Pub Date : 2025-01-15DOI: 10.1016/j.jqsrt.2025.109365
Soumyajyoti Jana, Mukunda M. Gogoi, T. C. Ajith, Prashant Hegde, Sobhan Kumar Kompalli, S. Suresh Babu
Estimating Top-of-Atmosphere (TOA) flux and radiance is essential for understanding Earth's radiation budget and climate dynamics. This study utilized polar nephelometer measurements of aerosol scattering coefficients at 17 angles (9–170°), enabling the experimental determination of aerosol phase functions and the calculation of Legendre moments. These moments were then used to estimate TOA flux and radiance. Conducted at a tropical coastal site in India, the study observed significant seasonal and diurnal variations in angular scattering patterns, with the highest scattering during winter and the lowest during the monsoon. Notably, a prominent secondary scattering mode, with varying magnitude across different seasons, was observed in the 20–30° angular range, highlighting the influence of different air masses and aerosol sources. Chemical analysis of size-segregated aerosols revealed that fine-mode aerosols were dominated by anthropogenic species, such as sulfate, nitrate, and ammonium, throughout all seasons. In contrast, coarse-mode aerosols showed a clear presence of sea-salt aerosols during the monsoon and mineral dust during the pre-monsoon periods. The presence of very large coarse-mode non-spherical aerosols caused increased oscillations in the phase function beyond 60° during the pre-monsoon and monsoon seasons. This also led to a weak association between the phase function derived from angular scattering measurements and those predicted by the Henyey-Greenstein approximation. As a result, TOA fluxes and radiances derived using the Henyey-Greenstein approximation (with the asymmetry parameter as input in the radiative transfer model) showed a significant difference - up to 24% in seasons with substantial coarse-mode aerosol presence - compared to those derived using the Legendre moments of the phase function. Therefore, TOA flux and radiance estimates using Legendre moments are generally more accurate in the presence of complex aerosol scattering characteristics, particularly for non-spherical or coarse-mode aerosols, while the Henyey-Greenstein phase function may yield less accurate results due to its simplified representation of scattering behavior.
{"title":"Estimation of TOA flux and radiance based on the angular distribution of aerosol light scattering measurements","authors":"Soumyajyoti Jana, Mukunda M. Gogoi, T. C. Ajith, Prashant Hegde, Sobhan Kumar Kompalli, S. Suresh Babu","doi":"10.1016/j.jqsrt.2025.109365","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109365","url":null,"abstract":"Estimating Top-of-Atmosphere (TOA) flux and radiance is essential for understanding Earth's radiation budget and climate dynamics. This study utilized polar nephelometer measurements of aerosol scattering coefficients at 17 angles (9–170°), enabling the experimental determination of aerosol phase functions and the calculation of Legendre moments. These moments were then used to estimate TOA flux and radiance. Conducted at a tropical coastal site in India, the study observed significant seasonal and diurnal variations in angular scattering patterns, with the highest scattering during winter and the lowest during the monsoon. Notably, a prominent secondary scattering mode, with varying magnitude across different seasons, was observed in the 20–30° angular range, highlighting the influence of different air masses and aerosol sources. Chemical analysis of size-segregated aerosols revealed that fine-mode aerosols were dominated by anthropogenic species, such as sulfate, nitrate, and ammonium, throughout all seasons. In contrast, coarse-mode aerosols showed a clear presence of sea-salt aerosols during the monsoon and mineral dust during the pre-monsoon periods. The presence of very large coarse-mode non-spherical aerosols caused increased oscillations in the phase function beyond 60° during the pre-monsoon and monsoon seasons. This also led to a weak association between the phase function derived from angular scattering measurements and those predicted by the Henyey-Greenstein approximation. As a result, TOA fluxes and radiances derived using the Henyey-Greenstein approximation (with the asymmetry parameter as input in the radiative transfer model) showed a significant difference - up to 24% in seasons with substantial coarse-mode aerosol presence - compared to those derived using the Legendre moments of the phase function. Therefore, TOA flux and radiance estimates using Legendre moments are generally more accurate in the presence of complex aerosol scattering characteristics, particularly for non-spherical or coarse-mode aerosols, while the Henyey-Greenstein phase function may yield less accurate results due to its simplified representation of scattering behavior.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"59 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143050016","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}
