Development of 15 K Pulse Tube Cold Fingers for Space Applications at CEA/SBT

Pulse tube coolers for space applications have been developed for many years at CEA/SBT. After successful developments of products in the 50 – 80 K range, our focus has changed to temperature below 20 K. Our work is based on compressors delivering about 100 W of mechanical input power to the cold fingers with a goal of several hundred milliwatts of cooling power. Most of the work performed to achieve such low temperature is based on an intercepted configuration, which permits us to focus our research on the low temperature stage. A review of the different phase shifting methods (including active phase shift and cold inertance) and the associated measured performances are presented. In parallel, studies on tube configuration and temperature at warm end have been undertaken. Experimental results are presented on a pulse tube cooler with minimum temperature below 15 K.