Three-dimensional modeling of microwave discharges in a waveguide-based plasma source with experimental comparison.
Three-dimensional modeling of microwave discharges in a waveguide-based plasma source with experimental comparison.
复制标题
DOI：
10.1103/physreve.108.065209
复制
发表时间：
2023-12
期刊：
影响因子：
--
通讯作者：
Wencong Zhang;Li Wu;Junwu Tao;Huacheng Zhu
中科院分区：
文献类型：
--
作者：
Wencong Zhang;Li Wu;Junwu Tao;Huacheng Zhu
本文提出了一个瞬态三维模型来模拟中等气压下波导等离子体源中的微波诱导放电。采用平面对称简化方法，将微波等离子体源在计算域中简化一半，大大减少了对计算资源和计算时间的需求。同时，数值模拟仍然是三维的，没有降维，这使得我们能够直接计算从入射微波到等离子体的功率耦合效率。此外，计算量的减少提高了数学模型的收敛性能，使其能够模拟1×10^{-9}~ 1×10^{4}s的整个放电过程。这一时期涵盖了瞬时微波击穿形成一个稳定的等离子体柱附近的稳定状态。结果揭示了微波等离子体源在放电过程中电磁波导结构的变化。计算了波导等离子体源在不同玻璃管厚度和折射率下的微波功率耦合效率，并与实验测量数据进行了比较。此外，还研究了玻璃管对行波微波沿等离子体柱沿着传播的电磁模式和放电特性的影响。数值计算结果与理论分析和实验数据基本吻合，验证了所提出的数学模型和平面对称简化方法的有效性。
This paper proposes a transient three-dimensional model to simulate microwave-induced discharges in a waveguide-based plasma source under intermediate pressures. A plane-symmetric simplification method is applied to simplify half of the microwave plasma source in the calculation domain, dramatically reducing the demand for computational resources and calculation time. Meanwhile, the numerical simulations remain in three dimensions without dimensionality reduction, which allows us to directly calculate the efficiency of power coupling from the incident microwave to the plasma. Besides, the computation decrease improves the convergence performance of the mathematical model, making it possible to model the entire discharge process from 1×10^{-9} to 1×10^{4}s. This period covers the instantaneous microwave breakdown to the formation of a stable plasma column near steady state. The results have revealed the electromagnetic waveguide structure change of the microwave plasma source during the discharge process. Several microwave power-coupling efficiencies of the waveguide-based plasma source with different thicknesses and permittivities of the glass tube are calculated and compared with the experimentally measured data. Furthermore, the effects of the glass tube on the electromagnetic modes of the traveling microwave propagating along the plasma column and the discharge properties are also investigated. The numerically obtained results generally agree with the theoretical analysis and the experimental data in our previous studies, demonstrating the validity of the proposed mathematical model and the plane-symmetric simplification method.