A Particle-in-Cell Method with Adaptive Phase-Space Remapping for Kinetic Plasmas

Dr. Bei Wang
Seminar

The numerical solution of the Vlasov equation is usually performed by the particle-in-cell (PIC) method. However, it is well known that, in some cases, the PIC method has difficulty in having an accurate description for the distribution function in phase space due to numerical noise, the inherent drawback of particle-based methods. In this talk, I will present an accurate and efficient PIC method for computing the dynamics of kinetic plasmas. The method overcomes the numerical noise by periodically remapping the distribution function on a hierarchy of locally refined grids in phase space. The positivity of the distribution function is enforced by redistributing excess phase space density in a local neighborhood. Remapping on phase space grid also provides an opportunity to integrate a collisional model and an associated grid-based solver. At the end of this talk, I will show our numerical results on a set of standard plasma physics problems; e.g., Landau damping and the two-stream instability in both 1D and 2D cases. It is shown that remapping reduces the numerical noise significantly and results in a more consistent second order method than the standard PIC method.