Rück Thomas, Pangerl Jonas, Escher Lukas, Jobst Simon, Müller Max, Bierl Rudolf, Matysik Frank-Michael
Sensorik-ApplikationsZentrum (SappZ), Regensburg University of Applied Sciences, Regensburg 93053, Germany.
Institute of Analytical Chemistry, Chemo, and Biosensing, University of Regensburg, Regensburg 93053, Germany.
Photoacoustics. 2024 Sep 27;40:100652. doi: 10.1016/j.pacs.2024.100652. eCollection 2024 Dec.
This study presents a detailed quantitative analysis of kinetic cooling in methane photoacoustic spectroscopy, leveraging the capabilities of a digital twin model. Using a quantum cascade laser tuned to 1210.01 cm⁻¹, we investigated the effects of varying nitrogen-oxygen matrix compositions on the photoacoustic signals of 15 ppmV methane. Notably, the photoacoustic signal amplitude decreased with increasing oxygen concentration, even falling below the background signal at oxygen levels higher than approximately 6 %V. This phenomenon was attributed to kinetic cooling, where thermal energy is extracted from the surrounding gas molecules rather than added, as validated by complex vector analysis using a previously published digital twin model. The model accurately reproduced complex signal patterns through simulations, providing insights into the underlying molecular mechanisms by quantifying individual collision contributions. These findings underscore the importance of digital twins in understanding the fundamentals of photoacoustic signal generation at the molecular level.
本研究利用数字孪生模型的能力，对甲烷光声光谱中的动力学冷却进行了详细的定量分析。使用调谐至1210.01 cm⁻¹的量子级联激光器，我们研究了不同氮氧基质组成对15 ppmV甲烷光声信号的影响。值得注意的是，光声信号幅度随氧气浓度的增加而降低，在氧气水平高于约6%V时甚至降至背景信号以下。这种现象归因于动力学冷却，即从周围气体分子中提取热能而非添加热能，这已通过使用先前发表的数字孪生模型进行的复杂矢量分析得到验证。该模型通过模拟准确再现了复杂的信号模式，通过量化单个碰撞贡献，深入了解了潜在的分子机制。这些发现强调了数字孪生在理解分子水平光声信号产生基本原理方面的重要性。
