Journal of Quantitative Spectroscopy & Radiative Transfer最新文献

{"title":"Stable computation of the electromagnetic T-matrix for high aspect ratio cylinders","authors":"Matt Majic,&nbsp;Eric C. Le Ru","doi":"10.1016/j.jqsrt.2025.109645","DOIUrl":"10.1016/j.jqsrt.2025.109645","url":null,"abstract":"<div><div>We analyze the stability of computing the T-matrix with the Extended Boundary Condition Method for electromagnetic scattering for long or flat cylinders. Some integrals in the auxiliary Q-matrix are unstable due to an oscillatory integrand over the longer side. As proposed by Waterman for the acoustic case [J. Acoust. Soc. Am. 125, 42 (2009)], we expand the integrands in powers of the size parameter, and find that the negative powers integrate to zero exactly when the surface is extended to infinity, hence the cancellations. To work around this, we split the integrals into low and high powers, integrate the high powers normally, and integrate the low powers over the complement of the cylinder surface that extends from the edge to infinity. Stable methods of matrix inversion are also explored. Overall, this approach provides stable computation of the T-matrix and physical properties such as optical cross sections over a much wider range of aspect ratios.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109645"},"PeriodicalIF":1.9,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118677","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":"Simulation research on simultaneous reconstruction of temperature and soot volume fraction distributions in axisymmetric hydrocarbon flames by a GN-HGA coupled method","authors":"Yang Liu ,&nbsp;Zhiwei Jiang ,&nbsp;Xiaolin Chen","doi":"10.1016/j.jqsrt.2025.109686","DOIUrl":"10.1016/j.jqsrt.2025.109686","url":null,"abstract":"<div><div>In inverse radiation analysis, flame temperature and soot volume fraction distributions are critical state parameters that characterize the combustion process. They effectively reflect the operational status of the combustion system and provide a basis for optimizing the control strategy to improve combustion efficiency and reduce harmful emissions. To reconstruct the temperature and soot volume fraction distributions, this study proposes a coupled method (GN-HGA) that integrates the Gauss-Newton (GN) method and the hybrid genetic algorithm (HGA). The simultaneous reconstruction of these parameters in an axisymmetric hydrocarbon flame is simulated, and the results are compared with those from the GN method and the GN-HGA coupled method. Simulation results demonstrate that, under a 5 % measurement error, the GN-HGA coupled method achieves an average relative error below 1 % for both parameters. Compared to the GN method, the GN-HGA coupled method provides higher reconstruction accuracy. This study highlights the advantages of combining local and global optimization strategies for inverse radiation problems and provides a promising framework for advanced combustion diagnostics and industrial applications requiring precise monitoring of flame characteristics.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109686"},"PeriodicalIF":1.9,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154569","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":"Quantitative study on the ground and low-lying electronic states of the KN+ cation","authors":"Zi-Yi Cheng,&nbsp;Lu-Lian Zhong,&nbsp;Zhao-Yang Li,&nbsp;Yan Chen,&nbsp;Shan-Jun Chen,&nbsp;Song Li","doi":"10.1016/j.jqsrt.2025.109682","DOIUrl":"10.1016/j.jqsrt.2025.109682","url":null,"abstract":"<div><div>In this study, high-level <em>ab initio</em> calculations were performed for the diatomic cation KN⁺, a system not yet systematically explored experimentally or theoretically, by using the internally contracted multireference configuration interaction method with Davidson correction and the all-electron ANO-R basis set. We have explored its molecular structures, electronic properties, and transition characteristics in detail by focusing on twelve Λ-S states related to the five lowest dissociation channels. Potential energy curves, spectroscopic constants, and vibrational energy levels are determined for the cation. Regarding the ground state X⁴Σ^-, the equilibrium bond length, harmonic vibrational constant, and dissociation energy is calculated to 3.09Å, 97.6 cm^-1, and 0.09 eV, respectively. The effect of spin-orbit coupling on the electronic states is also examined and is proved to be insignificant. To better understand transition behavior of the cation, we have obtained key spectroscopic parameters, including transition dipole moments from excited Ω states to the ground state, Einstein A coefficients, Franck–Condon factors, and radiative lifetimes. The presented results offer useful reference data to guide future experimental and theoretical investigations of KN⁺.