Pub Date : 2025-02-14DOI: 10.1016/j.elspec.2025.147523
Igor Novak
The vertical, valence ionization energies for several chemical warfare agents (CWA): nerve agents, choking agents and blister agents have been calculated (as free molecules) using high-level ab initio coupled-cluster method: IP-EOM-CCSD. The calculated vertical, valence ionization energies were used to simulate UV photoelectron spectra. We also calculated 1st adiabatic ionization energies for these CWA. Our results, especially 1st ionization energies (vertical and adiabatic) may be useful when applying photoionization techniques as part of hyphenated methods for detection and identification of CWA. The variations of vertical ionization energies were rationalized by the analysis of the electronic structure of CWA. The influence of electronic structures on toxicological properties is also discussed on the basis of calculated Hirshfeld type charges.
{"title":"Photoionization and electronic structure of chemical warfare agents","authors":"Igor Novak","doi":"10.1016/j.elspec.2025.147523","DOIUrl":"10.1016/j.elspec.2025.147523","url":null,"abstract":"<div><div>The vertical, valence ionization energies for several chemical warfare agents (CWA): nerve agents, choking agents and blister agents have been calculated (as free molecules) using high-level ab initio coupled-cluster method: IP-EOM-CCSD. The calculated vertical, valence ionization energies were used to simulate UV photoelectron spectra. We also calculated 1st adiabatic ionization energies for these CWA. Our results, especially 1st ionization energies (vertical and adiabatic) may be useful when applying photoionization techniques as part of hyphenated methods for detection and identification of CWA. The variations of vertical ionization energies were rationalized by the analysis of the electronic structure of CWA. The influence of electronic structures on toxicological properties is also discussed on the basis of calculated Hirshfeld type charges.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"279 ","pages":"Article 147523"},"PeriodicalIF":1.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2025-01-31DOI: 10.1016/j.elspec.2025.147514
Yasuo Nakayama , François C. Bocquet , Ryohei Tsuruta , Serguei Soubatch , F. Stefan Tautz
Low-energy high-resolution electron energy-loss spectroscopy (HREELS) is a useful technique for the characterization of various excitation processes at solid surfaces. However, no successful work has been reported on molecular single-crystal samples yet. In the present study, low-energy angle-resolved HREELS measurements were conducted on single-crystal pentacene, an organic semiconductor. The results confirmed the excitonic bands exhibiting energy–momentum dispersion and anisotropy of these depending on the surface crystallographic directions, corroborating the occurrence of exciton delocalization, contrary to the ordinary notion of the Frenkel exciton for weakly interacting van der Waals molecular solids. The present results demonstrate that low-energy angle-resolved HREELS is applicable to the precise examination of the excitonic characteristics of solid-state surfaces, even for molecular semiconductor single crystals.
{"title":"Anisotropic dispersion of excitonic bands of the single-crystal pentacene (001) surface as measured by low-energy angle-resolved high-resolution electron energy-loss spectroscopy","authors":"Yasuo Nakayama , François C. Bocquet , Ryohei Tsuruta , Serguei Soubatch , F. Stefan Tautz","doi":"10.1016/j.elspec.2025.147514","DOIUrl":"10.1016/j.elspec.2025.147514","url":null,"abstract":"<div><div>Low-energy high-resolution electron energy-loss spectroscopy (HREELS) is a useful technique for the characterization of various excitation processes at solid surfaces. However, no successful work has been reported on molecular single-crystal samples yet. In the present study, low-energy angle-resolved HREELS measurements were conducted on single-crystal pentacene, an organic semiconductor. The results confirmed the excitonic bands exhibiting energy–momentum dispersion and anisotropy of these depending on the surface crystallographic directions, corroborating the occurrence of exciton delocalization, contrary to the ordinary notion of the Frenkel exciton for weakly interacting van der Waals molecular solids. The present results demonstrate that low-energy angle-resolved HREELS is applicable to the precise examination of the excitonic characteristics of solid-state surfaces, even for molecular semiconductor single crystals.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"279 ","pages":"Article 147514"},"PeriodicalIF":1.8,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2025-01-25DOI: 10.1016/j.elspec.2025.147522
A.P. Chaynikov , A.G. Kochur , A.I. Dudenko
Cascade relaxation of inner-shell vacancies in tellurium atom produced by the electron capture decay of the 125I radionuclide is studied using Monte Carlo simulations. Final cascade ions yields and mean final ion charges upon the decay of single-inner-vacancy states TeX–15p5 (X = 1 s to 5 s) were calculated. The time evolution of the cascade ion states is simulated, and the mean final ion charge is found to be stabilized within τcasc = 10–12 s after the electron capture decay of the 125I nucleus. This time interval must be compared to the time τneutr needed for ions neutralization when 125I is used as an Auger emitter in radiotherapy. Depending on the relation between τcasc and τneutr, either ‘isolated-atom’ or ‘condensed-phase’ approximation should be used in theoretical descriptions of local energy deposition.
