Conditions for the break down of the Random Phase Screen Model in Reflectometry
Abstract
The use of reflectometry has revolutionized the study of turbulence in Tokamak plasmas by providing highly localized spatial and temporal information on the fluctuation characteristics. Unfortunately, the interpretation of the reflected waves is not so straight forward when the density fluctuation level increases above some threshold or when the fluctuation scale length is of the order of the free space wavelength of the microwave beam. One important model for reflectometry - the random phase screen model - has been particularly useful for interpreting reflectometer measurements at long wavelengths. In this paper we analyse the criteria for the breakdown of the phase screen model using 2-D full wave solutions of the scalar wave equation. Comparison to experimental data obtained on the C-MOD tokamak will be presented.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 1999
- Bibcode:
- 1999APS..DPP.KP137N