Stochastically Induced Gamma-Ray Burst Wakefield Processes
  We present a numerical study of Gamma-Ray Burst - Circumburst Medium interaction and plasma preconditioning via Compton scattering. The simulation tool employed is a unique hybrid model; it combines a highly parallelized (Vlasov) particle-in-cell approach with continuous weighting of particles and a sub-Debye Monte-Carlo binary particle interaction framework. These first results from 3D simulations with this new simulation tool, the PhotonPlasma code, suggests that magnetic fields and plasma density filaments are created in the wakefield of prompt gamma-ray bursts, and that the photon flux density gradient has a significant impact on particle acceleration in the burst head and wakefield. We discuss some possible implications of the circumburst medium preconditioning for the trailing afterglow, and also discuss which additional processes will be needed to improve future studies within this unique and powerful simulation framework. 
J. Trier Frederiksen