Microwave Spectroscopy


In this experiment you will measure high-resolution microwave spectra of inversion transitions of gaseous ammonia in the frequency range between 18 and 26 GHz. The setup comprises the typical technology and methodology of high-resolution microwave and THz spectrosopy, as deployed throughout this institute for e.g. the measurement of molecular rotational transitions.



The tutorial may be downloaded here in PDF format or alternatively be obtained personally from the assistant.


Dr. Matthew Horrobin – Room 220 – Tel: 470-3495
E-Mail: mjh (at) ph1.uni-koeln.de

Recommended reading

  1. Staatsexamensarbeit Sven Hees, S.1-53, S.58f
  2. Townes/Schawlow – the title can be borrowed from the assistant!
    Chapter 1: Rotational Spectra of Diatomic Molecules
    Chapter 3: Symmetric-Top Molecules
    Chapter 6: Quadrupol Hyperfine Structure in Molecules
    Chapter 8: p222f: Hyperfine-Structure of NH3
    Chapter 12: The Ammonia Spectrum and Hindered Motions
    Chapter 13: Shapes and Widths of Spectral Lines
  3. Alder/Baker: Quantitative Millimetre Wavelength Spectrometry
  4. G. Nimtz: Mikrowellen
  5. Hachenberg, O., Vowinkel, B.: Technische Grundlagen der Radioastronomie. B.I., 1982 – download book excerpt as PDF (3 MB) here!(in German only)
  6. P. Atkins, Physical Chemistry, Oxford University Press; available at USB
  7. Merck Sicherheitsdatenblatt Ammoniak-Lösung 25%