By Jean-Marc Duval
Cryocoolers and Space Cryogenics Laboratory (LCCS)
Very low temperatures, below 1 K, are required for the detectors of the most ambitious astrophysics mission in order to achieve exceptional resolutions. Reaching these temperatures, in space and for durations of several years, necessitates diverse and complex cooling technologies. Hence for each temperature range, different principles and specific technical implementations are developed. The process of designing and building such cryogenics chains is described, drawing on the example of the Athena mission. In addition, I will discuss two specific types of coolers starting with pulse tubes specifically for 15 K cooling. I will then present subkelvin technologies with a focus on Adiabatic Demagnetization refrigerator and the development of several prototypes for space instruments reaching 50 to 100 mK.