FLNR Scientific Program 2020

Synthesis and Properties of Superheavy Elements, Structure of Nuclei at the Limits of Nucleon Stability

Leader:	M.G. Itkis
Scientific leader:	Yu.Ts. Oganessian

Participating Countries and International Organizations:

Belgium, Bulgaria, CERN, China, Czech Republic, Egypt, Finland, France, Germany, India, Italy, Japan, Kazakhstan, Mongolia, Poland, Republic of Korea, Romania, Russia, Slovakia, South Africa, Spain, Sweden, Switzerland, United Kingdom, USA, Ukraine, Vietnam.

Issues addressed and main goals of research:

Synthesis of nuclei at stability limits and the investigation of their properties. Investigation of the mechanisms of heavy-ioninduced reactions. Study of the physical and chemical properties of heavy and superheavy elements



Expected main results in the current year:

• Experiments on the synthesis of superheavy elements, study of their nuclear and chemical properties in the ⁴⁸Ca, ⁵⁰Ti + ²⁴³Am, ²⁴²Pu, ²⁴⁴Pu reactions at the SHE Factory.
• Preparation for experiments on the synthesis of elements 119 and 120 in complete fusion reactions with ⁵⁰Ti ions.
• Experiments on the study of the decay properties (α-, β-, γ-spectroscopy) of Sg isotopes and heavy isotopes of Rf formed in reactions with ⁵⁴Cr and ²²Ne using the SHELS+GABRIELA separator. Experiments on measuring the multiplicity of prompt neutrons from the spontaneous fission of heavy Rf isotopes in reactions with ²²Ne. Test experiment on the spectroscopy of the decay properties of ²⁸⁸Mc isotopes and its daughter products in the ⁴⁸Ca + ²⁴³Am reaction.
• Formation and decay of double/di-nuclear nuclear system formed in the ⁸⁶Kr + ²³²Th, ²³⁸U reactions. Study of the mass–energy and angular distribution of fragments produced in these reactions. Investigation of the mechanism of multinucleon transfer. Study of the multi-body decay of low-excited heavy nuclei. Study of the multicluster decay of heavy and superheavy nuclei. Development of physics set-ups.
• Study of nuclei with Z<20 close to the nucleon drip lines. Analysis of the experimental data on the investigation of the structure of the exotic nuclei ⁷H, ^7,9Не, ¹⁰Li, and ²⁷S synthesized earlier using radioactive beams at the ACCULINNA-2 fragment separator.
• Experiments at MAVR for studying fast charged particles in coincidence with recoil nuclei. The studies are aimed at determining the reaction mechanism for experiments on the synthesis of new elements. Study of the yield of multinucleon transfer reaction products. Measurement of total reaction cross sections using low-intensity beams of exotic nuclei.
• Analysis of experiments conducted at the MASHA set-up aimed at studying the operational stability of a new design of the hot catcher during the separation of short-lived mercury and radon isotopes synthesized in complete fusion reactions. Measurements according to a prescribed methodology at MASHA for studying the influence of chemically inert coatings on the separation efficiency of the hot catcher – ERC ion source for inert gases and mercury system.
• Theoretical studies of the mechanisms of heavy-ion-induced reactions.
• Development and update of the network knowledge base on nuclear physics.
• Investigation of shapes and sizes of exotic nuclei employing laser spectroscopy methods.
• From 03-5-1130-2017/2021 item of the Topical plan for JINR research and international cooperation 2021.

Development of the FLNR Accelerator Complex
and Experimental Setups (DRIBS-III)

Leaders:	G.G. Gulbekian
	S.N. Dmitriev
	M.G. Itkis
Scientific leader:	Yu.Ts. Oganessian

Participating Countries and International Organizations:

Belgium, CERN, China, Canada, Czech Republic, Egypt, France, Germany, Italy, Kazakhstan, Mongolia, Poland, Republic of Korea, Romania, Russia, Serbia, Slovakia, South Africa, USA.