Aerosols are an important factor leading to reduced visibility. In order to better comprehend the connection between visibility and aerosols, aerosol optical depth (AOD) and Angström exponent (AE) data from the Himawari-8 Advanced Himawari Imager (AHI) are used for validation in comparison with the data from the Aerosol Robotic Network (AERONET) observations in this paper, which amounted to 69,026 sets of data. The results indicate that the AOD of AHI is in good agreement with AERONET observations, but AE performs poorly. The correlation coefficients between the AOD of AHI and AERONET data increase with decreasing visibility and the root mean square error increase. The AE of AHI performs poorly in different visibility conditions. The conclusion drawn from further analysis of the correlation between aerosol products and meteorological factors is that the factor with the highest correlation with visibility. Mixed aerosols dominate at higher visibility and biomass burning/urban-industrial aerosols dominate at lower visibility. The visibility in a typical city (Beijing) has a strong negative correlation with AOD, a weak negative correlation with AE, and a strong correlation with aerosol radiative forcing. The reduction in visibility may be caused by the scattering and adsorption effects of aerosols. The results are important for the improvement and application of AHI aerosol products in regional pollution studies.
{"title":"Study on the Himawari-8 aerosol products and aerosol types under the environmental pollution in selected regions of Asia","authors":"Qianjun Mao, Xiaoyan Zhang, Piaopiao Chen, Yunlu Tan, Xiaohu Wu","doi":"10.1016/j.jqsrt.2025.109363","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109363","url":null,"abstract":"Aerosols are an important factor leading to reduced visibility. In order to better comprehend the connection between visibility and aerosols, aerosol optical depth (AOD) and Angström exponent (AE) data from the Himawari-8 Advanced Himawari Imager (AHI) are used for validation in comparison with the data from the Aerosol Robotic Network (AERONET) observations in this paper, which amounted to 69,026 sets of data. The results indicate that the AOD of AHI is in good agreement with AERONET observations, but AE performs poorly. The correlation coefficients between the AOD of AHI and AERONET data increase with decreasing visibility and the root mean square error increase. The AE of AHI performs poorly in different visibility conditions. The conclusion drawn from further analysis of the correlation between aerosol products and meteorological factors is that the factor with the highest correlation with visibility. Mixed aerosols dominate at higher visibility and biomass burning/urban-industrial aerosols dominate at lower visibility. The visibility in a typical city (Beijing) has a strong negative correlation with AOD, a weak negative correlation with AE, and a strong correlation with aerosol radiative forcing. The reduction in visibility may be caused by the scattering and adsorption effects of aerosols. The results are important for the improvement and application of AHI aerosol products in regional pollution studies.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"7 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990271","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}
Pub Date : 2025-01-15DOI: 10.1016/j.jqsrt.2025.109344
Bingqiang Sun, Chenxu Gao
The scattering phase function of atmospheric particle usually has a strong forward peak due to the diffraction effect so that the scattering energy spans large order differences of magnitude in all scattering directions. Correspondingly, the accurate computation of multiple scattering processes in the radiative transfer is high resolution required and time-consuming. A decomposition method is described in this study for the separation of radiative transfer into a rapidly-varying process (RVP) and a slowly-varying process (SVP). The proposed diffraction decomposition order (DDO) method is developed by considering the difference between a delta function and the RVP in a series order of radiative transfer equations, and is generalized to solve the radiative transfer equation in a multi-layer atmosphere. The zeroth-order equation has the forward phase function reduced to the delta function, and the high-order equations successively consider the contribution of the RVP. In this study, the DDO radiative transfer calculation is realized by successive order of scattering approximation and is derived for the multi-layer polarized scenario. By considering the convergences in the orders of both scattering and decomposition, the radiative results are obtained efficiently and accurately as the sum over all order. Finally, numerical simulations are verified using the successive order of scattering method and their accuracy variation associated with orders is discussed.
