Influence of edge plasma turbulence on the low-threshold parametric decay instability at ECRH
Abstract
the saturation level of the two-Upper-Hybrid-plasmon (UH) low-threshold parametric decay instability (PDI) depend on the pump wave beam width. The edge plasma turbulence may lead to drastic distortion of the pump beam, thus generating PDI characteristics changes. Numerical evaluations of the PDI process are provided in this work for different turbulence scenarios. The average PDI characteristics are evaluated and compared to the simulation results for the pump beam unperturbed by the edge plasma turbulence. It is shown that up to the intermediate turbulence level the PDI characteristics are only gently modified. But at high edge turbulence level, which can happen in tokamaks, the threshold increases and the growth rate reduces. It is important to note that the anomalous absorption keeps a little reduction value, whatever the edge turbulence regimes.
Origin | Files produced by the author(s) |
---|