Miniature Compressor for Low Capacity Reverse Brayton Cryocooler

This proposal addresses the development of a miniature centrifugal compressor, a critical component for a low capacity, vibration free, long life cryocooler. Key features of the development include innovative fabrication methods to produce a unique rotor and impeller that allows the machine to achieve necessary speeds for good performance. The machine is intended for use in spaceborne cryocoolers where input power to the system is limited to about 100 watts. The compressor will be used in a reverse Brayton cycle in which the turbomachines run in high speed gas bearings. This configuration has the advantage that vibrations are negligible - an important consideration for IR sensors. Furthermore, the system is component oriented, allowing the flexibility in integration with sensor systems. The succesful development of this device enables the practical use of 0.5w - 2w at temperatures between 40K and 100K. Phase I consists of analysis and trade studies to produce a preliminary design and predict performance of the compressor and the cycle. In Phase II, a prototype device will be designed, fabricated and tested.