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109682"},"PeriodicalIF":1.9,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154566","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":"Helium atom embedded in dense semi-classical plasmas: Ground state and doubly excited singlet S states","authors":"Netai Das ,&nbsp;Biswajit Das ,&nbsp;Arijit Ghoshal ,&nbsp;Yew Kam Ho","doi":"10.1016/j.jqsrt.2025.109670","DOIUrl":"10.1016/j.jqsrt.2025.109670","url":null,"abstract":"<div><div>The properties of the ground state and the doubly excited singlet S states of the helium atom embedded in dense semi-classical plasma have been investigated theoretically. The organized effect of the plasma is described by a pseudopotential which takes care of the collective screening effect and quantum mechanical effect of diffraction through the screening parameter and the de Broglie wavelength. The ground state energy has been determined variationally by employing an extensive square-summable wavefunction, whereas the stabilization method is utilized to identify the doubly excited states (DES). The energies and widths of the DESs are extracted from the Lorentzian fittings of the density of the states. Six doubly excited singlet S states are seen to emerge in the stabilization diagram. Convergence of the results thus obtained are corroborated by gradually expanding the wavefunction. A comprehensive study is performed to examine the effects of increasing de Broglie wavelength at a fixed plasma screening strength on the energies and widths of the states. It is found that the energies of the states are gradually lifted due to an increase in the de Broglie wavelength. The increase in the ground state energy gradually makes the atom unstable. Special emphasis is given to accurately determine the critical values of the de Broglie wavelength (for a given plasma screening strength) which lead to the instability. However, it is observed that the widths of the states show distinctive behaviour. Attempts are made to analyse the behaviour of the energies and widths in a qualitative fashion.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109670"},"PeriodicalIF":1.9,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099502","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":"High-resolution infrared spectra of the Ar–SO2 complex in the ν3 region of SO2: A global analysis of rovibrational spectra","authors":"Xiang Li ,&nbsp;Kangning Peng ,&nbsp;Wei Luo ,&nbsp;Zhuang Liu ,&nbsp;Xiaobin Wang ,&nbsp;Rui Zheng","doi":"10.1016/j.jqsrt.2025.109681","DOIUrl":"10.1016/j.jqsrt.2025.109681","url":null,"abstract":"<div><div>In this work, infrared spectra and intermolecular potential energy surface of the Ar–SO₂ van der Waals complex are investigated experimentally and theoretically, respectively. Firstly, the infrared spectrum of the Ar–SO₂ complex in the <em>ν</em>₃ asymmetric stretching region of SO₂ is recorded using an external-cavity quantum cascade laser spectrometer in a supersonic slit jet expansion, and a total of 429 transitions are observed and assigned. A global analysis of these newly observed transitions, together with previously reported spectroscopic data of the microwave and SO₂ monomer <em>v</em>₁ excited state, is carried out using a Watson <em>A</em>-reduced asymmetric rotor Hamiltonian. The band origins of the spectra are accurately determined to be 1361.33300(21) and 1361.30097(18) cm^–1 for the two tunneling components, respectively. These values represent a blue shift of approximately 0.7 cm^–1 compared to the vibrational frequency of the SO₂ monomer <em>ν</em>₃ band. The tunneling splitting of Ar–SO₂ in the SO₂ monomer <em>v</em>₃ excited state is determined to be 960.0 (58) MHz, which is 22.3 and 103.4 MHz lower than that observed in the ground vibrational state and in the SO₂ monomer <em>v</em>₁ excited state, respectively. Furthermore, a three-dimensional intermolecular potential energy surface is constructed at the CCSD(T)/aug-cc-pVTZ level supplemented with bond functions, and the global minimum is determined to be a non-planar <em>C_s</em> geometry with structural parameters <em>R</em> = 3.59 Å, <em>θ</em> = 102.0°, and <em>φ</em> = 90.0°, respectively. What is more, the sign of the quartic centrifugal distortion constant <em>D_K</em> is found to strongly depend on transitions with different <em>K_a</em> quantum numbers, and this conclusion is supported by the good agreement between experimental observations and theoretical calculations.