Astronomy and Astrophysics – Astrophysics
Scientific paper
Jul 1989
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1989nsp..confq..17r&link_type=abstract
Presented at the 13th Conference on the Numerical Simulation of Plasmas, Santa Fe, NM, 17-20 Sep. 1989
Astronomy and Astrophysics
Astrophysics
Algorithms, Computerized Simulation, Electromagnetic Fields, Electromagnets, Laser Plasmas, Spatial Filtering, Wave Dispersion, Computer Programs, Finite Difference Theory
Scientific paper
There has been considerable interest over the last decade in the physics of intense electromagnetic signals in plasmas, much of it in the context of laser fusion and pulsar astrophysics. Simulations of these phenomena test the limits of particle simulation and in particular the standard leapfrog algorithm for advancing the electromagnetic fields. As shock fronts and sheaths develop within the plasma in response to intense electromagnetic waves, numerical dispersion intrinsic to the leapfrog algorithm can cause unphysical ripples to appear in the field solution which can interact with particles. Fourier analysis of the leapfrog scheme in 1D yields the dispersion relation for a Courant number (nu) (triple bond) c(Delta)t/(Delta)x = 0.5. As we can see, the phase velocity of the modes falls off the light line at high k(Delta)x. Thus modes that are poorly resolved will tend to disperse and trail the main pulse as ripples. There are several approaches to finding a remedy for these ripples. High-order finite difference methods can be considerably less dispersive. Also, improving resolution can move the physics to lower k(Delta)x where the dispersion is less. Often these options are not available, either because of difficulty in implementation or because computer resources are insufficient. This leaves filtering as the main option, with two routes to schemes that remove high k(Delta)x modes -- temporal and spatial filtering. In this paper we present techniques to remove dispersion from particle simulations using both methods.
Ambrosiano John J.
Friedman Alex
Nielsen Dale E. Jr.
Rambo Peter W.
No associations
LandOfFree
Temporal and spatial filtering remedies for dispersion in electromagnetic particle codes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Temporal and spatial filtering remedies for dispersion in electromagnetic particle codes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Temporal and spatial filtering remedies for dispersion in electromagnetic particle codes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1708430