The ATLAS SR1 CO2 cooling system is built to serve for ATLAS detector surface tests. It is designed to cool any test structure with evaporating CO2 at a given pressure. Cooling system allows for continuous operation at adjustable evaporation temperature inside the testing element in range of -400C to +200C.

The system of the ATLAS SR1 CO2 cooling station contains four main elements: cooling plant placed outside SR1 clean room, transfer line connecting building 6115 and SR1, distribution system inside SR1 and the dummy load.

Main system elements:

• The primary chiller, required as the low temperature heat sink to condensate returning two phases CO2 from the test structure into the condenser and to regulate the pressure into the accumulator. It is a standard commercial laboratory chiller.

• 2-phase accumulator is the pressure vessel made of two cylinders filled with liquefied and gaseous CO2 immersed into glycol bath. By regulating the pressure into the accumulator, system sets the evaporation pressure equal to evaporation temperature into the cooling channel. The primary brine is pumped from the chiller into the accumulator bath heat exchanger with control valve on the first supply. On the second supply accumulator glycol is pump to increase efficiency of the heat exchange between glycol and CO2.

• Liquid LEWA membrane pump with is used to ensure CO2 circulation.

• Transfer line connects the cooling plant with the distribution system

LINKS

SHAREPOINT “CO2 for SR1”: https://espace.cern.ch/CO2-SR1/default.aspx

EDMS DT cooling: https://edms.cern.ch/nav/P:CERN-0000006814:V0/P:CERN-0000096251:V0/TAB3