{"title":"Diffraction Decomposition Order Method for Solving the Vector Radiative Transfer Equation in the Multi-Layer Atmosphere","authors":"Bingqiang Sun, Chenxu Gao","doi":"10.1016/j.jqsrt.2025.109344","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109344","url":null,"abstract":"The scattering phase function of atmospheric particle usually has a strong forward peak due to the diffraction effect so that the scattering energy spans large order differences of magnitude in all scattering directions. Correspondingly, the accurate computation of multiple scattering processes in the radiative transfer is high resolution required and time-consuming. A decomposition method is described in this study for the separation of radiative transfer into a rapidly-varying process (RVP) and a slowly-varying process (SVP). The proposed diffraction decomposition order (DDO) method is developed by considering the difference between a delta function and the RVP in a series order of radiative transfer equations, and is generalized to solve the radiative transfer equation in a multi-layer atmosphere. The zeroth-order equation has the forward phase function reduced to the delta function, and the high-order equations successively consider the contribution of the RVP. In this study, the DDO radiative transfer calculation is realized by successive order of scattering approximation and is derived for the multi-layer polarized scenario. By considering the convergences in the orders of both scattering and decomposition, the radiative results are obtained efficiently and accurately as the sum over all order. Finally, numerical simulations are verified using the successive order of scattering method and their accuracy variation associated with orders is discussed.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"138 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990272","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}
Pub Date : 2025-01-15DOI: 10.1016/j.jqsrt.2025.109364
Saeid Esmaeil Nia, Ali Shokri
The attenuation of electromagnetic waves due to rainfall is a critical factor in radar and telecommunication systems, particularly in frequency bands above 10 GHz, which is increasingly utilised for data transfer. This study addresses the gaps in understanding how these attenuation effects vary across different rainfall intensities and Drop Size Distributions (DSD). By analytically investigating the irregularities in the cross-sections of raindrops within the 1 to 30 GHz frequency range, the study mentions significant peaks in attenuation at frequencies below 10 GHz, which are more pronounced as DSD changes with rainfall intensity. Using the extinction and efficiency cross-sections of raindrops in 1–30 GHz microwave transmission, the coefficients of rainfall-attenuation correlation were derived for each sector of rainfall intensity of 1–300 mm/hr. Building on these findings, we propose an enhanced rainfall-attenuation relationship, incorporating dynamic coefficients, varying with both factors, DSD and rainfall intensity. Unlike previous models that only suggest calibration of the attenuation-rainfall relationship with DSD, our results indicate that the coefficients should also dynamically adjust based on rainfall intensity. We further demonstrate how these varying coefficients differ from the ITU's recommendations, providing detailed graphical comparisons. This advancement allows for more accurate calculations of rainfall intensity, improving the precision of telecommunication and radar systems in diverse weather conditions.
