Novel approaches to suppress the numerical Cherenkov instability in Pseudo-Spectral Particle-in-Cell plasma simulation codes

Typically, the most serious numerical instability in particle-in-cell simulations of relativistic particle beams is the numerical Cherenkov instability, arising from coupling between electromagnetic and nonphysical beam modes.1 Over the past few years, we have developed a variety of approaches for ameliorating this instability in Pseudo-Spectral Time-Domain algorithms, quantitatively assessed their stability analytically, and verified results using the WARP simulation code.2–4