论文标题
刮擦层中斑点状等离子体丝的随机建模：理论基础
Stochastic modelling of blob-like plasma filaments in the scrape-off layer: Theoretical foundation
论文作者
论文摘要
提出了一个随机模型的随机脉冲，并随机分布振幅，大小，速度和到达时间。假定脉冲以固定形状径向移动，并且由于线性阻尼而及时衰减。脉冲速度被视为时间独立但随机分布。研究了脉冲大小，速度和振幅之间的分布和相关性的含义。对于指数脉冲和脉冲速度的离散均匀分布，得出了最低阶统计矩，概率密度函数和相关函数的表达式。结果描述了高平均颗粒密度，宽平均径向谱的许多特征，以及磁性限制的等离子体边界区域的大振幅，间歇性波动。随机模型阐明了这些现象与斑点样结构的统计数据如何相关。
A stochastic model is presented for a super-position of uncorrelated pulses with a random distribution of amplitudes, sizes, velocities and arrival times. The pulses are assumed to move radially with fixed shape and amplitudes decaying exponentially in time due to linear damping. The pulse velocities are taken to be time-independent but randomly distributed. The implications of a distribution of and correlations between pulse sizes, velocities and amplitudes are investigated. Expressions for the lowest order statistical moments, probability density functions and correlation functions for the process are derived for the case of exponential pulses and a discrete uniform distribution of pulse velocities. The results describe many features of high average particle densities, broad and flat average radial profiles, and large-amplitude, intermittent fluctuations at the boundary region of magnetically confined plasmas. The stochastic model elucidates how these phenomena are related to the statistics of blob-like structures.
