论文标题
磁场梯度和二级电子发射对EXB等离子体配置的不稳定性和传输的影响
Effects of magnetic field gradient and secondary electron emission on instabilities and transport in an ExB plasma configuration
论文作者
论文摘要
如今，在EXB配置中部分磁化的低温等离子体（LTP），其中应用磁场垂直于自符合的电场，具有重要的工业应用。 Hall推进器是一种静电等离子体推进，是主要的LTP技术之一，其进步受到不受欢迎的基础物理的影响，尤其是在等离子体不稳定性和相关的电子跨场运输方面。在这些现代跨场配置中，具有非常规磁场拓扑的大厅推进器的开发对不稳定性的特征和电子动力学提出了进一步的问题。因此，我们在这项工作中介绍了一系列关于四个因素对霍尔推进器的径向 - 齐路坐标中血浆过程的影响的研究，即磁场梯度，次级电子发射，电子中性碰撞，电子中性碰撞和质量密度密度。研究使用作者开发的降低粒子中的粒子（PIC）代码进行研究。径向 - 齐路模拟的设置在很大程度上遵循了一个明确的基准案例，该基准案例沿着磁场沿着半径定向，并施加恒定的轴向电场，垂直于模拟平面。我们研究中的显着发现是，在与血浆升高密度相对应的研究病例中，反向能量级联反应会导致形成长波长，高频方位角模式。此外，在存在强磁场梯度的情况下，该模式得到了充分的开发，并诱导了显着的电子跨场传输以及对离子种群的显着加热。
Today, partially magnetized low-temperature plasmas (LTP) in an ExB configuration, where the applied magnetic field is perpendicular to the self-consistent electric field, have important industrial applications. Hall thrusters, a type of electrostatic plasma propulsion, are one of the main LTP technologies whose advancement is hindered by the not-fully-understood underlying physics of operation, particularly, with respect to the plasma instabilities and the associated electron cross-field transport. The development of Hall thrusters with unconventional magnetic field topologies has imposed further questions regarding the instabilities' characteristics and the electrons' dynamics in these modern cross-field configurations. Accordingly, we present in this effort a series of studies on the influence of four factors on the plasma processes in the radial-azimuthal coordinates of a Hall thruster, namely, the magnetic field gradient, Secondary Electron Emission, electron-neutral collisions, and plasma number density. The studies are carried out using the reduced-order particle-in-cell (PIC) code developed by the authors. The setup of the radial-azimuthal simulations largely follows a well-defined benchmark case from the literature in which the magnetic field is oriented along the radius and a constant axial electric field is applied perpendicular to the simulation plane. The salient finding from our investigations is that, in the studied cases corresponding to elevated plasma densities, an inverse energy cascade leads to the formation of a long-wavelength, high-frequency azimuthal mode. Moreover, in the presence of strong magnetic field gradients, this mode is fully developed and induces a significant electron cross-field transport as well as a notable heating of the ion population.
