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This paper presents the effects of thermal grease on the electrical and thermal characteristics of GdBCO pancake coils, observed through charge-discharge, sudden discharge, over-current, and thermal quench testing. In charge-discharge and sudden discharge tests, a coil using thermal grease as an insulation material demonstrated faster charging/discharging rates compared to a coil without turn-to-turn insulation. In the case of over-current tests, the coil using thermal grease exhibited the highest electrical stability. Furthermore, thermal quench testing showed the coil employing thermal grease to possess superior thermal characteristics, with rapid cooling and low temperature rise. Overall, the use of thermal grease as an insulation material may be a potential solution to the problems observed with the existing insulation materials, possessing fast charging/discharging rates with superior thermal and electrical stabilities.

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This study examined the effects of external pressures on the thermal and electrical stabilities of stacked GdBCO CCs through quench tests. The minimum quench energies and two-dimensional normal zone propagation velocities of stacked GdBCO CCs connected electrically in series under various external pressures were examined. The quench test results showed that the minimum quench energy increased with increasing the external pressure. Longitudinal normal zone propagation velocities were greater than transverse normal zone propagation velocities. Moreover, normal zone propagation velocities increased with increasing applied pressure implying that applied pressure resulted in increased layer-to-layer thermal contact that allowed hot spots to dissipate more easily.Index Terms-GdBCO CC, minimum quench energy (MQE), normal zone propagation (NZP), thermal/electrical stability.