Full-PIC Simulation of Ion Thruster Plume and Thrust Vectoring Devices

Electric propulsion is a mature and widely used technology in modern spacecraft applications. This kind of propulsion has strongly demonstrated its main advantages both analytically and in-flight experimentally. However, during a mission the need to control the thrust vector may arise, since the displacement of the center of gravity may be caused by the propellant consumption and the rotation of solar arrays. Thus, the ability control the thrust vector orientation opens new possibilities for mission optimization; 8-10 degrees in all directions are sufficient to satisfy current needs. Normally, the thrust vector control (TVC) is achieved by mounting the thruster on a mechanically actuated gimbal platform or robotic arms; these techniques are found to be heavy and expensive, and may affect the overall reliability of the system. The purpose of this thesis is to contribute in collaboration with Advanced Propulsion Department of Thales Alenia Space to the development of non-mechanic TVC, applicable to the electric propulsion thrusters, capable to control the thrust direction in a reliable and efficient way, and characterized by being simple and low-cost. The control of the orientation of plasma plume emission in self-consistent electric field cannot be described by an analytical model. Therefore, a particle simulation is needed to the resolve the problem. For this reason the thesis presents Fully-Kinetic Particle-In-Cell numerical simulations of ion thruster plume and magnetic thrust vectoring concept. The full PIC method, using CST Particle solver, treats both ions and electrons as macro particles, and is applied to the VECMAN MTV concept first, with the twofold objective of verifying the suitability of the PIC model to analyze the plasma plume to the vectoring device and to verify the suitability of the VECMAN to perform vectoring.