fl is discussed. The maximum cross section of pb was measured for the 242Pu(48Ca, 3n)287Fl reaction. [ABSTRACT FROM AUTHOR]

We presented the results of the series of experiments on the synthesis of Mc isotopes in the 243Am + 48Ca reaction performed at the new separator DGFRS-2 and cyclotron DC280 of the SHE Factory at FLNR JINR. There were registered 110 new 288Mc decay chains, 10 289Mc chains, and 4 287Mc chains. Alpha decay of 268Db with an energy of 7.6–8.0 MeV, half-life h and α-branch % was registered for the first time together with a new spontaneously fissioning isotope 264Lr with a half-life of h The measured cross section of the 243Am(48Ca, 3n)288Mc reaction was pb, which is the largest for known superheavy nuclei. A new isotope 286Mc was synthesized with a half-life of 20 ms and an α-particle energy of 10.71 ± 0.02 MeV. Spontaneous fission of 279Rg was first observed in one of the four new decay chains of 287Mc. The reaction excitation function was measured at six 48Ca energies in the range of 239–259 MeV, which led to the first observation of the 5n channel with a cross section of 0.5 pb. The decay properties of 20 previously known isotopes have been determined with higher accuracy. [ABSTRACT FROM AUTHOR]

Estimates for energies of the -states are obtained proceeding from the existing correlation of the deformation energy and the lowest excitation energy. The considered systematics of energy ratios in the rotational band also makes it possible to obtain estimates for the and states. Comparison with results of other works has been carried out. [ABSTRACT FROM AUTHOR]

The progresses on production cross-sections of unknown nuclei in fusion evaporation (FE) reactions and multinucleon transfer (MNT) reactions are reviewed. The synthesis of the superheavy nuclei (SHN) with Z = 1 1 4 , 119, 120, 121, and 122 in FE reactions is presented. As a promising pathway to produce neutron-rich nuclei, the MNT reactions near the Coulomb barrier are applied to investigate the generation of neutron-rich heavy nuclei and the transuranium nuclei. The predicted production cross-sections of unknown neutron-rich nuclei in MNT reactions are summarized. We make a comparison of the radioactive beam-induced FE reactions and MNT process for producing the predicted double magic nuclei 2 9 8 Fl, which provides a possible pathway to approach the island of stability. [ABSTRACT FROM AUTHOR]

New algorithms to operate with new analog spectrometer of the DGFRS-2 installed at DC-280 cyclotron setup are presented. The main goal of application of these algorithms is to search an optimal time correlation recoil-alpha parameter directly during the acquisition C++ code execution. A new real-time flexible algorithm is presented in addition to the conventional ER-α one which is in use for a few years at the DGFRS-1 setup installed at the U-400 FLNR cyclotron. Note that the spectrometer operates together with the 48 × 128 strip DSSD (Double Side Strip Detector; 48 × 226 mm2) detector and low pressure pentane-filled gaseous detector (1.2 Torr; 80 × 230 mm2) are presented schematically. First beam test results in 48Ca induced nuclear reactions are presented too. [ABSTRACT FROM AUTHOR]

Heavy ion fusion reactions are used in the synthesis of superheavy elements. Besides the right choice of entrance channel, selection of optimal beam energy for synthesis of superheavy elements plays a crucial role. A thorough investigation with the advanced statistical and the dinuclear system models on the experiments performed for the synthesis of the successful superheavy elements Z = 104 –118 and failed superheavy elements Z = 119 –120 leads us to infer that improper choice of the beam energies may be responsible for too low production cross sections to measure and thus the cause for the debacle. We have predicted the optimal beam energies to obtain the maximum evaporation residue cross sections for the reactions used for the superheavy elements Z = 104 –120. Hope an exploitation of these predictions may be on the cards soon to extend the periodic table for the eighth period. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Almost thirty years ago the criteria that are currently used to verify claims for the discovery of a new element were set down by the comprehensive work of a Transfermium Working Group, TWG, jointly established by IUPAC and IUPAP. The recent completion of the naming of the 118 elements in the first seven periods of the Periodic Table of the Elements was considered as an opportunity for a review of these criteria in the light of the experimental and theoretical advances in the field. In late 2016 the Unions decided to establish a new Joint Working Group, JWG, consisting of six members determined by the Unions. A first meeting of the JWG was in May 2017. One year later this report was finished. In a first part the works and conclusions of the TWG and the Joint Working Parties, JWP, deciding on the discovery of the now named elements are summarized. Possible experimental developments for production and identification of new elements beyond the presently known ones are estimated. Criteria and guidelines for establishing priority of discovery of these potential new elements are presented. Special emphasis is given to a description for the application of the criteria and the limits for their applicability. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Experimental works performed on the Dubna gas-filled magnetic recoil separator (GFS) to study the reactions of formation of 294Ts and 294Og nuclides and the properties of their radioactive decay are described. Future possibilities of synthesizing new elements with Z = 119 and Z = 120 and performing experiments to study the properties of heavier isotopes of known superheavy nuclei Lv (Z = 116), Ts (Z = 117), and Og (Z = 118) are discussed. [ABSTRACT FROM AUTHOR]

