Microwave Scattering From Anisotropic Plasma Turbulence

Microwaves are scattered from an under-dense turbulent plasma. The plasma fluctuations are induced by the strong flow of gas through a discharge tube. The variation of scattered power as a function of scattering angle and angle of incidence is shown to be consistent with the spectral content of the plasma fluctuations as resolved by electrostatic probes provided that the turbulence is anisotropic with thin eddies stretched along the flow axis. An independent check for the existence of this anisotropy is obtained by observing that the backscattered signal becomes increasingly depolarized as grazing incidence is approached.