Design and construction of microminiature cryogenic refrigerators

The small size and small refrigeration requirements of superconducting sensors make these devices a poor match to conventional cryogenic refrigeration systems. We have considered the design and construction problems of building microminiature refrigerators for the cooling of these devices which would match their cooling requirements. Preliminary work is described on the construction of a first stage 77 K refrigerator built on a Si‐wafer using photolithography.