Wave-Number Spectral Characteristics of Drift Wave Micro-Turbulence with Large-Scale Structures

作     者：李继全 Y.KISHIMOTO 

作者机构：Graduate School of Energy Science Kyoto University 611-0011 Gokasho Uji Japan 

出 版 物：《Plasma Science and Technology》 (等离子体科学和技术（英文版）)

年 卷 期：2011年第13卷第3期

页      面：297-301页

核心收录：

学科分类：07[理学] 08[工学] 070401[理学-天体物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0704[理学-天文学] 

基　　金：Grant-in-Aid from JSPS JSPS-CAS Core University program in the field of 'Plasma and Nuclear Fusion' 

主　　题：spectral scaling law zonal flows micro-turbulence gyrofluid simulation 

摘      要：Wave-number spectral characteristics of drift wave micro-turbulence with large-scale structures （LSSs） including zonal flows （ZFs） and Kelvin-Holmheltz （KH） mode are investigated based on three dimensional gyrofluid simulations in a slab geometry. The focus is on the property of the wave-number spectral scaling law of the ambient turbulence under the back reaction of the self-generated LSSs. A comparison of the spectral scaling laws between ion/electron temperature gradient （ITG/ETG） driven turbulences is presented. It is shown that the spectral scaling of the ITG turbulence with robust ZFs is fitted well by an exponential-law function （Φ^2/2）E∝e^-λkx in kx and a power-law one in （Φ^2/2）p∝ky^-β in ky. However, the ETG turbulence is characterized by a mixing Kolmogorov-like power-law and exponential-law （Φ^2/2）E∝e-λkx＇yk^-3x,y/（1 ＋ k^2x,y）^2 scaling for both kx and ky spectra due to the ZFs and KH mode dynamics, with λ and β the slope index factors. The underlying physical mechanism is understood as the spectral scattering caused by the back-reaction of the LSSs on the ambient turbulence. These findings may provide helpful guideline to diagnose the plasma fluctuations and flow structures in experiments.