{"title":"Time evolution of ion states formed during the cascade decay of vacancies produced by the electron capture decay of the 125I radionuclide","authors":"A.P. Chaynikov , A.G. Kochur , A.I. Dudenko","doi":"10.1016/j.elspec.2025.147522","DOIUrl":"10.1016/j.elspec.2025.147522","url":null,"abstract":"<div><div>Cascade relaxation of inner-shell vacancies in tellurium atom produced by the electron capture decay of the <sup>125</sup>I radionuclide is studied using Monte Carlo simulations. Final cascade ions yields and mean final ion charges upon the decay of single-inner-vacancy states Te<em>X</em><sup>–1</sup>5<em>p</em><sup>5</sup> (<em>X</em> = 1 <em>s</em> to 5 <em>s</em>) were calculated. The time evolution of the cascade ion states is simulated, and the mean final ion charge is found to be stabilized within <em>τ</em><sub>casc</sub> = 10<sup>–12</sup> s after the electron capture decay of the <sup>125</sup>I nucleus. This time interval must be compared to the time <em>τ</em><sub>neutr</sub> needed for ions neutralization when <sup>125</sup>I is used as an Auger emitter in radiotherapy. Depending on the relation between <em>τ</em><sub>casc</sub> and <em>τ</em><sub>neutr</sub>, either ‘isolated-atom’ or ‘condensed-phase’ approximation should be used in theoretical descriptions of local energy deposition.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"279 ","pages":"Article 147522"},"PeriodicalIF":1.8,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-01-01DOI: 10.1016/j.elspec.2024.147512
Raul E. Gutierrez , Ivana Matanovic , Maciej P. Polak , Dane Morgan , Edl Schamiloglu
Density Functional Theory is utilized to study the electronic structure and dielectric properties of various metal oxide systems (Al2O3, MgO, Cu2O, TiO2, WO3) in comparison to their base metals (Al, Mg, Cu, Ti, and W). The properties studied include the density of states, energy band gap, Fermi energy, work function, ionization potential, and the frequency- and momentum-dependent energy loss function. This work provides high-quality first principles-calculated properties that can be further utilized in computational simulations which aim to model complicated electron inelastic scattering interactions in metal oxides and their corresponding metals. In general, properties of this nature might be of interest, but not limited, to those involved in the multipactor effect, magnetic confinement fusion, photovoltaics, charged particle accelerators, x-ray photoelectron spectroscopy, Auger electron spectroscopy, and photomultipliers.
