Bachelor thesis

The thesis deals with the application and characterization of a heterodyne emission spectrometer, with which due to a new design a broadband and highly accurate emission spectrum can be recorded. The intrinsic bandwidth is 2.5 GHz and the tuning range is between 73 and 110 GHz. First, there is a focus on the theory behind the relevant part of the laboratory astrophysics. Afterwards the experimental setup is presented and characterized. A large part of this work is spent on the analysis of the emission spectrum.

Since for the first time a spectrometer has been developed, which can selectively measure an emission or an absorption spectrum, the for the absorption spectrum necessary hot thermal radiator was developed. The resulting absorption spectrum was compared with that of a conventional absorption spectrometer and the emission spectrum. The obtained Results are a novelty: For the first time, the K structure of methyl cyanide (=3 mm) in emission was resolved and also the Hyperfine structure was partially detected. Furthermore the two vibration-excited states v₈ = 1 and v₈ = 2 were measured.

Some results can be found in this publication: