Stability of 2G HTS Double Pancake Coil With Metal Insulation and Two Parallel Resistors

The enhanced stability of 2G HTS double pancake (DP) coil with metal insulation and parallel resistor was observed in contrast with the case of only metal insulation. Here, we used stainless steel tape and additional indium metal sheet as metal insulator and parallel resistor. The total length of the DP coil was 66 m and the critical current (I c ) of the DP coil was about 78.1 A in liquid nitrogen in the criterion of 0.1 μV/cm. Minimum quench energies (MQEs) were 3.154 J at 60 A of the coil current in liquid nitrogen. MQE was 1.295 J at 60 A of the coil current and 77 K in conduction cool. New DP coil was fabricated by using the indium sheet resistor. MQE was 10.935 J in liquid nitrogen and 1.306 J in conduction cool. In this case, 2G DP MI coil attached with parallel resistors was robust under the condition of the quench induced by the heater.