Non-linear coupling between fluctuations at different radial locations is observed on the Large Helical Device (LHD) plasma. The summed bi-coherence between the low frequency macro-scale fluctuation (frequency is f=2.75kHz) at ρ=reff/a99=0.63 (where a99 is averaged plasma radius) and the high-frequency micro-scale fluctuations (frequency range of f>150kHz) at ρ=0.88 is found to converge to a non-zero and finite value. The bi-phase analysis provides another basis for the non-linear interaction across the long distance. These results are associated with the violation local closure for transport relation.
All Science Journal Classification (ASJC) codes