Status of the Closed-Cycle Dilution Refrigerator Development for Space Astrophysics

The closed-cycle dilution refrigerator for space applications is an on-going development to improve the performance of the open-cycle dilution refrigerator successfully used on the Planck mission. This solution has been considered in various projects in X-ray and far-infrared space instruments for astrophysics (ATHENA, SPICA) and in advanced studies for future CMB polarization surveys (COrE). It is shown that for sub-Kelvin applications, this refrigerator is fully competitive with some ADR-based solutions. Compared to ADR, the main advantages are (1) a stable cooling power adapted to long uninterrupted sky surveys (2) a low mass of the coldest stages (3) the absence of magnetic field. We present the current status of the development and discuss the options for the \(^{3}\) He compressor.