Collisions of an Atom with Atomic Particles in External Fields

K T Taylor, Munir Hasan Nayfeh, C. W. Clark

Oleg Prepelita

L. A. Bureyeva, Valerii S. Lisitsa

1. Introduction. Atomic Processes in Astrophysics 2. Radiative Transitions in an Atomic Potential 3. Polarization of Atoms. Polarization Radiation and Light Scattering 4. Atom in a Static Electric Field 5. Atom in a Magnetic Field and Crossed F-B Fields 6. Atom in a Variable Electric Field 7. Atom under Influence of Stochastic Peturbations 8. Relaxation and Decay of Atomic States 9. Excited Hydrogen-Like Atom in Electric Fields of Charged Particles. Foundation of Classical and Quantum Spectral Line Broadening Theory 10. Quasiclassical Theory of Atom - Charge Particle Collisions 11. Collision of the Atom with Atomic Particles in External Fields 12. Atomic Kinetics References Index

Vinod Prasad, Chanchal Yadav, Brijender Dahiya

Sergey G. Rautian

The properties of the collision integral in a quantum Boltzmann-type kinetic equation are studied under the conditions of spatially nonuniform distributions of colliding particles interacting with an external electromagnetic field. The components of the nonlinear resonances and the velocity distribution of the excited atoms, which are due to polarization transitions, are determined on the basis of the Kazantsev collision integral.

Yury V. Suleimanov, Roman V. Krems

Collision properties of atoms and molecules in low temperature gases can be controlled by applying an external magnetic or electric field. The external field shifts the energy levels of the colliding particles, which gives rise to Feshbach resonances modifying the scattering cross sections. The resonances occur at particular magnitudes of the external field, where a bound state of the collision complex is degenerate with a scattering state. The positions of the resonances in the external field are usually identified by computing either the scattering cross sections or the bound states of the collision complex as functions of the external field magnitude. We propose a more efficient method for locating Feshbach resonances that requires neither of these computations. In particular, we show that the positions of Feshbach resonances can be identified by computing the log-derivative of the total wave function in a classically allowed region as a function of the external field strength. This procedure is particularly useful for locating narrow Feshbach resonances that may be hard to identify with the other methods.