An improved closed-loop, two-stage pulse-tube refrigerator provides 4 W of cooling power at a temperature of 15 K. The original intended application of this refrigerator is in preventing boiloff of liquid hydrogen from a propellant tank aboard a spacecraft. The basic refrigerator design can also be adapted to terrestrial applications like cooling superconducting electronic devices.

The design operating frequency of this pulse-tube refrigerator is 30 Hz — an order of magnitude greater than the operating frequencies of other pulse-tube refrigerators. The higher frequency makes it possible to design a compressor that is much smaller and lighter, relative to the compressors of lower-frequency pulse-tube refrigerators of similar capacity.

This work was done by W. G. Dean of Dean Applied Technology Co., Inc., for Marshall Space Flight Center.

NASA Tech Briefs Magazine

This article first appeared in the September, 2002 issue of NASA Tech Briefs Magazine.

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