Sun Guang-Yu, Sun An-Bang, Zhang Guan-Jun
Research Center for Advanced High Voltage and Plasma Technology, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
Phys Rev E. 2020 Mar;101(3-1):033203. doi: 10.1103/PhysRevE.101.033203.
The plasma sheath is the non-neutral space charge region that isolates bulk plasma from a boundary. Radio-frequency (RF) sheaths are formed when applying RF voltage to electrodes. Generally, applied bias is mainly consumed by a RF sheath, which shields an external field. Here we report evidence that an intense boundary emission destroys a normal RF sheath and establishes a type of RF plasma where external bias is consumed by bulk plasma instead of a sheath. Ions are naturally confined while plasma electrons are unobstructed, generating a strong RF current in the entire plasma, combined with a unique particle and energy balance. The proposed model offers the possibility for ion erosion mitigation of a plasma-facing component. It also inspires techniques for reaction rate control in plasma processing and wave mode conversion.
等离子体鞘层是将体等离子体与边界隔离开的非中性空间电荷区域。当向电极施加射频（RF）电压时会形成射频鞘层。通常，施加的偏压主要被射频鞘层消耗，该鞘层屏蔽外部场。在此我们报告有证据表明，强烈的边界发射会破坏正常的射频鞘层，并建立一种射频等离子体，其中外部偏压由体等离子体而非鞘层消耗。离子自然被约束，而等离子体电子不受阻碍，在整个等离子体中产生强大的射频电流，并伴有独特的粒子和能量平衡。所提出的模型为减轻面向等离子体部件的离子侵蚀提供了可能性。它还激发了等离子体处理中反应速率控制和波模转换的技术。
