Enhanced normal zone propagation velocity in REBCO coated conductors using an intermetallic stabilizer coating

The Current Flow Diverter (CFD) is an established concept that has proven to effectively reduce the probability of destructive hot spots by boosting the normal zone propagation velocity (NZPV) in commercial REBa 2 Cu 3 O 7 (REBCO; RE = Rare Earth) coated conductors (CC). However, incorporating the CFD concept requires finding a scalable method that is also compatible with the already established R2R fabrication process used by CC manufacturers. This study presents a new simple & cost-effective proof-of-concept technique capable of recreating the CFD architecture in commercial CCs coated with silver. The technique is based on promoting a locally controlled thin film diffusion reaction between the silver stabilizer and pure indium. Due to fast diffusion in the Ag-In system, stable Intermetallic Compounds (IMC) are formed throughout the whole thickness of the silver layer reaching the REBCO interface. The presence of Ag-In IMC in the interface safely increases the interfacial resistance (Ω-cm 2 ) by orders of magnitude, thus allowing to safely form the CFD interlayer. Silver-coated tape samples altered using this CFD-IMC have shown an NZPV increase of 5–8x when compared with pristine samples.

Mots clés

coated conductors; HTS; NZPV; quench