Dissociation of Molecular Nitrogen

该项目涉及编制关于以下方面的基本数据： 原子和分子的氮，需要更好地了解 高层大气的能量流和化学电子 氮分子碰撞解离和光解 产生基态N（4S）或 其激发态之一，N（2D）或N（2P）。的反应性 原子氮及其在奇数氮循环中的作用取决于 对氮原子的激发态敏感。 预测热层NO浓度将发生100%的变化 当基态与激发态的比率 解离从50：50变化到46：54。 虽然一个比率 50：50是在理论上假设的，这个比例本身就有 从未被实验确定。 主要研究者 已经开发出一种新的技术， 在N2中产生的两个氮原子的激发态 清白的. 测量是在一个快速的光束中进行的。 利用激光激发研究氮分子的激发态 在10至18 eV的区域中的N2的状态。 这种技术将 可以用来精确地确定预解离的速率， N2的激发态和原子的激发态 形成氮产物。 N（4S）、N（2D）和N（2D）的分支比 然后通过对所有涉及的状态求和来获得N（2P 在N2的光解离和电子碰撞解离中。

This project is concerned with developing basic data on atomic and molecular nitrogen that is needed to better understand energy flow and chemistry in the upper atmosphere. Electron impact dissociation and photodissociation of molecular nitrogen produce atomic nitrogen in either the ground state N(4S) or in one of its excited states, N(2D) or N(2P). The reactivity of atomic nitrogen and its role in the odd nitrogen cycle depends sensitively upon the state of excitation of the nitrogen atom. Changes by 100% in thermospheric NO concentrations are predicted when the ratio of ground to excited states produced in dissociation is varied from 50:50 to 46:54. While a ratio of 50:50 is assumed on theoretical grounds, the ratio itself has never been determined experimentally. The principle investigator has developed a novel technique that permits direct measurement of the excitation state of both nitrogen atoms produced in N2 dissociation. The measurement is carried out in a fast beam of nitrogen molecules using laser excitation to study excited states of N2 in the region from 10 to 18 eV. This technique will be used to determine precisely the rate of predissociation of excited states of N2 and the state of excitation of the atomic nitrogen products formed. Branching ratios to N(4S), N(2D), and N(2P) are then obtained by summation over all the states involved in photodissociation and electron impact dissociation of N2.