Electron beam in electric field (ray-tracking)

I’m completely newbie in FF.
I know that is possible to simulate electric field distribution using FF.
But my question is, if it is an easy way to make one more additional step:
Pass electron beam thru this simulated field, to determinate path which electrons fly (to determinate the deflection of electron beam).
Of course, I speak about quite high accuracy simulation, which will show any imperfections/aberrations caused by deflection plates.
2D will be fine at this moment.

As far as I know, problem like this are usually solved by the finite volume or by discontinuous Galerkin methods. I guess, the last method could be implemented in FreeFem, but it’s a long way to go, so the answer is that is not easy.

Sorry for late reply. I thought maybe someone else would answer.
Well, I will try to get into the topic.