Abstract

Cusped field thruster is a novel electrostatic thruster suitable for space exploration, but with high plume divergence angle. In this article, a 2D Particle-in-cell plus Monte Carlo (PIC-MCC) model is built to study the influence of exit magnetic separatrix angle on controlling plume divergence of cusped field thruster. The electric potential contour line distribution characteristics near exit magnetic separatrix with different angle are obtained and their formation mechanism is explained by magnetic mirror effect and electron pressure term. Simulation results show laying additional magnetic ring at the exit of channel can transfer exit magnetic separatrix towards inward of channel, which can decrease angle between electric potential contour line and central axis and increase ion axial speed. It is mainly due to change of magnetic field line direction and enhancement of magnetic mirror effect. However, simulation results show that ionization intensity in the channel decreases after adopting the plume control method. The plume divergence control method increases the channel length and causes the exit magnetic cusp inside the channel. Therefore the influence of exit magnetic separatrix angle on the characteristics of electron and ion energy deposition distribution on wall is further investigated.

Graphical abstract

中文翻译：

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出口磁分离角对羽流发散控制影响的仿真研究

摘要

Cusped磁场推进器是一种新颖的静电推进器，适用于太空探索，但具有较大的羽流发散角。在本文中，建立了二维单元格内粒子加蒙特卡罗（PIC-MCC）模型，以研究出口磁分离角对控制尖顶磁场推进器羽流发散的影响。得到了不同角度出射磁分离线附近的电位轮廓线分布特性，并通过磁镜效应和电子压力项解释了它们的形成机理。仿真结果表明，在通道出口处放置额外的磁环可使出口磁分离线向通道内部转移，从而减小电势轮廓线与中心轴之间的夹角并增加离子轴向速度。这主要归因于磁场线方向的改变和磁镜效应的增强。然而，仿真结果表明，采用羽流控制方法后，通道中的电离强度降低。羽流散度控制方法会增加通道长度，并在通道内部引起出口磁尖。因此，进一步研究了出射磁偏角对壁上电子和离子能沉积特征的影响。

图形概要