Benchmarking sheath subgrid boundary conditions for macroscopic-scale simulations
Benchmarking sheath subgrid boundary conditions for macroscopic-scale simulations
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DOI：
10.1088/0963-0252/24/1/015020
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发表时间：
2014-12
影响因子：
3.8
通讯作者：
T. Jenkins;D. Smithe
中科院分区：
文献类型：
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作者：
T. Jenkins;D. Smithe
金属或电介质壁材料与等离子体接触时形成的鞘是普遍存在的，经常会引起物理现象(溅射、二次电子发射等)，从而影响材料界面附近和远处的等离子体性质和动力学。在本文中，我们使用第一性原理PIC模拟这类界面来形成一个次网格鞘边界条件，它封装了界面处鞘行为的基本方面。这种基于鞘的电容行为的边界条件在流体模拟中被证明是有用的，其中鞘的标尺长度显著小于其他相关物理过程的标尺长度(例如，射频波长)，因为它使得与鞘的存在相关联的动力学过程能够在没有诸如电子德拜长度或等离子体频率的空间和时间尺度的显式分辨率的情况下被数值模拟。
The formation of sheaths near metallic or dielectric-coated wall materials in contact with a plasma is ubiquitous, often giving rise to physical phenomena (sputtering, secondary electron emission, etc) which influence plasma properties and dynamics both near and far from the material interface. In this paper, we use first-principles PIC simulations of such interfaces to formulate a subgrid sheath boundary condition which encapsulates fundamental aspects of the sheath behavior at the interface. Such a boundary condition, based on the capacitive behavior of the sheath, is shown to be useful in fluid simulations wherein sheath scale lengths are substantially smaller than scale lengths for other relevant physical processes (e.g. radiofrequency wavelengths), in that it enables kinetic processes associated with the presence of the sheath to be numerically modeled without explicit resolution of spatial and temporal sheath scales such as electron Debye length or plasma frequency.