Laboratory Measurements of Dissociative Recombination with Cold Molecular Ions for Ground-Based Studies of Diffuse Molecular Clouds

用于弥散分子云地面研究的冷分子离子解离重组的实验室测量

• 批准号: 1907188
• 负责人: Daniel Wolf Savin
• 金额: $ 58.32万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1907188&HistoricalAwards=false
• 关键词: Laboratory; Measurements; Dissociative; Recombination; Cold; Laboratory; Measurements; Dissociative; Recombination; Cold

Dissociative recombination (DR) with electrons is the dominant process by which molecular ions are destroyed in the diffuse interstellar medium. This research project will determine the rates of DR reactions of three molecular ions CF+, CH+, and SH+ in the laboratory at low temperatures and pressures that simulate the conditions in space. Rates from the study will allow astronomers to infer accurate abundances of these ions and use them as probes of the physics and chemistry of the interstellar gas. The project will support the training of a postdoctoral scholar and provide research opportunities to an undergraduate student.The research team will perform the laboratory DR measurements using the Cryogenic Storage Ring (CSR) located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. The CSR can store ions for over 1,000 seconds, allowing them to cool radiatively to low rotational energy levels comparable to those in diffuse molecular clouds. Using the DR measurements, the team will generate accurate thermal rate coefficients at low temperatures relevant to diffuse clouds. Reliable DR data from the project will enable astronomers to use CF+, CH+, and SH+ abundances to probe key properties and processes in the diffuse gas.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

与电子的解离重组（DR）是在弥漫性星际培养基中破坏分子离子的主要过程。 该研究项目将确定实验室中三个分子离子CF+，CH+和SH+在低温和模拟空间条件的压力下的DR反应速率。 该研究的速率将使天文学家可以推断出这些离子的准确丰度，并将其用作星际气体物理和化学的探针。 该项目将支持对博士后学者的培训，并为本科生提供研究机会。研究小组将使用位于德国海德尔伯格的Max Planck核物理研究所的低温存储环（CSR）进行实验室DR测量。 企业社会责任可以将离子储存超过1,000秒，从而使它们能够辐射冷却至低旋转能级，可与弥漫性分子云相当。 使用DR测量值，团队将在与扩散云相关的低温下生成准确的热速率系数。 该项目的可靠DR数据将使天文学家能够使用CF+，CH+和SH+丰度来探测弥漫性气体中的关键特性和过程。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的审查标准来通过评估来获得支持的。