Kim Chang-Bae, An Chan-Yong, Min Byunghoon
Physics Department and Research Institute for Origin of Matter and Evolution of Galaxies, Soongsil University, Seoul, 156-743, Korea.
Sci Rep. 2018 Jun 5;8(1):8622. doi: 10.1038/s41598-018-26793-8.
The dynamics of the fluctuating electrostatic potential and the plasma density couched in the resistive-drift model at nearly adiabatic state are simulated. The linear modes are unstable if the phase difference between the potential and the density are positive. Exponential growth of the random small perturbations slows down due to the nonlinear E × B flows that work in two ways. They regulate the strength of the fluctuations by transferring the energy from the energy-producing scale to neighboring scales and reduce the cross phase at the same time. During quasi-steady relaxation sporadic appearance of very strong turbulent particle flux is observed that is characterized by the flat energy spectrum and the broad secondary peak in the mesoscale of the order of the gyro-radius. Such boost of the transport is found to be caused by presence of relatively large cross phase as the E × B flows are not effective in cancelling out the cross phase.
模拟了近绝热状态下电阻漂移模型中波动静电势和等离子体密度的动力学。如果电势和密度之间的相位差为正，则线性模式是不稳定的。由于非线性E×B流以两种方式起作用，随机小扰动的指数增长会减慢。它们通过将能量从能量产生尺度转移到相邻尺度来调节波动强度，并同时减小交叉相位。在准稳态弛豫期间，观察到非常强的湍流粒子流的零星出现，其特征是能量谱平坦，在陀螺半径量级的中尺度上有宽的次级峰值。发现这种传输增强是由相对较大的交叉相位的存在引起的，因为E×B流在抵消交叉相位方面无效。