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109681"},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099499","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":"Impact of the overlapping O2 Schumann-Runge and Herzberg continua with Schumann-Runge bands on photolysis rate coefficients: comparing the Koppers & Murtagh parameterization with line-by-line cross section","authors":"Orlando G. Tomazzeli ,&nbsp;Gustavo G. Palancar ,&nbsp;Kenneth Minschwaner ,&nbsp;Aoshuang Ji ,&nbsp;Sasha Madronich ,&nbsp;Rafael P. Fernandez","doi":"10.1016/j.jqsrt.2025.109678","DOIUrl":"10.1016/j.jqsrt.2025.109678","url":null,"abstract":"<div><div>In this study, we update and integrate a line-by-line (LBL) module for calculating the O₂ cross section (<em>σ</em>_<em>O2</em>) within the Schumann-Runge Bands (SRB, 175.4-206.2 nm) into the Tropospheric Ultraviolet Visible (TUV) model V5.4. This coupling allows us to analyze the impact of precise <em>σ</em>_<em>O2</em> calculations on the photolysis rate coefficient of O₂ (<em>J_O2</em>) and over 20 other molecules (<em>J-values</em>) at different altitudes. To compute <em>σ</em>_<em>O2</em> within the SRB, the LBL module uses the HIgh-resolution TRANsmission molecular absorption (HITRAN) 2020 database and the local O₂ absorption, while the standard TUV model uses the Koppers and Murtagh (K&amp;M) parameterization, which considers the overhead O₂ slant path. In addition to correcting previously unnoticed errors in HITRAN and K&amp;M datasets, the updated model now allows a separate handling of the underlying Herzberg (HZC) and Schumann-Runge (SRC) continuum in the wavelength region where they overlap with SRB (175.4-180 nm and 190-206.2 nm). Through TUV calculations, we found that <em>J_O2</em> differences between the standard K&amp;M and LBL versions are up to 6% in the upper mesosphere and –2 % in the middle-upper stratosphere. These variations affect the tropospheric and/or stratospheric <em>J-values</em> of several long-lived and short-lived halogenated species differently, depending on their individual cross sections and the extent of overlap with SRB. Despite variability, persistent altitude-dependent patterns are identified and explained by absorption contributions within the underlying SRC and HZC ranges. In particular, the LBL <em>J-values</em> of HCFC-22, CFC-115 and CHCl₃ are 12%, 8% and 2% lower in the middle-upper stratosphere, respectively, and up to 24% larger in the lower stratosphere, which is of relevance for the evolution of the ozone layer.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109678"},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219851","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":"Survey of the updated Oxygen line list in the HITRAN2024 spectroscopic database","authors":"Erin M. Adkins ,&nbsp;Joseph T. Hodges ,&nbsp;Katarzyna Bielska ,&nbsp;Alain Campargue ,&nbsp;Roman Ciuryło ,&nbsp;Jolanta Domysławska ,&nbsp;Rafael P. Fernandez ,&nbsp;Hélène Fleurbaey ,&nbsp;Maciej Gancewski ,&nbsp;Hubert Jóźwiak ,&nbsp;Samir Kassi ,&nbsp;Daniel Lisak ,&nbsp;Didier Mondelain ,&nbsp;Gustavo G. Palancar ,&nbsp;Wilfrid Somogyi ,&nbsp;Orlando G. Tomazzeli ,&nbsp;Ha Tran ,&nbsp;Piotr Wcisło ,&nbsp;Szymon Wójtewicz ,&nbsp;Sergei N. Yurchenko ,&nbsp;Iouli E. Gordon","doi":"10.1016/j.jqsrt.2025.109629","DOIUrl":"10.1016/j.jqsrt.2025.109629","url":null,"abstract":"<div><div>Light–matter interactions involving molecular oxygen (O₂) span numerous decades in the frequency of electromagnetic radiation and are important to many thermophysical and thermochemical mechanisms, ranging from atmospheric remote sensing of greenhouse gases, aerosols, pollutants, temperature and pressure, visible and infrared radiative exchange in the upper atmosphere, ozone formation and decomposition, and the search for life beyond Earth, among many other examples. Here, we highlight advances in the quantitative spectroscopy of O₂, for which updated band-specific, line-by-line parameters have been provided in the HITRAN2024 spectroscopic database. Theoretical results are presented for electric quadrupole transition intensities in the ground state of ¹⁶O₂, and the Noxon band in the near-infrared region has been included in HITRAN for the first time. Particular focus is placed on the 1.27 <span><math><mi>μ</mi></math></span>m, A- and B-bands of O₂, in which intensities, line-shape (including beyond-Voigt parameterizations), and position parameters with improved accuracy and/or extended spectral coverage are presented. Corrections to the Schumann–Runge bands are also reported. The paper closes with recommendations and an outlook on key challenges in advancing our understanding of the spectroscopy of O₂.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109629"},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219772","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":"On the accuracy of ab initio methods in predicting the electric dipole moment function of carbon monoxide","authors":"Jacek Koput","doi":"10.1016/j.jqsrt.2025.109673","DOIUrl":"10.1016/j.jqsrt.2025.109673","url":null,"abstract":"<div><div>Accurate electric dipole moment function of the CO molecule in its ground electronic state <span><math><mrow><mi>X</mi><msup><mrow><mspace></mspace></mrow><mrow><mn>1</mn></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math></span> has been determined using the single-reference coupled-cluster approach, up to the CCSDTQP level of approximation, in conjunction with the augmented core-valence correlation-consistent basis sets, aug-cc-pCV<span><math><mi>n</mi></math></span>Z, up to octuple-zeta quality. The ab initio predicted function is compared with its experimentally-derived counterparts. The accuracy of applied theoretical methods is discussed.