论文标题
光束中和中三维静电态和表面波的动力学建模
Kinetic modeling of three-dimensional electrostatic-solitary and surface waves in beam neutralization
论文作者
论文摘要
这项工作研究了使用粒子中的粒子模拟发出的电子对离子束的空间充电中和带中和的基本等离子体过程。虽然细丝中和是经济的，但以前的实验表明，在此过程中，各种波动会激发限制空间充电中和。在这项工作中，具有低耗散速率的静电孤波（ESW）的形成和运动是针对2D平面和3D圆柱梁的特征，并观察到可以产生长时间存活并减慢光束中和的过程的波。此外，通过一维伯恩斯坦 - 格林 - 克鲁斯卡尔（BGK）分析，我们发现梁电子的非麦克斯韦性质产生了大型ESW，这些ESW并未通过理论预测，该理论假设可以通过Maxwellian分布来描述电子。我们的PIC模拟足够敏感，能够在3D圆柱形几何形状中解决重要的三维效应，从而导致由于中和开始时存在高能电子而引起的TrivelPiepe-gould表面波的激发。
This work studies the fundamental plasma processes involved in the neutralization of an ion beam's space-charge by electrons emitted by a filament using Particle-in-Cell simulations. While filament neutralization is economical, previous experiments have shown that a variety of waves become excited in this process that limit the space-charge neutralization. In this work, the formation and movement of electrostatic solitary waves(ESWs), which have low dissipation rates, are characterized for 2D planar and 3D cylindrical beams and are observed to generate waves that survive for a long time and slow the process of beam neutralization. Further, through a 1D Bernstein-Greene-Kruskal (BGK) analysis, we find that the non-Maxwellian nature of the beam electrons gives rise to large-sized ESWs that are not predicted by theory which assumes that the electrons may be described by a Maxwellian distribution. Our PIC simulations are sufficiently sensitive to be able to resolve important three-dimensional effects in a 3D cylindrical geometry that lead to the excitation of Trivelpiece-Gould surface waves due to high-energy electrons present at the beginning of neutralization.