{"title":"Density functional theory calculations of the electronic structure and dielectric properties of metal oxide systems Al2O3, MgO, Cu2O, TiO2, WO3","authors":"Raul E. Gutierrez , Ivana Matanovic , Maciej P. Polak , Dane Morgan , Edl Schamiloglu","doi":"10.1016/j.elspec.2024.147512","DOIUrl":"10.1016/j.elspec.2024.147512","url":null,"abstract":"<div><div>Density Functional Theory is utilized to study the electronic structure and dielectric properties of various metal oxide systems (Al<sub>2</sub>O<sub>3</sub>, MgO, Cu<sub>2</sub>O, TiO<sub>2</sub>, WO<sub>3</sub>) in comparison to their base metals (Al, Mg, Cu, Ti, and W). The properties studied include the density of states, energy band gap, Fermi energy, work function, ionization potential, and the frequency- and momentum-dependent energy loss function. This work provides high-quality first principles-calculated properties that can be further utilized in computational simulations which aim to model complicated electron inelastic scattering interactions in metal oxides and their corresponding metals. In general, properties of this nature might be of interest, but not limited, to those involved in the multipactor effect, magnetic confinement fusion, photovoltaics, charged particle accelerators, x-ray photoelectron spectroscopy, Auger electron spectroscopy, and photomultipliers.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"278 ","pages":"Article 147512"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
In this work, the surface structure and chemical composition of U–Nb alloy after one year of oxidation under ambient conditions were investigated using X-ray photoelectron spectroscopy (XPS) depth profile methods. Furthermore, the in-situ oxidation of U–Nb was carried out under UHV conditions, providing insights into the initial oxidation behavior of U-Nb. Studies show that, an thin (1.5 nm) layer of UO2 intermixed with enriched Nb2O5 is formed on the top of the naturally oxidized U–Nb, with an inner oxide layer consisting of UO2-x intermixed with depleted NbO2 and NbO at below, followed by an inner layer of UO2-x intermixed with metallic U and Nb adjacent to the U-Nb substrate. During the initial oxidation stage, U oxidizes rapidly to form UO2-x, while the leaving Nb in the UO2-x lattice migrates inward and enriched at the metal side of the oxide/metal interface. As oxidation continues, oxidation-induced segregation of the leaving Nb in the UO2-x lattice toward the surface occurs and forms NbO and NbO2 at the gas-oxide interface. The affinities of U and Nb to OH and O anions may act as the driving force of the segregation.
{"title":"XPS study on the oxidation-induced segregation behavior of U–Nb alloy","authors":"Ruidong Liu, Xiaofang Wang, Lizhuo Luo, Yin Hu, Jianwei Qin, Yongchu Rao","doi":"10.1016/j.elspec.2024.147513","DOIUrl":"10.1016/j.elspec.2024.147513","url":null,"abstract":"<div><div>In this work, the surface structure and chemical composition of U–Nb alloy after one year of oxidation under ambient conditions were investigated using X-ray photoelectron spectroscopy (XPS) depth profile methods. Furthermore, the in-situ oxidation of U–Nb was carried out under UHV conditions, providing insights into the initial oxidation behavior of U-Nb. Studies show that, an thin (1.5 nm) layer of UO<sub>2</sub> intermixed with enriched Nb<sub>2</sub>O<sub>5</sub> is formed on the top of the naturally oxidized U–Nb, with an inner oxide layer consisting of UO<sub>2-x</sub> intermixed with depleted NbO<sub>2</sub> and NbO at below, followed by an inner layer of UO<sub>2-x</sub> intermixed with metallic U and Nb adjacent to the U-Nb substrate. During the initial oxidation stage, U oxidizes rapidly to form UO<sub>2-x</sub>, while the leaving Nb in the UO<sub>2-x</sub> lattice migrates inward and enriched at the metal side of the oxide/metal interface. As oxidation continues, oxidation-induced segregation of the leaving Nb in the UO<sub>2-x</sub> lattice toward the surface occurs and forms NbO and NbO<sub>2</sub> at the gas-oxide interface. The affinities of U and Nb to OH and O anions may act as the driving force of the segregation.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"278 ","pages":"Article 147513"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-01-01DOI: 10.1016/j.elspec.2024.147511
Paul S. Bagus , Connie J. Nelin
The importance of embedding cluster models of NiO that are used to predict and analyze the Ni 2p XPS spectra in this compound is studied. The XPS obtained with an isolated NiO6 cluster are compared with those obtained with the cluster embedded in a point charge field designed to reproduce the Madelung potential of the crystal. It is found that there is a remarkable and possibly unexpected similarity between the theoretical XPS spectra with and without point charge embedding. It is believed that this can be expected to be a general conclusion relevant for the XPS of other ionic compounds.
