Microwave - Infrared Double Resonance Spectrometer

微波-红外双共振光谱仪

• 批准号: 450096019
• 金额: --
• 依托单位: Universität zu Köln
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/450096019?language=en
• 关键词: Microwave; Infrared; Double; Resonance; Spectrometer

Double resonance spectroscopy (DRS) shall advance our high-resolution spectroscopy experiments in many substantial ways. In the proposed configuration we want to combine rotational spectroscopy in the microwave/THz frequency range and ro-vibrational spectroscopy in the infrared wavelength regime. The general idea is to address molecules in the gas phase by one radiation source in order to create a very sensitive and molecule specific signal. The second radiation source is used to create a difference signal which only arises when the two photons address a common molecular state. One part of the DRS instrument is a chirped pulse Fourier Transform Spectrometer (CPFTS) with a minimum frequency range of 2.5 – 18 GHz. This setup is able to address the lowest rotational states of most molecules over a very wide bandwidth in one chirp excitation pulse. The electronics to create a broad band chirp signal and to record the free induction decay (FID) signal is available in our laboratory but high-power amplifiers and an intense molecular beam to create the necessary sensitivity are missing and shall be purchased. For many experiments the broad band signal of the CPFTS serves as a very sensitive detector signal. In the second part radiation from a narrow line width but widely tunable Quantum Cascade laser addresses a ro-vibrational level associated with one molecule, one specific isomer or conformer and/or a specific vibrational state of this species. Therefore, it becomes possible to decipher complex spectra of molecular mixtures, experiments where different isomers, conformers and vibrational states are present at the same time. Thus DRS will be instrumental in analysing spectra of complex organic molecules and finally finding those species in astrophysical observations. In our highly sophisticated action spectroscopy experiments in ion traps the microwave/THz and infrared radiation sources change their role. The IR QCL shall be used to create a practically background free action spectroscopy signal, e.g. by promoting a chemical reaction through vibrational excitation. The microwave/THz photon is used to change the rotational population which results in recording the rotational spectra of molecular ions which is extremely hard or practically impossible to acchieve otherwise. Such a DRS instrument is not available commercially in one piece but building it from pieces becomes now possible and will put our research in a unique position.

双共振光谱学（DRS）将以许多实质性方式推进我们的高分辨率光谱实验。在所提出的配置中，我们希望结合联合收割机旋转光谱在微波/太赫兹频率范围和振转光谱在红外波长制度。一般的想法是通过一个辐射源来寻址气相中的分子，以便产生非常灵敏和分子特异性的信号。第二辐射源用于产生差信号，该差信号仅在两个光子寻址共同的分子状态时产生。DRS仪器的一部分是最小频率范围为2.5 - 18 GHz的啁啾脉冲傅里叶变换光谱仪（CPFTS）。这种设置能够在一个啁啾激发脉冲中在非常宽的带宽上解决大多数分子的最低旋转状态。我们的实验室提供了创建宽带啁啾信号和记录自由感应衰减（FID）信号的电子设备，但缺少高功率放大器和强分子束来创建必要的灵敏度，因此需要购买。对于许多实验，CPFTS的宽带信号用作非常灵敏的检测器信号。在第二部分中，来自窄线宽但可广泛调谐的量子级联激光器的辐射解决了与一个分子、一个特定异构体或构象异构体和/或该物质的特定振动态相关的振转能级。因此，它成为可能破译复杂的光谱的分子混合物，实验中不同的异构体，构象异构体和振动状态存在于同一时间。因此，DRS将有助于分析复杂有机分子的光谱，并最终在天体物理观测中找到这些物种。在我们高度复杂的离子阱作用光谱实验中，微波/太赫兹和红外辐射源改变了它们的作用。IR QCL应用于创建实际背景自由作用光谱信号，例如通过振动激发促进化学反应。微波/太赫兹光子被用来改变转动布居数，这导致记录分子离子的转动光谱，这是非常困难或实际上不可能实现的。这样的DRS仪器在商业上还无法整体使用，但现在可以通过碎片来构建它，这将使我们的研究处于独特的地位。