Overview
Primarly focused on full-wave simulations of doppler reflectometry. Particularly doppler backscattering and cross polarization scattering in tokamak plasmas. This is done using COMSOL with post processing in Python and automation in Java.
Background
Tokamak plasmas can have steep gradients and other spatial characteristics that make the WKB approximation stray from reality. Hence full-wave solvers are used. Particular phenomena of interest include the non-linear response as we exit the born region, ~5% dn/n, where trapping and saturation affect the power response of the scattered beam. Also the geometry of the perturbation and how the beam interacts with that perturbation affects the overall power response and the cross section of the back scattered beam. Understanding these effects will give insight into experimentally probing turbulence in tokamaks which then will help with mitigating it.
Insights
O mode has seemingly no enhanced response at angles larger than the bragg angle. It is possible that the enhanced response is due to a polarization shift in X mode.
- COMSOL Multiphysics
- Plasma Physics
- Python