High-resolution molecular spectroscopy using laser and synchrotron radiation

使用激光和同步辐射的高分辨率分子光谱

• 批准号: RGPIN-2017-05346
• 负责人: Tokaryk, Dennis
• 金额: $ 1.53万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=678207
• 关键词: resolution; molecular; spectroscopy; using; laser

The different wavelengths of light emitted or absorbed by molecules - the molecular spectrum - encodes a wealth of information about the internal structure and the physics inherent to the species being observed. Each molecule's spectrum is unique, and can be used like a fingerprint to identify it. This property is powerful, especially so in astrophysics, since the only information we receive from remote stars, galaxies, and the interstellar medium comes from the light they produce or absorb.******This proposal describes a program of research that records molecular spectra of species that have known or potential relevance to astrophsyics. Many of the molecules we study are quite unstable because they react with atmospheric gases and are quickly destroyed - but in space, where the density of matter is low, they persist for long times. We create these unstable molecules by stripping material from a rod housed in a vacuum chamber with a laser pulse. The hot plume of material then reacts with a fast-moving jet of helium gas entrained with stable reactant molecules like methane or methanol to produce the unstable species found in space. The jet is crossed with laser beams whose wavelengths can be continuously varied, and when the wavelength matches that of an absorption the molecule fluoresces, producing a signal that we can detect to map the spectrum. We specialize in molecules containing an atom of metal that comes from the rod, and is bonded to a ligand that comes from the reactant gas. Metal-bearing molecules like FeH and CrH; FeO, VO and TiO; and MgNC and MgCN have already been observed in the atmospheres of stars (including our sun). We will look for species like FeP, VP, and TiP which one day may be observed in space.******The construction of the Canadian Light Source synchrotron in Saskatoon, SK has added an exciting new possibility for molecular spectroscopy experiments - access to intense and well-collimated light at very long wavelengths. The synchrotron light allows us to rapidly acquire spectra of extremely high quality in the difficult 2-30 terahertz region of the electromagnetic spectrum, where the fundamental vibrations of many larger molecules of astrophysical interest lie. Many currently-active satellite-borne instruments are sensitive to this region, and the data my students and I collect provides a valuable database for comparison with the spectra these satellites collect from the universe around us.

分子发出或吸收的不同波长的光——分子光谱——编码了大量关于被观察物种的内部结构和物理特性的信息。每个分子的光谱都是独一无二的，可以像指纹一样用来识别它。这个特性非常强大，特别是在天体物理学中，因为我们从遥远的恒星、星系和星际介质中接收到的唯一信息来自它们产生或吸收的光。******此提案描述了一个研究项目，记录已知或潜在与天体物理学相关的物种的分子光谱。我们研究的许多分子都很不稳定，因为它们与大气中的气体发生反应，很快就会被破坏——但在物质密度低的太空中，它们会持续很长时间。我们制造这些不稳定分子的方法是用激光脉冲从真空室中的棒材上剥离材料。然后，炽热的物质羽流与带有稳定反应物分子（如甲烷或甲醇）的快速移动的氦气射流发生反应，产生在太空中发现的不稳定物质。射流与波长可以连续变化的激光束交叉，当波长与吸收分子的波长相匹配时，分子就会发出荧光，产生我们可以探测到的信号来绘制光谱。我们专门研究含有一个金属原子的分子，这个金属原子来自于棒状物质，并与一个来自于反应物气体的配体结合。含金属分子，如FeH和CrH；FeO、VO和TiO；MgNC和MgCN已经在恒星（包括我们的太阳）的大气层中被观测到。我们将寻找有一天可能在太空中观察到的FeP、VP和TiP等物种。******加拿大光源同步加速器在萨斯卡通的建设，SK增加了一个令人兴奋的分子光谱实验的新可能性-在非常长的波长获得强烈和良好的准直光。同步加速器光使我们能够在电磁波谱的2-30太赫兹区域快速获得极高质量的光谱，这是许多天体物理学感兴趣的大分子的基本振动所在。许多目前活跃的星载仪器对这个区域很敏感，我和我的学生收集的数据提供了一个有价值的数据库，可以与这些卫星从我们周围的宇宙收集的光谱进行比较。