A Neodymium Plate Regenerator for Low-Temperature Gifford-McMahon Refrigerators

Abstract

The present technology in low-temperature Gifford-McMahon cryogenic-refrigerators utilizes a regenerative type heat exchanger that is fabricated with rare-earth metal spheres having diameters of about 0.2 mm. A more effective regenerative heat exchanger could be constructed by precisely forming flow holes through neodymium (Nd) disks. Perforated disks were formed using a technique similar to that used to make superconducting wire. The disks were then stacked into a tube and this whole assembly was used as a regenerative heat exchanger. This type of regenerator should provide better heat transfer properties, lower pressure drop characteristics and reduced thermodynamic losses when compared to regenerators that utilize spherical particles. Pressure drop and performance test results of both types of regenerators are presented in this paper.