Microwave beam broadening due to turbulent plasma density fluctuations within the limit of the Born approximation and beyond
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Plasma Physics and Controlled Fusion, Volume 60, issue 7
AbstractPlasma 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.
density fluctuations, electromagnetic waves, electron cyclotron waves, magnetized plasmas, plasma turbulence, scattering of electromagnetic radiation, simulation
Köhn , A , Guidi , L , Holzhauer , E , Maj , O , Poli , E , Snicker , A & Weber , H 2018 , ' Microwave beam broadening due to turbulent plasma density fluctuations within the limit of the Born approximation and beyond ' , Plasma Physics and Controlled Fusion , vol. 60 , no. 7 , 075006 , pp. 1-13 . https://doi.org/10.1088/1361-6587/aac000