Cross Section Measurements for Excitation and Ionization of Atmospheric Species

大气物质激发和电离的横截面测量

• 批准号: 9705115
• 负责人: John Doering
• 金额: $ 27.63万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-05-15 至 2002-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9705115&HistoricalAwards=false
• 关键词: Cross; Section; Measurements; Excitation; Ionization

This continuing project will conduct laboratory investigations of electron impact excitation and ionization cross sections for atmospheric species at Johns Hopkins University. Ionization and excitation are produced by both photoelectrons produced by the sun's extreme ultraviolet photon flux on atmospheric constituents and precipitated accelerated electrons in auroral zones. Excitation and ionization are also the main processes by which thermospheric electrons lose energy to the ambient atmosphere. Thus, we must gain familiarity with the cross sections for these electron impact processes to understand the rate of electron energy loss as well as intensities of optical emissions they produce. Specifically, we plan to measure ionization-excitation branching ratios for atomic oxygen ion production in all final electronic states of the ion. The work should significantly advance thermospheric modeling and many processes of interest in planetary atmospheres.

这一继续进行的项目将在约翰霍普金斯大学对大气物种的电子碰撞激发和电离截面进行实验室调查。 电离和激发是由太阳的极紫外光子通量在大气成分上产生的光电子和极光区的沉淀加速电子产生的。 激发和电离也是热层电子向周围大气损失能量的主要过程。 因此，我们必须熟悉这些电子碰撞过程的横截面，以了解电子能量损失的速率以及它们产生的光发射强度。 具体来说，我们计划测量离子的所有最终电子态的原子氧离子生产的电离激发分支比。 这项工作将大大推进热层建模和行星大气中许多感兴趣的过程。