X‐mode scattering for the measurement of density fluctuations on TFTR (invited)

摘要: Most microwave scattering measurements in tokamaks are done with the polarization of incident radiation approximately parallel to toroidal field (ordinary mode) and at a frequency which is sufficiently above plasma ωpe that refraction effects small. However, as confinement devices get hotter, drift wave turbulence expected occur longer wavelengths. In order observe density fluctuations associated these phenomena good spatial resolution, ideal probe wavelength λi near or beyond ordinary cutoff λi=2πc/ωpe. As result, we have considered propagation extraordinary (X) mode where nearly perpendicular confining fields significantly higher than mode. We modeled X tokamak geometry shown typically remains local along ray path, simplifying in...