Tests on a 200 kA cable-in-conduit conductor for SMES application

This paper describes the tests conducted to characterize the performance of the 200 kA conductor used in the Bechtel Team´s SMES (superconducting magnetic energy storage) design. The CICC-type conductor was tested at operating temperature (1.8 K) and field by placing the sample in the bore of a dipole magnet and simultaneously ramping the current and the background field to simulate operation along the load line. The test sample and its return cables were the secondary of a superconducting transformer rated at 300 kA. Two test series were conducted with slightly different samples: one in which the cable had been soldered, the other without the solder. In both cases, the first quench along the load line occurred at 110% of the rated operating current. The training behavior and the observed critical current curve were slightly different for the samples. The tests validated the conductor design for application in the SMES coil, and also yielded a world record in current through a superconductor, reaching 303 kA along the 4.5 tesla load line.<>