On-Chip Detector Cooling for Space Applications

Vibration-free miniature Joule-Thomson (JT) coolers are of interest for cooling small optical detectors for future space missions. The European Space Agency is interested in on-chip detector cooling for the temperature range 70¶K¶-¶250¶K. This is the topic of a new project at the University of Twente. In this project, the focus is on the integration of Micro-ElectroMechanical Systems (MEMS) based JT coolers with small detectors for space applications. Furthermore, distributed micro cooling will be investigated, which means that multiple cold tips will be driven by a single compressor. The progress of this project is discussed in this paper. The application of JT coolers in the temperature range 70¶K¶-¶250¶K is investigated. The working fluid in a JT cold stage is optimized on basis of the thermodynamical properties of the fluid. The results of this optimization are discussed. Furthermore, a static model of the counter flow heat exchanger is built, in order to simulate the performance of a micro JT cold stage. The results of the simulations are compared with experimental data.