Studies of Electron Capture, Secondary Processes, and Photodetachment in High Pressure Ion Sources

本研究在化学部的分析和表面化学项目中，将研究分子捕获电子。电子捕获发现在识别和定量某些类别的分子，最突出的含卤素分子是生物和环境的重要性应用。Grimsrud教授的研究使用质谱法来观察电子捕获的过程，并量化样品中的痕量污染物。Grimsrud作品的独特之处在于他使用了光分离调制。这提高了分析测量的特异性和灵敏度。人们还可以区分基态和激发态的电子捕获能力，这对于理解光化学如何改变环境中卤化化合物的化学性质非常重要。二次过程（在电子捕获事件之前或之后的过程）的研究也指示了所研究化合物的大气压气相化学的细节，并且有助于理解分析测量中的意外灵敏度。

This research, in the Analytical and Surface Chemistry Program of the Chemistry Division, will study electron capture by molecules. Electron capture finds application in identification and quantification of certain classes of molecules, most prominently halogen containing molecules which are of biological and environmental importance. Prof. Grimsrud's research uses mass spectrometry to observe the process of electron capture and to quantify trace contaminants in samples. The unique aspect of Grimsrud's work is his use of photodetachment modulation. This improves specificity and sensitivity in analytical measurements. One can also differentiate electron capture capabilities of ground states and excited states, which is important in understanding how photochemistry modifies the chemistry of halogenated compounds in the environment. The study of secondary processes (processes preceeding or succeeding the electron capture event) also is indicative of details of atmospheric pressure gas-phase chemistry of the studied compounds, and is useful in understanding unexpected sensitivity in analytical measurements.