Demonstration of 10 kJ-Capacity Energy Storage Coil Made of MgB2 with Liquid Hydrogen Indirect Cooling

10 kJ-Capacity Energy Storage Coil Made of MgB 2 proposed in the Advanced Superconducting Power Conditioning System (ASPCS) was fabricated, and an electric current test was conducted with indirect liquid hydrogen cooling. This coil consists of three DP (double pancake) coils with an inner diameter of 400 mm and an outer diameter of 606 mm. The first DP was manufactured by the W&R (Wind and Reacted), and second and third DPs were manufactured by the R&W (React and Wind). A thermosiphon system is used for cooling the coils, in which the coolant is circulate without pump. For energization, several DC excitation and AC excitation tests were carried out with liquid hydrogen, and the rated current of 600 A was successfully achieved. The evaluation of both DC and AC losses were also performed, indicating needs to reduce the losses for stable operation under the indirect cooling conditions.