80 K Throttle-Cycle Refrigerator Cost Reduction

Abstract

Throttle cycle refrigerators have recently been introduced to the market which use a single oil lubricated air conditioning type compressor with an air cooled aftercooler and oil separator to supply a mixed refrigerant to a counter flow heat exchanger and throttle valve in a vacuum housing. The basic refrigerator presently sells for about $6,000 and is being used to replace LN2 dewars in applications such as X Ray and Gamma Ray detectors because no maintenance is required.

This paper describes the work being done to reduce the manufacturing cost in larger production volumes in order to facilitate applications of new high temperature superconductor, HTS, technology. One of the refrigerant mixtures that was tested with the experimental heat exchanger produced 7 W of cooling at 80 K with 450 W input power. An interface was built to cool an HTS-Sapphire Resonator which added several different options for reducing vibration to the basic cooler. Tests with the resonator showed good performance with the basic cooler.