In this work, new features and extensions of a currently used online atomic database management system are reported. A multiplatform flexible computation package is added to the present system, to allow the calculatio...In this work, new features and extensions of a currently used online atomic database management system are reported. A multiplatform flexible computation package is added to the present system, to allow the calculation of various atomic radiative and collisional processes, based on simplifying the use of some existing atomic codes adopted from the literature. The interaction between users and data is facilitated by a rather extensive Python graphical user interface working online and could be installed in personal computers of different classes. In particular, this study gives an overview of the use of one model of the package models （i.e., electron impact collisional excitation model）. The accuracy of computing capability of the electron impact collisional excitation in the adopted model, which follows the distorted wave approximation approach, is enhanced by implementing the Dirac R-matrix approximation approach. The validity and utility of this approach are presented through a comparison of the current computed results with earlier available theoretical and experimental results. Finally, the source code is made available under the general public license and being distributed freely in the hope that it will be useful to a wide community of laboratory and astrophysical plasma diagnostics.展开更多
Energy levels, radiative rates, and lifetimes are calculated for all levels of 3s23p, 3s23d, 3s3p2, 3s3d2, 3s3p3d, 3p23d, 3s3d2, 3p3d2, 3p3, and 3d3 configurations of Al-like tungsten ion （W XLVII）. Multiconfigurati...Energy levels, radiative rates, and lifetimes are calculated for all levels of 3s23p, 3s23d, 3s3p2, 3s3d2, 3s3p3d, 3p23d, 3s3d2, 3p3d2, 3p3, and 3d3 configurations of Al-like tungsten ion （W XLVII）. Multiconfigurational Dirac-Fock （MCDF） method is adopted for calculating energy levels and radiative rates. Oscillator strengths, radiative rates, and line strengths are reported for some E1 transitions from the ground level. Comparisons are made with the available data in the literature and good agreement has been found which confirms the reliability of our results.展开更多
Energy levels and emission line wavelengths of high-Z materials are useful for impurity diagnostics due to their potential application in the next generation fusion devices.For this purpose,we have calculated the fine...Energy levels and emission line wavelengths of high-Z materials are useful for impurity diagnostics due to their potential application in the next generation fusion devices.For this purpose,we have calculated the fine structural energies of the 67 levels belonging to the 1s 2,1s2l,1s3l,1s4l,1s5l,and 1s6l configurations of Kr XXXV using GRASP（general purpose relativistic atomic structure package） code.Additionally,we have reported the transition probabilities,oscillator strengths,line strengths,and transition wavelengths for some electric dipole（E1） transitions among these levels.We predict new energy levels and radiative rates,which have not been reported experimentally or theoretically,forming the basis for future experimental work.展开更多
Energy levels, wavefunction compositions and lifetimes have been computed for all levels of ls^22s^22p^5, ls^22s^2p^6, ls^22s^22p^43s, ls^22s^22p^43p, and ls^22s^22p^43d configurations in highly charged F-like tungste...Energy levels, wavefunction compositions and lifetimes have been computed for all levels of ls^22s^22p^5, ls^22s^2p^6, ls^22s^22p^43s, ls^22s^22p^43p, and ls^22s^22p^43d configurations in highly charged F-like tungsten ion. The multiconfigurational Dirac-Fock method （MCDF） is adopted to generate the wavefunctions. We have also presented the transition wavelengths, oscillator strengths, transition probabilities, and line strengths for the electric dipole （El） and magnetic quadrupole （M2） transition from the ls^22s^22p^5 ground configuration. We have performed parallel calculations with the flexible atomic code （FAC） for comparing the atomic data. The reliability of present data is assessed by comparison with other theoretical and experimental data available in the literature. Good agreement is found between our results and those obtained using different approaches confirm the quality of our results. Additionally, we have predicted some new atomic data for F-like W that were not available so far and may be important for plasma diagnostic analysis in fusion plasma.展开更多
In view of the difficulty in calculating the atomic structure parameters of high-Z elements,the Hartree–Fock with relativistic corrections(HFR)theory in combination with the ridge regression(RR)algorithm rather than ...In view of the difficulty in calculating the atomic structure parameters of high-Z elements,the Hartree–Fock with relativistic corrections(HFR)theory in combination with the ridge regression(RR)algorithm rather than the Cowan code’s least squares fitting(LSF)method is proposed and applied.By analyzing the energy level structure parameters of the HFR theory and using the fitting experimental energy level extrapolation method,some excited state energy levels of the Yb I(Z=70)atom including the 4f open shell are calculated.The advantages of the ridge regression algorithm are demonstrated by comparing it with Cowan code’s LSF results.In addition,the results obtained by the new method are compared with the experimental results and other theoretical results to demonstrate the reliability and accuracy of our approach.展开更多
