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Faisal, F. H. M.

Publications and source records attributed to Faisal, F. H. M..

Multiple absorption of laser photons by atoms.

Using a space translation operation, it is shown that the Schroedinger equation for an atom in an external electromagnetic field can be solved with sufficient accuracy to obtain the transition probabilities for multiphoton absorption from a monochromatic laser beam of arbitrary intensity or frequency. The specific applicability conditions of the method are discussed.

Faisal, F. H. M.↗

Electron detachment of H- by e- collision.

An impact parameter method using Coulomb trajectories is applied to the calculation of cross sections for two electron detachment processes. The asymptotic behavior of the cross sections at high energies is investigated in detail. Energy distributions of ejected electrons at three different incident energies are also calculated. Some of the results obtained are compared with available experimental data.

Faisal, F. H. M.↗

Application of the adiabatic-nuclei theory to vibrational excitation.

The adiabatic-nuclei theory is shown to be quantitatively applicable to vibrational excitation of diatomic molecules by electron impact. When the dependence of the fixed-nuclei phase shifts on internuclear separation is approximated by a two-term Taylor series, the resulting formulas are transparent and easily evaluated. Application to e-H2 excitation is made, phase-shift derivatives are estimated, and the theory is found to fit experimental data.

Faisal, F. H. M.↗

Electron impact ionization of H

The results of theoretical calculations for the reactions between electrons and negative hydrogen atoms are discussed for an electron colliding with a negative hydrogen ion and neutralizing the hydrogen ion by stripping the loosely bound electron from it, and the two free electrons moving away. A semi-quantum description of the process is presented in which the target is described in terms of quantum mechanics, and the projectile electron is described in a classical fashion.

Faisal, F. H. M.↗

Analytic cross sections for 1 1S, to 1 1S to 2 1S, 1 1S to 2 1P transitions in helium by electron impact

The 1 1s yields 1 1s elastic and 1 1s yields 2 1s and 1 1s yields 2 excitation cross sections of Helium atoms by collision with a charged particle are obtained as analytic functions of incident velocity. The first order time dependent scattering theory is used. Numerical values of electron -He cross sections are obtained for incident energies in the range 30 eV to 800 eV and compared with earlier Born approximation calculations and with available experimental data. It is found that at 100 eV and above, the present results are in good agreement with the experimental results. They are also closer to the experimental results than the corresponding Born calculations.

Sukumar, C. V.↗