Two-dimensional bispectral analysis of drift wave turbulence in a cylindrical plasma
- Graduate School of Frontier Sciences, University of Tokyo, Kashiwa 277-8561 (Japan)
- Research Institute for Applied Mechanics, Kyushu University, Kasuga 816-8580 (Japan)
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580 (Japan)
- National Institute for Fusion Science, Toki 509-5292 (Japan)
Bispectral analysis and multichannel measurement are becoming attractive investigation tools in plasma fluctuation studies. In the Large Mirror Device-Upgrade, the measurement of fluctuations in the ion saturation-current with a 64-channel poloidal Langmuir probe array was performed. The two-dimensional (2D) (poloidal wave number and frequency) power spectrum showed a number of pronounced peaks and broadband fluctuations in the poloidal wave number-frequency space. We applied 2D bispectral analysis, which considers both the matching conditions of poloidal wave number and frequency, to the spatiotemporal waveform, and confirmed the nonlinear couplings between coherent-coherent, coherent-broadband, and broadband-broadband fluctuation components. More than ten peaks were revealed to have as their origins only three original parent modes generated in the plasma. Comparison between the theoretical estimate and experimental observation for the bicoherence showed good agreement.
- OSTI ID:
- 21371115
- Journal Information:
- Physics of Plasmas, Vol. 17, Issue 5; Other Information: DOI: 10.1063/1.3429674; (c) 2010 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Wave-wave interactions in solar type III radio bursts
Convergence study of bispectral analysis in experiments of high temperature plasmas