论文标题
在存在不均匀背景的情况下，纵向束 - 血浆不稳定性的生长
The growth of the longitudinal beam-plasma instability in the presence of an inhomogeneous background
论文作者
论文摘要
我们研究了背景血浆中密度不均匀性的情况下，梁血浆系统的纵向稳定性。先前的作品集中在非权威主义方案上，其中使用流体动力学模型来进化不均匀背景等离子体内的langmuir波。在这里，我们第一次以全面的方式研究动力学方程的问题。我们不假定存在Langmuir波，我们专注于从初始扰动中在此类系统中激发波的速率和机制。我们得出了不稳定模式的结构，并计算其生长速率的分析近似。我们的计算仅限于稀释和冷束，并且与使用锋利代码进行的粒子中的粒子模拟显示出非常一致的一致性。我们表明，由于这种不均匀性，在播层间介质中的毒力束 - 气值不稳定性不会被抑制，但是它们在太阳风中的对应物可以被抑制，因为传播型III太阳能无线电爆发可以证明。
We study the longitudinal stability of beam-plasma systems in the presence of a density inhomogeneity in the background plasma. Previous works have focused on the non-relativistic regime where hydrodynamical models are used to evolve pre-existing Langmuir waves within inhomogeneous background plasmas. Here, for the first time we study the problem with kinetic equations in a fully-relativistic way. We do not assume the existence of Langmuir waves, and we focus on the rate and the mechanism by which waves are excited in such systems from an initial perturbation. We derive the structure of the unstable modes and compute an analytical approximation for their growth rates. Our computation is limited to dilute and cold beams, and shows an excellent agreement with particle-in-cell simulations performed using the SHARP code. We show that, due to such an inhomogeneity, the virulent beam-plasma instabilities in the intergalactic medium are not suppressed but their counterparts in the solar wind can be suppressed as evidenced by propagating type-III solar radio bursts.