{"title":"Embedding of cluster models of oxides: Implications for XPS predictions","authors":"Paul S. Bagus , Connie J. Nelin","doi":"10.1016/j.elspec.2024.147511","DOIUrl":"10.1016/j.elspec.2024.147511","url":null,"abstract":"<div><div>The importance of embedding cluster models of NiO that are used to predict and analyze the Ni 2p XPS spectra in this compound is studied. The XPS obtained with an isolated NiO<sub>6</sub> cluster are compared with those obtained with the cluster embedded in a point charge field designed to reproduce the Madelung potential of the crystal. It is found that there is a remarkable and possibly unexpected similarity between the theoretical XPS spectra with and without point charge embedding. It is believed that this can be expected to be a general conclusion relevant for the XPS of other ionic compounds.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"278 ","pages":"Article 147511"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-11-22DOI: 10.1016/j.elspec.2024.147501
E.E. Krasovskii
Circular dichroism (CD) of photoemission from a surface state on Bi(111) is considered within an ab initio one-step theory of photoemission. The symmetry of the azimuthal distribution of CD for different spin directions is discussed in terms of the spin structure of the initial states. Both normal and off-normal light incidence are considered. Strong photon energy dependence of photoemission in the ultraviolet range is observed. The principal difference between the initial state spin polarization and the spin photocurrent is emphasized and problems with revealing the orbital angular moment with photoemission are pointed to.
根据光致发光的ab initio一步理论，研究了Bi(111)表面态光致发光的圆二色性（CD）。根据初始态的自旋结构，讨论了不同自旋方向 CD 方位角分布的对称性。研究同时考虑了正常光入射和非正常光入射。在紫外线范围内观察到了光发射的强烈光子能量依赖性。强调了初始态自旋极化与自旋光电流之间的主要区别，并指出了用光辐射揭示轨道角矩的问题。
{"title":"Theory of circular dichroism in angle- and spin-resolved photoemission from the surface state on Bi(111)","authors":"E.E. Krasovskii","doi":"10.1016/j.elspec.2024.147501","DOIUrl":"10.1016/j.elspec.2024.147501","url":null,"abstract":"<div><div>Circular dichroism (CD) of photoemission from a surface state on Bi(111) is considered within an <em>ab initio</em> one-step theory of photoemission. The symmetry of the azimuthal distribution of CD for different spin directions is discussed in terms of the spin structure of the initial states. Both normal and off-normal light incidence are considered. Strong photon energy dependence of photoemission in the ultraviolet range is observed. The principal difference between the initial state spin polarization and the spin photocurrent is emphasized and problems with revealing the orbital angular moment with photoemission are pointed to.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"277 ","pages":"Article 147501"},"PeriodicalIF":1.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-11-14DOI: 10.1016/j.elspec.2024.147500
J.L. Endrino
This work makes a first comparison of the structural features of the amorphous carbon matrix in a-C:Mo and a-C:Au films deposited using the pulsed filter cathodic arc technique. The present study combines synchrotron X-ray absorption (XAS) and emission (XES) in conjunction with transmission electron microscopy observations and selective area diffraction (SADP). While diffraction techniques can be used to indicate the formation of crystalline particles for the metal phase, and transmission electron microscope (TEM) images can be used to indicate the clustering and formation of metallic nanoparticles, the collection of X-ray absorption (XAS) and X-ray emission (XES) spectra is a valuable approach to elucidate the electronic structure of the surrounding amorphous carbon phase and interpret their physical properties.
