scholarly journals Intensities in Complex Spectra of Highly Ionized Atoms

1984 ◽  
Vol 86 ◽  
pp. 44-44
Author(s):  
M. Klapisch ◽  
A. Bar-Shalom ◽  
A. Cohen
Keyword(s):  
Cross Sections ◽  
Wave Functions ◽  
Coupling Scheme ◽  
Distorted Wave ◽  
Intermediate Coupling ◽  
Potential Wave ◽  
Excitation Cross Sections ◽  
Collisional Radiative Model ◽  
Radiative Model ◽  
Efficient Program

We describe a package of programs for the implementation of the collisional-radiative model to complex configurations. The number of levels taken into account may be several hundreds. The heart of the package is a very efficient program for excitation cross sections in the Distorted Wave framework, using the Relativistic Parametric Potential wave functions. The basic jj coupling scheme actually simplified the computations, enabling a useful factorization into radial and angular parts. Intermediate coupling and configuration interactions are accounted for. We computed ratios of intensities of 3d9 − 3d84s (E2) to 3d9 −3d84p (El) transitions as functions of ne and Te in Xe XXVIII and other Co-like spectra. The atomic model involves all the levels of configurations (3p6)3d9; −3d84s, −3d84p, −3d84d, −3d84f, and (3p5) −3d10, −3d94p. (275 levels) and all the transitions between them. Results compare very well with experimental spectra from TFR.

scholarly journals Recombination Spectra of Planetary Nebulae

1983 ◽  
Vol 103 ◽  
pp. 514-516
Author(s):  
P.O. Bogdanovich ◽  
Z.B. Rudzikas ◽  
T. H. Feklistova ◽  
A.F. Kholtygin ◽  
A.A. Nikitin ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Planetary Nebulae ◽  
Dielectronic Recombination ◽  
Wave Functions ◽  
Energy Spectra ◽  
Coupling Scheme ◽  
Intermediate Coupling ◽  
Hartree Fock ◽  
Radiative Transitions ◽  
Intermediate Coupling Scheme

The lines of the transitions between the subordinate levels of the CIII, NIII etc. ions are observed in the spectra of planetary nebulae (PN) (1). Their theoretical intensities may be found by solving the stationarity equations and accounting for both the recombination and cascade radiative transitions. It is possible to calculate the recombination spectra in various approaches: the single- or multi-configuration approximations (SCA and MCA) making use of both the superposition of configurations (SC) or the multiconfigurational Hartree-Fock-Jucys equations (2), taking into consideration the contribution of the dielectronic recombination to the intensities of the recombination lines. The energy spectra, the transition probabilities etc., as a rule ought to be calculated in the intermediate coupling scheme (2). Both analytical or numerical (e.g. Hartree-Fock) wave functions may be adopted.

Non L.T.E. Properties of Quasistationary Oxygen Plasmas

1976 ◽  
Vol 31 (3-4) ◽  
pp. 362-368 ◽  
Author(s):  
M. Cacciatore ◽  
M. Capitelli
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Ground State ◽  
Radiative Recombination ◽  
Local Thermodynamic Equilibrium ◽  
Collisional Radiative Model ◽  
Radiative Model ◽  
Ionization Coefficients ◽  
Selection Of ◽  
The Continuum

The non L.T.E. (local thermodynamic equilibrium) properties of optically thin and thick quasistationary oxygen plasmas have been calculated for the temperature range k T = 0.5 - 1.5 eV and for the electron density interval 108 - 1016 cm-3 , by using the collisional-radiative model of Bates, Kingston and McWhirther. The results include1 the coefficients r0(i) and r1(i), which represent the contribution to the population density of the ith quantum level from the continuum and from the ground state, respectively2 the values of α and S, which are the collisional-radiative recombination and ionization coefficients, respectively. The accuracy of the present results is discussed in connection with the adopted plasma model and with the selection of the collisional cross sections for forbidden and allowed transitions. A discussion is also presented of the influence of the two low lying excited states of oxygen atoms (i.e. the states 2p41D, 2p41S) on the non L.T.E. properties of these plasmas. A satisfactory agreement is found with the calculations of Julienne et al. and with the experimental results of Jones.

Relativistic Distorted-Wave Calculations of Electron Impact Excitation Cross Sections of Be-Like C 2+ Ions

2007 ◽  
Vol 24 (3) ◽  
pp. 691-694 ◽  
Author(s):  
Jiang Jun ◽  
Dong Chen-Zhong ◽  
Xie Lu-You ◽  
Wang Jian-Guo ◽  
Yan Jun ◽  
...  
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Distorted Wave ◽  
Excitation Cross Sections

Electron excitation of the Group IV elements

2002 ◽  
Vol 80 (6) ◽  
pp. 687-696 ◽  
Author(s):  
R Srivastava ◽  
R P McEachran ◽  
A D Stauffer
Keyword(s):  
Cross Sections ◽  
Ground State ◽  
Silicon Germanium ◽  
Electron Excitation ◽  
Group Iv ◽  
Coupling Scheme ◽  
Distorted Wave ◽  
J Coupling ◽  
Group Iv Elements ◽  
Distorted Wave Method

We investigated the electron excitation of the fine-structure levels of the 3P ground state and the first excited 1D state of the first four elements of Group IV: carbon, silicon, germanium, and tin. These calculations were carried out in the j–j coupling scheme using the relativistic distorted-wave method. Results are presented for the differential cross sections and spin-polarization parameters for incident electron energies of 25 and 40 eV. PACS Nos.: 34.80Dp, 34.80Nz

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