EPOCH is a plasma physics simulatio

EPOCH is a plasma physics simulation code which uses the Particle in Cell (PIC) method. In this method, collections of physical particles are represented using a smaller number of pseudoparticles, and the fields generated by the motion of these pseudoparticles are calculated using a finite difference time domain technique on an underlying grid of fixed spatial resolution. The forces on the pseudoparticles due to the calculated fields are then used to update the pseudoparticle velocities, and these velocities are then used to update the pseudoparticle positions. This leads to a scheme which can reproduce the full range of classical micro-scale behaviour of a collection of charged particles.