Numerical study of microwave reflectometry in plasmas with two-dimensional turbulent fluctuations
- Princeton Plasma Physics Laboratory, Princeton, New Jersey08543 (United States)
This article describes a numerical study of the role played by two-dimensional turbulent fluctuations in microwave reflectometry{emdash}a radar technique for density measurements using the reflection of electromagnetic waves from a plasma cutoff. The results indicate that, if the amplitude of fluctuations is below a threshold which is set by the spectrum of poloidal wave numbers, the measured backward field appears to originate from a virtual location behind the reflecting layer, and to arise from the phase modulation of the probing wave, with an amplitude given by one-dimensional geometric optics. These results suggest a possible scheme for turbulence measurements in tokamaks, where the backward field is collected with a wide aperture antenna, and the virtual reflecting layer is imaged onto the plane of an array of detectors. Such a scheme should be capable of providing additional information on the nature of the short-scale turbulence observed in tokamaks, which still remains one of the unresolved issues in fusion research. {copyright} {ital 1998 American Institute of Physics.}
- OSTI ID:
- 627580
- Journal Information:
- Review of Scientific Instruments, Vol. 69, Issue 4; Other Information: PBD: Apr 1998
- Country of Publication:
- United States
- Language:
- English
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