The program will design and demonstrate a reversible cycle Pulse Tube cryogenic refrigerator that can be scaled to produce fractional to several watts of cryogenic refrigeration at temperatures down to 1 OK while rejecting to a 300K heat sink. The concept is based on integrating a set of regenerator/pulse tube modules with a like set of linear motion thermodynamic engines incorporating flexure bearings, clearance seals, electro- dynamic linear motors, and integrated compressor/warm displacer pistons. Innovative aspects include the particular flexure bearing utilized, the integration and assembly of the electro dynamic motor, bearings and displacement sensor, the use of a linear drive integrated compressor/warm displacer piston, the implementation of the compressor/displacer phase shifting by fluid circuit layout, and the unique manufacturing processes selected to enhance performance and reduce costs. Phase I will compare the predicted thermodynamic performance of the proposed concept with equal swept volume Stirling and Orifice Pulse Tube alternatives. A layout of the selected configuration for the total refrigerator will be prepared, sized to a specific design point. For Phase 11, an engineering model of the Phase I design will be detailed, fabricated, and tested.Moderate cost, high efficiency, long life cryogenic refrigerators can find commercial applications in the field of high temperature superconductivity applications, medical treatment, advanced high speed cryogenic computers, cryogenic processing of materials, and extended storage of cryogenic fluids.
Keywords: Phase_I, NASA, Abstract, FY94