{"title":"Exploring the impact of rainfall intensity on the attenuation-rainfall relationship","authors":"Saeid Esmaeil Nia, Ali Shokri","doi":"10.1016/j.jqsrt.2025.109364","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109364","url":null,"abstract":"The attenuation of electromagnetic waves due to rainfall is a critical factor in radar and telecommunication systems, particularly in frequency bands above 10 GHz, which is increasingly utilised for data transfer. This study addresses the gaps in understanding how these attenuation effects vary across different rainfall intensities and Drop Size Distributions (DSD). By analytically investigating the irregularities in the cross-sections of raindrops within the 1 to 30 GHz frequency range, the study mentions significant peaks in attenuation at frequencies below 10 GHz, which are more pronounced as DSD changes with rainfall intensity. Using the extinction and efficiency cross-sections of raindrops in 1–30 GHz microwave transmission, the coefficients of rainfall-attenuation correlation were derived for each sector of rainfall intensity of 1–300 mm/hr. Building on these findings, we propose an enhanced rainfall-attenuation relationship, incorporating dynamic coefficients, varying with both factors, DSD and rainfall intensity. Unlike previous models that only suggest calibration of the attenuation-rainfall relationship with DSD, our results indicate that the coefficients should also dynamically adjust based on rainfall intensity. We further demonstrate how these varying coefficients differ from the ITU's recommendations, providing detailed graphical comparisons. This advancement allows for more accurate calculations of rainfall intensity, improving the precision of telecommunication and radar systems in diverse weather conditions.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"23 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143050017","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}
Pub Date : 2025-01-14DOI: 10.1016/j.jqsrt.2025.109361
F. Hendaoui, D. Jacquemart, A. Hessani, B. Tremblay, H. Aroui, H. Tran
He-collision-induced line-shape parameters of CO2 lines were measured in the ν3 band using Fourier transform spectra recorded at room temperature and with pressures ranging from 263 mbar to 1106 mbar. The measured transmission spectra were analyzed with the Voigt profile combined with the first-order line-mixing approximation, accounting for the instrument line-shape function. The He-broadening coefficients, pressure shifts, and first-order line-mixing parameters were determined for 51 lines, from the P(50) to the R(51). The obtained He-broadening coefficients are in excellent agreement with various literature values. These broadening coefficients, together with data for higher J lines, extrapolated from available high-temperature measurements, allowed us to propose an improved dataset for He-broadening coefficients of CO2 lines. We demonstrated that accounting for line-mixing effects is essential to accurately determine the pressure shifts. The latter, measured for the first time for the ν3 band, exhibited a weak rotational dependence, in contrast to the strong dependence observed for air- and self-pressure shifts for CO2. The obtained line-mixing coefficients agree well with those calculated using the Energy Corrected Sudden model. The results of this study significantly enhance the line-shape parameters dataset for CO2 perturbed by He, providing improved data for spectroscopic databases and for studies of planetary and exoplanetary atmospheres.
{"title":"Measurements of He-collision-induced line-shape parameters of CO2 lines in the ν3 band","authors":"F. Hendaoui, D. Jacquemart, A. Hessani, B. Tremblay, H. Aroui, H. Tran","doi":"10.1016/j.jqsrt.2025.109361","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109361","url":null,"abstract":"He-collision-induced line-shape parameters of CO<ce:inf loc=\"post\">2</ce:inf> lines were measured in the ν<ce:inf loc=\"post\">3</ce:inf> band using Fourier transform spectra recorded at room temperature and with pressures ranging from 263 mbar to 1106 mbar. The measured transmission spectra were analyzed with the Voigt profile combined with the first-order line-mixing approximation, accounting for the instrument line-shape function. The He-broadening coefficients, pressure shifts, and first-order line-mixing parameters were determined for 51 lines, from the <ce:italic>P</ce:italic>(50) to the <ce:italic>R</ce:italic>(51). The obtained He-broadening coefficients are in excellent agreement with various literature values. These broadening coefficients, together with data for higher <ce:italic>J</ce:italic> lines, extrapolated from available high-temperature measurements, allowed us to propose an improved dataset for He-broadening coefficients of CO<ce:inf loc=\"post\">2</ce:inf> lines. We demonstrated that accounting for line-mixing effects is essential to accurately determine the pressure shifts. The latter, measured for the first time for the <ce:italic>ν</ce:italic><ce:inf loc=\"post\">3</ce:inf> band, exhibited a weak rotational dependence, in contrast to the strong dependence observed for air- and self-pressure shifts for CO<ce:inf loc=\"post\">2</ce:inf>. The obtained line-mixing coefficients agree well with those calculated using the Energy Corrected Sudden model. The results of this study significantly enhance the line-shape parameters dataset for CO<ce:inf loc=\"post\">2</ce:inf> perturbed by He, providing improved data for spectroscopic databases and for studies of planetary and exoplanetary atmospheres.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"28 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143050018","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}
