In the first half of February, a complete cooling of the MPD (Multi-Purpose Detector) solenoidal magnet began for the first time at the MPD Experimental Facility of the NICA Accelerator Complex. Prior to this, in November–December 2023, trial cooling was carried out to a temperature of 250 K (-23.15°C) to test the technological feasibility of the process while maintaining the cooling parameters specified by the manufacturer.

As VBLHEP Deputy Chief Engineer Konstantin Mukhin said, working in shifts, MPD personnel expect to reach a solenoid temperature of 80 K (-193.15°C) and carry out thermophysical tests (estimate the heat flow to the solenoid and components of the cryogenic system, implement leak tests, estimate the possible operability when the circulation of refrigerants is disrupted, etc.). It is necessary to note that as part of the cooling process, a specially developed pipeline system for the transfer of engineering gases is currently tested that allows the detector to be transported over the entire range (from the “assembly” position to the “beam” position) without heating it above 80 K. This is very important, since reducing cooling/heating cycles extends the life cycle of the magnet. If the tests are successful, the next step will be gradual cooling of the magnet to an operating temperature of 4.5 K (-268.65°C).

In spring–summer 2024, it is expected to prepare and test the power supplies for the MPD solenoidal magnet and its correction coils, test the stored energy output system, and eventually measure the magnetic field in the detector volume. After all these procedures, a power frame will be installed in the solenoid (that is already positioned in the MPD Hall) and the installation of subdetectors will start.