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New insight on ammonia 1.5 µm overtone spectra from two-temperature analysis in supersonic jet
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SYSNO ASEP 0511924 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title New insight on ammonia 1.5 µm overtone spectra from two-temperature analysis in supersonic jet Author(s) Svoboda, Vít (UFCH-W) ORCID
Rakovský, Jozef (UFCH-W) RID, ORCID
Votava, Ondřej (UFCH-W) RID, ORCIDSource Title Journal of Quantitative Spectroscopy and Radiative Transfer. - : Elsevier - ISSN 0022-4073
Roč. 227, APR 2019 (2019), s. 201-210Number of pages 10 s. Language eng - English Country GB - United Kingdom Keywords potential-energy surface ; electronic ground-state ; enhanced absorption-spectroscopy ; near-infrared region ; combination band ; nh3 ; assignments ; (nh3)-n-14 ; inversion Subject RIV CF - Physical ; Theoretical Chemistry OECD category Physical chemistry R&D Projects GA13-11635S GA ČR - Czech Science Foundation (CSF) Method of publishing Limited access Institutional support UFCH-W - RVO:61388955 UT WOS 000462803700022 EID SCOPUS 85061744942 DOI 10.1016/j.jqsrt.2019.01.030 Annotation The paper presents new high-resolution spectroscopic data for the 1.5 mu m region of ammonia. All measurements have been taken in the slit-jet supersonic expansion leading to effective rotational cooling and thus facilitating significant simplification of the spectra. We demonstrate the method of controlling the expansion temperature by changing the ammonia concentration and total stagnation pressure in the jet. This allows recording spectra at 20 K and 80 K, respectively. We demonstrate two-temperature technique based on line intensity analysis using those jet spectra, that proves very effective in determining the lower state energies for states with J '' = 0, 1, and 2. The transitions originating from such states are especially important for the identification of vibrational band origins and a critical evaluation of the accuracy of the latest theoretical calculations. Empirical rotational assignments were performed for 46 ro-vibrational transitions between 6500 cm(-1) and 6900 cm(-1), respectively. Seven lines have been identified as R(0) transitions with J '' = K '' = 0, four of which are first-time identifications and/or corrections of previous misassignments. The assignments were then reconfirmed using the R(0) P(2) ground state combination differences. Additional corresponding P(1) transitions terminating in the J' = K' = 0 upper level were found. These point straight to the vibrational band origins. Altogether, band origins for 7 vibrations have been determined and the corresponding R(0), P(1) and P(2) lines have been assigned. Finally, the experimental data are compared to highly-accurate theoretical predictions for ammonia in this spectral range. (C) 2019 Elsevier Ltd. All rights reserved. Workplace J. Heyrovsky Institute of Physical Chemistry Contact Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Year of Publishing 2020 Electronic address http://hdl.handle.net/11104/0302157
Number of the records: 1