NICA Project NEWS

MPD solenoid relocation

On 14 April, specialists moved for the first time the 800-ton superconducting solenoid in the current configuration in the Multi-Purpose Detector (MPD) pavilion of the NICA Accelerator Complex in the Laboratory of High Energy Physics JINR.

In addition, inseparably from the solenoid, they moved the side platform for electronic equipment designed for reading data from MPD detectors. The relocation was required to solve the problems of electronics installation and became a good rehearsal of this complex technological manipulation for the project team.

The MPD configuration now includes the solenoid itself, which is a huge magnet of over 5 metres in diameter, the magnet yoke, in which it is installed, and the upper platform with partially placed cryogenic equipment. Specialists moved the construction with the side platform by 1.8 m from the wall due to technological reasons as they are going to begin the installation of equipment. Experts placed a weight of about 13 tons at the side platform of the magnet, simulating the total mass of the equipment planned to be installed here by the end of May.

MPD collaboration

On 18 April, the 11th Collaboration Meeting of the MPD Experiment at the NICA Facility started. The three-day meeting is taking place at the Laboratory of High Energy Physics and online. More than 150 participants gathered to discuss the progress in the implementation of the project.

During the opening of the meeting, JINR Vice Director, Leader of the NICA Megascience Project Vladimir Kekelidze noted the successful result of the longest commissioning run in the history of the facility. The session ended in the February this year. “For the first time, all the elements of the accelerator cascade worked properly for more than four thousand hours. As a result of the run, the BM@N Collaboration collected more than half a billion events. It means that the first physical programme at NICA has started”, he highlighted. Vladimir Kekelidze also said that all the magnets of the collider are ready for operation. 80 dipole magnets have already been installed in the arches of the tunnel. Construction works at the facility have been completed and the delivery of engineering equipment is expected. The cryogenic complex of the NICA Project will be put into operation within the next few months. The main electrical substation is already functioning. “Due to external circumstances, there are difficulties with the delivery of finished equipment and the fulfilment of contract terms by our colleagues. Despite this, the MPD Сollaboration finds solutions to these problems, and the project develops,” Vladimir Kekelidze stressed. He also expressed hope that at the end of this year it will be possible to start the technical launch of the collider.

The collaboration’s spokesman Victor Riabov (PNPI) reported on the current status of the collaboration and progress in the implementation of the MPD Project. The project brings together more than 500 participants from 34 institutes of 10 countries. During the meeting, the Institutional Council of the collaboration will consider the candidacy of VBLHEP JINR leading researcher Arkady Taranenko as Deputy Leader of the collaboration. “The collaboration is changing, it grows and develops,” Victor Riabov stressed. The number of publications is increasing. Thus, about 200 articles on physical research, equipment, and software of the experiment have already been published.

According to Victor Riabov, the most difficult and delicate stages in the implementation of the MPD Project will be the cooling of the magnet and its connection to the power supply. Work on the relocation of refrigerators at the technological cryogenic platform and their connection with the rest of the equipment is currently carried out in the MPD Hall. In addition, specialists are adjusting the control and power supply systems of the facility.

Head of the MPD Project at the NICA Accelerator Complex JINR Viacheslav Golovatyuk said that at the end of April the team will start pumping the solenoid to its working vacuum inside the cover. In late May – early June, specialists plan to start cooling the magnet to the temperature of liquid nitrogen. From June to September, work on MPD will be halt so that specialists can paint the walls of the hall for fire safety purposes. Then, from October to December, the project team is going to cool the magnet down to the temperature of liquid helium. Magnetic field measurements are preliminary scheduled for early 2024. The commissioning of the MPD Detector and the first data set are now scheduled for 2025.

All components of the first stage of the MPD Experiment are actively being developed and tested. Speakers will present reports on each system at the meeting. Participants will discuss the software and computing infrastructure of the detector, as well as reconstruction of events in the experiment. Speakers of physical working groups will deliver progress reports. As part of the meeting programme, participants will be able to get acquainted with the status of the works during an excursion to the Nuclotron and MPD Halls, which will take place on 19 April. Recordings of reports will be available on the event’s website at the end of the meeting.

Applied research at NICA

During the fourth commissioning session at the NICA accelerator complex, the first applied research on high-energy xenon ion beams extracted from the Nuclotron was carried out. JINR's long-standing partner, the Institute for Biomedical Problems, was among the first institutes that were able to use the infrastructure of the ARIADNA complex for applied research. The IBMP RAS staff has studied two new materials for radiation resistance to protect the cabins of Russian cosmonauts on the International Space Station. Seeds of plants of practical relevance for cultivation in spaceflight were also irradiated in the session.

