Laser spectroscopic determination of electric fields, electron densities, and electron temperatures in atmospheric pressure microdischarges

激光电场测量和汤姆逊散射可以提供微放电中主要等离子体参数的非侵入性诊断。特别是等离子体密度、电子速度分布函数和局部电场可以以ns-time分辨率和优于100 μm的空间分辨率进行测量。激光测量结合了超快速和光谱分辨的光学诊断和电学测量。应用将应用于ns脉冲和rf操作的射流。虽然后一种喷气机已经在研究小组中投入使用，但新型喷气机是一种新的发展。与rf射流相比，rf射流只需要在氦中使用小分子外加剂，而ns射流中的短高压脉冲将允许在分子气体中直接操作。特别是，在氮气中的操作将允许直接电场测量。诊断提供的数据将作为这些微等离子体模拟和模型的基准。

Laser electric field measurements and Thomson scattering can provide non-intrusive diagnostics of major plasma parameters in microdischarges. In particular plasma densities, the electron velocity distribution function, and the local electric field can be measured with ns-time resolution and spatial resolutions of better than 100 μm. The laser measurements are combined with ultra-fast and spectrally resolved optical diagnostics and electrical measurements. Application will be to ns-pulsed and RF-operated jets. While the latter jets are already operational in the research group, the ns-jets are a novel development. In contrast to the RF-jets which require operation in helium with only small molecular admixtures, the short high voltage pulses in the ns-jets will allow direct operation in molecular gases. In particular, operation in nitrogen will allow direct electric field measurements. The data provided by the diagnostics will serves as benchmarks for simulations and models of these micro plasmas.