The KIEL Microwave Laboratory

Location:
        Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany

Key Scientists:
        Helmut Dreizler, Antonio Guarnieri, Heinrich Mäder, Dieter Sutter

Overview:
       This has been a very influential laboratory in the field of rotational spectroscopy.  It was established in 1969 when  Helmut Dreizler and several colleagues moved from the University of Freiburg, Germany.  This laboratory was engaged in all aspects of rotational spectroscopy and achieved considerable eminence in spectrometer design.  They are probably best known for development of many variants of Fourier Transform Microwave (FTMW) spectrometers, including unique waveguide FTMW spectrometers operating at room temperature.  One of the spectrometers has been patented and was involved in a promotional campaign for industrial analytical use (no luck!). 

       The impressive scientific legacy of the Kiel laboratory is reflected by the enormous publication list of close to 600 papers. The tenured professors have retired but the traditions of the laboratory are continued by its past members who have established new research groups:  Wolfgang Stahl in Aachen (Germany), Jens-Uwe Grabow in Hannover (Germany),  Wolfgang Jäger in Edmonton (Canada).

        A biography of Helmut Dreizler appeared in Journal of Molecular Structure several years after his formal retirement: Jose L. Alonso, Juan C.Lopez, Alberto Lesarri, J.Mol.Struct. 612 (2002) 81–82.


Documents:

KIEL history History of the Kiel laboratory written by its professors
Publication list Publication list of the Kiel laboratory
Kiel FTMW patent US Patent 5124653 describing the "Method and Apparatus for Determining the Concentration of Compounds in a Gas Mixture by Microwave Gas Analysis"

 

Picture gallery:

Select any picture with the mouse to enter the gallery mode. Successive pictures can then be conveniently inspected in various ways, also by using the mouse scroll wheel.

First members of the Kiel group who moved from Freiburg (1969). Top (from left) : H.Legell, U.Andresen, D.H.Sutter. Bottom (from left) : A.Guarnieri, H.Dreizler, H.Mäder. Note that nobody is as yet looking at a computer screen. Move to Kiel (1969). In the top picture the central building is the Institute of Physical Chemistry and the main part of the microwave laboratory was based on the fifth (=top) floor, while the Zeeman spectrometer was located in the basement. The CH3CH2CN molecular example of investigation of internal rotation and internal rotation vibration interaction with principal investigators (1974). Installation of the 20 ton magnet for the Zeeman MW spectrometer (1970). The magnet was manufactured by Bruker, Karlsruhe and its installation in the basement of the building required heavy transport equipment. Zeeman MW spectrometer with E.Hamer (1970). The magnet pole distance could be changed by lifting the top pole with four hydraulic jacks and changing spacers. The achievable magnetic field was 21 kG for 6 cm pole spacing. The detector end of a J-band sample cell is visible in the magnet. Measurements with this cell were made over the 5.3-40 GHz frequency region. After a heavy storm, the Institute labs, especially in the fifth floor, were severely damaged (January 1983). Various achievements of the Kiel group were presented several times at the Hannover industrial fair (left). The right picture records presentation of the homemade transient digitizer for the extraction of weak periodic signals from the noise (1988). The digitizer was especially designed for waveguide Fourier-transform spectroscopy and could average up to 25k records per second, each up to 4096 points and 40 microseconds long. Several MW group members are in attendance: U.Andresen (1st left), Ch.Keussen (4th from left), H.Dreizler (5th from left). The commercialised MB MWFT spectrometer designed for detection of air pollution in the atmosphere. The spectrometer was described in detail in Andresen et al., Fresenius J. Anal. Chem., 349,272-276(1994), and was covered by several patents including US patent 5124653 granted in 1992. The operational frequency range was 6-26.4 GHz and detection performance at the ppm level was demonstrated. The spectrometer was exhibited in 1993 at the Hannover industrial fair. Helmut Dreizler (2012). Antonio Guarnieri. Picture taken in 2007 in his laboratory relocated to the Technical Faculty of the of Kiel University. Heinrich Mäder. Picture from 2009 taken in the garden of Wolfgang Jäger in Edmonton. Dieter Sutter in retirement (2012).

Photo Credits: H. Dreizler, A.Guarnieri, H. Mader, D.H. Sutter, "Contributions to Microwave Spectroscopy by the group at the University of Kiel, Germany" (March, 2012).

 

The K-band waveguide FTMW spectrometer and H.Mäder. Its characteristic feature is the use of a circular waveguide cell, which runs under the ceiling for most of the length of the 5th floor corridor. The rectangular to circular waveguide connections are made with specially designed Marie transitions. The X- and P-band waveguide FTMW spectrometer in the basement laboratory (+ H.Mäder). This spectrometer uses a standard rectangular X-band cell, of 10-metre length, suspended under the ceiling. The large supersonic expansion FTMW spectrometer based on Fabry-Perot microwave resonator with 60 cm mirrors. The instrument is posed with Simmy Jacobsen, a student in the Kiel group. Compact version of the supersonic expansion FTMW spectrometer used for electric discharge and laser ablation studies. H.Mäder is pointing out the laser input port. The spectrometer is equipped with Helmholtz coils for cancelling the Earth magnetic field, which is mandatory in studies of paramagnetic molecules. An example of creative recycling of microwave equipment at the end of the fifth floor corridor.

Photo Credits: Z. Kisiel (2002).