Discussion Forum

Hi,

I am trying to simulate moving charged particles through an external electric field and I want to include the influence of the space charge density, as well as the self-field of the charged particles. I am new in Comsol and I will appreciate a little help.

I am really confused how this bidirectionally coupled interface study works. In the help file, it is stated, that it creates time-dependent solver which solve all degrees of freedom related to the particles and all other degrees of freedom are computed with stationary solver, and these two solvers are repeated using a for-end loop. Probably, I don't understand well this definition, but...

When I solve my model, the results for the spatial distribution of the potential of the electric field, as well as the charged particle trajectories don't seem to be affected by the self-field of the particles. But when I include space charge density node in the electrostatics interface and space charge density calculation in the charged particle tracing interface, the whole picture is changed. Anyway, the results for the spatial distribution of the potential of the electric field seems to be affected somehow by the space charge density of the particles, but for the particles, it gives me totally wrong results. But the real confusion comes when I watch the results for the spatial distribution of the potential in time, the results are the same at all the times, which does not have sense. From the definition of the bidirectionally coupled particle tracing study I have understood, that for every time-step of the particles the field is recalculated too, am I wrong? So, in time 0 it has to be a result without the internal field of the particles because in this time there are no particles in the modelling domain.

I apologize if I repeat the topic with an existing one and if my question is silly.

Regards, Dimitar