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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762598
• 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.

分子发射或吸收的不同波长的光--分子光谱--编码了关于被观测物种的内部结构和固有物理的丰富信息。每个分子的光谱都是独一无二的，可以像指纹一样被用来识别它。这一性质是强大的，特别是在天体物理学中，因为我们从遥远的恒星、星系和星际介质获得的唯一信息来自它们产生或吸收的光。这项建议描述了一个研究计划，记录与天体物理学已知或潜在相关的物种的分子光谱。我们研究的许多分子非常不稳定，因为它们与大气气体反应，很快就会被摧毁--但在物质密度较低的太空中，它们会持续很长时间。我们用激光脉冲从装在真空室中的棒中剥离物质，从而产生这些不稳定的分子。然后，炽热的物质羽流与快速移动的氦气射流发生反应，氦气中夹带着甲烷或甲醇等稳定的反应物分子，产生在太空中发现的不稳定物质。喷流与波长可以连续变化的激光交叉，当波长与吸收的波长匹配时，分子会发出荧光，产生我们可以检测到的信号来绘制光谱图。我们专门研究含有金属原子的分子，这些原子来自棒，并与来自反应气体的配体键合。在恒星(包括太阳)的大气层中已经观察到了FeH和CrH，FeO，VO和TiO，以及MgNC和MgCN等金属分子。我们将寻找有朝一日可能在太空中观察到的像FEP、VP和TIP这样的物种。位于SK萨斯卡通的加拿大光源同步加速器的建设为分子光谱实验增加了一种令人兴奋的新可能性--能够在非常长的波长下获得强烈且准直良好的光。同步加速器光使我们能够在电磁光谱中困难的2-30太赫兹范围内快速获得极高质量的光谱，许多具有天体物理意义的较大分子的基本振动都位于该区域。许多目前活跃的星载仪器对这一区域很敏感，我和我的学生收集的数据提供了一个宝贵的数据库，可以与这些卫星从我们周围宇宙收集的光谱进行比较。