Test results from the SMES proof of principle experiment

A proof-of-principle experiment (POPE) has been conducted to demonstrate the stability and operation of the superconducting magnetic energy storage (SMES) conductor in an engineering test model (ETM) design. The experimental facility includes: a 100-kA DC power supply; a 4-T, 1-m bore, background field split solenoid: a three-turn-1-m-diameter test coil for the ETM conductor; a dewar for operation of the solenoid and test coil, at 1.8 K and 1 atm; and support systems for vacuum, helium supply and recovery, and data acquisition. The test facility exactly duplicates the electric, magnetic, and thermal conditions expected for the ETM conductor. A report is presented on measurements of conductor stability vs. transport current, applied magnetic field, and cooling from liquid helium. The measurements characterize the conductor's stability against finite-length traveling normal zones and against quenches resulting from transient normal zones. The data qualify the conductor for dependable use at 50 kA, 4 T, and 1.8 K.