VIPER: an industrially scalable high-current high-temperature superconductor cable

High-temperature superconductors (HTS) promise to revolutionize high-power applications likewind generators, DC power cables, particle accelerators, and fusion energy devices. A practicalHTS cable must not degrade under severe mechanical, electrical, and thermal conditions; havesimple, low-resistance, and manufacturable electrical joints; high thermal stability; and rapiddetection of thermal runaway quench events. We have designed and experimentally qualified avacuum pressure impregnated, insulated, partially transposed, extruded, and roll-formed(VIPER) cable that simultaneously satisfies all of these requirements for the first time. VIPERcable critical currents are stable over thousands of mechanical cycles at extremeelectromechanical force levels, multiple cryogenic thermal cycles, and dozens of quench-liketransient events. Electrical joints between VIPER cables are simple, robust, and demountable.Two independent, integrated fiber-optic quench detectors outperform standard quench detectionapproaches. VIPER cable represents a key milestone in next-step energy generation andtransmission technologies and in the maturity of HTS as a technology.