This project involves the development of a currentlimiting device designed to operate as a component in high energyfusion plasma power conditioning subsystems. The active element inthe planned current limiter is based on the high temperaturesuperconducting material YBa2Cu.07..' Recent advances in theprocessing of this material greatly improve its electricalcharacteristics; devices that will operate in the tens of kiloampsrange with voltages up to hundreds of kilovolts can now beassembled. Switching speeds on the order of 2 microseconds willalso be demonstrated. Probable applications include use as asafety device that protects power supply thyristors and asultrafast circuit-breaking switches. In Phase I, these advancedsuperconductor materials are being fabricated and characterized todemonstrate their viability in full-scale plasma confinementsystems. This could lead to the design, assembly, and testing ofa prototype full scale current-limiting device during Phase II.Anticipated Results/Potential Commercial Applications as described by the awardee:The use of superconducting current limiters inplasma confinement power supply subsystems will provide a highlyreliable safety device to protect expensive circuitry frominadvertent current discharges, while imposing no losses on thesystem during routine operation. Such current limiters will findwidespread commercial application in utility distribution systemsby protecting equipment from fault current events.