本研究首次比较了使用脉冲滤波阴极电弧技术沉积的 a-C:Mo 和 a-C:Au 薄膜中无定形碳基质的结构特征。本研究将同步辐射 X 射线吸收（XAS）和发射（XES）与透射电子显微镜观察和选择性区域衍射（SADP）相结合。虽然衍射技术可用于显示金属相结晶颗粒的形成，透射电子显微镜（TEM）图像可用于显示金属纳米颗粒的聚集和形成，但收集 X 射线吸收（XAS）和 X 射线发射（XES）光谱是阐明周围无定形碳相电子结构和解释其物理性质的重要方法。
{"title":"Elucidating the structure of amorphous-carbon films containing carbide and non-carbide-forming metals","authors":"J.L. Endrino","doi":"10.1016/j.elspec.2024.147500","DOIUrl":"10.1016/j.elspec.2024.147500","url":null,"abstract":"<div><div>This work makes a first comparison of the structural features of the amorphous carbon matrix in <em>a-</em>C:Mo and <em>a-</em>C:Au films deposited using the pulsed filter cathodic arc technique. The present study combines synchrotron X-ray absorption (XAS) and emission (XES) in conjunction with transmission electron microscopy observations and selective area diffraction (SADP). While diffraction techniques can be used to indicate the formation of crystalline particles for the metal phase, and transmission electron microscope (TEM) images can be used to indicate the clustering and formation of metallic nanoparticles, the collection of X-ray absorption (XAS) and X-ray emission (XES) spectra is a valuable approach to elucidate the electronic structure of the surrounding amorphous carbon phase and interpret their physical properties.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"277 ","pages":"Article 147500"},"PeriodicalIF":1.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-11-14DOI: 10.1016/j.elspec.2024.147499
A.A. El-Maaref , A.E. Elmeshneb , W. Osman
In the current study, we present a comprehensive investigation of Ne-like tungsten, W LXV. Spectroscopic properties, energies, and transition rates of the configuration list containing 2 s22p6, 2 s22p53l, 2 s22p43l2, 2s2p63l, and 2s2p53l3l´, l = s, p, and d, and l´ = p and d, have been computed using the multi-configuration Dirac-Hartree-Fock method (MCDHF) and FAC code. Single and double electron excitations are performed to calculate the atomic data precisely. Also, the correlations from the upper atomic states with the principal quantum number, and , are involved in the present calculations. All contributions from the orbitals and have also been correlated to configuration interaction (CI) calculations. In addition to CI and upper-level correlations, the quantum-electrodynamics effects have been considered as well. Moreover, the FAC code has been utilized to evaluate the ionization cross-section by electron impact of the present ion. The electron impact (EI) cross-sections of the ionizing states 2 s22p6 (1S0) and 2 s22p53 s (1P1, 3P0,1,2) to 2 s22p5 (2P3/2) have been computed, as well as the total cross-sections of previously mentioned states in W LXV for a wide range of collision energies (up to 150 keV). Furthermore, the effect of increasing the principal quantum number (n) and the inclusion of a complete set of configurations on the cross-section values is examined.
在本研究中，我们对类氖钨 W LXV 进行了全面研究。我们使用多构型狄拉克-哈特里-福克方法（MCDHF）和 FAC 代码计算了包含 2 s22p6、2 s22p53l、2 s22p43l2、2s2p63l 和 2s2p53l3l´（l = s、p 和 d，l´ = p 和 d）的构型表的光谱特性、能量和转变率。为了精确计算原子数据，还进行了单电子和双电子激发。此外，本计算还涉及主量子数 n=4、5 和 6 的上原子态的相关性。来自 s、p、d、f 和 g 轨道的所有贡献也都与构型相互作用（CI）计算相关联。除了 CI 和高层相关之外，量子电动力学效应也被考虑在内。此外，还利用 FAC 代码评估了本离子的电子撞击电离截面。计算了电离状态 2 s22p6 (1S0) 和 2 s22p53 s (1P1, 3P0,1,2) 到 2 s22p5 (2P3/2) 的电子撞击（EI）截面，以及 W LXV 中前面提到的状态在宽碰撞能量范围（高达 150 keV）内的总截面。此外，还研究了增加主量子数（n）和包含全套构型对截面值的影响。
