Performances of the 50 mK ADR/sorption cooler

CEA/SBT is currently testing a 50 mK cooler developed in the framework of a European Space Agency Technological Research Program targeted for the Advanced Telescope for High Energy Astrophysics space mission. This cooler is composed of a small demagnetization refrigerator pre cooled by a sorption cooler stage. This Engineering Model is able to produce 1 mu W of net heat lift at 50 mK and an additional 10 mu W at 300 mK provided by the sorption cooler stage. The autonomy of the cooler is 24 h, and once the low temperature phase at 50 mK is over, it can be recycled in about 8 h with 10 mu W and 100 mu W available at respectively the 2.5 and 15 K heat sinks. These performances are in agreement with the European Space Agency requirements. In this paper, we present the detailed thermal performances of the cooler in nominal conditions as well as sensitivity measurements of the variation of the heat sink and the cold end temperatures. (c) 2012 Elsevier Ltd. All rights reserved.