Journal of Quantitative Spectroscopy & Radiative Transfer最新文献

{"title":"Simulated Raman libraries of gaseous CO, H2, N2, O2, CO2, and H2O for high-temperature diagnostics","authors":"Johannes Lill ,&nbsp;Andreas Dreizler ,&nbsp;Dirk Geyer","doi":"10.1016/j.jqsrt.2025.109449","DOIUrl":"10.1016/j.jqsrt.2025.109449","url":null,"abstract":"<div><div>In this paper, we present libraries of simulated Raman spectra of di- and triatomic gaseous species relevant for reactive flows in high-temperature environments such as flames, ranging from 1 to 2500 K. The libraries encompass the most abundant isotopologues for key species, including CO <figure><img></figure> . Simulation methodologies and results were primarily drawn from and validated in previous studies, with additional validation data provided in this work. Compiled into directly usable line lists and pseudo line lists, the simulated spectra are available in an online repository to support research groups engaged in species concentration determination, temperature measurement, and other Raman spectroscopy applications.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"340 ","pages":"Article 109449"},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Description of vibrational excitations of the OCS molecule using a local algebraic approach","authors":"E. Suárez,&nbsp;O. Guzmán-Juárez,&nbsp;R. Lemus","doi":"10.1016/j.jqsrt.2025.109432","DOIUrl":"10.1016/j.jqsrt.2025.109432","url":null,"abstract":"<div><div>A study of vibrational excitations of the OCS molecule in the framework of a polyad conserving local algebraic model is presented. The description starts establishing the Hamiltonian in configuration space in terms of normal modes and later on translated into an algebraic representation by introducing the bosonic realization for harmonic oscillator. Then a canonical transformation to local operators is applied, which in turn are mapped to <span><math><mrow><mi>S</mi><mi>U</mi><mrow><mo>(</mo><mn>2</mn><mo>)</mo></mrow></mrow></math></span> Morse like ladder operators to take into account anharmonicities from the outset. The obtained Hamiltonian is given in terms of local operators suitable to be applied to any molecular system, even to molecules with strong normal mode behavior. Our approach represents an advantage over methods based on configuration space at this level of approximation. This approach is applied to the principal isotopologue of OCS. The vibrational description was carried out including 86 experimental energies with <span><math><mrow><mi>rm</mi><mi>s</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>36</mn><mspace></mspace><msup><mrow><mi>cm</mi></mrow><mrow><mtext>-1</mtext></mrow></msup></mrow></math></span>, with a Hamiltonian involving 22 spectroscopic parameters plus three external parameters associated with the depth of the local potentials. A study of the isotopologues shows a correlation between a normal/local parameter recently introduced and their spectroscopic properties.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"340 ","pages":"Article 109432"},"PeriodicalIF":2.3,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precision frequency comb spectroscopy of the 14N2O, 14N15NO, 15N14NO, and 15N2O isotopocules in the 3300 – 3550 cm–1 range","authors":"Adrian Hjältén ,&nbsp;Ibrahim Sadiek ,&nbsp;Aleksandra Foltynowicz","doi":"10.1016/j.jqsrt.2025.109452","DOIUrl":"10.1016/j.jqsrt.2025.109452","url":null,"abstract":"<div><div>Nitrous oxide is a long-lived greenhouse gas. Its isotopic composition provides valuable insights into sources and sinks, and about the mechanisms of formation. A major challenge in the spectroscopic analysis of the isotopocule compositions is the availability of accurate spectroscopic parameters, particularly for the minor ¹⁵N isotopocules. In this work, we introduce high-resolution spectroscopic measurements of four isotopocules of nitrous oxide: ¹⁴N₂O, ¹⁴N¹⁵NO, ¹⁵N¹⁴NO, and ¹⁵N₂O in the mid-infrared range of 3300 – 3550 cm^–1 using a frequency comb-based Fourier transform spectrometer. The nitrous oxide samples were obtained from a chemical synthesis involving acid-catalyzed amine-borane reduction of equimolar amounts of ¹⁵N isotopically enriched sodium nitrite and ¹⁴N sodium nitrite. The high-resolution spectra, measured in a temperature-controlled single-pass absorption cell, were used to retrieve line center frequencies and relative intensities for a total of 426 rovibrational transitions of the ν₁ + ν₃ band of the four isotopocules, and of the one order of magnitude weaker 2ν₂ + ν₃ and ν₁ + ν₂ + ν₃ – ν₂ bands in the same spectral region. We compare the determined line center frequencies and relative intensities with spectroscopic parameters available in high-resolution molecular databases. For ¹⁴N₂O, ¹⁴N¹⁵NO and ¹⁵N¹⁴NO we find good agreement with the HITRAN database. The ¹⁵N₂O isotopocule is missing in HITRAN, and we find that its line center frequencies in the GEISA database, the Institute of Atmospheric Optics database, as well as the Ames-1 line list deviate severely from the comb measurements.