基于PIC-MCC法的颗粒物在等离子体中荷电仿真

harging of particulates in low temperature plasma is instantaneously finished and the process is complicated. The motion and trapping of the particulates are directly determined by the charges of themselves. Here a numerical model based on Particle-in-Cell (PIC) and Monte-Carlo Collision (MCC) hybrid method was developed to study the charging characteristics of fine particles immersed in low temperature argon plasma. The net charge of a fine particulate was evaluated by counting the number of electrons and ions reached the surface of the particulate. Meanwhile, the profiles of charged particles and self-consistent electric field were obtained. For the particulate with a radius of 15 μm in the plasma, the charge is approximately 78000 e and the electric potential of the surface is about -7.5 V. Also the potential quickly increases to 0 V within 100 μm. In the vicinity of the particulate, the ion number density is always greater than that of the electron. Ion density quickly raises to the undisturbed zone density near the wall, however, the electron density relatively slowly enlarged to the background concentration. In addition, the charge of a particulate is proportional to its diameter.