{"title":"Atomic data, and ionization cross-sections by electron impact of tungsten ions, W LXV","authors":"A.A. El-Maaref , A.E. Elmeshneb , W. Osman","doi":"10.1016/j.elspec.2024.147499","DOIUrl":"10.1016/j.elspec.2024.147499","url":null,"abstract":"<div><div>In the current study, we present a comprehensive investigation of Ne-like tungsten, W LXV. Spectroscopic properties, energies, and transition rates of the configuration list containing 2 s<sup>2</sup>2p<sup>6</sup>, 2 s<sup>2</sup>2p<sup>5</sup>3<em>l</em>, 2 s<sup>2</sup>2p<sup>4</sup>3<em>l</em><sup>2</sup>, 2s2p<sup>6</sup>3<em>l</em>, and 2s2p<sup>5</sup>3<em>l</em>3<em>l´, l</em> = s, p, and d, and <em>l´</em> = <em>p</em> and <em>d</em>, have been computed using the multi-configuration Dirac-Hartree-Fock method (MCDHF) and FAC code. Single and double electron excitations are performed to calculate the atomic data precisely. Also, the correlations from the upper atomic states with the principal quantum number, <span><math><mrow><mi>n</mi><mo>=</mo><mspace></mspace><mn>4</mn><mo>,</mo><mspace></mspace><mn>5</mn><mo>,</mo></mrow></math></span> and <span><math><mn>6</mn></math></span>, are involved in the present calculations. All contributions from the orbitals <span><math><mrow><mi>s</mi><mo>,</mo><mi>p</mi><mo>,</mo><mi>d</mi><mo>,</mo><mi>f</mi><mo>,</mo></mrow></math></span> and <span><math><mi>g</mi></math></span> have also been correlated to configuration interaction (CI) calculations. In addition to CI and upper-level correlations, the quantum-electrodynamics effects have been considered as well. Moreover, the FAC code has been utilized to evaluate the ionization cross-section by electron impact of the present ion. The electron impact (EI) cross-sections of the ionizing states 2 s<sup>2</sup>2p<sup>6</sup> (<sub>1</sub>S<sub>0</sub>) and 2 s<sup>2</sup>2p<sup>5</sup>3 s (<sup>1</sup>P<sub>1</sub>, <sup>3</sup>P<sub>0,1,2</sub>) to 2 s<sup>2</sup>2p<sup>5</sup> (<sup>2</sup>P<sub>3/2</sub>) have been computed, as well as the total cross-sections of previously mentioned states in W LXV for a wide range of collision energies (up to 150 keV). Furthermore, the effect of increasing the principal quantum number (n) and the inclusion of a complete set of configurations on the cross-section values is examined.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"277 ","pages":"Article 147499"},"PeriodicalIF":1.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-11-09DOI: 10.1016/j.elspec.2024.147498
Jalmari Passilahti, Anton Vladyka, Johannes Niskanen
Encoder–decoder neural networks (EDNN) condense information most relevant to the output of the feedforward network to activation values at a bottleneck layer. We study the use of this architecture in emulation and interpretation of simulated X-ray spectroscopic data with the aim to identify key structural characteristics for the spectra, previously studied using emulator-based component analysis (ECA). We find an EDNN to outperform ECA in covered target variable variance, but also discover complications in interpreting the latent variables in physical terms. As a compromise of the benefits of these two approaches, we develop a network where the linear projection of ECA is used, thus maintaining the beneficial characteristics of vector expansion from the latent variables for their interpretation. These results underline the necessity of information recovery after its condensation and identification of decisive structural degrees of freedom for the output spectra for a justified interpretation.
编码器-解码器神经网络（EDNN）将与前馈网络输出最相关的信息浓缩为瓶颈层的激活值。我们研究了这种结构在模拟和解释模拟 X 射线光谱数据中的应用，目的是识别光谱的关键结构特征。我们发现，EDNN 在覆盖目标变量方差方面优于 ECA，但也发现了用物理术语解释潜变量的复杂性。作为这两种方法优点的折中，我们开发了一种使用 ECA 线性投影的网络，从而保持了潜变量向量扩展的有利特性，以便对其进行解释。这些结果表明，有必要在信息浓缩后对其进行恢复，并确定输出频谱的决定性结构自由度，以便进行合理的解释。
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