METHOD OF PERSISTENT CURRENT MODE SPLICING OF 2G ReBCO HIGH TEMPERATURE SUPERCONDUCTORS USING SOLID STATE PRESSURIZED ATOMS DIFFUSION BY DIRECT FACE-TO-FACE CONTACT OF HIGH TEMPERATURE SUPERCONDUCTING LAYERS AND RECOVERING SUPERCONDUCTIVITY BY OXYGENATION ANNEALING

摘要

Disclosed is a method of splicing ReBCO high temperature superconductors (HTSs), which ensures excellent superconductivity after splicing. The method of splicing 2G ReBCO HTSs allows a superconductors-spliced assembly to exhibit excellent superconductivity by direct contact of high temperature superconducting layers of two strands of 2G ReBCO HTSs and solid state atoms diffusion pressurized splicing there between at a ReBCO below peritectic reaction temperature in a vacuum, and enables loss of superconductivity caused by loss of oxygen due to transport and out-diffusion of oxygen to atoms during splicing to be recovered through oxygenation annealing.

主权项

1. A method of splicing second generation ReBCO high temperature superconductors (2G ReBCO HTSs), comprising:
(a) preparing, as splicing targets, two strands of 2G ReBCO HTSs each including a ReBCO high temperature superconducting layer (ReBa2Cu3O7-x, wherein Re is a rare-earth material, and x ranges from 0≦x≦0.6) and other layers; (b) drilling holes in a splicing portion of each of the 2G ReBCO HTSs; (c) etching the splicing portion of each of the 2G ReBCO HTSs to remove the Copper (Cu) and/or Silver (Ag) layer from and expose the ReBCO high temperature superconducting layers at the splicing portion; (d) loading the 2G ReBCO HTSs into a splicing furnace, and arranging the 2G ReBCO HTSs such that the exposed surfaces of the two 2G ReBCO HTSs directly abut, or such that the two exposed surfaces of the 2G ReBCO high temperature superconducting layers directly abut an exposed surface of a 2G ReBCO high temperature superconducting layer of a third 2G ReBCO HTS; (e) performing solid state pressurized splicing of the Copper (Cu) stabilizing layer and/or Silver (Ag) overlayer at both ends of the exposed surfaces of the ReBCO high temperature superconducting layers at atmospheric pressure in the splicing furnace to increase bonding strength of the entire 2G HTSs; (f) performing solid state atoms diffusion by pressurized splicing of the exposed surfaces of the 2G ReBCO high temperature superconducting layers of the 2G ReBCO HTSs by evacuating the splicing furnace and heating the splicing furnace to a below ReBCO peritectic reaction temperature; (g) annealing a spliced zone between the 2G ReBCO HTSs under oxygen atmosphere to supply oxygen to the 2G ReBCO high temperature superconducting layer in each of the 2G ReBCO HTS CCs; (h) coating the spliced zone between the 2G ReBCO HTS CCs with silver (Ag) so as to prevent quenching by bypassing over-current at the spliced zone; and (i) reinforcing the spliced zone between the 2G ReBCO HTS CCs with solder or epoxy.