Multi-Channel MMW Interferometry for Plasma Diagnostics

70689S02-II Interferometric measurements of plasma density distribution, needed in fusion energy research, require an improvement in productivity. To address this need, this project will develop a new millimeter-wave interferometer with electronically switched multiple channels. Phase I demonstrated the feasibility of the approach using low density plasma. All millimeter-wave components of the interferometer, including the millimeter-wave switches, were designed, fabricated, and tested. Phase II will complete the design of the interferometer including millimeter-wave and low frequency electronics. Then, the instrument will be fabricated and tested. Commercial Applications and Other Benefits as described by awardee: The instrument should provide compactness, versatility, and cost-effectiveness and dramatically enhance the productivity of measurements of plasma-density distributions. It should be attractive for installation at plasma facilities all over the world, including tokamaks and stellarators. The technology also could be used in a front-end sensor for millimeter-wave imaging, with a potential market in automobile collision avoidance and aircraft landing instrumentation.