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"340 ","pages":"Article 109452"},"PeriodicalIF":2.3,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential chirped-pulse dual-comb spectroscopy for complex line shape fitting the R(6) manifold of the 2ν3 band of methane","authors":"Jasper R. Stroud,&nbsp;David F. Plusquellic","doi":"10.1016/j.jqsrt.2025.109454","DOIUrl":"10.1016/j.jqsrt.2025.109454","url":null,"abstract":"<div><div>We use a dual electro-optic comb system (EO<img>OFC) and a differential chirped-pulse down conversion technique to study the R(6) manifold of the 2ν₃ band (1645 nm) of methane at low pressure (&lt; 1 kPa). In the frequency domain, the EO<img>OFC method magnifies of the temporal dynamics of the system and due to of the 6-component asymmetric line shape, is shown to give unique amplitude and phase spectra that depend on the chirp direction. We model the frequency domain complex response function using chirped-pulse multiplication and convolution with the Kramers-Kronig transfer function of the molecular system. We then compare how the predicted Voigt line shape with parameters from HITRAN2012 and HITRAN2020 databases and the Hartmann-Tran profile (HTP) perform for fitting both the temporally magnified magnitude and phase profiles in the frequency domain and following the removal of these effects from back transformation, the traditional (natural) line shape components in the time domain. The complex responses in the two domains give unique insight into the physical nature of time dependent absorption processes that may help guide development of molecular models to improve their predictive behavior of both amplitude and phase.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"340 ","pages":"Article 109454"},"PeriodicalIF":2.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of hot and dense plasmas on photoionization dynamic of hydrogen-like ions","authors":"Simei Lu ,&nbsp;Fuyang Zhou ,&nbsp;Xiang Gao ,&nbsp;Luyou Xie ,&nbsp;Guopeng Zhao ,&nbsp;Yong Wu ,&nbsp;Jianguo Wang","doi":"10.1016/j.jqsrt.2025.109447","DOIUrl":"10.1016/j.jqsrt.2025.109447","url":null,"abstract":"<div><div>In hot and dense plasma of solar and stellar interiors, Coulomb potentials between the nucleus and electrons are screened due to the complicated many-body interactions, resulting in significant alterations in atomic structures and dynamic properties of the embedded ions as well as the macroscopic transport properties, such as opacities. Here, the photoionization dynamics of the <em>n ≤</em> 2 states of hydrogen-like ions (He⁺, B⁴⁺, Ne⁹⁺, P¹⁴⁺, Ca¹⁹⁺, Fe²⁵⁺) are investigated employing the atomic-state-dependent (ASD) screening model based on the multiconfiguration Dirac-Hartree-Fock method. It is found that the photoionization cross sections are significantly increased by the plasma screening effects, especially for the denser plasmas. For example, the photoionization cross section of 2p_3/2→<em>ε</em>d_3/2 for Ne⁹⁺ increases nearly 10 times at a condition of <em>T</em>_e =150 eV and <em>n</em>_e=1.0 × 10²⁵ cm^-3. The present results from the ASD model show reasonable agreement with the classical Debye Hückel (DH) model in low-density plasmas, however, the DH model overestimates the densities of plasma electrons in dense plasmas due to neglecting the electron degeneracy effects. The influence of plasma screening on cross section decreases with increasing atomic number and is more significant for the excited states than the ground state. The photoionization cross sections of the ground state approximately follow the scaling law as atomic number varies, but this law can not be applied to excited states because plasma electron distribution in the ASD model depends on specific bound states. The present investigation can be applied to study the opacity under solar and stellar interior conditions.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"340 ","pages":"Article 109447"},"PeriodicalIF":2.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CDSD-2024-PI: The update of the CDSD databank for the principal isotopologue of carbon dioxide","authors":"R.V. Kochanov,&nbsp;V.I. Perevalov","doi":"10.1016/j.jqsrt.2025.109428","DOIUrl":"10.1016/j.jqsrt.2025.109428","url":null,"abstract":"<div><div>The new room temperature ¹²C¹⁶O₂ line list (CDSD-2024-PI) is presented. This semi empirical line list contains the calculated line parameters (positions, intensities, air- and self-broadened half-widths, exponents of temperature dependence of air-broadened half-widths, and air pressure induced shifts). The reference temperature is 296 K, and intensity cutoff is 10^-30 cm^-1/(molecule cm^-2). More than 170,000 lines covering the 345 – 15383 cm^-1 spectral range are included in the line list. The line positions and intensities are based on the modeling within the framework of the method of effective operators. The air- and self-broadening coefficients were calculated using the empirical Padé approximations proposed in the works by Hashemi et al. [JQSRT <strong>256</strong>, 107283 (2020)] and Tan et al. [ApJS <strong>262</strong>:40 (2022)]. The air pressure induced line shift coefficients were calculated following the work by Hartmann [JQSRT <strong>110</strong>, 2019 (2009)]. Compared to the ¹²C¹⁶O₂ line list of the CDSD-296 databank (Tashkun et al. [JQSRT <strong>228</strong>, 124 (2019)]) this line list is extended to the higher wavenumber region and improved with the utilization of the new highly accurate experimental data for the fitting of the effective Hamiltonian and of the effective dipole moment parameters. CDSD-2024-PI is freely accessible via the Internet site of V.E. Zuev Institute of Atmospheric Optics SB RAS https://ftp.iao.ru/pub/LTS/CDSD-2024-PI/.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"341 ","pages":"Article 109428"},"PeriodicalIF":2.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying the impact of the transition to LED lighting on night sky brightness and colour using ground-based measurements and satellite imagery","authors":"Camille Labrousse ,&nbsp;Carynelisa Haspel ,&nbsp;Noam Levin","doi":"10.1016/j.jqsrt.2025.109450","DOIUrl":"10.1016/j.jqsrt.2025.109450","url":null,"abstract":"<div><div>Nighttime light pollution is gaining significant interest in the scientific community and the public due to its harmful effects on human health, ecosystems, and leisure activities. Recently, many countries worldwide have been retrofitting their streetlights with light emitting diodes (LEDs) to enable smart street lighting while reducing energy use for street lights. However, little is known about the rate of change in brightness and even less about the new composition of the nighttime light spectrum. In this study, we investigated the changes of brightness and colour of light pollution at night in a major road interchange, conducting measurements before and after the transition from high pressure sodium (HPS) yellow street lights to white LED lights. We used two ground-based photometers, one fixed (TESS-4C) and one mobile (LANcube), which provided long-term record of the artificial light at night at this location. We also quantified changes in nighttime lights as observed by the multispectral nighttime lights satellite SDGSAT-1. To ensure non-biased conditions, we used a random forest model to discriminate between clear and cloudy nights for our analysis of the TESS-4C measurements. These instruments offer a comprehensive analysis by measuring night-time brightness in various units and capturing distinct response spectra across different colour bands. We found an increase in nighttime brightness after the interchange was equipped with LED lamps compared to the previous HPS lamps. However, this increase was only identified by the ground sensors and not by the satellite. All sensors identified a shift in the emitted spectrum towards shorter wavelengths, with an increase in the red/green ratio being the most consistent across the sensors in quantifying the spectral change. We discuss the advantages of each instrument used and explore the expected changes in artificial nighttime light for areas that are retrofitting their streetlights with similar LED lamps.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"340 ","pages":"Article 109450"},"PeriodicalIF":2.3,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature dependence of the air-broadened line-shape parameters of the 1.27 µm O2-band","authors":"Joscha Klemm,&nbsp;Alain Campargue,&nbsp;Hélène Fleurbaey,&nbsp;Samir Kassi,&nbsp;Daniele Romanini,&nbsp;Didier Mondelain","doi":"10.1016/j.jqsrt.2025.109448","DOIUrl":"10.1016/j.jqsrt.2025.109448","url":null,"abstract":"<div><div>Satellite missions are considering the atmospheric O₂ band at 1.27 µm to determine the air-column. A prerequisite of these demanding atmospheric applications is an accurate knowledge of the spectroscopy of this band, in particular of the line profiles and their temperature dependence. In the present work, fifty-five transitions of the 1.27 µm band of O₂ have been studied with a cavity ring down spectrometer linked to an optical frequency comb referenced to a GPS-disciplined Rb oscillator. The comb-coherence transfer (CCT) technique was applied to obtain a RF tunable narrow-line comb-disciplined laser source from a set of distributed feedback laser diodes and a simple electro-optic modulator. High-quality spectra were