For the laboratory astrophysics community, those spectroscopic modeling codes extensively used in astronomy, e.g. Chianti, AtomDB, Cloudy and Xstar, cannot be directly applied to analyzing laboratory measurements due ...For the laboratory astrophysics community, those spectroscopic modeling codes extensively used in astronomy, e.g. Chianti, AtomDB, Cloudy and Xstar, cannot be directly applied to analyzing laboratory measurements due to their discrepancies from astrophysical cases. For example, plasma from an electron beam ion trap has an electron energy distribution that follows a Gaussian profile, instead of a Maxwellian one. The laboratory miniature for a compact object produced by a laser-driven implo- sion shows a departure from equilibrium, that often occurs in celestial objects, so we setup a spectral analysis system for astrophysical and laboratory （SASAL） plasmas to act as a bridge between them, which benefits the laboratory astrophysical community.展开更多
The photoionization cross sections of the levels belonging to the ground configuration [Ne]3s^2 3p^6 3d of Ge^13＋ are investigated using the fully relativistic R-matrix method in the 2p - 3d excitation region. The ph...The photoionization cross sections of the levels belonging to the ground configuration [Ne]3s^2 3p^6 3d of Ge^13＋ are investigated using the fully relativistic R-matrix method in the 2p - 3d excitation region. The photoionization cross section is dominated by 2p - 3d resonances. The detailed resonance structures are described and analysed with the resonance positions, widths and oscillator strengths to be determined. Good agreement is obtained between the length and velocity forms of the resonance oscillator strengths. The relative difference is less than 8%.展开更多
Energy levels, radiative rates, oscillator strengths and line strengths are reported for transitions among the lowest 97 levels of the（1s22s22p6） 3s23p2, 3s23p3 d, 3s3p3, 3p4, 3s3p23 d, and 3s23d2 configurations of ...Energy levels, radiative rates, oscillator strengths and line strengths are reported for transitions among the lowest 97 levels of the（1s22s22p6） 3s23p2, 3s23p3 d, 3s3p3, 3p4, 3s3p23 d, and 3s23d2 configurations of Rb XXIV. A multiconfiguration Dirac-Fock（MCDF） method is adopted for the calculations. Radiative rates, oscillator strengths, and line strengths are provided for all electric dipole（E1）, magnetic dipole（M1）, electric quadrupole（E2）, and magnetic quadrupole（M2）transitions from the ground level to all 97 levels, although calculations are performed for a much larger number of levels.To achieve the accuracy of the data, comparisons are provided with similar data obtained from the Flexible Atomic Code（FAC） and also with the available theoretical and experimental results. Our energy levels are found to be accurate to better than 1.2%. Wavelengths calculated are found to lie in EUV（extreme ultraviolet） and x-ray regions. Additionally, lifetimes for all 97 levels are obtained for the first time.展开更多
This paper presents data from a 21 cm H I emission drift scan observation of a field partially covering the NGC 4636 galaxy group with the Five-hundred meter Aperture Radio Telescope(FAST). We construct a pipeline to ...This paper presents data from a 21 cm H I emission drift scan observation of a field partially covering the NGC 4636 galaxy group with the Five-hundred meter Aperture Radio Telescope(FAST). We construct a pipeline to reduce the data, and use So Fi A for source finding. When not contaminated by Radio Frequency Interference(RFI), the FAST observations are capable of detecting all of the galaxies previously detected by the Arecibo Legacy Fast ALFA(ALFALFA) survey in the same region. Comparing to ALFALFA for the detections in common, the FAST data show consistent integrated spectra when the H I disks are spatially unresolved, and capture more flux when the H I disks are resolved. The FAST data further reveal 10 new detections in the region mutually covered with ALFALFA, and 18 new detections beyond the footprint of ALFALFA. All of the new detections have the matching optical counterparts. For the member galaxies of the NGC 4636 group, the detection limit of FAST is deeper by 0.4 dex in H I mass than that of the ALFALFA data. After correcting for the incompleteness caused by RFI contamination, we show that the H I detection rate of galaxies rises steeply with radius out to the virial radius of the group, and flattens beyond that. We also examine four spatially resolved galaxy systems with potential tidal interaction features in detail. Considering that the data have been taken during the“shared-risk” period before a major source of local RFI was eliminated, the results highlight the power of FAST in detecting extragalactic H I.展开更多
