Radially symmetric patterns are observed in pin-to-plane DC plasma systems where a liquid solution is used as a planar resistive anode. The size and structure of these patterns depends on the plasma current and salt concentration of the liquid anode. We propose that these patterns initiate due to the reaction and diffusion of electrons in the anode sheath, where electron impact ionization serves as an autocatalytic reaction. The resulting system of reaction-diffusion equations is amenable to Turing stability analysis, which we use to theoretically predict the transition from a uniform plasma to a ring-shaped pattern state. Expressing the stability criteria in terms of plasma current and solution salt concentration, we derive a theoretical phase boundary for the onset of pattern formation, which is in excellent agreement with experimental results.

中文翻译：

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等离子体-液体界面上的图灵模式

在将液体溶液用作平面电阻阳极的引脚到平面DC等离子系统中，观察到径向对称图案。这些图案的尺寸和结构取决于等离子体电流和液体阳极的盐浓度。我们提出这些模式是由于电子在阳极鞘中的反应和扩散而引发的，其中电子碰撞电离充当自催化反应。所得的反应扩散方程系统适用于Turing稳定性分析，该分析用于理论上预测从均匀等离子体到环形图案状态的跃迁。用等离子电流和溶液盐浓度表示稳定性标准，我们推导了图案形成开始的理论相界，这与实验结果非常吻合。