Efficient simulation of electron trapping in laser and plasma wakefield acceleration

The two-dimensional quasistatic simulation code WAKE [P. Mora and T. Antonsen, Phys. Plasmas 4, 217 (1997)] used to model laser pulse propagation in tenuous plasma is modified to describe the dynamics of energetic particles. In the original code, all particles were assumed to satisfy the quasistatic approximation, which assumes that the driver and its wakefields are undisturbed during the transit time of plasma electrons through the pulse. Here, WAKE is modified to include the effects of electron trapping and beam loading by introducing a population of beam electrons, which are no longer subject to the quasistatic approximation. Algorithms for populating the group of beam particles are considered and are benchmarked to the full particle-in-cell simulations and experimental results. These modifications to WAKE provide a tool for simulating GeV laser or plasma wakefield acceleration on desktop computers.