ABSTRACT
If the density of the charged particles is sufÀciently large, we have to account for their interaction by electric and magnetic forces. Basically, this interaction can take place in two different forms. First it can be by a collisional process which essentially involves two particles only. Alternatively we can imagine situations where a large number of particles simultaneously inÁuence the trajectory of a selected reference particle. In this limit we talk about “collective interaction” of charged particles. Properly speaking this is what we also call the plasma limit, as discussed later.
