After seven years of construction at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, the Booster synchrotron at the brand-new NICA (Nuclotron-Based Ion Collider Facility) Complex has accelerated its first beam. On 19 December helium ions were injected into the synchrotron and a stable circulation of the beam was obtained at an energy of 3.2 MeV. The milestone marks an important step in establishing the NICA facility, which is estimated to be completed by 2022.
At this energy, ordinary matter and the quark-gluon plasma coexist in a mixed phase
The NICA accelerator complex will allow studies of the properties of nuclear matter in the region of maximum baryonic density. By colliding heavy gold ions at energies corresponding to the deconfinement phase transition (4.5 GeV), NICA will access the transition of the quark-gluon plasma (QGP) into hadrons. At this energy, ordinary matter and the QGP are able to exist in a so-called mixed phase – complementing studies at higher energy colliders such as the LHC.
The NICA booster is a 211 m circumference superconducting synchrotron which will accelerate beams to 500 MeV. It uses 2.2 m-long dipole and quadrupole magnets made up of a window frame iron yoke and a winding made of a hollow niobium-titanium superconducting cable cooled with a two-phase helium flow. Beams will then be transported to a separate ring surrounding the booster, the “nuclotron”, and accelerated to the GeV range. The nuclotron was originally built between 1987 and 1992 as part of the Dubna “syncrophasotron modernisation” programme, and was Europe’s first superconducting accelerator of heavy ions to high energies. Finally, beams will be injected into two identical 503 m storage rings, which will collide the beams at two detectors: the Multi-Purpose Detector (MPD) and the Spin-Physics Detector (SPD). The MPD facility is designed to study dense baryonic matter, while SPD will study collisions between polarised beams of protons and deuterons.
The complex is one of six Russian “megascience” facilities that are part of the CREMLIN project, which aims to use large-scale science facilities to improve and strengthen relations and networks between European and Russian research infrastructures. The CREMLIN consortium comprises 19 European and Russian research infrastructures, including CERN, and DESY. Other “megascience” facilities included in this project are the Super-Charm-Tau Factory at the Budker Institute of Nuclear Physics, and the Special-purpose Synchrotron-Radiation Source (SSRS-4) at the NRC Kurchatov Institute.
“This is a historical moment for our Laboratory and a great milestone in realization of our flagship megascience project – we have to thank the grant programme CREMLIN helping us in these challenges,” says Vladimir Kekelidze, the NICA project leader. “The final step before the physical launch of the Booster will be the adjustment of the beam acceleration mode, which will then allow focus to switch to the construction of the beam transport systems from the Booster to the Nuclotron.”