Khoram Mansour, Masoudi S Farhad
Department of Basic Sciences and Engineering, Borujerd Branch, Islamic Azad University, P. O. Box 6915136111, Borujerd, Iran.
Department of Physics, K. N. Toosi University of Technology, P. O. Box 15875-4416, Tehran, Iran.
Sci Rep. 2021 Sep 15;11(1):18359. doi: 10.1038/s41598-021-97750-1.
The plasma boundary layer is analyzed for a plasma in contact with a conducting plain surface where the ion temperature is comparable with the electron temperature and the plasma pressure is sufficiently high. The variations of electrical potential from the plasma-presheath boundary to the wall is studied using the fluidal formalism of plasma in three approaches; plasma and sheath asymptotic solutions and full solution. In the full solution approach, fluidal equations lead to a singularity when the ion velocity reaches the ion thermal speed. It is shown that removing the singularity causes a well-defined eigenvalue problem and leads to smooth solutions for the model equations. Some of the applicable aspects such as the floating velocity and density of ions, the floating electrical potential and an estimation of the floating thickness of the boundary layer are obtained. The dependency of these quantities on the ionization degree, the ion temperature and ion-neutral collision is examined too.
对与导电平面接触的等离子体的等离子体边界层进行了分析，其中离子温度与电子温度相当，且等离子体压力足够高。使用等离子体的流体形式，通过三种方法研究了从等离子体预鞘层边界到壁面的电势变化；等离子体和鞘层渐近解以及全解。在全解方法中，当离子速度达到离子热速度时，流体方程会导致奇点。结果表明，消除奇点会导致一个定义明确的特征值问题，并为模型方程带来平滑解。获得了一些适用的方面，如离子的浮动速度和密度、浮动电势以及边界层浮动厚度的估计。还研究了这些量对电离度、离子温度和离子-中性碰撞的依赖性。
