Description |
High-resolution terahertz (THz) spectroscopy is a vivid
field of current research due to its importance in
astrophysics and molecular physics. New THz telescope
facilities like ALMA, Herschel, and SOFIA make use of
accurate (<1 MHz) laboratory line positions in the
frequency range up to 2 THz to identify interstellar
molecules and to derive their astrophysical abundance.
This talk presents current laboratory activities to provide
the necessary transition frequencies for molecular
rotation and ro-vibration in the range from 300 GHz up
to 3 THz. The continuous development and fabrication
of monochromatic submillimeter (sub-mm) wave
radiation sources is a key to recent successes of THz
spectroscopy in laboratory and space. High-resolution
spectrometers, based on backward wave oscillators,
multiplier techniques, and laser side band generation and examples of molecules studied at the
laboratory will be presented. General features of the instruments such as frequency accuracy and
sensitivity will be discussed in detail.
Applications include the study of light hydrides, complex molecules, radicals, and molecular ions.
These transient species are very important molecules in the astrophysical environment because of
their chemical activity. However characterization of these molecules in the laboratory, is
experimentally as well as theoretically demanding. Combination of supersonic jets to THz
spectroscopy will be discussed as recent developments in our laboratory to meet the challenge.
Carbon Clusters Produced in a Supersonic Jet
Expansion of a Laser Ablation Source.
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