Effects of Magnetic Field and Ion Velocity on SPT Plasma Sheath Characteristics  

作　　者：段萍 周新维 刘媛 曹安宁 覃海娟 陈龙 殷燕 

机构地区：[1]Department of Physics,Dalian Maritime University [2]Faculty of Physics and Optoelectronic Technology,Dalian University of Technology

出　　处：《Plasma Science and Technology》2014年第2期161-167,共7页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China(Nos.11275034,11175052,11005025,10975026,11375039);Key Project of Science and Technology of Liaoning Province,China(No.2011224007)

摘　　要：The distribution of magnetic field in Hall thruster channel has significant effect on its discharge process and wall plasma sheath characteristics. By creating physical models for the wall sheath region and adopting two-dimensional particle in cell simulation method, this work aims to investigate the effects of magnitude and direction of magnetic field and ion velocity on the plasma sheath characteristics. The simulation results show that magnetic field magnitudes have small impact on the sheath potential and the secondary electron emission coefficient, magnetic azimuth between the magnetic field direction and the channel radial direction is proportional to the absolute value of the sheath potential, but inversely proportional to the secondary electron emission coefficient. With the increase of the ion incident velocity, secondary electron emission coefficient is enhanced, however, electron density number, sheath potential and radial electric field are decreased. When the boundary condition is determined, with an increase of the sinmlation area radial scale, the sheath potential oscillation is aggravated, and the stability of the sheath is reduced.The distribution of magnetic field in Hall thruster channel has significant effect on its discharge process and wall plasma sheath characteristics. By creating physical models for the wall sheath region and adopting two-dimensional particle in cell simulation method, this work aims to investigate the effects of magnitude and direction of magnetic field and ion velocity on the plasma sheath characteristics. The simulation results show that magnetic field magnitudes have small impact on the sheath potential and the secondary electron emission coefficient, magnetic azimuth between the magnetic field direction and the channel radial direction is proportional to the absolute value of the sheath potential, but inversely proportional to the secondary electron emission coefficient. With the increase of the ion incident velocity, secondary electron emission coefficient is enhanced, however, electron density number, sheath potential and radial electric field are decreased. When the boundary condition is determined, with an increase of the sinmlation area radial scale, the sheath potential oscillation is aggravated, and the stability of the sheath is reduced.

关 键 词：magnetic field ion velocity sheath potential secondary electron emission 

分 类 号：O53[理学—等离子体物理]