Cryogenics

TARLA liquid helium system consists of helium buffer, two compressors, oil removal system (ORS), cols box 1 (CB1), cold box 2 (CB2), warm vacuum pumps (WVP) and vaporizer. Helium gas kept under normal conditions in buffer is transferred to the compressors 1 and 2, passing through ORS. Pressurized helium gas in compressors is kept under constant temperature by aid of external water cooling (not shown in PID). Mixture of pressurized helium gas and oil is separated in ORS. Then purified helium gas is transferred to CB1 where it is liquefied up to 4K. Liquid helium is stored in dewar. CB2 has the ability to adjust the flow rate of liquid helium according to the power demand of cryomodules, and cool up to 1.8K using low pressure generated by WVP. Throughout the process liquid nitrogen is used for thermal shielding of liquid helium.