Search

Schwinger variational approach to the process of direct electronic excitation of atoms by impact of ions at intermediate and high impact energies was shown to be successful in predicting the excitation cross sections of ion-atom collisions [1,2]. In this study, we present a new method based on the fractional form of the Schwinger variational principle to evaluate the Balmer-α excitation cross sections σ (Hα) of hydrogen atom by proton impact. We study also in this work, the linear polarization fraction Π (Hα) (first Stokes parameter). For impact energies between 10 to 200 keV, our theoretical predictions stay globally in good agreement with the available experimental data [3-5] and other theoretical calculations [6-13]. [ABSTRACT FROM AUTHOR]

The theory of electron impact ionization of one- and two-electron atoms has advanced significantly in the past two years. This paper will summarize the progress that the members of our research center have contributed to. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Hyperspherical partial wave theory has been applied in the study of ionization of hydrogen atoms by electron impact from very low energies (1.0eV, 0.5eV and 0.3eV above threshold) to intermediate energies (60eV). The various ionization cross sections which have been calculated are generally in good agreement with the experiments. Some times the agreements are even better than those of other high level theories, like ECS and CCC theories, requiring elaborate computations. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]