Issues addressed and main goals of research:

The implementation of the DRIBs-III project that includes the upgrade and development of the FLNR cyclotron complex, expansion of the experimental infrastructure of the Laboratory (construction of new physics set-ups), and development of
accelerator systems. The project aims at improving the operation stability of accelerators, increasing the intensity and
improving the quality of ion beams of stable and radioactive nuclides in the energy range from 5 to 100 MeV/nucleon, while
at the same time reducing power consumption. The project objective is to significantly improve the efficiency of experiments
on the synthesis of superheavy elements and light nuclei at nucleon drip lines and study of their properties. Moreover, the programme of experiments with beams of radioactive nuclides is anticipated to be expanded.

Expected major results in the current year:

• Experiments on the synthesis of superheavy elements Fl–Lv, study of their properties using a new gas-filled recoil separator (GFS-2) of the Factory of Superheavy Elements (SHE).
• Preparation for experiments on the synthesis of elements 119 and 120 in complete fusion reactions with ⁵⁰Ti ions.
• Construction of a pre-separator for radiochemical studies of SHE and a new gas-filled recoil separator (GFS-3).
• Development of the infrastructure of the ACCULINNA-2 fragment separator (RF kicker, tritium system).
• Upgrade of the U-400M cyclotron.
• Project development and construction of the U-400 (U-400R) experimental hall.
• Implementation of the programme for physics experiments at the U-400 cyclotron.
• Development of new methods for diagnostics of beams of stable and radioactive nuclides.
• Further work on the construction of a new gas cell based laser ionization set-up GALS for on-line separation of nuclear reaction products by selective laser ionization.
• Further work on the construction of the gas ion catcher.
• Start of construction of the DC-140 cyclotron complex.
  

From 03-0-1129-2017/2021 item of the Topical plan for JINR research and international cooperation 2020.

Radiation Physics, Radiochemistry, and Nanotechnology Investigations Using Beams of Accelerated Heavy Ions

Leaders:

S.N. Dmitriev P.Yu. Apel

Participating Countries and International Organizations:

Belarus, Bulgaria, China, Cuba, Czech Republic, Germany, Hungary, Kazakhstan, Moldova, Mongolia, Poland, Romania, Russia, Serbia, Slovak Republic, South Africa, Spain, Ukraine, United Kingdom, USA, Vietnam.

Scientific Programme:Transition to a new level of research and development in the fields of radiation solid state physics, applied radiochemistry and materials science, with a prospect of to nanotechnology applications. The main emphasis will be on the modification of the materials at the nanometer scale and on the study of the effects produced by heavy ions in matter with the aim of revealing the fundamental mechanisms and of the development of nanotechnology applications for ion beams. Modernization of the FLNR facilities for the production of medical isotopes and developement of materials modification methods.

Expected main results in 2020:

• Study of temperature dependence of latent track morphology in radiation resistant insulators.
• Study of structural changes induced by heavy ions of fission fragment energy in oxide and carbide nanoparticles in oxide dispersion-strengthened alloys.
• Study of the effect of high energy heavy ion irradiation on the helium and hydrogen agglomeration processes in ceramics and ODS alloys.
• Study of sorption, diffusion, and osmotic processes in nanopores fabricated using ion track technology.
• Development and study of SERS sensors based on track membranes modified with nanostrusctured layers of silver and silicon monoxide.
• Investigation of properties of silver nanosuspensions obtained by electric discharge method as SERS-active coating for high sensitivity membrane sensors.
• Application of nuclear physics analysis methods to investigate microelement composition of environment (Bulgaria, Mongolia, RSA).
• Development of techniques for the synthesis and radiochemical extraction of radionuclides that have great potential for nuclear medicine and radioecology. Development of equipment and conducting of experiments with beams at the MT-25 microtron.
  

From 04-5-1131-2017/2021 item of the Topical plan for JINR research and international cooperation 2020.