A no-insulation (NI) winding technique has been utilized in high-temperature superconducting (HTS) coils owing to enhanced thermal and electrical stabilities as well as high mechanical strength. However, the charge-discharge rate of the NI coil is considerably slower than that of completely insulated coils. Although metal-insulation (MI) and partial-insulation (PI) winding techniques have been suggested to ameliorate the slow charge-discharge rate of the NI coil, the current density of MI coils and mechanical strength of PI coils are respectively lower than those of their NI counterparts. Therefore, a metallic cladding (MC) winding technique that utilizes the HTS tape employing a μm-thick metallic cladding layer has recently been developed to resolve the drawbacks of the PI and MI coils. In this study, we examined the charge-discharge rate and thermal/electrical stabilities of the MC GdBCO coil through charge-discharge, sudden discharge and over-current tests. Based on the test results, we discussed the feasibility of the MC winding technique to obtain a thermally stable and mechanically robust HTS magnet with an enhanced overall current density.
Acknowledgement: This work was supported by the Materials and Components Technology Development Program of KEIT [10053590, Development of MgB2 wire and coil with a high critical current and long length for superconducting medical-electric power equipment] and in part by the Korea Basic Science Institute under Grant D37614.
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