This paper presents a review about the radiative properties (transition probabilities and oscillator strengths) of two xenon ions (Xe<sup>9+</sup>, Xe<sup>10+</sup>) and three members of Er I i...This paper presents a review about the radiative properties (transition probabilities and oscillator strengths) of two xenon ions (Xe<sup>9+</sup>, Xe<sup>10+</sup>) and three members of Er I isoelectronic sequence (Lu<sup>3+</sup>, Hf<sup>4+</sup>, Ta<sup>5+</sup>) of interest in controlled thermonuclear fusion, including our recent theoretical data obtained using two independent theoretical atomic structure computational approaches (semi-empirical Hartree-Fock with relativistic corrections method (HFR) and the <em>ab initio</em> multiconfiguration Dirac-Hartree-Fock (MCDHF)). The tables, from the second one, summarize the recommended data expected to be useful for plasma modelling in fusion.展开更多
文摘In this work, new features and extensions of a currently used online atomic database management system are reported. A multiplatform flexible computation package is added to the present system, to allow the calculation of various atomic radiative and collisional processes, based on simplifying the use of some existing atomic codes adopted from the literature. The interaction between users and data is facilitated by a rather extensive Python graphical user interface working online and could be installed in personal computers of different classes. In particular, this study gives an overview of the use of one model of the package models （i.e., electron impact collisional excitation model）. The accuracy of computing capability of the electron impact collisional excitation in the adopted model, which follows the distorted wave approximation approach, is enhanced by implementing the Dirac R-matrix approximation approach. The validity and utility of this approach are presented through a comparison of the current computed results with earlier available theoretical and experimental results. Finally, the source code is made available under the general public license and being distributed freely in the hope that it will be useful to a wide community of laboratory and astrophysical plasma diagnostics.
基金D. S. T. (INDIA)U. G. C. (INDIA)the University of Delhi under R & D research programme
文摘Energy levels, radiative rates, and lifetimes are calculated for all levels of 3s23p, 3s23d, 3s3p2, 3s3d2, 3s3p3d, 3p23d, 3s3d2, 3p3d2, 3p3, and 3d3 configurations of Al-like tungsten ion （W XLVII）. Multiconfigurational Dirac-Fock （MCDF） method is adopted for calculating energy levels and radiative rates. Oscillator strengths, radiative rates, and line strengths are reported for some E1 transitions from the ground level. Comparisons are made with the available data in the literature and good agreement has been found which confirms the reliability of our results.
文摘Energy levels and emission line wavelengths of high-Z materials are useful for impurity diagnostics due to their potential application in the next generation fusion devices.For this purpose,we have calculated the fine structural energies of the 67 levels belonging to the 1s 2,1s2l,1s3l,1s4l,1s5l,and 1s6l configurations of Kr XXXV using GRASP（general purpose relativistic atomic structure package） code.Additionally,we have reported the transition probabilities,oscillator strengths,line strengths,and transition wavelengths for some electric dipole（E1） transitions among these levels.We predict new energy levels and radiative rates,which have not been reported experimentally or theoretically,forming the basis for future experimental work.
文摘Energy levels, wavefunction compositions and lifetimes have been computed for all levels of ls^22s^22p^5, ls^22s^2p^6, ls^22s^22p^43s, ls^22s^22p^43p, and ls^22s^22p^43d configurations in highly charged F-like tungsten ion. The multiconfigurational Dirac-Fock method （MCDF） is adopted to generate the wavefunctions. We have also presented the transition wavelengths, oscillator strengths, transition probabilities, and line strengths for the electric dipole （El） and magnetic quadrupole （M2） transition from the ls^22s^22p^5 ground configuration. We have performed parallel calculations with the flexible atomic code （FAC） for comparing the atomic data. The reliability of present data is assessed by comparison with other theoretical and experimental data available in the literature. Good agreement is found between our results and those obtained using different approaches confirm the quality of our results. Additionally, we have predicted some new atomic data for F-like W that were not available so far and may be important for plasma diagnostic analysis in fusion plasma.
基金the Fundamental Research Funds for the Central Universities(Grant No.10822041A2038).
文摘In view of the difficulty in calculating the atomic structure parameters of high-Z elements,the Hartree–Fock with relativistic corrections(HFR)theory in combination with the ridge regression(RR)algorithm rather than the Cowan code’s least squares fitting(LSF)method is proposed and applied.By analyzing the energy level structure parameters of the HFR theory and using the fitting experimental energy level extrapolation method,some excited state energy levels of the Yb I(Z=70)atom including the 4f open shell are calculated.The advantages of the ridge regression algorithm are demonstrated by comparing it with Cowan code’s LSF results.In addition,the results obtained by the new method are compared with the experimental results and other theoretical results to demonstrate the reliability and accuracy of our approach.
