Laboratory Studies of Oxygen Atom Recombination in Nitrogen at Mesospheric Temperatures

该奖项支持实验室实验，以研究分子氮环境中氧原子重组过程的动力学，以及在与地球中间层相关的温度下导致分子氧（O2）激发态的途径。该项目将提供解释和模拟高层大气中重要过程所需的基本物理测量，如O2气辉和大气动力学。除了航空学的观测和理论研究外，这项工作还有助于行星大气的研究。该项目将为一名或多名博士后和本科生提供培训和研究经验。研究了碰撞弛豫的作用、温度相关的复合速率系数、主要的能量流动途径以及由此产生的O2激发态产率。这些测量是对大气及其气辉排放的定量理解和可靠建模所必需的。了解激发态O2产生的相关细节对大气成分、能量传递、气辉和传输动力学的研究和建模至关重要。实验方法包括在合适的浴气中通过准分子激光的紫外辐射脉冲光引发o原子重组。荧光和共振增强多光子电离（REMPI）技术用于监测o原子居群的衰变和检测激发态O2分子，从而深入了解重组后产生的激发态O2的相关去除率系数、能量流动途径和产率。

This award supports laboratory experiments to study the kinetics of the process of oxygen atom recombination in a molecular nitrogen environment and the pathways that lead to excited states of molecular oxygen (O2) at temperatures relevant to the Earth's mesosphere. The project will supply basic physical measurements needed to interpret and model important processes in the upper atmosphere, such as O2 airglow and atmospheric dynamics. In addition to observational and theoretical studies of Aeronomy, this work could benefit research on planetary atmospheres. The project will contribute to the training and research experience of one or more postdoctoral fellows and undergraduate students. The role of collisional relaxation, the temperature-dependent recombination rate coefficient, the dominant energy flow pathways, and the resulting O2 excited state yields will be studied. These measurements are needed for a quantitative understanding and reliable modeling of the atmosphere and its airglow emissions. Knowledge of the details relevant to the production of excited O2 is critical input for the study and modeling of atmospheric composition, energy transfer, airglow, and transport dynamics. The experimental methodology involves the photoinitiation of O-atom recombination in a suitable bath gas by an ultraviolet radiation pulse from an excimer laser. Fluorescence and resonance-enhanced multiphoton ionization (REMPI) techniques are used to monitor the decay of the O-atom population and detect excited O2 molecules, thus providing insight into the relevant removal rate coefficients, energy flow pathways, and yields of the excited O2 states produced following recombination.