First experiments of pulse compression radar reflectometry for density measurements on JET plasmas

摘要: The different reflectometry methods currently used for the determination of electron density profiles fusion plasmas suffer serious limitations due mainly to plasma fluctuations and parasitic reflections in transmission waveguides. An advanced method, based on pulse compression radar techniques, can be applied overcome these limitations. This paper reports two series results obtained at JET, which first time validate method thermonuclear plasmas. are a reflector positioned short distance beyond end long, complex oversized waveguide. same waveguide is reception, inducing many reflections. second from measurements JET plasmas, using configurations. Results both with show that multiple within line eliminated by correction technique signal analysis procedure. A precision typically 1 cm measured position reflector, or cutoff layer, only 20-50 frequency steps. With fast synthesizers available, complete measurement could made 2-5 mu s, thereby freezing MHD most microturbulence.