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ELEMENTARY PARTICLES AND FIELDS Experiment

Status of NICA Project* I. N. Meshkov** Joint Institute for Nuclear Research, Dubna, Russia Received March 31, 2011

Abstract—The project of Nuclotron-based Ion Collider fAcility NICA/MPD (+ MultiPurpose Detector) under development at JINR (Dubna) is presented. The general goals of the project are providing of colliding beams for experimental studies of both hot and dense strongly interacting baryonic matter and search for the mixed phase and critical endpoint and spin physics in collisions of polarized √ protons (deuterons). The first program requires providing of heavy-ion collisions in the energy range of sN N = 4−11 GeV at average luminosity of L √ = 1 × 1027 cm−2 s−1 for 197 Au79+ . The polarized beams mode is proposed to be used in energy range of s = 12−27 GeV (protons) at luminosity of L ≥ 1 × 1030 cm−2 s−1 . The report contains description of the facility scheme and characteristics in heavy-ion operation mode, status and plans of the project development. DOI: 10.1134/S106377881205016X

1. NUCLOTRON-M & NICA PROJECT The Nuclotron-based Ion Collider fAcility (NICA) is a new accelerator complex (Fig. 1) being constructed at JINR. It is aimed to provide collider experiments with √ (i) heavy ions 197 Au79+ at sN N = 4−11 GeV (1–4.5 GeV/u ion kinetic energy) at average lumi√ nosity of 1 × 1027 cm−2 s−1 (at sN N = 9 GeV); (ii) light–heavy ions colliding beams of the same energy range and luminosity; √ (iii) polarized beams of protons s = 12−27 √ GeV (5–12.6 GeV kinetic energy) and deuterons sN N = 4−13.8 GeV (2–5.9 GeV/u ion kinetic energy) at average luminosity 1 × 1030 cm−2 s−1 . The proposed facility consists of the following elements (Fig. 1): 1. “Old” injector (pos. 1): set of light-ion sources including source of polarized protons and deuterons and Alvarez-type linac LU-20. 2. “New” injector (pos. 2, under construction): ESIS-type ion source that provides 197 Au32+ ions of the intensity of 2 × 109 ions per pulse of about 7-μs duration at repetition rate up to 50 Hz and linear accelerator consisting of RFQ and RFQ Drift Tube Linac (RFQ DTL) sections. The linac accelerates the ions at A/q ≤ 8 up to the energy of 6 MeV/u at efficiency not less than 80%. ∗ **

The text was submitted by the author in English. E-mail: [email protected]

3. Booster-synchrotron housed inside Synchrophasotron yoke (pos. 3). The Booster (pos. 4) has superconducting (SC) magnetic system that provides maximum magnetic rigidity of 25 T m at the ring circumference of 215 m. It is equipped with electron cooling system that allows to provide cooling of the ion beam in the energy range from injection energy up to 100 MeV/u. The maximum energy of 197 Au32+ ions accelerated in the Booster is of 600 MeV/u. Stripping foil placed in the transfer line from the Booster to the Nuclotron allows to provide the stripping efficiency at the maximum Booster energy not less than 80%. 4. Nuclotron—SC proton synchrotron (pos. 5) has maximum magnetic rigidity of 45 T m and the circumference of 251.52 m, provides the acceler