Development of a 4K Regenerator and Pulse Tube Test Facility
Michael A. Lewis, Peter E. Bradley, Ryan P. Taylor, Ray Radebaugh
Recent advances in superconducting electronic systems are requiring larger envelopes for cooling power, efficiency, and operational environments from commercial based cryogenic cooling systems. One such system targeted at meeting these requirements is the pulse tube cryocooler. While the pulse tube cryocooler system is a well-documented technology at moderate cryogenic temperatures (40-80 K), its behavior at 4 K is not well understood. Recent modeling results using REGEN3.3 and CFD models have shown that 4 K pulse tube cryocoolers can be successfully applied to superconducting electronic systems. To gain confidence in the modeling predictions, experimental validation is required. This paper discusses a test facility designed and constructed to allow for precise measurement of all relevant regenerator and pulse tube energy flows when operating over the temperature range of 4-30 K, frequency range of 10-30 Hz, and cold end phase angle range of -15° to -45°. The novel features of this test facility include independent regenerator and pulse tube characterization, modulation of the system phasing using a commercial expander operating at 4 K, precise off-axis rotation, and rapid experimental turnaround time.