论文标题
离子驱动的环形电子等离子体的不稳定 - 3D3VPIC模拟
Ion-driven destabilization of a toroidal electron plasma -- A 3D3VPIC Simulation
论文作者
论文摘要
据报道，使用高富达3D3V PIC求解器，以$ {ar}^+$离子为$ {ar}^+$离子，在紧密的纵横比轴对称环形设备中，环形电子等离子体的离子共振不稳定。最近发现的静态准稳态状态（QQS）的静态电子等离子体从“种子”溶液中获得的熵溶液中的熵极端化，这是零惯性的，这是少量离子种群的存在。电子等离子体达到QQS状态后，将离子分数（$ f $）和相应数量的二次电子预加载到系统中。在离子驱动的情况下，电子等离子体表现出不稳定的“电荷运动中心”（$ m = 1 $），以及增加的poloidal模式耦合（$ m = 1 $至$ 9 $），并且主要$ m = 2 $模式。壁探头电流的增长本质上是代数，$ f $ \ $ \ geq $ 0.005 $增加，以后显示饱和。离子温度的值高于电子温度，这表明通过离子谐振和伴随的离子加热从电子等离子体到离子的共振能量转移。电子等离子体的体积平均温度值通过模拟时间升高，在模拟时间结束时达到了准稳态的性质。正如保存绝热不变剂可以预期的那样，沿平行和垂直方向的通量管平均电子温度分别为$ 1/r^2 $和$ 1/r $，其中$ r $是主要的radialable，尽管血浆几乎无碰撞。
Ion resonance instability of toroidal electron plasmas in a tight aspect ratio axisymmetric toroidal device is reported for ${Ar}^+$ ions of different initial density values using a high fidelity 3D3V PIC solver. Stability of a recently discovered quiescent quasi-steady state (QQS) of a toroidal electron plasma obtained from "seed" solution as a result of entropy extremization at zero inertia, is addressed to the presence of a small ion population. An ion fraction ($f$) and corresponding number of secondary electrons are preloaded into the system after the electron plasma attains a QQS state. Driven by the ions, the electron plasma exhibits destabilized "center of charge motion" ($m = 1$) along with increased poloidal mode coupling ($m = 1$ to $9$) with dominant $m = 2$ mode. The growth in wall probe current is algebraic in nature and increases for $f$ $\geq$ $0.005$, showing saturation at later time. Higher values of ion temperatures than the electron temperatures indicate a resonant energy transfer from electron plasma to ions via ion-resonance and concomitant ion heating. The volume averaged temperature value of the electron plasma rises with simulation time, attaining a quasi-steady nature near the end of the simulation time. As can be expected from conservation of adiabatic invariants, the flux tube averaged electron temperatures along parallel and perpendicular directions are found to scale as $1/R^2$ and $1/R$ respectively, where $R$ is the major radial variable, though the plasma is nearly collision-less.
