Particle-in-cell simulation of the cathodic arc thruster

Abstract

The cathodic arc thruster is a newly developed electric propulsion system. It provides a stream of ions with very high velocities from a solid conducting cathode. This high ion velocity in combination with a high ionization fraction makes the cathodic arc thruster attractive for spacecraft propulsion. In the past, a record-high specific impulse was measured for such thrusters. The thruster uses a voltage of −220 V at the cathode for several microseconds, producing plasma from the cathode material which then streams out of the thruster producing thrust. In this work, a two-dimensional axial-symmetric particle-in-cell code with Monte-Carlo collisions is used to simulate the plasma of a cathodic arc thruster with a simplified wall model for the initial triggering of the arc. The work concentrates on the plasma transport and aims not at a self-consistent description of the arc, including plasma-wall interaction, e.g., description of the erosion and surface heating. The interaction of the arc beam with the background plasma results in a plasma-beam instability. Due to this instability charge separation can be detected that leads to large electric fields. By this electric field, plasma particles are accelerated and contribute to the thrust.

Numerical simulation of the plasma acceleration process in a magnetically enhanced micro-cathode vacuum arc thruster

“…In order to reduce the amount of numerical calculations while maintaining the fully kinetic character of the model, the size of the calculation domain in this study is scaled down using a self-similar method as reported in [31][32][33][34][35][36]. The selfsimilar method was inspired by the similar design method often used in thruster design.…”

PIC Simulations of the MS4 Thruster

“…The two-dimensional (2D), cylinder-symmetric, electrostatic Particle-in-Cell (PIC) code used to simulate the MS4 has been widely applied to various ion thrusters [6][7][8]. The model follows superparticle trajectories of neutrals, ions, doubly charged ions and electrons.…”

Plasma instability of magnetically enhanced vacuum arc thruster

“…III D), and characteristic radius of R = 0.03 m is made use of referring to previous studies. 20,28 The radial density profile is shown in Fig. 2, a typical plasma distribution near the exit of MEVAT.…”

“…[7][8][9][10][11][12] Due to the nonuniform configurations of equilibrium magnetic field, discharge area and plume, plasma rotation driven by Lorentz force commonly occurs in various electric thrusters. [13][14][15][16] A few analytical models have been developed or/and applied to describe this flowing phenomenon, [17][18][19][20][21] but little attention was given to the resulted plasma instability which, however, can effect the propulsion efficiency, precise control, durable reliability and life time significantly. 22,23 This paper considers an emerging plasma propulsion technology, namely magnetically enhanced vacuum a) Electronic mail: leichang@scu.edu.cn arc thruster (MEVAT), [24][25][26][27][28] as an example and studies the instability evolution caused by plasma rotation and axial flow in detail.…”