Performance of the Algorithms for Bispectral Analysis on Turbulence and Their Application in Edge Plasmas
Yu-Hang Shen, Jia Li, Tian Li · Journal of the Physical Society of Japan · 2020
Bispectrum technology gives people a deeper experimental understanding of the nonlinear wave process. Determining how to use the specific techniques for bispectral analysis on turbulence is a crucial issue for the correctness and accuracy of the results. In this research, the performance and effectiveness of the complete iterative algorithm were studied in specific turbulence systems and compared with those of Kim’s algorithm [J. S. Kim et al., Phys. Plasmas 3, 3998 (1996)]. The simulation turbulence with the pre-set ideal output spectra and the typical plasma turbulence were introduced in order to perform a numerical study on the performance of the two algorithms. The results showed that Kim’s algorithm was, indeed, more suitable for the study of edge plasma turbulence than the complete iterative algorithm. Based on this consequence, we utilized Kim’s algorithm to carry out a bispectral analysis of the edge plasma turbulence in a tokamak. Then it was observed that the energy was transferred from the linear-growing wave to the damping wave and the energy was transferred between different frequency domains of the turbulence, which was important evidence for the existence of both an energy cascade and an inverse cascade in the plasma turbulence.