Photoionization of ground 1s2 2s2 2p6 1Se0 and excited 1s2 2S22p53S 3Po0,1,2 states of Si V using relativistic Breit–Pauli R-matrix method

2006 ◽  
Vol 84 (8) ◽  
pp. 707-715 ◽  
Author(s):  
AK S Jha ◽  
N Singh ◽  
N Verma ◽  
M Mohan
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Configuration Interaction ◽  
Matrix Method ◽  
Relativistic Effects ◽  
Wave Functions ◽  
Close Coupling ◽  
R Matrix ◽  
Matrix Expansion ◽  
Target States

The close-coupling R-matrix method has been used to calculate photoionization cross sections for the ground and the lowest three excited states using the relativistic Breit–Pauli approximation. Configuration interaction wave-functions are used to represent eleven lowest LSJ target states of Si VI retained in the R-matrix expansion. Relativistic effects are clearly revealed from resonance converging on the excited states of Si VI.PACS No.: 32.80.Fb

Photoionization of Al X from ground state using the relativistic R-matrix close-coupling method

2014 ◽  
Vol 92 (3) ◽  
pp. 241-245 ◽  
Author(s):  
Liang Liang ◽  
Xu-yang Liu ◽  
Chao Zhou
Keyword(s):  
Cross Sections ◽  
Ground State ◽  
Energy Levels ◽  
Resonance Energy ◽  
Photoionization Cross Section ◽  
Rydberg Series ◽  
Close Coupling ◽  
R Matrix ◽  
Target States ◽  
Distorted Wave Method

The relativistic R-matrix method is used to calculate the total photoionization cross sections from the ground state 1s22s2 1S0 of Al X for photon energies ranges from the first ionization threshold to just above the eighth threshold of the residual ion Al XI. In this work, the relativistic distorted-wave method is employed to calculate the fine-structure energy levels and radial functions. The lowest eight level target states of Al XI are used in the photoionization calculations of Al X and should provide a reasonably complete database for practical application for photoionization cross section for Al X. The resonance energy levels and widths of 18 Rydberg series have been investigated.

scholarly journals Partial Photoionization Cross Sections of Chromium from the Ground and Excited States

Atoms ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 51
Author(s):  
Oleg Zatsarinny ◽  
Swaraj Tayal
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Bound States ◽  
Close Coupling ◽  
R Matrix ◽  
Hartree Fock ◽  
Nonresonant Background ◽  
Ionic States ◽  
Matrix Calculation

Partial and total photoionization cross sections of iron-peak elements are important for the determination of abundances in late-type stars and nebular objects. We have investigated photoionization of neutral chromium from the ground and excited states in the low energy region from the first ionization threshold at 6.77 eV to 30 eV. Accurate descriptions of the initial bound states of Cr I and the final residual Cr II ionic states have been obtained in the multiconfiguration Hartree-Fock method together with adjustable configuration expansions and term-dependent non-orthogonal orbitals. The B-spline R-matrix method has been used for the calculation of photoionization cross sections. The 194 LS final ionic states of Cr II 3d44s, 3d34s2, 3d5, 3d44p, and 3d34s4p principal configurations have been included in the close-coupling expansion. The inclusion of all terms of these configurations has significant impact on the near-threshold resonance structures as well as on the nonresonant background cross sections. Total photoionization cross sections from the ground 3d54sa7S and excited 3d54sa5S, 3d44s2a5D, 3d54pz5P, and 3d44s4py5P states of Cr I have been compared with other available R-matrix calculation to estimate the likely uncertainties in photoionization cross sections. We analyzed the partial photoionization cross sections for leaving the residual ion in various states to identify the important scattering channels, and noted that 3d electron ionization channel becomes dominant at higher energies.

Continuous Ultraviolet Absorption BY Si+(4Pe): an Exploratory R-Matrix Calculation

1988 ◽  
Vol 102 ◽  
pp. 185-188
Author(s):  
J.A. Tully
Keyword(s):  
Excited State ◽  
Cross Sections ◽  
Configuration Interaction ◽  
Matrix Method ◽  
Ultraviolet Absorption ◽  
Total Cross Sections ◽  
R Matrix ◽  
First Excited State ◽  
Matrix Calculation

AbstractThe R-matrix method is used to calculate photoionisation from the first excited state 3s3p23Pe of Si+. The lowest two triplet terms 3s3p3Poand 3p23Peof the residual ion Si++are included in the calculation. They are approximated by configuration interaction wavefunctions which are constructed from six spectroscopic orbitals: 1s,2s,2p,3s,3p,3d. Partial and total cross-sections are tabulated for photon energies ranging from threshold (705 A) up to 2.5 Ryd (365 A). Some of the 3p2np autoionising resonances are delineated and shown graphically.

