Numerical Study of Microwave Reflectometry in Plasmas with 2D Turbulent Fluctuations
This paper describes a numerical study of the role played by 2D turbulent fluctuations in microwave reflectometry -- 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 wavenumbers, 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 1D 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.
- Research Organization:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 4523
- Report Number(s):
- PPPL-3287; ON: DE00004523
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microwave Imaging Reflectometry for the Measurement of Turbulent Fluctuations in Tokamaks
The application of X-mode reflectometry to the study of large scale fluctuations in TFTR