Pub Date : 2025-01-13DOI: 10.1016/j.jqsrt.2025.109347
Fangshi Jia, Zhaoying Chen, Jialin Liu, Jihui Chen, Liangyu Huang, Zhencen He, Yaming Zou, Yunqing Fu, Baoren Wei, Ke Yao
The spectroscopic investigations on <mml:math altimg="si128.svg" display="inline"><mml:mrow><mml:mn>3</mml:mn><mml:msup><mml:mrow><mml:mi>p</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math><mml:math altimg="si129.svg" display="inline"><mml:mrow><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mn>5</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math altimg="si130.svg" display="inline"><mml:mo>−</mml:mo></mml:math><mml:math altimg="si131.svg" display="inline"><mml:mrow><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math> transitions of phosphorus-like Ge<mml:math altimg="si79.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>17</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>, As<mml:math altimg="si80.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>18</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>, Se<mml:math altimg="si81.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>19</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>, Br<mml:math altimg="si82.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>20</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>, and Kr<mml:math altimg="si76.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>21</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math> ions at an electron beam ion trap were presented. The direct wavelength measurements were reported for the first time for Ge<mml:math altimg="si79.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>17</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math><mml:math altimg="si130.svg" display="inline"><mml:mo>−</mml:mo></mml:math>Br<mml:math altimg="si82.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>20</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math> ions. All the measurements reached precision levels of a few ppm. The theoretical calculations were carried out using multi-configuration Dirac–Hartree–Fock and relativistic configuration interaction methods including a large set of configuration state functions, in which the Breit interaction and QED effects were taken into account. The present results showed a good agreement between the theory and the experiment, and the divisions were less than 0.6%. Especially for the Kr<mml:math altimg="si76.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>21</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math> ions, meticulous scrutiny of line strengths with charge state distributions and continuity of results with isoelectronic
{"title":"Determination of the energy splitting between [formula omitted][formula omitted] and [formula omitted] states in phosphorus-like ions","authors":"Fangshi Jia, Zhaoying Chen, Jialin Liu, Jihui Chen, Liangyu Huang, Zhencen He, Yaming Zou, Yunqing Fu, Baoren Wei, Ke Yao","doi":"10.1016/j.jqsrt.2025.109347","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109347","url":null,"abstract":"The spectroscopic investigations on <mml:math altimg=\"si128.svg\" display=\"inline\"><mml:mrow><mml:mn>3</mml:mn><mml:msup><mml:mrow><mml:mi>p</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math><mml:math altimg=\"si129.svg\" display=\"inline\"><mml:mrow><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mn>5</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math altimg=\"si130.svg\" display=\"inline\"><mml:mo>−</mml:mo></mml:math><mml:math altimg=\"si131.svg\" display=\"inline\"><mml:mrow><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math> transitions of phosphorus-like Ge<mml:math altimg=\"si79.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>17</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>, As<mml:math altimg=\"si80.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>18</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>, Se<mml:math altimg=\"si81.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>19</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>, Br<mml:math altimg=\"si82.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>20</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>, and Kr<mml:math altimg=\"si76.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>21</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math> ions at an electron beam ion trap were presented. The direct wavelength measurements were reported for the first time for Ge<mml:math altimg=\"si79.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>17</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math><mml:math altimg=\"si130.svg\" display=\"inline\"><mml:mo>−</mml:mo></mml:math>Br<mml:math altimg=\"si82.