Jansen Charlotte, Juurlink Ludo B F, van Lent Richard, Chadwick Helen
Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300RA Leiden, The Netherlands.
Department of Chemistry, Faculty of Science and Engineering, Swansea University, Swansea SA2 8PP, United Kingdom.
Rev Sci Instrum. 2024 May 1;95(5). doi: 10.1063/5.0203641.
State-resolved experiments can provide fundamental insight into the mechanisms behind chemical reactions. Here, we describe our methods for characterizing state-resolved experiments probing the outcome of the collision between CO2 molecules and surfaces. We create a molecular beam from a supersonic expansion that passes through an ultra-high vacuum system. The CO2 is vibrationally excited by a continuous wave infrared (IR) laser using rapid adiabatic passage. We attenuate the fractional excitation using a CO2 absorption cell in the IR beam path. We combine Monte Carlo simulations and molecular beam energy measurements to find the initial rotational state distribution of the molecular beam. We find that our pure CO2 beam from a 300 K source has a rotational temperature of ∼26 K.
态分辨实验能够为化学反应背后的机制提供基本的见解。在此，我们描述了我们用于表征态分辨实验的方法，这些实验探究二氧化碳分子与表面碰撞的结果。我们通过超声速膨胀产生分子束，该分子束穿过超高真空系统。使用快速绝热通道，二氧化碳被连续波红外（IR）激光进行振动激发。我们在红外光束路径中使用二氧化碳吸收池来衰减分数激发。我们结合蒙特卡罗模拟和分子束能量测量来确定分子束的初始转动状态分布。我们发现，来自300 K源的纯二氧化碳束的转动温度约为26 K。
