Development of a Compact Dilution Refrigerator for Zero Gravity Operation
A compact dilution refrigerator of unique design using internal charcoal adsorption pumps is being modified and tested for operation in zero gravity. This commercially-available refrigerator is self-contained with no external pumps or gas handling system and provides very reliable operation since it has no moving parts. All operations are performed with heaters and are completely computer controlled. The refrigerator provides many hours of operation at very low temperature before the charcoal pumps must be recycled.
This single-cycle system will have porous sintered metal added to its liquid chambers in order to confine and control the liquid phases at low temperatures. A detailed analysis has shown that operation down to 0.05 K should be possible. Successful operation with the sinter in a normal configuration will be followed by testing with the liquid chambers in an inverted geometry to simulate −1 G acceleration. These tests will demonstrate the gravity-independence of the design and will guarantee the ability to operate in zero G. Further modifications to achieve continuous operation will then be implemented.
KeywordsHelium Assure Charcoal
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