Hybrid 3D model for the interaction of plasma thruster plumes with nearby objects

Abstract

This paper presents a hybrid particle-in-cell (PIC) fluid approach to model the interaction of a plasma plume with a spacecraft and/or any nearby object. Ions and neutrals are modeled with a PIC approach, while electrons are treated as a fluid. After a first iteration of the code, the domain is split into quasineutral and non-neutral regions, based on non-neutrality criteria, such as the relative charge density and the Debye length-to-cell size ratio. At the material boundaries of the former quasineutral region, a dedicated algorithm ensures that the Bohm condition is met. In the latter non-neutral regions, the electron density and electric potential are obtained by solving the coupled electron momentum balance and Poisson equations. Boundary conditions for both the electric current and potential are finally obtained with a plasma sheath sub-code and an equivalent circuit model. The hybrid code is validated by applying it to a typical plasma plume-spacecraft interaction scenario, and the physics and capabilities of the model are finally discussed.The research leading to the results of this paper was initiated within the LEOSWEEP project (“Improving Low Earth Orbit Security With Enhanced Electric Propulsion”), funded by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement N.607457. Additional funding to complete it has been received by Spain’s R&D National Plan, under grant ESP2016-75887

    Similar works