FD-TD analysis of scattered fields excited by a high energy pulsed beam of charged particles using point charge responses

In this paper, me show a finite-difference time-domain (FD-TD) analysis of scattered fields excited by a pulsed beam using point charge responses and convolution. The advantages of this approach are easy handling of arbitrary beam trajectories and waveforms; efficient absorption for excited fields on open boundaries; and small amount of incident field calculation, In addition, we describe the relation between the temporal resolution and the allowable aliasing error since the point charge held as an incident field has very high frequency spectrum.