Cold atmospheric pressure plasma jets make important contributions to a range of fields, such as materials processing and plasma medicine. In order to optimise the effect of those plasma sources, a detailed understanding of the chemical reaction networks is pivotal. However, the small diameter of plasma jets makes diagnostics challenging. A promising approach to obtain absolute number densities is the utilisation of cavity-enhanced absorption spectroscopy methods, by which line-of-sight averaged densities are determined. Here, we present first measurements on how the spatial distribution of HO 2 in the effluent of a cold atmospheric pressure plasma jet can be obtained by cavity ring-down spectroscopy in an efficient way. Instead of recording fully wavelength resolved spectra, we will demonstrate that it is sufficient to measure the absorption coefficient at two wavelengths, corresponding to the laser being on and off the molecular resonance. By sampling the effluent fr...

中文翻译：

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腔衰荡光谱研究大气压等离子体射流中HO 2的空间分布

大气压冷等离子射流在诸如材料加工和等离子医学等一系列领域做出了重要贡献。为了优化那些等离子体源的效果，对化学反应网络的详细了解至关重要。然而，等离子流的小直径使诊断具有挑战性。获得绝对数密度的一种有前途的方法是利用腔增强吸收光谱法，从而确定视线的平均密度。在这里，我们介绍如何通过腔衰荡光谱法以有效的方式获得冷大气压等离子体射流流出物中HO 2的空间分布的首次测量。而不是记录全波长分辨光谱，我们将证明，测量两个波长下的吸收系数就足够了，这与激光开启和关闭分子共振相对应。通过采样废水