PIC/MCC数值模拟四阳极直流辉光放电

Numerical simulation of four anodes DC glow discharge by PIC/MCC

利用OOPIC代码并结合MCC方法考察四阳极低气压直流辉光放电中粒子间的碰撞,并对其进行了数值模拟。首先分析OOPIC代码的计算流程,给出模拟的边界条件和时间、空间步进;然后对所得到的等离子体密度、温度的分布情况进行了分析。结果表明,放电气压、电流以及环电极的有效宽度均影响等离子体密度和温度的径向分布。当气压为300Pa时,电子密度在径向较大范围内是均匀分布的,而当气压升高到800Pa时,其径向不均匀增大,且总的密度和电子的平均温度下降。放电电流的增大使得等离子体密度和温度均相应升高。但环电极有效宽度的减小使得等离子体密度的分布更不均匀,并使总的密度和平均温度均下降。

In order to obtain the characteristics of the plasma generated in the low helium pressure four anodes DC glow discharge, numerical simulation of the discharge using the code OOPIC and MCC has been carried out. Firstly, the OOPIC calculating flow is analyzed and the boundary conditions, the mesh spacing, and the time step in the simulation are presented. Then, the results about the distributions of the plasma density and temperature are analyzed. The results show that, the gas pressure, electrical current, and the virtual breadth of the annular electrode affect the radial distribution of the plasma density and temperature. When the helium pressure is 300Pa, the electrons are distributed equally in almost radial range. But when the pressure is up to 800Pa, radical electron distribution varies greatly, and the total density and the average temperature of electron descend. The augmentation of the electrical current makes the plasma density and temperature higher. But the lessening of virtual breadth of the annular electrode makes the radial distribution of plasma density more unequal, and the total density and the average temperature lower.