基金Supported by the National Natural Science Foundation of China
文摘For the laboratory astrophysics community, those spectroscopic modeling codes extensively used in astronomy, e.g. Chianti, AtomDB, Cloudy and Xstar, cannot be directly applied to analyzing laboratory measurements due to their discrepancies from astrophysical cases. For example, plasma from an electron beam ion trap has an electron energy distribution that follows a Gaussian profile, instead of a Maxwellian one. The laboratory miniature for a compact object produced by a laser-driven implo- sion shows a departure from equilibrium, that often occurs in celestial objects, so we setup a spectral analysis system for astrophysical and laboratory （SASAL） plasmas to act as a bridge between them, which benefits the laboratory astrophysical community.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10433010, 10373014 and 10403007, and Beljing Key Laboratory for Nano-Photonics and Nano-Structures.
文摘The photoionization cross sections of the levels belonging to the ground configuration [Ne]3s^2 3p^6 3d of Ge^13＋ are investigated using the fully relativistic R-matrix method in the 2p - 3d excitation region. The photoionization cross section is dominated by 2p - 3d resonances. The detailed resonance structures are described and analysed with the resonance positions, widths and oscillator strengths to be determined. Good agreement is obtained between the length and velocity forms of the resonance oscillator strengths. The relative difference is less than 8%.
基金supported by the U.G.C.,India for their Junior Research FellowshipMan Mohan by the U.G.C.for Basic Science Research Fellowship
文摘Energy levels, radiative rates, oscillator strengths and line strengths are reported for transitions among the lowest 97 levels of the（1s22s22p6） 3s23p2, 3s23p3 d, 3s3p3, 3p4, 3s3p23 d, and 3s23d2 configurations of Rb XXIV. A multiconfiguration Dirac-Fock（MCDF） method is adopted for the calculations. Radiative rates, oscillator strengths, and line strengths are provided for all electric dipole（E1）, magnetic dipole（M1）, electric quadrupole（E2）, and magnetic quadrupole（M2）transitions from the ground level to all 97 levels, although calculations are performed for a much larger number of levels.To achieve the accuracy of the data, comparisons are provided with similar data obtained from the Flexible Atomic Code（FAC） and also with the available theoretical and experimental results. Our energy levels are found to be accurate to better than 1.2%. Wavelengths calculated are found to lie in EUV（extreme ultraviolet） and x-ray regions. Additionally, lifetimes for all 97 levels are obtained for the first time.
基金supported by the National Natural Science Foundation of China (11988101,11721303,11991052,12011540375,12073002,11903003)the China Manned Space Project (CMS-CSST-2021-A04+3 种基金CMS-CSST-2021-A06)support from the science research grants from the China Manned Space Project with No.CMS-CS ST-2021-B02the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D),through project No.CE170100013support from the Natural Sciences and Engineering Research Council of Canada (NSERC)。
文摘This paper presents data from a 21 cm H I emission drift scan observation of a field partially covering the NGC 4636 galaxy group with the Five-hundred meter Aperture Radio Telescope(FAST). We construct a pipeline to reduce the data, and use So Fi A for source finding. When not contaminated by Radio Frequency Interference(RFI), the FAST observations are capable of detecting all of the galaxies previously detected by the Arecibo Legacy Fast ALFA(ALFALFA) survey in the same region. Comparing to ALFALFA for the detections in common, the FAST data show consistent integrated spectra when the H I disks are spatially unresolved, and capture more flux when the H I disks are resolved. The FAST data further reveal 10 new detections in the region mutually covered with ALFALFA, and 18 new detections beyond the footprint of ALFALFA. All of the new detections have the matching optical counterparts. For the member galaxies of the NGC 4636 group, the detection limit of FAST is deeper by 0.4 dex in H I mass than that of the ALFALFA data. After correcting for the incompleteness caused by RFI contamination, we show that the H I detection rate of galaxies rises steeply with radius out to the virial radius of the group, and flattens beyond that. We also examine four spatially resolved galaxy systems with potential tidal interaction features in detail. Considering that the data have been taken during the“shared-risk” period before a major source of local RFI was eliminated, the results highlight the power of FAST in detecting extragalactic H I.
文摘This paper presents a review about the radiative properties (transition probabilities and oscillator strengths) of two xenon ions (Xe<sup>9+</sup>, Xe<sup>10+</sup>) and three members of Er I isoelectronic sequence (Lu<sup>3+</sup>, Hf<sup>4+</sup>, Ta<sup>5+</sup>) of interest in controlled thermonuclear fusion, including our recent theoretical data obtained using two independent theoretical atomic structure computational approaches (semi-empirical Hartree-Fock with relativistic corrections method (HFR) and the <em>ab initio</em> multiconfiguration Dirac-Hartree-Fock (MCDHF)). The tables, from the second one, summarize the recommended data expected to be useful for plasma modelling in fusion.