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>20</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math> ions. All the measurements reached precision levels of a few ppm. The theoretical calculations were carried out using multi-configuration Dirac–Hartree–Fock and relativistic configuration interaction methods including a large set of configuration state functions, in which the Breit interaction and QED effects were taken into account. The present results showed a good agreement between the theory and the experiment, and the divisions were less than 0.6%. Especially for the Kr<mml:math altimg=\"si76.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>21</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math> ions, meticulous scrutiny of line strengths with charge state distributions and continuity of results with isoelectronic ","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"45 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990273","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}
Pub Date : 2025-01-10DOI: 10.1016/j.jqsrt.2025.109346
M. Ganesh, Stuart C. Hawkins
Using extensive numerical computations for several benchmark geometries, we demonstrate the physical correctness and numerical stability of a two-step algorithm for computing the electromagnetic-scattering T-matrix of homogeneous penetrable three-dimensional scatterers with smooth boundaries. Our numerical results show that the T-matrices computed with our algorithm have high accuracy, even at size parameters and aspect ratios exceeding the upper limits that can be tackled using the current state-of-the-art algorithm, the Extended Boundary Condition Method. The two-step algorithm is an extension to penetrable scatterers of the algorithm introduced in Ganesh and Hawkins (2010) for perfect conductors. The numerical stability of the T-matrix algorithm stems from the application of an efficient new high-order method in the first step, and a stable fully-discrete Laplace–Fourier transform in the second step. The high-order method is based on a recently established surface integral equation formulation for electromagnetic scattering by bounded penetrable media, for which stability at all-frequencies has been proven.
{"title":"T-matrix computations for light scattering by penetrable particles with large aspect ratios","authors":"M. Ganesh, Stuart C. Hawkins","doi":"10.1016/j.jqsrt.2025.109346","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109346","url":null,"abstract":"Using extensive numerical computations for several benchmark geometries, we demonstrate the physical correctness and numerical stability of a two-step algorithm for computing the electromagnetic-scattering T-matrix of homogeneous penetrable three-dimensional scatterers with smooth boundaries. Our numerical results show that the T-matrices computed with our algorithm have high accuracy, even at size parameters and aspect ratios exceeding the upper limits that can be tackled using the current state-of-the-art algorithm, the Extended Boundary Condition Method. The two-step algorithm is an extension to penetrable scatterers of the algorithm introduced in Ganesh and Hawkins (2010) for perfect conductors. The numerical stability of the T-matrix algorithm stems from the application of an efficient new high-order method in the first step, and a stable fully-discrete Laplace–Fourier transform in the second step. The high-order method is based on a recently established surface integral equation formulation for electromagnetic scattering by bounded penetrable media, for which stability at all-frequencies has been proven.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"54 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990274","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}
Pub Date : 2025-01-09DOI: 10.1016/j.jqsrt.2025.109339
Xiaozhi Shen, Juan Liu, Chenming Wang, Huaying Wang, Zhanbin Chen, Yan Sun
Based on the multiconfiguration Dirac–Hartree–Fock (MCDHF) method, accurate atomic spectra data including the transition rates, line strengths, and oscillator strengths for the inner-shell excited configuration 2s2p<mml:math altimg="si129.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> (<mml:math altimg="si130.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:math>P)3p in N II ion are reported by taking into account the core-core, core-valence and valence correlation effects as well as the Breit interaction. Good accordance can be found in the comparison with other calculations and measurements. Meanwhile, by studying the effects of electron correlations on the energy levels and transition rates of 2s2p<mml:math altimg="si129.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> (<mml:math altimg="si130.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:math>P)3p configuration, it is found that the valence correlations of active space <mml:math altimg="si5.svg" display="inline"><mml:mrow><mml:mi>n</mml:mi><mml:mi>l</mml:mi></mml:mrow></mml:math> = {<mml:math altimg="si3183.svg" display="inline"><mml:mi>n</mml:mi></mml:math> = 2–7, <mml:math altimg="si235.svg" display="inline"><mml:mi>l</mml:mi></mml:math> = s–i} and the core correlations with regard to 1<mml:math altimg="si8.svg" display="inline"><mml:msup><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> electrons have the strongly adjusted effect and the balancing influence, respectively. Furthermore, the quintet transitions 2s2p<mml:math altimg="si129.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> (<mml:math altimg="si130.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:math>P)3s <mml:math altimg="si144.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>5</mml:mn></mml:mrow></mml:msup></mml:math>P–2s2p<mml:math altimg="si129.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> (<mml:math altimg="si130.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:math>P)3p <mml:math altimg="si144.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>5</mml:mn></mml:mrow></mml:msup></mml:math>L<mml:math altimg="si145.svg" display="inline"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mo>∘</mml:mo></mml:mrow></mml:msup></mml:math> (L = P, D) are found to strictly obey the selection rule <mml:math altimg="si3236.svg" display="inline"><mml:mi>Δ</mml:mi></mml:math>S = 0. The branching fractions under this case tend to 1, which is a peculiar
{"title":"Transition rates and electron correlation effects for the 2s2p[formula omitted] ([formula omitted]P)3p configuration in N II","authors":"Xiaozhi Shen, Juan Liu, Chenming Wang, Huaying Wang, Zhanbin Chen, Yan Sun","doi":"10.1016/j.jqsrt.2025.109339","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109339","url":null,"abstract":"Based on the multiconfiguration Dirac–Hartree–Fock (MCDHF) method, accurate atomic spectra data including the transition rates, line strengths, and oscillator strengths for the inner-shell excited configuration 2s2p<mml:math altimg=\"si129.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> (<mml:math altimg=\"si130.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:math>P)3p in N II ion are reported by taking into account the core-core, core-valence and valence correlation effects as well as the Breit interaction. Good accordance can be found in the comparison with other calculations and measurements. Meanwhile, by studying the effects of electron correlations on the energy levels and transition rates of 2s2p<mml:math altimg=\"si129.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> (<mml:math altimg=\"si130.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:math>P)3p configuration, it is found that the valence correlations of active space <mml:math altimg=\"si5.svg\" display=\"inline\"><mml:mrow><mml:mi>n</mml:mi><mml:mi>l</mml:mi></mml:mrow></mml:math> = {<mml:math altimg=\"si3183.svg\" display=\"inline\"><mml:mi>n</mml:mi></mml:math> = 2–7, <mml:math altimg=\"si235.svg\" display=\"inline\"><mml:mi>l</mml:mi></mml:math> = s–i} and the core correlations with regard to 1<mml:math altimg=\"si8.svg\" display=\"inline\"><mml:msup><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> electrons have the strongly adjusted effect and the balancing influence, respectively. Furthermore, the quintet transitions 2s2p<mml:math altimg=\"si129.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> (<mml:math altimg=\"si130.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:math>P)3s <mml:math altimg=\"si144.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>5</mml:mn></mml:mrow></mml:msup></mml:math>P–2s2p<mml:math altimg=\"si129.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> (<mml:math altimg=\"si130.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:math>P)3p <mml:math altimg=\"si144.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mn>5</mml:mn></mml:mrow></mml:msup></mml:math>L<mml:math altimg=\"si145.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mo>∘</mml:mo></mml:mrow></mml:msup></mml:math> (L = P, D) are found to strictly obey the selection rule <mml:math altimg=\"si3236.svg\" display=\"inline\"><mml:mi>Δ</mml:mi></mml:math>S = 0. The branching fractions under this case tend to 1, which is a peculiar","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"31 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990276","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}
Pub Date : 2025-01-09DOI: 10.1016/j.jqsrt.2025.109348
A.P. Chaynikov, A.G. Kochur, A.I. Dudenko
Emission of electrons and photons during the cascade decay of inner-shell vacancies created after the decay of unstable 125I radionuclide is simulated by construction and analysis of the cascade decay trees in isolated-ion approximation. The yields of final cascade ions, the number of emitted electrons and photons, and their spectra, are calculated. During one transformation of 125I, the total energy emitted to the environment is 61.7 keV, of which 43.3 keV is emitted by photons, mostly high-energy KL photons produced at the first step of the decays of the 1s vacancies. If 125I is used as an agent for Auger therapy of cancer, only the energy absorbed by the tumor tissues in the nearest vicinity of the emitter is important. This energy is 18.6 keV, most of which is provided by cascade-produced electrons. The contribution of low-energy photons and cascade-produced ions to local energy deposition are 0.15 keV and 0.7 keV, respectively. Additional monopole ejection of electrons (shake off) during the cascades progression, and upon the internal conversion of 125Te* nuclide produced by the electron capture decay of 125I, is shown to affect little the final ions charges and emitted energies.
