Due to large particle exhaust velocity and specific impulse, electric propulsion systems have an edge over chemical propulsion for missions targeting regions outside the Earth's atmosphere. Stationary plasma thrusters and helicon plasma thrusters (HPTs) are commonly used electric propulsion devices for a space mission. In HPTs or expanding magnetic field plasma thrusters, plasma expands from the source region to the expansion region in an externally applied expanding magnetic field. Due to plasma expansion in such a magnetic field configuration, a current free double layer is found to form, which accelerates bulk ions, and a directional ion beam is generated, which causes thrust in the opposite direction. A Particle In Cell (PIC) solver with Monte Carlo Collision (MCC) scheme which resolves the axial direction and all three velocity degrees of freedom (1D-3V PIC-MCC) that captures the 2D spatial plasma expansion effect via a 1D flux conserving model is developed to simulate an argon plasma in an expanding magnetic field. Using the 1D-3V PIC-MCC solver, double layer formation due to plasma expansion, thrust generation, and optimization of thrust studies over a large parameter set, such as fill pressure of Ar, is presented. We compare our results with a particle loss model, which is commonly used as the simplest model for HPTs.

中文翻译：

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使用 1D-3V PIC 模拟在膨胀等离子体中形成双层和产生推力

由于较大的粒子排放速度和比冲，电力推进系统在针对地球大气层以外区域的任务中比化学推进系统具有优势。固定等离子体推进器和螺旋等离子体推进器 (HPT) 是空间任务常用的电力推进装置。在 HPT 或扩展磁场等离子体推进器中，等离子体在外部施加的扩展磁场中从源区扩展到扩展区。由于在这种磁场配置中的等离子体膨胀，发现形成了电流自由双层，这会加速体离子，并产生定向离子束，从而导致相反方向的推力。具有蒙特卡罗碰撞 (MCC) 方案的单元内粒子 (PIC) 求解器，可解析轴向和所有三个速度自由度 (1D-3V PIC-MCC)，通过一维通量守恒模型捕获二维空间等离子体膨胀效应开发用于模拟扩展磁场中的氩等离子体。使用 1D-3V PIC-MCC 求解器，介绍了由于等离子体膨胀、推力生成和推力研究优化对大参数集（例如 Ar 的填充压力）的双层形成。我们将我们的结果与粒子损失模型进行比较，后者通常用作 HPT 的最简单模型。介绍了由于等离子体膨胀、推力生成和推力研究在大参数集（例如 Ar 的填充压力）上的优化而形成的双层。我们将我们的结果与粒子损失模型进行比较，后者通常用作 HPT 的最简单模型。介绍了由于等离子体膨胀、推力生成和推力研究在大参数集（例如 Ar 的填充压力）上的优化而形成的双层。我们将我们的结果与粒子损失模型进行比较，后者通常用作 HPT 的最简单模型。