Photoionization of Al-like Si using the R-matrix method

2011 ◽  
Vol 89 (11) ◽  
pp. 1119-1126 ◽  
Author(s):  
Jagjit Singh ◽  
Sunny Aggarwal ◽  
A.K.S. Jha ◽  
A.K. Singh ◽  
M. Mohan
Keyword(s):  
Cross Sections ◽  
Matrix Method ◽  
Relativistic Effects ◽  
Coupling Scheme ◽  
Rydberg Series ◽  
Channel Coupling ◽  
R Matrix ◽  
Practical Applications ◽  
Physical Effects ◽  
Ionic States

Relativistic calculations are made for photoionization of the ground state 3s23p ([Formula: see text]) and the lowest six excited states 3s23p ([Formula: see text]), 3s3p2 (4P1/2,3/2,5/2), and 3s3p2 (2D3/2,5/2) of Al-like Si, using the Breit–Pauli Hamiltonian within the R-matrix method. Cross sections are determined by the Rydberg series of autoionizing resonances converging to various ionic states. Relativistic effects as well as all the important physical effects like exchange, channel coupling, and short-range correlations have been considered in the present calculations. The present relativistic calculations for this ion using the lowest 20 target levels of Si III in the LSJ coupling scheme will enhance the database sufficiently for practical applications of photoionization cross sections of Si II.

Excitation cross sections of theH2(XΣg+1→bΣu+3) by the combined close-coupling—R-matrix method

1982 ◽  
Vol 26 (4) ◽  
pp. 1852-1857 ◽  
Author(s):  
Thomas K. Holley ◽  
Sunggi Chung ◽  
Chun C. Lin ◽  
Edward T. P. Lee
Keyword(s):  
Cross Sections ◽  
Matrix Method ◽  
Close Coupling ◽  
R Matrix ◽  
Excitation Cross Sections

scholarly journals Relativistic B-Spline R-Matrix Calculations for Electron Collisions with Ytterbium

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 47
Author(s):  
Kathryn R. Hamilton ◽  
Klaus Bartschat ◽  
Oleg Zatsarinny
Keyword(s):  
Experimental Data ◽  
Electron Scattering ◽  
Cross Sections ◽  
Matrix Method ◽  
Model Potential ◽  
Electron Collisions ◽  
R Matrix ◽  
B Spline ◽  
Potential Approach

We have applied the full-relativistic Dirac B-Spline R-matrix method to obtain cross sections for electron scattering from ytterbium atoms. The results are compared with those obtained from a semi-relativistic (Breit-Pauli) model-potential approach and the few available experimental data.

HIGH FREQUENCY LIMITS OF THE TWO-ELECTRON PHOTOIONIZATION CROSS SECTIONS

2002 ◽  
Vol 09 (02) ◽  
pp. 1161-1166 ◽  
Author(s):  
R. KRIVEC ◽  
M. YA. AMUSIA ◽  
V. B. MANDELZWEIG
Keyword(s):  
Wave Function ◽  
Excited States ◽  
Cross Sections ◽  
High Frequency ◽  
Nuclear Charge ◽  
Principal Quantum Number ◽  
Dipole Approximation ◽  
Wave Functions ◽  
Initial State ◽  
First Order

Several cross sections of two-electron processes at high but nonrelativistic photon energies ω are considered, which are expressed solely via the initial state wave function of the ionized two-electron object. The new high precision and locally correct nonvariational wave functions describing the ground and several lowest excited states of H -, He and helium-like ions are used in calculations of different cross sections in the pure dipole approximation and with account of first order corrections in ω/c2, and a number of the cross sections' ratios. The dependencies of all these quantities on the nuclear charge Z and the principal quantum number n (for 1 < n < 5) of the initial state excitation are studied.

scholarly journals Electron Scattering from the Ground and Excited States of Barium

1999 ◽  
Vol 52 (3) ◽  
pp. 603
Author(s):  
Dmitry V. Fursa
Keyword(s):  
Excited States ◽  
Electron Scattering ◽  
Cross Sections ◽  
Differential Cross ◽  
Ground State ◽  
Differential Cross Sections ◽  
Close Coupling ◽  
Angular Correlations ◽  
Electron Photon ◽  
Good Agreement

We have used the nonrelativistic convergent close-coupling (CCC) method to investigate electron scattering from the ground (6s2)1S state and excited (6s6p)1 Po1 and (6s5d)1,3De2 states of barium. For the scattering from the barium ground state, we have found very good agreement with measurements of (6s6p)1 Po1 apparent cross sections at all energies. Similarly, good agreement is found for differential cross sections for elastic scattering and (6s6p)1 Po and (6s5d)1 De2 excitations and with the (6s6p)1 Po1 state electron{photon angular correlations. For the scattering from excited states of barium we have found good agreement with elastic (6s6p)1 Po1 scattering and the (6s5d)1De2 → (6s6p)1 Po1 transition for both differential cross sections and electron–photon angular correlations.

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