Characterization and explorative application of a novel miniature micorwave ICP

高频或微波驱动的等离子体射流是传统等离子体腔的一种有吸引力的替代方案，并使许多创新的等离子体技术应用成为可能。等离子体射流的固有优势是成本低，空间尺寸小。然而，它们的效率目前并不令人满意：通常的电磁能量的电容耦合会导致护套电压，从而导致高的电气损耗。作为早期项目的一部分，首次有可能将感应耦合原理转移到微型微波等离子体喷射器上。获得了很高的电子密度(3.5×10^19)，但放电仍远未达到热平衡。这一概念的核心是一种紧凑的微波操作谐振器，它可以被视为平板电容器与两个圈数为1的圆柱形线圈的并联。在这些线圈中诱导出一个强烈的方位向涡旋场，以保持气体流经的陶瓷管中的等离子体具有较低的表面层张力。该项目的重点是进一步调查基本的、等离子体物理问题和操作的技术方面，以及第一次探索新来源的应用潜力。规划了一种基于实验和理论方法的协调方法。计划对复杂的S11参数进行实验空间分辨发射光谱和吸收光谱以及时间分辨电学测量。特别令人感兴趣的是具有各种气体的源的表征、模式转变的表征和自由基物种的等离子体化学。与时间相关的电学测量允许深入了解点火和模式转换过程中源的动态。在理论层面上，最初的计划是在全球模型中描述新的运行气体的更复杂的等离子体化学。此外，基于商用仿真软件，对谐振器结构进行了充分的电磁仿真。随着现有等离子体工具的增加，这将被扩展并合并为混合模型。从技术角度来看，探索与压力、功率、气体组成有关的参数范围是重要的，以便能够评估来源对各种潜在应用的适用性。还计划使用两种不同的工作气体进行双电感耦合等离子体的运行。特别令人感兴趣的是将几个源相互连接以形成线性源的可能性。作为朝这一方向迈出的第一步，计划将两个双ICP联网。

High-frequency or microwave-powered plasma jets represent an attractive alternative to conventional plasma chambers and enable many innovative plasma technology applications. The inherent advantages of plasma jets are low cost and small spatial dimensions. However, their efficiency is currently unsatisfactory: The usual capacitive coupling of the electromagnetic energy leads to sheath voltages and thus to high electrical losses. As part of an earlier project, it was possible for the first time to transfer the principle of inductive coupling to a miniaturized microwave plasma jet. Very high electron densities (3.5 x10^19) were achieved, while the discharge was still far from thermal equilibrium. The core of the concept is a compact, microwave-operated resonator, which can be seen as a parallel connection of a plate capacitor with two cylindrical coils with a turn number of one. A strong azimuthal vortex field is induced in these coils, which can maintain a plasma with a low surface layer tension in the ceramic tubes through which gas flows. The focus of the project is the further investigation of basic, plasma-physical questions and technical aspects of the operation, as well as a first exploration of the application potential of the new source. A coordinated approach based on experimental and theoretical methods is planned. Experimentally spatially resolved emission and absorption spectroscopy as well as time resolved electrical measurements of the complex S11 parameters are planned. Of particular interest are the characterization of the source with various gases, the characterization of the mode transitions and the plasma chemistry of the radical species. The time-dependent electrical measurements allow insights into the dynamics of the source, during the ignition and the mode transitions. At a theoretical level, it is initially planned to describe the more complex plasma chemistry of the new operating gases in a global model. Furthermore, an adequate electromagnetic simulation of the resonator structure is planned based on a commercial simulation software. With the addition of an existing plasma tool, this is to be expanded and combined into a hybrid model. From a technical point of view, the exploration of the parameter range with regard to pressure, power, gas composition is important in order to be able to assess the suitability of the source for the diverse potential applications. The operation of a double ICP with two different operating gases is also planned. Of particular interest will be the possibility of interconnecting several sources to form a linear source. As a first step in this direction, the interconnection of two double ICPs is planned.