Near Plume Modeling of a Micro Cathode Arc Thruster

Abstract

For the past four years, the Micropropulsion and Nanotechnology Laboratory at the George Washington University has been developing a novel thruster for microsatellites based on an ablative vacuum arc technology, so called micro-cathode arc thruster (µCAT). Ablative microthrusters, such as the µCAT, offer a number of advantages for small satellite missions, especially ones utilizing the CubeSat technology. However, before the thruster can be operated in the space environment, it is necessary to obtain a better understanding of its performance, plume profile, and any potential adverse effects to the host spacecraft. Complicating data collection is the miniature size of the device, which reduces the usefulness of traditional probing methods. In this paper we report on an on-going numerical analysis performed in support of the experimental characterization of the thruster. Namely, we investigate the formation of the discharge beam from the initial cathode spot under an applied magnetic field.

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

“…This electric field formed by charge separation is the main reason for the ion acceleration derived from this simulation. The charge separation phenomenon has also been found in recent PIC simulations of a vacuum arc thruster [30,35,36]. It is noted that the magnetic field due to charge separation evolves over time, making measurement and verification very difficult.…”

“…Therefore, the selection of the size of the calculation domain, grid scale, and time step are all related to the characteristics of the plasma. Based on the parameters of the plasma at the entrance, the estimated Debye length is approximately 10 −5 m [29,30]. Moreover, during the expansion of the metal vapor plasma jet, the mass of the electrons is much smaller than that of the ions, and the velocity is higher than that of the ions, which will cause a charge separation.…”

Three‐dimensional immersed finite‐element method for anisotropic magnetostatic/electrostatic interface problems with nonhomogeneous flux jump

“…Finally, a discharge spot is formed in the ionization zone and the copper atom vapor is ionized to form copper plasma. Moreover, in the whole operation procedure of the microcathode arc thruster, the discharge spot will rotate along the ionization zone . Therefore, as shown in Figure , the location of f is set to be inside 16 uniformly distributed discharge cylinders in the ionization zone.…”

“…As mentioned above, this is due to the fact that the ionization zone of the microcathode arc thruster is actually a set of discrete discharge spots. Therefore, compared with the two‐dimensional axisymmetric model (such as the model in Reference ), the 3D model can better reflect the discharge process of the microcathode arc thruster.…”

Numerical Simulation of the Chemical Combination and Dissociation Reactions of Neutral Particles in a Rarefied Plasma Arc Jet

“…In the rarefied plasma transport processes, neutral particle diffusion have an impact on the movement of the ions and electrons, especially in the rarefied plasma flow of a cathodic vacuum arc [10], [11], where neutral particle collisions as well as chemical dissociation and recombination reactions have an important role in the distribution of the charged particles during the diffusion process. The main numerical simulation DSMC/PIC method is currently used to solve such plasma transport problems in a rarefied environment [2], [3], [6]- [8], [10]- [12]. The PIC method can simulate the movement of charged particles in a self-consistent electrostatic field, and the DSMC method can be implemented to simulate the particle movement and collisions between neutral particles as well as charged particles.…”