Performance improvement of a pulse tube cooler below 4 K by use of GdAlO 3 regenerator material

Abstract

The cooling power and coefficient of performance of a two-stage pulse tube cooler below 4 K have been increased greatly by using the newly developed ceramic magnetic regenerative material GdAlO 3 (GAP). Cooling powers of 200 mW at 2.8 K, 300 mW at 3.13 K, and 400 mW at 3.70 K have been achieved with a compressor input power of about 4.8 kW. The results show that the cooling power near 3.0 K increases by 150% compared to that of the same pulse tube cooler (PTC) employing only conventional HoCu 2 and ErNi regenerator materials.