Study of RADAR-enhanced scattering on a magnetized rf discharge

RADAR-enhanced scattering (RES) is a sensitive diagnostic for measuring the wavenumber spectra of small-scale density fluctuations. It makes use of the small group velocity of the extraordinary wave near the upper-hybrid resonance (UHR). Microwave pulses irradiating a magnetized plasma are backscattered off density fluctuations with a measurable time delay which is proportional to the fluctuation wavenumber. In the present investigation, we study the RES diagnostic on an rf-generated linear discharge. Reasonable results are achieved using externally excited lower-hybrid waves as test fluctuations. The features of the RES diagnostic are discussed.