Collision strength and effective collision strength for Ba XLVIII

2017 ◽  
Vol 95 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Man Mohan ◽  
Arun Goyal ◽  
Indu Khatri ◽  
Shougaijm Somorendro Singh ◽  
A.K. Singh
Keyword(s):  
Plasma Diagnostics ◽  
Ground State ◽  
Threshold Region ◽  
Wave Method ◽  
Distorted Wave ◽  
R Matrix ◽  
Collision Strength ◽  
Forbidden Transitions ◽  
Distorted Wave Method ◽  
Effective Collision

Collision strengths for the lowest 52 fine-structure levels of Ba XLVIII have been computed using Dirac atomic R-matrix code (DARC). Resonances in the threshold region have been completely resolved and the contributions of these resonances to allowed and forbidden transitions have been presented. Effective collision strengths have also been determined within a temperature range from the ground state. Collision strengths from ground state have also been computed with the relativistic distorted wave method, the flexible atomic code (FAC) was used for checking the accuracy of our results. The present work represents a new and significant work with improvement in the field. We believe that our presented data of collision and effective collision strengths may be useful in the future for benchmark calculations and for plasma diagnostics.

Collision strength and effective collision strength for Br XXVII

2017 ◽  
Vol 95 (11) ◽  
pp. 1127-1135 ◽  
Author(s):  
Arun Goyal ◽  
Rinku Sharma ◽  
Indu Khatri ◽  
A.K. Singh ◽  
Shougaijm Somorendro Singh ◽  
...  
Keyword(s):  
Fine Structure ◽  
Plasma Diagnostics ◽  
Threshold Region ◽  
Wave Method ◽  
Distorted Wave ◽  
R Matrix ◽  
Collision Strength ◽  
Forbidden Transitions ◽  
Distorted Wave Method ◽  
Effective Collision

Collision strengths for all 1326 transitions among lowest 52 fine-structure levels of Br XXVII have been computed using Dirac atomic R-matrix code (DARC). Resonances in the threshold region have been completely resolved and the contributions of these resonances to allowed and forbidden transitions have been presented. The partial collision strength for each angular momentum has been studied graphically. Effective collision strengths have also been determined within the temperature range for all 1326 transitions among the lowest 52 levels. Target state energies of the lowest 52 fine-structure levels have been computed from the multi-configuration Dirac–Fock method (MCDF). Additionally, similar calculations with the relativistic distorted wave method and flexible atomic code (FAC) have also been performed to check the accuracy of our results. The present work represents a new and significant work with improvement in the field. We believe that our presented data of collision and effective collision strengths may be useful in the future for benchmark calculations and for plasma diagnostics.

The excitation of the 2 3 P state of helium by electron impact

1960 ◽  
Vol 258 (1293) ◽  
pp. 147-158 ◽  
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Ground State ◽  
Wave Method ◽  
Distorted Wave ◽  
Polarization Of Radiation ◽  
Oppenheimer Approximation ◽  
Distorted Wave Method

Cross-sections for excitation of the 2 3 P state of helium from the ground state have been calculated by the distorted-wave method. The polarization of radiation emitted as a result of the excitation is also calculated. Comparison is made with the corresponding results given by the Born—Oppenheimer approximation. Although there are considerable differences at electron energies below 100 eV these are much less marked than for the excitation of the 2 3 S state. The distorted wave method gives cross-sections in closer agreement with observation but substantial discrepancies still remain. It is difficult, however, to estimate their magnitude with any certainty because there are inconsistencies in the observed data.

scholarly journals Collision strengths and effective collision strengths for Ne-like Ge

2017 ◽  
Vol 95 (11) ◽  
pp. 1161-1179
Author(s):  
Wessameldin S. Abdelaziz
Keyword(s):  
Energy Range ◽  
Electron Impact ◽  
Electron Energy ◽  
Electron Plasma ◽  
Wave Method ◽  
Distorted Wave ◽  
Resonance Effects ◽  
Distorted Wave Method ◽  
Effective Collision

We have carried out a calculation of 241 levels for Ne-like Ge (Z = 36) to calculate electron impact collision strengths and effective collision strengths belonging to 1s22s22p5nl, 1s22s12p6nl (n = 3, 4, 5, 6; l = s, p, d, f, g, and h) configurations, which have been calculated by the fully relativistic flexible atomic code (FAC). Our calculations, based on the distorted-wave method with large configuration interactions, are included. Collision strengths have been generated over an electron energy range of (10–20 000 eV) and they have been listed at seven representative energies of 65.33, 1714.98, 2944.1, 4868.3, 7564.6, 11 040, and 15 221 eV in this work, and effective collision strengths data have been calculated from these at electron plasma temperatures 650, 850, 1050, 1250, 1450, 1650, and 1850 eV. Our results are compared with those available in the literature. It is found that the resonance effects are important in calculating the effective collision strengths.

