Numerical simulations have proven a valuable tool to study plasma behavior, especially for conditions in astrophysical scenarios and which are not readily accessible under laboratory conditions. Whenever single particle behavior becomes important or the development of non-thermal components is of interest fluid descriptions have to be replaced by more accurate but also more expensive kinetic descriptions. A very popular such method is the Particle-in-Cell method. Conceptually this method combines the integration of motion if individual elementary particles with field quantities that are restricted to a spatial grid. Both the analytic derivation of the method as well as the computational feasibility require the use of phase space samples instead of the more readily envisioned individual elementary particles. Each macroparticle represents an ensemble of particles of one species that are close to each other in phase space and carries the total charge and mass of the ensemble. Unlike the elementary particles the macroparticle does not necessarily have a vanishing spatial extent. Different choices of the form factor, that is spatial distribution of the particle quantities within the macroparticle, are investigated. Included are the standard choices NGP, CIC and TSC as well as new schemes of higher order.
Numerical Modeling of Space Plasma Flows (ASTRONUM2012)
- Pub Date:
- April 2013