NICA project: Challenges for heavy ion collider

The global scientific goal of the NICA/MPD (Nuclotron-based Ion Collider fAcility/Multy Purpose Detector) project realizing at JINR is to explore the phase diagram of strongly interacting matter in the region of high compression. The proposed program allows to search for possible signs of the phase transitions and critical phenomena in heavy ion (up to Au) collisions at centre-of-mass energies up to 11 GeV/u. The collider experiment provides optimum conditions for efficient measurements at energy scan. However, to reach required average luminosity of the order of 1027 cm−2 ·s−1 is a complicated accelerator task. In difference to high energy collider the luminosity is limited by Lasslet tune shift mainly, the beam-beam parameter is almost negligible. A flexible procedure of the beam storage and short bunch formation is to be applied to provide maximum peak luminosity in a wide energy range. To suppress luminosity dilution due to intra-beam scattering (IBS) an application of beam cooling methods is mandatory. A solution of these and other problems is presented on example of the NICA collider design