Spectroscopic studies of planetary atmospheres and high-temperature processes (e.g., combustion) require absorption line-shape models that are accurate over extended temperature ranges. To date, advanced line shapes, like the speed-dependent Voigt and Rautian profiles, have not been tested above room temperature with broadband spectrometers. We investigate pure water vapor spectra from 296 to 1305 K acquired with a dual-frequency comb spectrometer spanning from 6800 to 7200 cm at a point spacing of 0.0033 cm and absolute frequency accuracy of 3.3 × 10 cm. Using a multispectral fitting analysis, we show that only the speed-dependent Voigt accurately models this temperature range with a single power-law temperature-scaling exponent for the broadening coefficients. Only the data from the analysis using this profile fall within theoretical predictions, suggesting that this mechanism captures the dominant narrowing physics for these high-temperature conditions.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8207537 | PMC |
| http://dx.doi.org/10.1103/PhysRevA.96.022514 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Full quantum calculations of the line shape for H2O perturbed by Ar at temperatures from 20 to 300 K.
J Chem Phys
July 2024
Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
This work theoretically studied the spectral line shape of H2O perturbed by Ar in the temperature range of 20-300 K for the pure rotational lines below 360 cm-1, as well as three lines (31, 2 ← 44, 1, 54, 2 ← 41, 3, and 73, 5 ← 60, 6) in the v2 band. In order to perform precise dynamical calculations at low collision energies, a full-dimensional long-range potential energy surface was constructed for the H2O-Ar system for the first time to correct the long range of our newly developed intermolecular potential energy surface. Subsequently, the six line-shape parameters (pressure-broadening and -shifting parameters, their speed dependencies, and the complex Dicke parameters) were determined from the generalized spectroscopic cross section by the full quantum time-independent close-coupling approach on this new potential energy surface.
View Article and Find Full Text PDFCRDS line-shape study of the (7-0) band of CO.
Spectrochim Acta A Mol Biomol Spectrosc
May 2024
Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Toruń, Poland. Electronic address:
We present the results of the spectral line-shape study of the first measurement of the extremely weak (7-0) band of the CO molecule. Measurements were done with a highly sensitive cavity ring-down spectrometer. Collisional narrowing, analyzed in terms of speed-dependent effects, was observed for the first time for transitions with line intensities below 2⋅10 cm/molecule at 296 K.
View Article and Find Full Text PDFFull quantum scattering calculations of the line-shape parameters for the P and R branches of HF perturbed by Ar.
J Chem Phys
October 2023
Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
This work studied the rovibrational absorption spectral line-shape parameters of the P(1)-P(10) and R(0)-R(9) lines for Hydrogen fluoride perturbed by argon in the 0-0, 1-0, and 2-0 vibrational bands at 20-1000 K. A dataset of beyond-Voigt line-shape parameters (pressure broadening and shifting parameters, their speed dependencies, and the complex Dicke parameters) has been theoretically determined for the first time from generalized spectroscopic cross-section calculated by the full quantum scattering calculations. Then these parameters were employed to predict the line shape and asymmetry based on the partially-correlated speed-dependent hard-collision and the partially-correlated quadratic-speed-dependent hard-collision profiles.
View Article and Find Full Text PDFConversion efficiency of flight power is low, but increases with flight speed in the migratory bat .
Proc Biol Sci
May 2023
Department of Biology, Lund University, 223 62 Lund, Sweden.
The efficiency with which flying animals convert metabolic power to mechanical power dictates an individual's flight behaviour and energy requirements. Despite the significance of this parameter, we lack empirical data on conversion efficiency for most species as measurements are notoriously difficult to obtain. Furthermore, conversion efficiency is often assumed to be constant across flight speeds, even though the components driving flight power are speed-dependent.
View Article and Find Full Text PDFImprovement of the spectroscopic parameters of the air- and self-broadened NO and CO lines for the HITRAN2020 database applications.
J Quant Spectrosc Radiat Transf
September 2021
Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA.
This paper outlines the major updates of the line-shape parameters that were performed for the nitrous oxide (NO) and carbon monoxide (CO) molecules listed in the HITRAN2020 database. We reviewed the collected measurements for the air- and self-broadened NO and CO spectra to determine proper values for the spectroscopic parameters. Careful comparisons of broadening parameters using the Voigt and speed-dependent Voigt line-shape profiles were performed among various published results for both NO and CO.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!