A Study on the Electrical Characteristics of Metal-Clad GdBCO Coils

This paper reports the effectiveness of metal-cladding (MC) winding technique employing a GdBCO tape with a micrometer-thick stainless-steel clad as experimentally compared with that of the partial insulation (PI) winding technique. The investigation included charge-discharge, sudden-discharge, and overcurrent tests. The charge-discharge and sudden-discharge tests showed that the charge/discharge process of the coil using the metal-clad GdBCO tape was considerably shorter than those of the PI coils, because the effective resistance of the MC coil was higher than those of the PI coils. Although the MC coil exhibited lower electrical stability than the PI coils did (when the current is high enough), the MC coil was virtually more stable than any fully insulated coil. This study confirms that the MC winding technique is promising for the development of electrically stable high-field magnets allowing relatively high rates of ramping up and down.