obtained with a high-finesse cavity regulated at 253, 273 and 333 K. For each transition and each temperature, series of synthetic dry air spectra were recorded for five pressures, from 50 to 750 Torr. The line-shape parameters were retrieved thanks to a multi-spectrum fit procedure with a quadratic speed-dependent Nelkin-Ghatak profile and first-order line-mixing effect when required. For each transition, the temperature dependence exponents and coefficients of the different line profile parameters together with their values at the reference temperature of 296 K were determined. Absolute positions and intensities are provided by the fit with an average accuracy of 240 kHz (or 8 × 10^–6 cm^-1) and 0.2 %, respectively. An effect of intensity depletion with pressure on the order of 0.4 % atm^-1 is evidenced. Comparison with literature, in particular with the HITRAN2020 database is discussed.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"342 ","pages":"Article 109448"},"PeriodicalIF":2.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring single parameter evolution over the course of interferogram acquisition in FTIR systems: Application to gas leak measurement","authors":"David Santalices ,&nbsp;Juan Meléndez ,&nbsp;Susana Briz","doi":"10.1016/j.jqsrt.2025.109429","DOIUrl":"10.1016/j.jqsrt.2025.109429","url":null,"abstract":"<div><div>This study presents a novel methodology for retrieving the temporal evolution of a single physical parameter throughout the course of measurements conducted with imaging-FTIR systems. Rather than operating in the spectral domain, the proposed approach performs parameter fitting directly in the interferogram (i.e., the time or Optical Path Difference (OPD) domain). The method is based on a linearization of the incoming radiance, formulated as a function of a single parameter. This enables the decomposition of the interferogram into an average component and a fluctuating component. The calculation of the derivative of this component with respect to the parameter of interest makes it possible to retrieve the instantaneous value of the parameter. Validation is conducted via numerical simulations and subsequently applied to a real-world scenario involving a gas leak, where the fluctuating parameter is the column density of the gas. By achieving temporal resolution within a single measurement, this methodology addresses the inherent temporal resolution limitations of imaging FTIR systems. These advancements significantly enhance the applicability of FTIR systems for studying the temporal dynamics of scenarios requiring high temporal resolution.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"339 ","pages":"Article 109429"},"PeriodicalIF":2.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving emissivity measurement accuracy using FTIR-based infrared ellipsometer for narrow-angle directional thermal radiation","authors":"Azusa Sudo ,&nbsp;Ryunosuke Moriya ,&nbsp;Sumitaka Tachikawa ,&nbsp;Atsushi Sakurai","doi":"10.1016/j.jqsrt.2025.109446","DOIUrl":"10.1016/j.jqsrt.2025.109446","url":null,"abstract":"<div><div>Accurate emissivity measurement is essential for characterizing metasurfaces with highly directional thermal radiation. Traditional Fourier-transform infrared (FTIR) spectroscopy, particularly when using focusing optics, introduces measurement artifacts due to divergence angle effects, leading to underestimated emissivity and angular deviations. This study investigates the use of FTIR-based infrared ellipsometer to improve emissivity measurement accuracy for narrow-angle thermal emitters. By systematically comparing a focusing FTIR system and an FTIR-based ellipsometer, we quantitatively evaluate the impact of divergence angle on emissivity measurements. The results indicate that the divergence angle in focusing FTIR systems leads to a reduction in measured emissivity to less than two-thirds of the expected value, while the ellipsometer, when properly configured, mitigates these errors through controlled collimation of incident light. Furthermore, we propose a method to determine and correct divergence angle effects using mathematical modeling and optical path analysis. The divergence angles were measured as 11°–13° for the focusing FTIR system and 1.04°–2.08° for the ellipsometer, demonstrating the effectiveness of ellipsometer in reducing measurement uncertainties. These findings provide valuable insights for optimizing measurement techniques in narrow-angle thermal radiation characterization. By improving emissivity measurement accuracy, this study facilitates advancements in thermophotovoltaics, infrared sensing, and radiative heat transfer applications.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"340 ","pages":"Article 109446"},"PeriodicalIF":2.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}