Dual mode (ordinary-extraordinary) correlation reflectometry for magnetic field and turbulence measurements (invited)

Dual mode [ordinary-extraordinary (O-X)] correlation reflectometry has the potential advantage of being able to determine magnetic field strength, \(B) under bar\, simultaneously with correlation properties of turbulence (e.g., radial correlation length, coherency, power spectra, etc.). Controlled dual mode correlation reflectometry experiments, conducted in the Large Plasma Device at UCLA, are presented. The purpose of these experiments was (1) to demonstrate the proof of principle of parallel toB_parallel to measurement, and (2) to make detailed comparisons between dual mode and single mode (O-O,X-X) reflectometer, and Langmuir probe radial correlation measurements. It is shown that, in these experiments, \(B) under bar\ can be determined from O-X correlation measurements, interpreted via a one-dimensional numerical model. In addition, good agreement is found between correlation lengths (within 10%-15%), coherency, and power spectra measured by O-X, O-O, and X-X reflectometry, and a Langmuir probe array. (C) 2001 American Institute of Physics.