SAFARI engineering model 50 mK cooler

SAFARI is an infrared instrument developed by a European based consortium to be flown in SPICA, a Japanese led mission. The SAFARI detectors are transition edge sensors (TES) and require temperatures down to 50 mK for their operation. For that purpose we have developed a hybrid architecture based on the combination of a 300 mK sorption stage and a small adiabatic demagnetization stage. An engineering model has been designed to provide net heat lifts of 0.4 and 14 mu W respectively at 50 and 300 mK, with an overall cycle duration of 48 h and a duty cycle objective of over 75%. The cooler is self-contained, fits in a volume of 156 x 312 x 182 mm and is expected to weigh 5.1 kg. It has been designed to withstand static loads of 120 g and a random vibration level of 21 g RMS. (C) 2014 Elsevier Ltd. All rights reserved.