Brief annotation and scientific rationale:
The goal of the project is the construction of the U-400R accelerator complex for the detailed study of the mechanisms of nuclear reactions with stable heavy-ion beams (fusion–fission, quasifission, multinucleon transfer, etc.), synthesis of new nuclides in these reactions, and decay spectroscopy of nuclei under investigation.

The project encompasses such tasks as the construction of a new experimental hall, the upgrade of the U-400 cyclotron (U-400R following the modernization), and the construction of new separators and ion-guide systems for beam transport.

The accelerator complex will be used for the detailed study of the properties of the isotopes of heavy and superheavy elements and in searches for novel methods of synthesizing heavy nuclides. The studies do not imply the use of radiactive target material in amounts exceeding 10⁵Bq.

Expected results upon completion of the project:
Upgrade of the U-400 cyclotron → U-400R.

Construction of a new experimental hall of U-400R.

Construction of new experimental set-ups and beam transport channels from U-400R.

Commissioning of the DC-140 accelerator complex for complex applied research.

Expected results of the project in the current year:
Implementation of the experimental programme at the U-400 cyclotron.

Construction of the U-400R experimental hall.

Start of the reconstruction of the U-400 (U-400R) cyclotron.

Construction of a beamline transport system following from building No. 131 to the U-400R experimental hall.

Development of a design of the STAR kinematic separator of multinucleon transfer reaction products.

Development of the design concepts of the SCIF-D set-up for studying nuclear reaction mechanisms and work on the project.

Construction of the DC-140 cyclotron,

Development of methods for beam diagnostics of stable and radioactive nuclides.

Brief annotation and scientific rationale:
Nowadays acceleration of high-intensity beams at the DC-280 cyclotron (SHE Factory) provides sufficient statistics in experiments on the synthesis of superheavy nuclei in the vicinity of the island of stability (Z=114, N=184), thereby opening up new avenues for research. Among the new opportunities the SHE Factory offers are first and foremost studies of the chemical properties of short-lived (T_1/2<0.5 s) isotopes of superheavy elements and precise measurements of their masses.

The project aims to create novel state-of-the-art experimental instruments. Experimental set-ups to be installed at the DC-280 cyclotron will be used for synthesizing and studying the physical and chemical properties of the isotopes of heavy and superheavy elements as well as in studies of nuclear reaction mechanisms, in nuclear spectrometry and mass spectrometry. To attain these goals, we are planning to construct a new gas-filled GASSOL separator whose key elements are a superconducting solenoid and a multi-reflection time-of-flight mass spectrometer.

Based on a superconducting solenoid magnet, the magnetic gas-filled separator (GASSOL) is intended for studying the physical and chemical properties of superheavy elements, including their short-lived (T_1/2< 0.5 s) isotopes, thereby establishing a pathway to elements heavier than Fl. In addition to the efficient separation of reaction products, the separator will focus nuclei of interest into a spot not exceeding 1 cm in diameter.

The specialized high-resolution mass spectrometer is designed for measuring the masses of superheavy elements with Z=104–118 and A=266–294 and their radioactive decay products with an accuracy of <100 keV. Its principle of operation is based on the multi-reflection time-of-flight (MR TOF) technique.


Expected results upon completion of the project:
Development of methods for producing intensive beams of ⁴⁸Ca, ⁵⁰Ti, ⁵⁴Cr, etc.

Assembly of the solenoid magnet of the superconducting gas-filled GASSOL separator.

Construction of a multi-reflection time-of-flight mass spectrometer.

Expected results of the project in the current year:
Enabling experiments on the synthesis of superheavy elements and study of their properties at the Superheavy Element Factory.

Assembly and commissioning of the superconducting gas-filled GASSOL separator. Installation of the GASSOL engineering systems and a beamline transport system from DC-280 to the separator.

Design of a multi-reflection time-of-flight mass spectrometer. Test run of the cryogenic gas ion catcher.