Development of technology and techniques for reflectometry

Development efforts are directed at advanced reflectometry systems for next generation tokamaks such as ITER. Laboratory tests have been successfully completed for a pulsed radar reflectometer (τ≂200 ps) to be tested on DIII‐D. In addition, there exists a need for sources and components beyond those commercially available. Monolithic quasi‐optical spatial power combined arrays of solid state devices will provide continuous, watt level swept source coverage up to 200 GHz as well as electronically controlled beam steering, focusing, and modulation. Studies are also underway to address the feasibility of instantaneous profile coverage using monolithic impulse generators (τ≂1–3 ps) comprised of spatially combined nonlinear transmission lines, employing novel quantum barrier varactors.