Feasibility of an Electromagnetic Diaphragm Compressor for Cryocoolers.

This Phase I SBIR report documents the establishment of feasibility of a electromagnetic diaphragm compressor which is designed to drive cryocoolers. Two prototype compressors were built and tested as part of this feasibility establishment program. The first prototype used permanent magnet bias while the second prototype used electromagnet bias. Testing the first prototype indicated that the diaphragm used in it is too stiff for satisfactory operation. As a result, electromagnet was used as biasing device in the second prototype and the stiff diaphragm is replaced by a more flexible one. In addition to this prototype building activity, a computer code to analyze and size this type of compressor has been developed in this phase I effort. Testing the prototype has indicated that it can develop pressure ratios of up to 1.7 at frequencies of up to 60 diaphragms Hz. Since the prototype demonstrated performance parameters that are within the realm of cryocoolers, we conclude that it is feasible to engineer an electromagnetic diaphragm compressor that can meet the design requirements of cryocoolers. As a result, it is recommended to move the project to Phase II