"We were looking forward to the start of this session, when particles with "our" energies will appear at the NICA complex: up to several GeV per nucleon. It is they that allow to simulate space radiation, producing fluxes of those very particles: the nuclei of carbon, nitrogen, oxygen, iron, xenon and others. For us, NICA is a kind of space radiation simulator that affects, among other things, spacecraft crews," Head of the Department of Radiation Safety for Manned Space Flight of IBMP RAS Vyacheslav Shurshakov commented.

SPD collaboration

At the 57th session of the Programme Advisory Committee for Particle Physics, the SPD collaboration presented for the first time the technical design of the experimental facility. The 300+ page document contains a detailed description of the subsystems and infrastructure of the detector for the basic configuration, when the initial beam energies and luminosity are much lower than the nominal ones and for the complete detector configuration. The presented report was positively confirmed by the new members of the Committee.

The major milestone in the development of the SPD project this year will be the preparation of working design documentation for the development of a superconducting solenoidal magnet. A magnet with a field strength of up to 1.2 T per axis and a stored energy of about 20 MJ will be produced in Novosibirsk at the Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences. Novosibirsk scientists already have experience in producing a central solenoidal superconducting magnet for the PANDA (FAIR) facility that is however somewhat inferior to the SPD magnet in size. The same technology, as well as the development gained in the production of the magnet for PANDA will be used for the manufacture of the SPD magnet. Due to the high degree of integration of the magnet into the design and infrastructure of the SPD facility, engineers and physicists from JINR are extensively involved in the preparation of working documentation. In the current year, work on the development and optimization of prototypes of plant subsystems will also be carried out. Particular attention is paid to the detectors that will already be involved in the first phase of the experiment.

In recent months, the representatives of the collaboration have visited universities and research institutes in Kazakhstan, Belarus, South Africa and Egypt to establish new scientific contacts. As a result, the Kazakhstan Institute of Nuclear Physics (Almaty) has joined the collaboration and some of its representatives have long been extensively involved in the work on the track system of the SPD facility. Collaboration and further joint work within the framework of the SPD project with scientific groups from Mexico will be carried out.

Cryogenic complex of the NICA collider

In 2022, a large amount of work was carried out to develop and commission the equipment of the cryogenic complex. The facilities of the complex under construction are located in several buildings, part of the equipment is located outdoors. New equipment is needed to ensure the operation of the superconducting rings of the NICA complex: the collider magnets should be cooled to a temperature of 4,5 K.

An accelerating session of record duration was carried out, in which the cryogenic complex facilities worked for 4,5 months.

The magnetic cryostat system (MCS) of the booster was cooled from 300 K to 4.5 K according to the standard scheme: a helium satellite refrigerator RSG 2000/4,5 No.1 with a cooling capacity of 2000 W at 4.5 K was used. Liquid helium supplied from the refrigerator to each half-ring of the booster was provided through cryogenic pipelines with vacuum screen insulation and a nitrogen screen.

Two new separators with a capacity of 500 liters each were used for subcooling liquid helium. During the last run of the accelerators, the nitrogen cryogenic system equipment installed in August 2022 was used: two 30 m³ VRV nitrogen tanks complete with liquid nitrogen centrifugal pumping units.

Currently, work is underway on the installation of equipment and pipelines required for cooling the collider of the NICA complex. In room 177 of building 17, the installation of two satellite refrigerators RSG 2000 No.2 and 3 that will ensure the supply of liquid helium to the collider half rings is near completion.

The installation of process pipelines is underway to supply compressed helium from the new compressor station (CS) to refrigerators and liquefiers located in building 1B and building 17. The construction of the second stage of the overpass to the collider building has started.

Thermal engineering tests of the helium container of the KCG 40/0.5 tank were carried out. The product made two flights to the helium plant in Orenburg. Operations for its refueling and transportation to a distribution point in the Moscow region were successfully carried out.

The technology of cooling and refueling of the container was developed using the largest helium liquefier OG 1000 in Russia - the installation of the cryogenic complex of the NICA collider. The installation of technological equipment in a new cryogenic compressor station has been completed.

Helium screw compressor components Cascade 110/30, nitrogen centrifugal compressors Aerocom 2/179 18 and SM5000, piston nitrogen compressors 6GSh1.6 2/1.1 200 2, air compressor Atlas Copco GA18 were assembled and tied. The installation of the Marley NC8409 Modular Fan Cooling Tower has also been completed.

In 2023, work at the cryogenic complex will be aimed at ensuring the cooling of the collider ring. To do this, it is necessary to complete the construction of the second stage of the overpass, to manufacture and install technological pipelines, to carry out adjustment of helium refrigerators and commissioning of the equipment of the cryogenic compressor station. Another important task is to complete the work on the development of a closed nitrogen supply system for the complex. The nitrogen liquefier, recondensers and tanks with pumping units will be connected by cryogenic and gas lines into one system that will ensure reliable operation of all consumers of liquid nitrogen: cryogenic helium plants, high-temperature current leads, heat shields of the booster, Nuclotron and collider.

Based on materials from the JINR Press Office and NICA Bulletin