Proof-of-Principle Measurements of the Superfluid Joule-Thomson Refrigerator Concept

The performance of the first Superfluid Joule-Thomson Refrigerator (SJTR) is described. The SJTR has achieved a low temperature of 0.68 K when exhausting its waste heat to a thermal reservoir at a temperature of 1.2 K. Cooling power versus temperature measurements were conducted with two different throttles and with different compressor speeds