Ion dynamics driven by a strongly nonlinear plasma wake
Ion dynamics driven by a strongly nonlinear plasma wake
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由强非线性等离子体尾流驱动的离子动力学
DOI：
10.1088/1361-6587/ac4523
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发表时间：
2022
影响因子：
2.2
通讯作者：
Downer, M C
中科院分区：
文献类型：
--
作者：
Khudiakov, V K;Lotov, K V;Downer, M C
在等离子体尾场加速器中，等离子体中激发的波最终破裂并留下缓慢变化的场和电流，扰乱离子密度背景。我们使用高级加速器实验测试设施 (FACET) 实验的例子对这一过程进行了数值研究，其中波是由径向束缚等离子体中气泡区域中的电子束激发的。离子动力学的基础有四种物理效应：（1）驱动器和波的场将离子向轴吸引，导致密度峰值的形成，（2）密度峰值衰减后产生离子声孤子，（3）波破碎后等离子体正充电，导致一些离子沿径向加速，以及（4）波破碎期间产生的电流产生等离子体箍缩。这些效应的相互作用导致形成各种径向密度分布，这是很难用任何其他方式产生的。
In plasma wakefield accelerators, the wave excited in the plasma eventually breaks and leaves behind slowly changing fields and currents that perturb the ion density background. We study this process numerically using the example of a Facility for Advanced aCcelerator Experimental Tests (FACET) experiment where the wave is excited by an electron bunch in the bubble regime in a radially bounded plasma. Four physical effects underlie the dynamics of ions:(1) attraction of ions toward the axis by the fields of the driver and the wave, resulting in formation of a density peak,(2) generation of ion-acoustic solitons following the decay of the density peak,(3) positive plasma charging after wave breaking, leading to acceleration of some ions in the radial direction, and (4) plasma pinching by the current generated during the wave-breaking. The interplay of these effects results in the formation of various radial density profiles, which are difficult to produce in any other way.