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109673"},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099500","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":"EUV photoabsorption investigations of Ti2+, Ti3+ and Ti4+ using dual laser plasma technique","authors":"Rui-Xuan Pan ,&nbsp;Kai-Xuan Zhang ,&nbsp;Jin-Feng Chen ,&nbsp;Kun Ma ,&nbsp;Guang-Yue Hu ,&nbsp;Lin-Fan Zhu","doi":"10.1016/j.jqsrt.2025.109672","DOIUrl":"10.1016/j.jqsrt.2025.109672","url":null,"abstract":"<div><div>The extreme ultraviolet (EUV) photoabsorption spectra of Ti<span><math><msup><mrow></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>, Ti<span><math><msup><mrow></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msup></math></span> and Ti<span><math><msup><mrow></mrow><mrow><mn>4</mn><mo>+</mo></mrow></msup></math></span> have been measured by employing the dual laser plasma technique. With the help of the theoretical calculations using the multi-configuration Dirac–Fock (MCDF) method, the prominent transitions of 3s to <span><math><mi>n</mi></math></span>p for Ti<span><math><msup><mrow></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> and Ti<span><math><msup><mrow></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msup></math></span> and the double excitations of 3p<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> to 3d<span><math><mi>n</mi></math></span>p for Ti<span><math><msup><mrow></mrow><mrow><mn>4</mn><mo>+</mo></mrow></msup></math></span> are identified, and their transition energies and line profile parameters are determined by fitting the identified photoabsorption features. The reported spectroscopic data of Ti<span><math><msup><mrow></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>, Ti<span><math><msup><mrow></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msup></math></span> and Ti<span><math><msup><mrow></mrow><mrow><mn>4</mn><mo>+</mo></mrow></msup></math></span> supplement the fundamental atomic database, serve as benchmarks for theoretical calculations, and hold potential applications in astrophysics and plasma sciences.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109672"},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099501","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":"Rubidium excited state line shapes from 4D-nF (n = 9, 12, 15, 20) broadened by helium","authors":"Timothy M. True,&nbsp;Dillon Nice,&nbsp;Jordan Mindrup,&nbsp;Christopher A. Rice,&nbsp;Glen P. Perram","doi":"10.1016/j.jqsrt.2025.109655","DOIUrl":"10.1016/j.jqsrt.2025.109655","url":null,"abstract":"<div><div>Pump-modulated laser absorption spectroscopy was used to experimentally measure the rubidium <span><math><mrow><msup><mrow><mn>4</mn></mrow><mrow><mn>2</mn></mrow></msup><msub><mrow><mi>D</mi></mrow><mrow><mn>5</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>→</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>F</mi></mrow></math></span> line shapes broadened by 0-200 Torr of helium. The broadening rates are 175.4<span><math><mo>±</mo></math></span>6.6, 144<span><math><mo>±</mo></math></span>4, 104<span><math><mo>±</mo></math></span>23, and 118<span><math><mo>±</mo></math></span>88 MHz/Torr for <span><math><mrow><mi>n</mi><mo>=</mo><mn>9</mn><mo>,</mo><mn>12</mn><mo>,</mo><mn>15</mn><mo>,</mo><mn>20</mn></mrow></math></span> respectively, while the shift rates are +36<span><math><mo>±</mo></math></span>8, +113<span><math><mo>±</mo></math></span>5, +143<span><math><mo>±</mo></math></span>19, and +155<span><math><mo>±</mo></math></span>68 MHz/Torr. No asymmetry rates are reported. Broadening rates are seen to decrease slightly with <span><math><mi>n</mi></math></span>. The direction of the shift is to the blue, as with other Rb–He transitions, and the magnitude of the shift increases with <span><math><mi>n</mi></math></span>. Stark broadening is observed on the <span><math><mrow><mn>4</mn><msub><mrow><mi>D</mi></mrow><mrow><mn>5</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>→</mo><mn>1</mn><msup><mrow><mn>5</mn></mrow><mrow><mn>2</mn></mrow></msup><mi>F</mi></mrow></math></span> and <span><math><mrow><mn>4</mn><msub><mrow><mi>D</mi></mrow><mrow><mn>5</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>→</mo><mn>2</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>2</mn></mrow></msup><mi>F</mi></mrow></math></span> transitions at pressures above 10 Torr, with fractional ionization of about 9%.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"347 ","pages":"Article 109655"},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154568","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}