RUI - Precision Measurements of the Fine Structure of High-Angular Momentum Rydberg States of Rotationally Excited Molecular Hydrogen

RUI - 旋转激发氢分子高角动量里德伯态精细结构的精密测量

• 批准号: 0969692
• 负责人: Erica Simoson
• 金额: $ 20万
• 依托单位: SUNY College at Fredonia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0969692&HistoricalAwards=false
• 关键词: RUI; Precision; Measurements; Fine; Structure

This work will obtain precise measurements of the fine structure of high-angular momentum Rydberg states of rotationally excited molecular hydrogen, H2. This study will lead to precise determinations of such fundamental properties of the molecular hydrogen ion as multipole moments, polarizabilities and hyperfine constants. Of particular interest are the properties of the rotationally excited states (R=2 and 3) of the ground vibrational state (v=0) of H2+ that have thus far been experimentally inaccessible. There are few existing direct measurements of H2+ because of the lack of stable excited states. However, an excited electron, bound to an ion core, in a large nearly circular orbit can act as a very sensitive probe to investigate electric and magnetic properties of the ion core. High angular momentum Rydberg states meet this criterion and, therefore, precise studies of these spectra afford the opportunity to detect long-range properties of the ion. The basic model in molecular physics, H2+, has been studied extensively by theorists, but there are comparatively few precise experimental measurements. The need for accurate models beyond the adiabatic approximation is increasing, and several theoretical approaches have been developed. This study will provide an excellent avenue to test the accuracy of the theoretical models. A novel approach to the detection techniques of Resonant Excitation Stark Ionization Spectroscopy (RESIS) will allow the first measurements of the higher rotational levels of H2 that were unattainable in previous studies due to their fast autoionization rates. This work will provide precise measurements relevant to the advances in H2+ theory, which are necessary in other areas such as ultracold molecules and interstellar chemistry. The new measurements will also provide immediate improvement to the best existing spectral measurement in H2+. The experimental program will have broad impact at three levels. First, undergraduate students at State University of New York at Fredonia in general would be positively impacted though the modeling of an active researcher, infusion of current research into course work, active participation in research, and experience in presenting research results at multiple levels. Studies in the precise measurement of the fine structure of high-L Rydberg states offers students the opportunity to gain experience with several types of equipment used quite universally in research labs. In addition, the theoretical analysis of these nearly classical high-L Rydberg systems can be understood by an upper-level undergraduate student. It clearly demonstrates the use of perturbation theory in quantum mechanics, and several concepts a student would learn in a typical electricity and magnetism course, such as the multipole expansion. This research project will be used for discussion of various topics in the PI's undergraduate classroom, in a range of courses from algebra-based physics to 400-level physics courses. Second, the funding of this research program will help establish the career of a new faculty researcher, increase the on-campus experimental research, develop interdisciplinary research interests between the Departments of Physics and Chemistry, and further expand the presence of atomic, molecular, and optical physics at small undergraduate institutions. Third, the research at a rurally situated public university of higher education, which is part of the K-16 educational pipeline, positively impacts undergraduate students who are underrepresented in the STEM pipeline such as women, economically disadvantaged students who enter higher education through community college and continue through publicly funded regional universities, first generation college students, and students who come from rural, geographically isolated areas. Presentations at local community colleges and/or other regional institutions in this rural area positively extend the impact of this research into this under-served area.

这项工作将获得旋转激发的氢分子H2的高角动量里德堡态的精细结构的精确测量。这项研究将导致分子氢离子的基本性质，如多极矩，极化率和超精细常数的精确测定。特别令人感兴趣的是迄今为止实验上无法获得的H2+的基态振动态（v=0）的旋转激发态（R=2和3）的性质。由于缺乏稳定的激发态，目前对H2+的直接测量很少。然而，在一个大的近圆形轨道中，与离子核结合的激发电子可以作为一个非常灵敏的探针来研究离子核的电磁性质。高角动量里德堡态满足这一标准，因此，对这些光谱的精确研究提供了检测离子长程性质的机会。分子物理学中的基本模型H2+已经被理论家们广泛研究，但精确的实验测量相对较少。对超越绝热近似的精确模型的需求正在增加，并且已经开发了几种理论方法。这项研究将提供一个很好的途径来检验理论模型的准确性。共振激发斯塔克电离光谱（RESIS）检测技术的一种新方法将允许首次测量H2的更高旋转水平，这在以前的研究中是无法实现的，因为它们的快速自电离速率。这项工作将提供与H2+理论进展相关的精确测量，这在超冷分子和星际化学等其他领域是必要的。新的测量也将提供对H2+中最好的现有光谱测量的即时改进。该实验方案将在三个层面产生广泛影响。首先，本科生在州立大学的纽约弗雷多尼亚一般会受到积极的影响，通过建模的积极研究人员，注入当前的研究到课程工作，积极参与研究，并在多个层次上呈现研究成果的经验。在高-L里德堡态的精细结构的精确测量的研究为学生提供了机会，以获得在研究实验室中非常普遍使用的几种类型的设备的经验。此外，这些接近经典的高L里德堡系统的理论分析可以理解的高水平的本科生。它清楚地演示了微扰理论在量子力学中的应用，以及学生在典型的电学和磁学课程中会学到的几个概念，如多极展开。这个研究项目将用于PI的本科课堂上的各种主题的讨论，在一系列的课程，从代数为基础的物理400级物理课程。其次，该研究计划的资金将有助于建立一个新的教师研究员的职业生涯，增加校园实验研究，发展物理和化学系之间的跨学科研究兴趣，并进一步扩大原子，分子和光学物理在小型本科院校的存在。第三，在一所位于农村的公立高等教育大学进行的研究，这是K-16教育管道的一部分，对STEM管道中代表性不足的本科生产生了积极影响，如女性，通过社区学院进入高等教育并继续通过公共资助的区域大学，第一代大学生和来自农村的学生，地理上孤立的地区。在当地社区学院和/或其他区域机构在这个农村地区的演讲积极扩展到这个服务不足的地区本研究的影响。