Self-consistent Particle-In-Cell (PIC) simulations provide more realistic and detailed information about modelled plasma processes than fluid simulations do. This benefit is, however, balanced by far greater demands in terms of computational resources.
In the past PIC computations were usually accelerated using the intrinsic symmetry of the particular modelled phenomenon. This approach led to 1D and 2D PIC models with many successful applications. Nevertheless, a large class of plasma-solid interactions cannot be precisely described by this simplified approach. Often the reason is the magnetic field which in certain configurations decreases symmetry of otherwise regular structures of the solid surface such as a hollow cylindrical bore. In these cases a seemingly reasonable approximation would be e.g. to disregard small deviations of magnetic field from the axis of symmetry of the cavity and thus transform the simulation to a feasible 2D PIC model.
Our previous work [Pekarek Z, Hrach R; Vacuum, accepted] demonstrated that this assumption is in certain configurations incorrect and that even minor deviations of the magnetic field can have significant impact on measured quantities, such as density distributions of ions impinging on the inner walls of the cylinder. These results were obtained using our newly developed 3D PIC code for a model configuration of fully ionized isothermal hydrogen plasma.
In this contribution we will take into account collisions in slightly ionized argon plasma and the effect of collisions on the results of this kind of model. From the modelling point of view we will discuss the computational complexity of the model and feasible ways of further improvement.
From the practical perspective we will consider applicability to e.g. modelling of magnetic field assisted deposition of ions onto porous media, represented in this model case by the cylindrical cavity. Further model extensions aspiring to better represent a particular substrate and/or plasma will be briefly discussed as well. |