Abstract
Plasma turbulence, and edge density fluctuations in particular, can under certain conditions broaden the cross-section of injected microwave beams significantly. This can be a severe problem for applications relying on well-localized deposition of the microwave power, like the control of MHD instabilities. Here we investigate this broadening mechanism as a function of fluctuation level, background density and propagation length in a fusion-relevant scenario using two numerical codes, the full-wave code IPF-FDMC and the novel wave kinetic equation solver WKBeam. The latter treats the effects of fluctuations using a statistical approach, based on an iterative solution of the scattering problem (Born approximation). The full-wave simulations are used to benchmark this approach. The Born approximation is shown to be valid over a large parameter range, including ITER-relevant scenarios.
| Original language | English |
|---|---|
| Article number | 075006 |
| Journal | Plasma Physics and Controlled Fusion |
| Volume | 60 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 15 May 2018 |
| MoE publication type | A1 Journal article-refereed |
Funding
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under grant agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Keywords
- density fluctuations
- electromagnetic waves
- electron cyclotron waves
- magnetized plasmas
- plasma turbulence
- scattering of electromagnetic radiation
- simulation
