Wehres N, Maßen J, Borisov K, Schmidt B, Lewen F, Graf U U, Honingh C E, Higgins D R, Schlemmer S
I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, Köln, Germany.
Phys Chem Chem Phys. 2018 Feb 21;20(8):5530-5544. doi: 10.1039/c7cp06394f.
We present first results on a newly built broadband emission spectrometer for the laboratory making use of a double sideband (DSB) heterodyne receiver. The new spectrometer is perfectly suited for high-resolution emission spectroscopy of molecules of astrophysical importance. The current SIS receiver operates at RF frequencies between 270 and 390 GHz, coincident with Band 7 of the ALMA telescope. The instantaneous bandwidth is 5 GHz (DSB). In this work the full spectrometer and its components are described. Its performance, in particular its sensitivity, stability, reproducibility and systematic errors, is characterized in detail. For this purpose very broad band emission spectra of methyl cyanide have been recorded and compared to theoretical spectra. Isotopic variants are found in natural abundance and features attributed to vibrationally excited species are all recorded in the same spectrum. The performance of the new spectrometer is compared extensively to that of a traditional FM-absorption spectrometer and to recent versions of chirped-pulse spectrometers operated in the mm-wave regime. Further applications and future advancements of the current instrument are discussed.
我们展示了一种新建造的用于实验室的宽带发射光谱仪的初步结果，该光谱仪采用双边带（DSB）外差接收器。这种新光谱仪非常适合用于对具有天体物理重要性的分子进行高分辨率发射光谱分析。当前的SIS接收器在270至390 GHz的射频频率下工作，与阿塔卡马大型毫米/亚毫米波阵列（ALMA）望远镜的第7波段一致。瞬时带宽为5 GHz（双边带）。在这项工作中，描述了整个光谱仪及其组件。详细表征了其性能，特别是其灵敏度、稳定性、再现性和系统误差。为此，记录了氰化甲基的非常宽带发射光谱，并与理论光谱进行了比较。发现了天然丰度的同位素变体，并且在同一光谱中记录了归因于振动激发物种的特征。将新光谱仪的性能与传统调频吸收光谱仪以及毫米波波段运行的最新啁啾脉冲光谱仪的性能进行了广泛比较。讨论了当前仪器的进一步应用和未来进展。
