为了详细描述等离子体形成过程中鞘层的产生、演化过程,建立了平等板内部等离子体流动过程的PIC模型.在考虑壁面二次电子发射的前提下,模拟得到了放电开始直到放电稳定后的平板等离子体内部和边界处的电场强度、电子密度、离子密度、电势等一系列参数分布,并分析了二次电子发射系数对鞘层厚度的影响分析.模拟结果表明:平等板内部电势相对于边界处较高,中部的电场强度为零,电子密度近似等于离子密度,而在边界处电子密度略低于离子密度,电场方向指向边界处,在等离子体边界处有明显的鞘层.%In order to describe in detail the information and evolution of sheath during plasma formation,the PIC model of internal plasma flow in an equal plate is established. On the premise of considering the two electron emission from the wall,a series of parameters such as electric filed intensity,electron density,ion density and electric potential are obtained at the inner and boundary of the plate plasma at the beginning of the discharge until the discharge is stable. The influence of two electron emission coefficient on sheath thickness was analyzed. Simulation results show that:the internal potential of an equal plate is higher than that at the boundary,the strength of the electric filed in the middle is zero,and the electron density is approximately equal to the ion density. At the boundary,the electron density is slightly lower than the ion densi-ty,having an approximate positive electric field distribution,its direction is directed to the border. There is obvious sheath at the plasma boundary.
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