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

Summary form only given. 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
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. Currently, we are developing novel approaches that promise to be even more effective at suppressing numerical instabilities in relativistic beam simulations.
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In this presentation, we describe briefly the new algorithms, present numerical dispersion relations quantifying their stability, and again substantiate results with WARP simulations. Finally, we compare these new algorithms with earlier ones from the perspectives of both effectiveness and efficiency.