Continuous Fabrication of IBAD-MgO Based Coated Conductors

Abstract

Reel-to-reel tape processing capable of fabricating tens of meters of coated conductor has been set up at Los Alamos National Laboratory. These reel-to-reel facilities include electropolishing, IBAD-MgO texturing, buffer layer deposition, REBaCuO pulsed laser deposition and position dependent critical current and ac-loss measurement. The systems enable development of long-length coated conductors as well as high-throughput experimentation. IBAD-MgO is an extremely fast process, demonstrated at 100 meters/hour, but requires smooth surfaces over long lengths, which is achieved in our laboratory by electropolishing of metal alloy tapes. Barrier and buffer layers are optimized to minimize interdiffusion from the substrate into the superconductor and to maximize crystalline alignment. YBCO is deposited in a multi-zone heater that allows for an engineered heating power profile as the YBCO film is deposited. Currently the best critical current result on a 1 meter length for a 3 /spl mu/m thick YBCO layer is 350 A (self field, 75.5 K).