scholarly journals Elastic scattering of electrons by barium atoms using the distorted wave method

2020 ◽  
Vol 1 (1) ◽  
pp. 33-38
Author(s):  
J. N. Kago ◽  
J. Okumu ◽  
C. S. Singh
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Experimental Results ◽  
Wave Method ◽  
Distorted Wave ◽  
Initial State ◽  
Partial Wave Expansion ◽  
Distorted Waves ◽  
Distorted Wave Method ◽  
Theoretical Results

Differential and integral cross sections of elastic scattering of electrons by barium atoms at intermediate energies (10 – 200 eV) were calculated using the distorted wave method. Being an elastic scattering both the initial and final distortion potentials were taken as the static potential of a barium atom in the initial state. The distorted waves are determined by the partial wave expansion method by expanding them in terms of spherical harmonics while the radial equation corresponding to distorted waves is evaluated using the Numerov method. A computer program DWBA1, for scattering was modified to perform numerical calculations for scattering and the results obtained are compared with the experimental and theoretical results available. The present integral cross sections are in good qualitative agreement with the experimental results and most of the theoretical results. For energies in the range 30 – 100 eV the present differential cross sections are in satisfactory agreement with the other theoretical and experimental results.

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.

The cross-section for ionization of O 5+ by electron impact

1963 ◽  
Vol 271 (1346) ◽  
pp. 379-386 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ionization Energy ◽  
Wave Method ◽  
Distorted Wave ◽  
Ionization Cross ◽  
The Cross ◽  
Ionization Cross Sections ◽  
Distorted Wave Method ◽  
Hydrogenic Ions

The calculation of ionization cross-sections is described. For O 5+ a Coulomb-Born-Oppenheimer method is used. Previous calculations for O 4+ with the distorted wave method are corrected and extended. The results are given in tables 1 to 4 and in figure 1. For O 4+ (ionization energy E i — 8·37 x 13·6 eV) the cross-section Q has its maximum at an energy of the incident electron E = 2·3 E i : Q max. = 2·74 x 10 -2 π a 2 0 = 2·42 x 10 -18 cm 2 . For O 5+ ( E i = 10·15 x 13·6 eV) the maximum is at E = 1·85 E i : Q max. = 0·97 x 10 -2 π a 2 0 = 0·86 x 10 -18 cm 2 . The corresponding reduced cross-sections Q red. = ( E i /13·6 eV ) 2 x Q /Kζπ a 2 0 ) are for O 4+ (ζ = 2): Q red. = 0·96, and for O 5+ (ζ = 1): Q red. = 1·00. The results are similar to those of Rudge & Burgess (1962) for hydrogenic ions.

scholarly journals Total Ionisation Cross Sections in e??H(2S) Scattering

1989 ◽  
Vol 42 (5) ◽  
pp. 475 ◽  
Author(s):  
KK Mukherjee ◽  
Keka Basu Choudhury ◽  
N Ranjit Singh ◽  
PS Mazumdar ◽  
S Brajamani
Keyword(s):  
Cross Sections ◽  
Atomic Hydrogen ◽  
Wave Method ◽  
Distorted Wave ◽  
Total Cross Sections ◽  
Theoretical Predictions ◽  
Impact Ionisation ◽  
Distorted Wave Method ◽  
Final Channel ◽  
Experimental Findings

Total cross sections for the electron impact ionisation from the 2S state of atomic hydrogen have been calculated in the energy range 5 �1-68 eV of the incident electron by using a rigorous distorted wave method in which the effects of both the initial and final channel distortions are taken into account. The present results show improved agreement with experimental findings in comparison with other theoretical predictions.

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