Detection and reaction kinetics of reactive species in particle-forming environments using IR modulation spectroscopy by the example of dusty plasmas

该项目旨在开发和测试高灵敏度吸收光谱调制技术，用于对粒子形成环境中的瞬态物质进行时间分辨探测。测量将在红外（IR）光谱范围内进行，因此能够定量检测多种气相物质。在这里，重点是设置在尘埃甲烷和乙炔等离子体中的小碳氢自由基CH 3，C2H和C2H3的光谱和化学动力学的调查。一般来说，通过监测正在进行的颗粒形成过程中（等离子体中，火焰中，大气气溶胶中）气相物质的浓度分布，新的检测系统将有可能得出关于表面反应及其对整体气相化学反应的反馈作用的结论。通过这种方式，可以更容易地识别由反应表面或等离子体中的特殊条件介导的新反应途径。

The project aims at the development and testing of highly sensitive absorption spectroscopic modulation techniques for time-resolved detection of transient species in particle forming environments. Measurements will be performed in the infrared (IR) spectral range, hence enabling the quantitative detection of multiple gas phase species. Here, a focus is set on the investigation of the spectroscopy and chemical kinetics of the small hydrocarbon radicals CH3, C2H und C2H3 in dusty methane and acetylene plasmas. In general, by monitoring the concentration profiles of gas phase species during ongoing particle formation processes (in plasmas, in flames, in atmospheric aerosols), the new detection system will make it possible to draw conclusions about the role of surface reactions and their feedbacks on the overall gas phase chemistry. In this way, new reaction pathways that are mediated by the reactive surfaces or the special conditions in a plasma can be more easily identified.