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Combustion Chemical Vapor Deposition of High Temperature Ceramic Insulator Coatings on Superconductor Wire--MicroCoating Technologies, 3901 Green Industrial Way, Chamblee, GA 30341-1913; 770-457-8400
Dr. Shara S. Shoup, Principal Investigator
Mr. Jerome J. Schmitt, Business Official
DOE Grant No. DE-FG02-98ER82545
Amount: $600,000
Accelerator dipole and quadruple magnets with increased field strengths to at least 15 T, but optimally 20 T, are needed for high energy physics experiments. One of the practical superconducting materials capable of critical fields high enough to support very high critical current densities is Bi2212. However, to enable the use of Bi2212 in practical devices, insulation capable of withstanding over 900° C processing temperatures is needed for this superconducting wire. This project will develop a low-cost, open atmosphere Combustion Chemical Vapor Deposition (CCVD) technique to deposit dense, insulating, submicron oxide coatings onto Ag-clad Bi2212 wire and tape. In Phase I, oxygen-permeable, electrically insulating oxide coatings were deposited onto Ag-clad Bi2212 using the CCVD technique. The critical superconducting current of the heat treated wire was not degraded by the coatings, indicating that the wire can be used to first wind and then react the HTS coil, a major benefit to magnet manufacture. Over 110 meters of Ag wire and Ag-clad Bi2212 tape were coated using a reel-to-reel system, demonstrating process scalability. This is believed to be the longest length of oxide thin film coated superconducting type wire. In Phase II, experiments will focus on optimizing the CCVD process parameters to deposit insulating coatings onto the Ag-clad Bi2212 wire and investigating the thickness of coating necessary to insulate over a range of voltages. The reel-to-reel system will be upgraded to coat at least 1 km length of Bi2212 wire by the end of the project.
Commercial Applications and other Benefits as described by the application: The use of CCVD to deposit thin, high-temperature insulation should enable superconducting materials capable of reaching high field critical current densities to be used in coils and cables. The CCVD process should be used in the manufacture of long-length superconductor wire because of its scalability. This market should exceed $10 million/year in 3 years, if successful.