General Principles of Particle Motion

Charged-particle optics investigates primarily the properties of bundles of rays in analogy to light optics. Important ensembles are homocentric bundles, whose trajectories originate from a common point, which is usually a point of an object or source. Within the frame of our considerations, we neglect Coulomb interactions between the charged particles of the beam. In this case, we can consider the beam as an ensemble of noninteracting particles, whose trajectories are entirely defined by the external electromagnetic fields.