Topic/Type: 2.5 Adaptative & multi-scale methods, Poster

Multi-Scale Simulation Method Based on Micro Plasma Simulator

S. Ishiguro1, 2, B. Li3, A. Maluckov4, R. Horiuchi1, 2, M. M. Skoric1, 2

1 National Institute for Fusion Science, Toki, Japan
2 The Graduate University for Advanced Studies (SOKENDAI), Toki, Japan
3 Institute of Applied Physics and Computational Mathematics, Beijing, China
4 Faculty of Sciences and Mathematics, University of Nis, Nis, Serbia

Recently, so called Equation Free Projective Integration (EFPI) framework which is attempting to perform macro-scale simulation while still taking into account the effects of micro-scale physics has been proposed for multi-scale problems in science and engineering [1]. Based on a micro-physics simulator the macro-scale dynamics is determined by repeatedly extrapolating forward macro variables obtained by short micro-physics simulation. Applications of above ideas to plasma simulations have been only recently attempted by using different schemes for reconstruction and mapping between macro and micro phase space[2-4].

Here, we investigate a primal-EFPI method in which electron dynamics is coarse grained by using velocity distribution function[5]. We employ standard electrostatic particle-in-cell (PIC) simulation code as a micro simulator. Ions are assumed inherently coarse grained as compared to electron-micro-scale dynamics; so, ion orbits are simply traced and extrapolated in time. The electric potential is averaged over the electron plasma period to extrapolate. The non-uniform macro-scale electron density is found by solving the coarse grained Poisson equation. Our primal EFPI simulation can nicely follow full PIC simulation results of the nonlinear evolution of ion acoustic wave before the ion trapping becomes significant. We study simulations over a wide rage of parameters and discuss limitation in EFPI framework.

[1] I. G. Kevrekidis, et al., Commu. Math. Sci. 1 (2003) 715.

[2]M. A. Shay, et al., J. Comp. Phys. 226 (2007) 571.

[3]G. Stanthev et al., APS DPP 2006 (VP1.00144)

[4]A. M. Maluckov et al., Comm. Comp. Phys. 4 (2008) 556.

[5]M. Skoric et al., Plasma and Fusion Research, 3 (2008)021.