Development of a Superconducting Magnet System for Magnetic Refrigeration Using a Switching Power Supply

Magnetic refrigeration, utilizing the magnetocaloric effect, has seen various applications due to its theoretically high efficiency, including helium liquefaction at 4 K, hydrogen liquefaction at 20 K, and room temperature magnetic cooling. Generally, the magnetocaloric effect becomes more significant with stronger magnetic fields, so when a substantial cooling capacity is required, superconducting magnets are employed. Superconducting magnets are cooled by GM cryocoolers and require dedicated power supplies. Generally, the dedicated power supplies for superconducting magnets are large in size and expensive. In this study, a superconducting magnet system has been fabricated and operated with small switching power supplies rather than a dedicated power supply for superconducting magnet, to examine the feasibility and controllability of superconducting magnet operation.