A spectral comparison of two methods of removing errors in Gauss´ law in a 2-dimensional PIC plasma simulation

Summary form only given, as follows. Non-charge conserving current collection algorithms for relativistic PIC plasma simulations can cause errors in Gauss´ law. These errors arise from violations of the continuity equation, /spl nabla//spl middot/J=-/spl delta/p//spl delta/t. Two techniques for removing these errors are examined and compared, the Marder correction, a method which corrects electric fields locally and primarily affects short wavelengths, and a divergence correction, which uses a Poisson solve to correct the electric fields so that Gauss´ law is enforced. The effect of each method on the the spectrum of the error (short wavelengths vs. long) are examined. Computational efficiency and accuracy of the two techniques is compared. Particular cases of interest include corrections in electromagnetic relativistic beam simulations.