Progress and Challenges of Sub-Kelvin Sorption Cooler and Its Prospects for Space Application

The helium sorption cooler plays an important role in both ground and space application because it does not require a magnetic field and is not dependent on gravity. At present, one research focus of sorption cooler is the development of multistage to overcome the disadvantages of the originally developed single-stage structure. The other focus is the development of continuous sorption cooler. Although the sorption cooler has been widely employed in astronomy and Earth atmospherics sciences, space mission and other fields, there are still lots of technologies that can be further improved, such as superfluid film suppression, the development of high on-off ratio gas-gap heat switch and rapidly responsive sorption pump. This paper reviews the principle, structure and performance parameters of the sorption cooler and its suitability to the space application. In addition, the technical challenges and the efforts that scholars are trying will also be introduced.