Ion cyclotron range of frequency (ICRF) power is anticipated to be an auxiliary heating source in tokamak experiments like the International Thermonuclear Experimental Reactor (ITER). An ICRF system utilizes an antenna to couple power to the plasmas. From a technological perspective, electrical breakdown is a significant challenge. Current antennas use materials with high conductivity, like copper, where the copper has been deposited onto a structural material like Inconel. However, copper's low melting temperature and deteriorating mechanical properties at elevated temperatures result in electrical breakdown of the antenna. ICRF antenna performance can be significantly improved by replacing the copper coating with a refractory metal such as tungsten. During this investigation, innovative Vacuum Plasma Spray (VPS) coating techniques have been developed to enable the deposition of tungsten coatings on ICRF antenna materials. Microstructural and physical properties results for the VPS tungsten deposits will be presented along with results from electrical breakdown testing.
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