Polarization effects on heavy-ion scattering in the distorted-wave method

1985 ◽  
Vol 441 (2) ◽  
pp. 381-396 ◽  
Author(s):  
R. Wolf ◽  
O. Tanimura ◽  
R. Kaps ◽  
U. Mosel
Keyword(s):  
Heavy Ion ◽  
Wave Method ◽  
Distorted Wave ◽  
Ion Scattering ◽  
Polarization Effects ◽  
Heavy Ion Scattering ◽  
Distorted Wave Method

scholarly journals THE SUCCESS OF THE DISTORTED WAVE METHOD AT VERY HIGH INCIDENT ENERGY

1986 ◽  
Vol 47 (C4) ◽  
pp. C4-179-C4-182
Author(s):  
J. BARRETTE ◽  
B. BERTHIER ◽  
J. GASTEBOIS ◽  
A. GILLIBERT ◽  
R. LUCAS ◽  
...  
Keyword(s):  
Incident Energy ◽  
Wave Method ◽  
Distorted Wave ◽  
High Incident Energy ◽  
Distorted Wave Method ◽  
Very High

scholarly journals Collisional Excitation of Fluorine Like Tungsten using Relativistic Dirac Atomic R-matrix Method

2015 ◽  
Vol 2 (1) ◽  
pp. 1-14
Author(s):  
Arun Goyal ◽  
Indu Khatri ◽  
Sunny Aggarwal ◽  
A. K. Singh ◽  
Rinku Sharma ◽  
...  
Keyword(s):  
Fine Structure ◽  
Energy Levels ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Collisional Excitation ◽  
Distorted Wave ◽  
Fusion Plasma ◽  
R Matrix ◽  
Target States ◽  
Effective Collision

We report the new extensive calculations for collision strengths and effective collision strengths of Electron impact excitation of fine structure transitions in F-like W using fully relativistic Dirac Atomic R-matrix Code. We have included all 113 target states which belong to 2s22p5, 2s2p6, 2s22p43l, 2s2p53l, 2p63l configurations. The convergence of reported collision strengths is tested by performingthe same calculations for lesser number of target states which verify the individuality of our results.Effective collision strengthsover a wide temperature range 104-107K are computed. Further, to assess the accuracy and authenticity of our target states energies, a similar parallel calculation has also been performed using a fully relativistic distorted wave (RDW) method and a comparison of energy levels with NIST, FAC and other experimental observations has been made. We believe that the collision strength results for all forbidden transitions within the 113 fine structure levels, presented in this paper will play a substantial role in fusion plasma diagnostics.

scholarly journals Ionisationsquerschnitt von OV gegenüber Elektronenstoß unter teilweiser Berücksichtigung des Austauschs

1961 ◽  
Vol 16 (6) ◽  
pp. 583-598 ◽  
Author(s):  
F. B. Malik ◽  
E. Trefftz
Keyword(s):  
Angular Momentum ◽  
Kinetic Energy ◽  
Cross Section ◽  
Ionization Energy ◽  
Total Angular Momentum ◽  
Ionization Cross Section ◽  
Wave Method ◽  
Distorted Wave ◽  
Ionization Cross ◽  
Distorted Wave Method

The ionization cross-section of highly ionized oxygen, O4+, is calculated according to the “distorted-wave” method. Exchange between the scattered and the ejected electron is taken into account as far as it is of long range nature. It is shown that contributions of high total angular momentum L are essential, L=0 giving only 3% of the total cross-section. This result should qualitatively be the same for all highly ionized atoms, whereas the following seems to be a special feature of O V ionization: for energies around twice the ionization energy the contributions of the optically allowed transitions of the ejected electron (angular momentum lej=1) are relatively small. The contributions of lej =0, 1, 2 and 3 are about 16%, 18%, 24% and 19% respectively for E=20.13.6 eV=2.39 × Ionization energy. The maximum cross section is 0.112 at. u. = 0.31 ·10-18 cm2 for electrons of 310 eV kinetic energy (2.8 × ionization energy). It is about twice as large as given by the ELWERT formula.

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