Development of an Adaptive Grid Code for Particle in Cell Simulation in Plasmaphysics

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Development of a particle-in-cell code for simulation of space plasma operating on an adaptive grid is to accomplish. In contrast to a static grid the adaptive grid is self adapting. Its grid parameters are variable in space and time. The mesh sizes should adapt automatically to the local plasma structures. The time steps also should adapt accordingly to the numerical stability criteria. The new code will be based on known hydrodynamic and magnetohydrodynamic adaptive grid codes. The major new development will be the handling of the plasma particles. In consequence of the dynamic mesh sizes identical numerical particles representing one plasma species have to be replaced by numerical particles with floating numerical weight. In order to ensure an acceptable particle statistics the code has to preserve the same order of magnitude of the numerical particle number in small grid cells as in big cells. However, in smaller cells the numerical weight has to be smaller, and vice versa. The necessary particle splitting in small cells and the coalescence in big cells has to be performed in such a way that the kinetic character of the plasma within all grid cells is maintained. With an adaptive grid a significant increase of the numerical efficiency will be reached. The implementation of the code has to show an effective usability on a parallel computer.