Study of Quench Behavior of ReBCO Impregnated Pancake Coil with a 75-μm-thick Copper Stabilizer Under Conduction-cooled Conditions

Recently, high performance ReBa2Cu3Ox (ReBCO) coated conductor, such as those with over 500 A per 1 cm in width at 77 K, have become commercially available. The quench detection of ReBCO pancake coils under conduction-cooled conditions is an important issue for the safe operation of superconducting applications. Although experimental data on the quench characteristics of ReBCO coated conductors have been reported, there is no sufficient database available regarding ReBCO impregnated pancake coils. In this work, a ReBCO impregnated pancake coil was fabricated using ReBCO coated conductors laminated with a 75-μm-thick copper stabilizer. The inner diameter of the ReBCO coil was 50 mm, and the outer diameter was approximately 73 mm. The measured longitudinal normal-zone propagation velocities (NZPV) in the ReBCO coil were 3–27 mm/s at 50–20 K. It was also confirmed that the ReBCO coil was shut down from 100 A to 240 A by a balance voltage detection at 40–100 mV under conduction-cooled conditions without degradation.