Resolving the propagation direction of tokamak microturbulence via homodyne spectroscopy

Abstract
A new homodyne spectroscopy technique [T. Tsukishima and O. Asada, Jpn. J. Appl. Phys. 17, 2059 (1978)] has been applied to tokamak microturbulence measurements in order to resolve the frequency spectra and wave propagation direction of low-frequency density fluctuations. Application of this method provides a high-resolution, inexpensive, and easily implemented alternative to the more technically demanding heterodyne detection schemes typically available. Comparison of heterodyne and the new homodyne spectroscopy results will be made.