Cool-Down Processes of the NICA Accelerator Complex

A new accelerator complex NICA (The Nuclotron-based Ion Collider fAcility) will be constructed in the next four years on the base of the Nuclotron. It will include, except the Nuclotron, a superconducting booster and a collider. Additional new accelerator rings will be cooled by two "satellite" refrigerators and a 1000 l/h helium liquefier located at the central cryogenic plant. In this paper we describe flow-schemes for the cool-down of the NICA superconducting magnets. According to these schemes, in addition to their main purpose, "satellite" refrigerators are used as a cool-down apparatus. At the first stage of the cool-down process, the refrigerator capacity will be produced by nitrogen refrigerators and the liquid helium flow from the central cryogenic plant at the second stage. Calculations of basic parameters of cool-down processes for the new accelerators are presented.