论文标题
连续注入相对论的电子束松弛到具有大尺度密度梯度的等离子体的数值模拟
Numerical simulations of a continuously injected relativistic electron beam relaxation into a plasma with large-scale density gradients
论文作者
论文摘要
在本文中，磁化等离子体密度的大规模降低和增加的梯度对连续注射的相对论电子束的弛豫过程，其能量为611 keV（$ v_b = 0.9c $），并且使用粒子中的数字模拟研究了俯仰式的分布。已经发现，对于所选参数，在平稳降低梯度的情况下，在同质等离子体中，会发生大幅度振幅的空间有限的等离子体振荡的形成。在这种情况下，会发展不稳定，并形成了离子密度的长波纵向调制。另外，血浆波的幅度大幅度会加速等离子体电子，从而在梁能量的顺序上加速能量。在增加和急剧降低梯度的情况下，观察到等离子体振荡的幅度显着下降，并且观察到湍流离子密度谱的形成。还证明了将梁电子加速到能量的可能性是梁颗粒的初始能量的2倍以上。该过程不仅发生在束生长的血浆密度中，而且发生在均匀的血浆中，由于束颗粒与大幅度的等离子体振荡的相互作用。
In this paper the influence of large-scale decreasing and increasing gradients of the density of magnetized plasma on the relaxation process of a continuously injected relativistic electron beam with an energy of 611 keV ($v_b=0.9c$) and a pitch-angle distribution is studied using particle-in-cell numerical simulations. It is found that for the selected parameters in the case of a smoothly decreasing gradient and in a homogeneous plasma the formation of spatially limited plasma oscillations of large amplitude occurs. In such cases, modulation instability develops and a long-wave longitudinal modulation of the ion density is formed. In addition, the large amplitude of plasma waves accelerates plasma electrons to energies on the order of the beam energy. In the case of increasing and sharply decreasing gradients, a significant decrease in the amplitude of plasma oscillations and the formation of a turbulent ion density spectrum are observed. The possibility of acceleration of beam electrons to energies more than 2 times higher than the initial energy of the beam particles is also demonstrated. This process takes place not only during beam propagation in growing plasma density, but also in homogeneous plasma due to interaction of beam particles with plasma oscillations of large amplitude.
