Related Experiment Video
Updated: Feb 18, 2026

Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry
Published on: August 1, 2017
A laboratory heterodyne emission spectrometer at submillimeter wavelengths
1I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, Köln, Germany. wehres@ph1.uni-koeln.de schlemmer@ph1.uni-koeln.de.
Abstract:
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.
Related Concept Videos
Atomic Emission Spectroscopy: Lab
Atomic Emission Spectroscopy: Instrumentation
Molecular Spectroscopy: Absorption and Emission
UV–Vis Spectrometers
Inductively Coupled Plasma Atomic Emission Spectroscopy: Instrumentation
There are three main types of inductively coupled plasma atomic emission spectroscopy (ICP-AES) instruments: sequential, simultaneous multichannel, and Fourier transform instruments, with the latter being less commonly used....
UV–Vis Spectroscopy: Molecular Electronic Transitions

