Topic/Type: 1.1 Space & astrophysical plasmas, Poster

Applying a Multigrid Method to Analysis of Spacecraft-Plasma Interactions using Electrostatic Particle-In-Cell Simulations

H. O. Ueda1, 2, T. Muranaka3, I. Shinohara1, H. Usui4

1 Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
2 Core Research of Evolutional Science & Technology, Japan Science and Technology Agency
3 JAXA?s Engineering Digital Innovation Center, Japan Aerospace Exploration Agency
4 Graduate School of Engineering, Kobe University

We have analyzed spacecraft-plasma interactions using a conventional electrostatic full particle-in-cell (PIC) simulation code optimized for parallel supercomputers achieving high accuracy as well as reasonable performance. Characteristics of onboard potential probes were discussed under the drifting satellite environment in the low earth orbit and also under the precipitating aurora electrons [1]. As another application, a correlation between floating potential of a satellite and the photoelectron current in the magnetospheric plasma environment comparing with the observation by the satellite was shown [2].
Meanwhile, realistic modeling for some analyses, such for a charging of solar sail with large membrane or for an influence of dense plasma plume to the spacecraft, has been restricted by enormous dynamic range. We have improved the code supporting the nested grid for achieving high special resolution in the regions of interest as well as reducing the number of grids and saving computer resources. A multigrid method with red-black Gauss-Seidel method [3] is adopted as a numerical algorithm for solving the Poisson equation on the hierarchical grid instead of Fourier transform method on uniform grid for the conventional code.
The accuracy of the Poisson solver and the performance of the improved code which is parallelized by a domain partition algorithm are discussed. Realistic simulations by the code will be utilized for study of future mission as well as designing new spacecrafts.

[1] H. O. Ueda, M. Okada, H. Usui, T. Muranaka, I. Shinohara: Estimation of Auroral Environment by Electrostatic Full-particle Simulations Modeling of REIMEI Satellite Observations, Trans. JSASS Space Tech. Japan, vol.7, no.ists26, pp.Pr\_2\_13-Pr\_2\_18, 2009.

[2] T. Muranaka, H. O. Ueda, H. Usui and I. Shinohara: Numerical Evaluation of Electric Field Observed in the Magnetospheric Plasma, 47th AIAA Aerospace Sciences Meeting and Exhibit, AIAA-2009-0457, 2009.

[3] W. H. Press and S. A. Teukolsky: Multigrid methods for boundary value problems. 1., Compt. in Phys., vol.5, pp.514-519, 1991.