Hannover 2020 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 14: Vibrational and Rotational Spectroscopy

MO 14.2: Hauptvortrag

Mittwoch, 11. März 2020, 14:30–15:00, f142

Rotational Studies of (chiral) Molecules/Complexes in Jets (& Flames) — •Jens-Uwe Grabow — Leibniz Universität, Hannover, Germany

Rotational spectroscopy is the most precise and unambiguous method to detect and characterize molecular species important in environmental and astro-chemistry.

The dual excitation-emission propagation in-phase/quadrature-phase modulation passage-acquired coherence technique (DEEP-IMPACT) Fourier-transform microwave (FTMW) spectrometer delivers broadband spectra at a resolution similar to the resolving power of the narrowband but more sensitive excitation pulse-induced coherence coaxial orientation beamresonator arrangement (EPIC-COBRA) FTMW spectroscopy.

Nevertheless, the single-horn feed used in the dual off-axis parabolic reflector arrangement limits the applicable excitation power and therefore is severely reducing the polarization efficiency. Rotating of the field vector direction of the linearly polarized microwave radiation allows for a dual-feed horn. This novel setup prevails the high spectral resolution but increases the sensitivity dramatically while allowing the very high-power needed for less polar species. In this contribution we present the apparatus in detail as well as experimental results obtained with the EPIC-COBRA FT-MW spectrometer that also adopts instrumental aspects of the DEEP-IMPACT FTMW technique. Furthermore, we will try to elucidate the nature of double-quantum coherence and some of its recent applications towards chiral molecules as well as jet-sources to observe more reactive intermediates produced in combustion reactions.