Electron-atom scattering modified by a resonant laser field

M. Ya. Agre, Л. П. Рапопорт

Marvin H. Mittleman

In the first paper of this series a formal theory of atomic scattering of electrons in the presence of an intense electromagnetic field was given. Cross sections, near the forward direction, between atomic states (modified by the laser) were obtained. However, it was assumed that the atom could not emit spontaneous radiation. In this paper the effect of spontaneous radiation is included, and it is shown that in most cases the measured cross section will be a weighted average of the two different cross sections starting from the two different initial states which are those atomic states resonantly linked by the laser. The Born approximation for the scattering is obtained, and it is shown that for the simplest description of the spontaneous radiation field the effect of the laser on the cross sections is simply to multiply them by a factor which depends upon the laser detuning.

Ingolf Volker Hertel

Svetlana Vučić

We show that both the laser-assisted and field-free cross sections for electron scattering by an excited state of an atom, or molecule, can be found by analyzing the resonant laser-assisted scattering process, provided that the initial low-lying state is brought into resonance with the excited state. The method relies on the adiabatic evolution of the laser field throughout the resonance, and its subsequent adiabatic switchoff out of the resonant region.

S. P. Purohit, Anoop K. Jain, K. C. Mathur

Within the framework of the rotating wave approximation the elastic scattering of electrons by metastable 2s state of hydrogen atoms is studied in the presence of a resonant laser field. The frequency of the circularly polarized laser field is chosen to match the 2s-3p transition frequency in the hydrogen atom. Variation of the cross section with laser intensity and with incident electron energy (50-150 eV) is investigated.

R. K. Colegrave, Ursula A.T. Ramjit