Projects of the 21st century

MPD: 0.57 Tesla design field reached

VBLHEP has passed another important stage in the implementation of the NICA Mega-Science Project. The superconducting magnet of the multipurpose detector (MPD) has been successfully derived for the design parameters of the field. This achievement allows us to proceed to the next stage of work - preparation for the installation of MPD subsystems in the magnet aperture.

On 26 February, 2026, at 7:20 PM Moscow time, stationary 3D Hall sensors located on the inner surface of the solenoid cryostat registered a magnetic field with a design value of 0.57 Tesla. All systems functioned regularly: the temperature was stable, no current fluctuations were observed. The stability of the operating parameters confirmed the reliability of the MPD magnetic system and the quality of the engineering decisions made.

The achievement of this result was the result of the hard work of engineers that had to take responsibility for commissioning the key element of the magnet - the superconducting solenoid. Deputy Chief Engineer of VBLHEP Konstantin Mukhin emphasized that success became possible thanks to the professionalism and perseverance of the Institute's specialists.

"The path has been long and challenging. We had to take on great responsibility for finalizing and launching the superconducting solenoid after the suspension of participation in the ASG Superconductors project," Konstantin Mukhin said. "Step by step, the team coped with the task, developing a new equipment and working out the algorithms of the unique experimental facility."

In the near future, a detailed measurement of the properties of the field will be carried out. In March, the JINR specialists, together with the colleagues from the G.I.Budker Institute of Nuclear Physics (INP SB RAS, Novosibirsk) will carry out a magnetic field mapping procedure. Successful completion of this stage will allow in April installing the power frame and starting the installation of internal detector systems MPD (TPC, TOF, ECAL, others) in the magnet aperture.

Certificate

The magnet of the MPD multipurpose detector consists of a massive iron yoke (magnetic core), a superconducting solenoid in a cryostat, as well as extra correction coils at the ends that close the magnetic field. It is about 9 meters long and about 7 meters in diameter. In the world, only a few magnets of a comparable size and purpose operate on megascience-class facilities.

The MPD experiment is aimed at studying superdense nuclear matter in the maximum baryon densities achieved in the NICA energy range. Its main goal is to identify key markers of the phase structure of QCD when the facility is operating in a collider mode (√s_NN = 4-11 GeV) and with a fixed target (√s_NN = 2.4-3.5 GeV). Simulation of these states will allow obtaining experimental data relevant for understanding the internal structure of neutron stars and supplementing the current astrophysical observations.