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By
Baliyan, K S; Srivastava, M K
The triple differential crosssections for the ionization of atomic hydrogen by fast electrons are considered in the case of a coplanar symmetric energysharing geometry. They are estimated in the modified Glauber (MG) approximation. It is found that MG results are significantly different from those in the second Born approximation only for 90°⩽ϑ⩽110°. Outside this range they are almost identical.
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By
Suja, K; Desai, H S
A systematic study is made to find out the differential scattering crosssection in the case of electronatom collisions. The first and the second Born terms ofO(1/k_{i}) are calculated in the framework of Yates high energy higher order Born approximation. The second Born term ofO(1/k_{i}^{2}
) is calculated using the second order Wallace term, the third term is calculated using the Glaubereikonal series of Yates. The method is applied to the elastic scattering of electrons by atomic hydrogen in the energy range 100–400 eV and by helium for energies 200 eV and 400 eV. Comparison is made with other theoretical results and the experimental data.
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By
Das, J N
8 Citations
The hyperspherical partial wave method (Das [7]) has been presented here in a symmetric form so that effects of coupling among different partial waves may be included in a systematic way. It is also outlined here how to solve the relevant coupled set of radial wave equations numerically. Some preliminary results are presented forS, P andD waves in the low energy domain of 30–50 eV for the incident electron. In this calculation only two important partial waves are included in each channel. The results are compared with experimental ones and appear very encouraging.
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By
Das, J N; Chakrabarti, K
6 Citations
A hyperspherical partial wave method of Das to calculate cross sections for ionization of hydrogen atoms by electrons has been applied for low energies. Here effect of coupling among different partial waves is neglected.
By
Joshipura, K N; Mohanan, S
Theoretical differential crosssections are obtained for the elastic scattering of fast (E_{i} ⩾ 200 eV) positrons by oxygen molecules. Employing the independent atom model, the atomic scattering amplitudes are calculated with the (static + polarization) model potentials, in the partial wave analysis (PWA). Comparisons made with the theory and experiments on the incident electrons, show significant differences at small angles.
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By
Chakraborty, S
A theoretical study of theLshell ionization of atoms by relativistic electrons is made for atomic numbers in the range 47 to 92. A new potential model recently proposed by Das and Chakraborty dealing with atomic screening effect in a better way has been used. The results are in satisfactory agreement when compared with some available experimental results and also with the theoretical results of Scofield.
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By
Joshipura, K N; Patel, P M
8 Citations
Total (elastic+inelastic) cross sections fore^{−}O,e^{−}O_{2} ande^{−}O_{3} scattering have been calculated at sample energies between 100 and 1000eV. The basice^{−}O atom scattering amplitudes are obtained from the partial wave analysis with a complex optical potential. Thee^{−}O_{2} ande^{−}O_{3} crosssections are obtained through the independent atom model. Oure^{−}O_{2} crosssections reproduce the experimental data quite well. Adequate comparisons are made in all the three cases.
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By
Garg, R K; Dandawate, Vasant
Collision induced nonradiative transitions in neon plasma have been studied using high intracavity radiation field of a 633 nm HeNe laser. The transitions, induced from 3s_{2} energy level to 4s_{1} and 5s_{1} groups of energy levels, have been detected as changes in intensities of the spectral lines originating from these energy levels. From these intensity measurements, the quantities governing the transitions i.e. (i)S_{3}^{e}
/S_{3RT}, the ratio of the probabilities of electronic deexcitation to the total radiative deexcitation of energy level 3 (ii) 〈r_{23}^{e}v_{e}〉, rate of excitation transfer per particle and (iii)S_{23}^{e}
, the total probability for excitation transfer from level 2 to level 3 at a certain value of electron density have been calculated.
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By
Joshipura, K N
12 Citations
Elastic differential crosssections for theeO_{2} andeO_{3} systems are obtained in the independent atom model at high energies (E_{i} ⩾ 300 eV). The basic atomic scattering amplitudes are obtained in the partial wave method through a sum of static exchange and polarization potentials. OureO_{2} results agree with experiments except for small angles. No data are available for O_{3}, for comparison.
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By
Das, J N; Seal, Samita
10 Citations
Triple differential crosssections for ionization of hydrogen atoms by electrons and positrons have been calculated for symmetric coplanar geometry following a multiple scattering method suggested and used earlier by the authors. Results show single binary peaks exactly at 45° and double binary peaks exactly at 135° for higher energies as are expected from an analysis of Briggs [3]. At lower energies there are certain deviations from these values. An analysis of scattering mechanism at peaks are also given. This supports Briggs’ explanation.
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