General research activities

    The research activities of the Laboratory of High Resolution Molecular Spectroscopy in Prague generally focus on the study of molecules in gaseous state using microwave and millimeterwave spectroscopy with subsequent theoretical analysis of obtained spectra and their using to obtain extremely accuratte molecular structure and electrodynamical parameters. In addition to that, this spectroscopy offers us a unique technique of remote sensing detection, which is the most essential method in investigation of atmosphere. Nowadays, research on this field is accelerated by global climate changes, by long-time increasing ecological stress and by alarming evolution of the ozone sphere and increasing amount of greenhouse-effect gases. All of these phenomena are mostly the result of antropological activities and a sped and the most accurate qualitative and quantitative remote sensing detection of all the atmospheric species (species of trace amount, too) are the first steps to understand all the chemical and physical processes in atmosphere. At present is developed a whole range of europian and world  campaignes, when is the spectrometer brought up with a stratospherical balloon, a satelite, a shuttle, or a plane to obtain high resolution spectra of upper spheres of atmosphere. For interpretation of this spectra are needed laboratory sampling spectra of high quality, accurate description of the line shapes at several atmospherical conditions, detailed analysis of hyperfine structures, etc. At present it is indicated, that the sampling spectra are not of sufficient quality for detailed analysis of molecules, which are splitted by hyperfine interaction.  Unsufficient are too laboratory informations about line shapes at defined atmospherical conditions and informations about line intensities.

 

Definition of the realised subjects in the research plan:

  1. To elaborate a technique for measurment of true spectral line shapes and to apply this technique for measuring of atmospherical components, with the purpose to supply the data for resulting remote sensing measurments.

  2. To elaborate a technique for measurment of nuclear hyperfine structures of rotational lines and to measure shapes of rotational lines with overlapped hyperfine structure of enviromentally important component of atmosphere and to compile these lines theoretically.

 

Strategy and methods of treatment of the research plan:

    Needful theory of hyperfine effects will be started to develope and adequate algorithms and software for theoretical analysis of these structures in experimental spectrum will be created. The method for theoretical description of experimental rotational line shapes, which are affected by the inner nuclear qudrupole structure, will be developed.

    Microwave spectra of environmentally important components of atmosphere will be experimentally studied at various partial pressures, which are corresponding to the conditions of the upper spheres of atmosphere.

 

Time schedule of solving the research plan:

2005-2006

Modelling of rotational spectral lines with overlapped hyperfine structure at atmospheric conditions (control with publications).

2006-2007

Improvement of sensitivity of the spectrometer and introduction of the Lamb dip spectroscopy. Resolution  of spin-spin structure in spectra of simple atmospherical molecules.

2007-2008

Enlargement of the spectrometer for saturation two-photons spectroscopy.

 

Expected results of solving the research plan:

  1. High accurate rotational frequencies (including pressure shifts) and detailed spectral line shapes in modelled atmospherical background of basic atmospherical gases (not yet measured needed lines of CO, SO2, NOx, etc.) will be obtained. These usually not yet measured data are needed for interpretation of atmosphere monitoring experiments in the range of europian or global campaignes (satellite, stratospheric, etc. measurments).

  2. For systems with outstanding hyperfine structure (atmospheric molecules and fragments containing nuclei with spin greater than one half N, Cl, Br) will be on the basis of analysed hyperfine structure, modelled composite envelope of the spectrum and the obtained theoretical model will be used for description of experimental line shapes, which are very important for analysis of atmospherical measurments.

  3. Possibility of studium of simple organic substances and resolution of their spatial conformers in gaseous phase with the aid of high resolution microwave spectroscopy will be tested. These studies can have important analytical and structural aspects.