Methods for detecting rare α-decays of heavy nuclei lately implemented at JINR's Flerov Laboratory of Nuclear Reactions (FLNR) are reviewed. Particular attention is paid to developing the active-correlation technique and various algorithms for real-time searches for correlated subprocesses in the nucleosynthesis of superheavy elements. These are required for suppressing the background events generated by the JINR heavy-ion cyclotron. A novel flexible approach to the search for correlated events based on a probabilistic algorithm is proposed. A simple criterion for optimizing the procedure of radical background suppression in full-fusion reactions is formulated. The implementation of the approaches proposed in this paper is motivated by the ever-increasing intensities of heavy-ion beams. [ABSTRACT FROM AUTHOR]

Almost thirty years ago the criteria that are currently used to verify claims for the discovery of a new element were set down by the comprehensive work of a Transfermium Working Group, TWG, jointly established by IUPAC and IUPAP. The recent completion of the naming of the 118 elements in the first seven periods of the Periodic Table of the Elements was considered as an opportunity for a review of these criteria in the light of the experimental and theoretical advances in the field. In late 2016 the Unions decided to establish a new Joint Working Group, JWG, consisting of six members determined by the Unions. A first meeting of the JWG was in May 2017. One year later this report was finished. In a first part the works and conclusions of the TWG and the Joint Working Parties, JWP, deciding on the discovery of the now named elements are summarized. Possible experimental developments for production and identification of new elements beyond the presently known ones are estimated. Criteria and guidelines for establishing priority of discovery of these potential new elements are presented. Special emphasis is given to a description for the application of the criteria and the limits for their applicability. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Durability of targets and window foils irradiated by intense heavy ion (HI) beams in the experiments on synthesis of superheavy nuclei, which are carried out in Dubna with Gas-Filled Recoil Separator (DGFRS), has been viewed in various ways. High fluxes of HI and heat generations, which are realized within relatively small areas and thicknesses of these elements of DGFRS, are inherent in such experiments. The lifetimes of the targets and window foils are estimated as the result of HI beam actions such as radiation damages, sputtering and evaporation of atoms. The most critical processes determining the durability of the targets and window foils are discussed. The processes of heat transfer due to thermal conductivity, convection and radiation are also considered from the point of view of possible ways of cooling of the elements irradiated by an intense HI beam. Temperatures of the targets and window foils as functions of time are calculated in the conditions of their pulse heating by the beam followed by radiative cooling of their surfaces. Such pulsing mode is realized in the DGFRS operation with the rotation of target and window foils irradiated by a continuous HI beam. Estimates show that radiative cooling in such conditions can be the most effective way of heat removal at the temperature of several hundred degrees. Such temperature can be reached on the surfaces of the target and window foils irradiated by HI beams at the intensity ~10 s. [ABSTRACT FROM AUTHOR]

Spontaneous fission properties of transuranium isotopes are reviewed. Specific emphasis was laid on brief historical overviews of theoretical descriptions and experimental determination of basic properties as spontaneous fission half-lives, fission barriers, or total kinetic energy release in fission. Experimental spontaneous fission half-lives are compared with the results of recent theoretical predictions. Hindrance factors for spontaneous fission of odd-mass nuclei are discussed in context with the configuration (spin, parity) of the fissioning states and the change in energy of single particle levels at deformation. Kinetic energy release and mass distributions are discussed in the context of different fission modes, as symmetric and asymmetric or fission from elongated or compact shapes of the nascent fission fragments. An overview of recent fission barrier calculations of superheavy elements on the basis of macroscopic-microscopic models or self-consistent calculations is given, and the results are compared for selected examples. [ABSTRACT FROM AUTHOR]