M. Marinescu

RETARDED LONG-RANGE POTENTIALS FOR THE ALKALI-METAL ATOMS AND A PERFECTLY CONDUCTING WALL

The retarded long-range potentials for hydrogen and alkali-metal atoms in their ground states and a perfectly conducting wall are calculated. The potentials are given over a wide range of atom-wall distances and the validity of the approximations used is established.

Resonant Raman scattering in O2

Raman scattering of molecular oxygen in the region of the Schumann–Runge absorption band system is calculated from first principles in the second order of perturbation theory in the interaction of photon–electron operator. Quantitative predictions are given for the cross sections for scattering of photons and a detailed comparison is made with available measurements. The behavior of Raman spectra near the predissociating rovibronic level (v′=5,N′) in the B 3Σu− electronic state of O2 is investigated and shown to have significant dependence on the detuning of the incident laser frequency. By casting the Raman transition matrix in a form similar to the Fano formalism, we are able to investigate the nature of the resonant and nonresonant scattering in the language of configuration interaction. By varying the predissociating width of the (v′=5,N′) resonance, we make a comparison with an earlier time-dependent wave-packet analysis. We also calculate the depolarization ratio of the scattered photons parallel an...

High-frequency two-photon ionization of helium and cesium

Calculations of the two-photon ionization of metastable levels of helium and the first three s levels of cesium are presented. The calculations are carried out to second order in a perturbation expansion and are valid for low laser intensities. The behavior of the ionization cross section at high photon frequencies ω is studied, and it is found that the N-photon ionization cross section behaves as σ(N) ∝ ω−(2N+1/2). This analytic asymptotic behavior is verified numerically in the case of two-photon ionization.