A parasitic magnetic refrigerator for cooling superconducting magnet

Experimental results are presented for a practical magnetic refrigerator equipped with a large-field racetrack superconducting magnet, an auxiliary GM (Gifford-McMahon) refrigerator, and a liquid-helium vessel for magnetic refrigeration cooling. In this design the magnetic refrigerator is equipped with 14 pieces of GGG (gadolinium-gallium-garnet) single-crystal material on a rotating disk that operates along the gradient of the magnetic field produced by the racetrack superconducting magnet. The heat generated by the magnetic refrigerator is removed by an auxiliary GM refrigerator through the heat absorber made of a high-thermal-conductivity metal. The cold station of the magnetic refrigerator can be connected to the liquid-helium vessel by a high-thermal-conductivity rod to recondense the gaseous helium in the vessel. Refrigeration power measurements are presented and discussed.