Model description of a two-dimensional electrostatic particle-in-cell simulation parallelized with a graphics processing unit for plasma discharges

Abstract

Many key aspects of low-temperature plasmas include nonlinear, transient, and kinetic effects related to the spatio-temporal variation of electron energy distribution function (EEDF) which cannot be treated in a fluid simulation model. The particle-in-cell (PIC) simulation calculates kinetic effects through the statistical representation of the EEDF using many particles and thus gives accurate results. However, the computational cost is very expensive to resolve all aspects in a plasma discharge with millions of computational particles as well as hundreds of thousands of grids during millions of time steps. Additionally, the simulation of discharge plasmas should handle the collision processes and the rapid increase in the total number of simulation particles. In this presentation, details of a two-dimensional PIC simulation parallelized with graphics processing units (GPUs) are explained for the improvement of computation speed. The resulting GPU-PIC code executes aggregate time steps in two-dimensional geometry from 80 to 140 times faster than a conventional single CPU-PIC code with the same numerical scheme modelling a standard capacitively coupled plasma (CCP) reactor.