{"title":"Emission of electrons and photons and formation of cascade ions during the decay of 125I radionuclide","authors":"A.P. Chaynikov, A.G. Kochur, A.I. Dudenko","doi":"10.1016/j.jqsrt.2025.109348","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109348","url":null,"abstract":"Emission of electrons and photons during the cascade decay of inner-shell vacancies created after the decay of unstable <ce:sup loc=\"post\">125</ce:sup>I radionuclide is simulated by construction and analysis of the cascade decay trees in isolated-ion approximation. The yields of final cascade ions, the number of emitted electrons and photons, and their spectra, are calculated. During one transformation of <ce:sup loc=\"post\">125</ce:sup>I, the total energy emitted to the environment is 61.7 keV, of which 43.3 keV is emitted by photons, mostly high-energy <ce:italic>KL</ce:italic> photons produced at the first step of the decays of the 1<ce:italic>s</ce:italic> vacancies. If <ce:sup loc=\"post\">125</ce:sup>I is used as an agent for Auger therapy of cancer, only the energy absorbed by the tumor tissues in the nearest vicinity of the emitter is important. This energy is 18.6 keV, most of which is provided by cascade-produced electrons. The contribution of low-energy photons and cascade-produced ions to local energy deposition are 0.15 keV and 0.7 keV, respectively. Additional monopole ejection of electrons (shake off) during the cascades progression, and upon the internal conversion of <ce:sup loc=\"post\">125</ce:sup>Te* nuclide produced by the electron capture decay of <ce:sup loc=\"post\">125</ce:sup>I, is shown to affect little the final ions charges and emitted energies.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"7 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990275","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}
The work proposes a two-step indirect method for evaluating the beam shape coefficients (BSCs) of the electromagnetic (EM) field of shaped beams. The spherical wave expansion of the EM field is based on the expansion of the scalar potential function so that the BSCs of the EM field are obtained as the linear combinations of the BSCs of the potential function. By using the scalar translational addition theorem, the BSCs of the potential function in the particle coordinate system are obtained from those in the beam system. The beams having circular profile and carrying no topological charge are considered in the work. The method simplifies the formulation of the BSCs and speeds up the numerical calculations. The numerical results for the Gaussian beam validate the method in evaluating the BSCs and reproducing the beam field in both accuracy and efficiency.
{"title":"Speed up the beam shape coefficient evaluation by using scalar spherical wave expansion and scalar translational addition theorem","authors":"Jianqi Shen, Yu Wang, Shiliang Zhong, Yiqian Tian, Haoyu Jiang","doi":"10.1016/j.jqsrt.2025.109343","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2025.109343","url":null,"abstract":"The work proposes a two-step indirect method for evaluating the beam shape coefficients (BSCs) of the electromagnetic (EM) field of shaped beams. The spherical wave expansion of the EM field is based on the expansion of the scalar potential function so that the BSCs of the EM field are obtained as the linear combinations of the BSCs of the potential function. By using the scalar translational addition theorem, the BSCs of the potential function in the particle coordinate system are obtained from those in the beam system. The beams having circular profile and carrying no topological charge are considered in the work. The method simplifies the formulation of the BSCs and speeds up the numerical calculations. The numerical results for the Gaussian beam validate the method in evaluating the BSCs and reproducing the beam field in both accuracy and efficiency.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"58 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967933","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}
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