Improvement of liquefaction efficiency of the heat pipe type magnetic refrigerator

The Carnot type magnetic refrigeration in the temperature range from 4.2 K to 15 K has been studied. This paper describes the additional experimental results to improve the liquefaction efficiency. The liquefaction losses in the demagnetization process largely depend on the gap width of the heat pipe-GGG system. At each initial temperature, there was an optimum gap width and magnetic field sweep rate. The maximum liquefaction efficiency was obtained for the gap width of 400 to 600 μ at 4.2 K