Progress in the Development of the IXO 50 mK Sorption-ADR stage

The nominal temperature of the new generations of detectors for the next space mission International X-ray Observatory (IXO) is expected to be around 50 mK. The coupling of a 3He cooler with an ADR provides an elegant cooler in this temperature range with low mass and few interfaces. As part of an ESA contract to develop such a solution, we designed an efficient assembly based on low thermal interfaces at 15 K and at 2.5 K. The cooler is sized to provide simultaneously net heat lifts of 1 μW at 50 mK and 10 μW at 300 mK for an autonomy exceeding 24 hours. The design of an engineering model is presented, as well as mechanical analysis and simulated results. The influence of the interface parameters are discussed together with different cycling scenario possibility. INTRODUCTION ESA awarded CEA the contract ESA/ESTEC n