Particle‐in‐Cell Simulation of Stationary Plasma Thruster

Abstract

A very good example for the application of PIC techniques for detailed studies of low-temperature plasmas is the Hall thrusters. Here, a variety of models with different complexities are needed to get better insight into the physics of these systems. Particular emphasis has been spent for the geometrical scaling, for the simulation of the plasma-wall interaction inside the acceleration channel and for ion-neutral collision into the plume emitted from the thruster. Results show the axial acceleration mechanism, the secondary electron emission instability, the azimuthal fluctuations into the channel and the ion backflow and electron trapping in the plume. However, until now, many propulsive systems have employed a solid, liquid or gaseous propellant and chemical propulsion to equip launcher spacecrafts for interplanetary missions and satellites. Alternatively, many electric systems have been proposed for satellite propulsion (microwave, arc-jet, stationary plasma thruster (SPT), pulsed plasma thruster (PPT), thruster with electric field (FEEP), gridded ion thruster, etc.) or for planetary missions (magneto-plasma-dynamic thruster (MPD)). Among these plasma sources, the Stationary Plasma Thruster (SPT) is one of the more promising devices for satellite station keeping, in particular due to the gain in mass (around 300 kg for a 3t-class satellite) and a long lifetime (up to 7000 h). Since 1970, almost 90 SPT thrusters have been tested on board Russian satellites (Meteor, Galls) and nowadays, all space agencies recognize the usefulness of SPTs for North-South, East-West (NS-EW) station keeping or attitude control of geostationary telecommunication satellites. The SPT was successfully used in the European lunar probe mission SMART1 and has been proposed for the future satellite constellations. In order to study and to manufacture Hall thrusters, a large effort is now being made in Europe, Russia, Japan and USA, while some other countries such as China, India and Israel are also interested in applying electric propulsion to spacecraft.A SPT [1], also known as Hall effect thruster (HET) or thruster with closed electron drift, can be schematically described (figure 1) as an anode-cathode system, with a dielectric annular chamber where the propellant ionization and acceleration process occurs. This thruster works using a perpendicular electric and magnetic fields configuration. A magnetic circuit generates an axis-symmetric and quasi-radial magnetic field between the inner and outer poles. In operation, an electrical discharge is established between an anode (deep inside the channel), which is acting also as a gas distributor, and an external cathode, which is used also as an electron emitter. In this configuration, cathode electrons are drawn to the positively charged anode, but the radial magnetic field creates large impedance, trapping the electrons in cyclotron motion which follows a closed drift path inside the annular chamber. The trapped electrons act as a volumetric zone of ionization for neutral propellant atoms a...

Particle‐in‐cell simulation of the effect of curved magnetic field on wall bombardment and erosion in a hall thruster

“…As no effective experimental method exists currently to measure the parameters of ions bombarding the wall (flux, energy, and angle of incidence), a PIC numerical method, which has been widely used in the study of Hall thrusters, is applied in this article. Compared with other simulation methods, the PIC method has the unique advantage of studying the behaviour of ions bombarding the wall by tracking the movement of a large number of particles and obtaining the characteristics of the associated macroscopic parameters.…”

Kinetic Simulations of SPT and HEMP Thrusters Including the Near-Field Plume Region

“…Thus, PIC simulations give us an important insight into the physics of the thruster, providing information which is difficult or impossible to get in experiments. The PIC method proved itself as a powerful tool suited for simulation of the large variety of low-temperature laboratory plasmas including ion thrusters plasmas [4], [5].…”

Approximate semi-analytical solutions for the steady-state expansion of a contactor plasma

“…In this way one can still satisfy some (but not all) of the equations (12)- (17). For simplicity, and to be adherent to earlier literature, we consider in this section the case where E = 0, and thus u θ = 0.…”

“…which is unfortunately not separable, and this is the source of the over-determination of the system of equations (12)- (17). In order to make equation (60) separable, one has to make the assumption…”

“…Therefore, numerical simulations are usually constrained to either the near-or the far-field expansion, i.e. to a restricted simulation domain [12][13][14][15][16][17][18].…”