Quench detection method for 2G HTS wire

Abstract

2G HTS conductors are increasingly used in various commercial applications and theirthermal and electrical stability is an important reliability factor. Detection and preventionof quenches in 2G wire-based cables and solenoids has proven to be a difficult engineeringtask. This is largely due to a very slow normal zone propagation in coated conductors thatleads to formation of localized hotspots while the rest of the conductor remains in thesuperconducting state. We propose an original method of quench and hotspot detection for2G wires and coils that is based upon local magnetic sensing and takes advantage of 2Gwire planar geometry. We demonstrate our technique experimentally and show that itssensitivity is superior to the known voltage detection scheme. A unique feature of themethod is its capability to remotely detect instant degradation of the wire criticalcurrent even before a normal zone is developed within the conductor. Variousmodifications of the method applicable to practical device configurations are discussed.