Hansen, J P | Search NASA

DOE OSTI2011

Ionization of water molecules by fast charged projectiles

Single-ionization cross sections of water molecules colliding with fast protons are calculated from lowest-order perturbation theory by taking all electrons and molecular orientations consistently into account. Explicit analytical formulas based on the peaking approximation are obtained for differential ionization cross sections with the partial contribution from the various electron orbitals accounted for. The results, which are in very good agreement with total and partial cross sections at high electron and projectile energies, display a strong variation on molecular orientation and molecular orbitals.

74 ATOMIC AND MOLECULAR PHYSICS↗

DOE OSTI2011

Interatom intrashell blockade

We demonstrate a feature of the Rydberg blockade mechanism which occurs between two initially excited circular Rydberg atoms. When both atoms are exposed to weak time-dependent electric fields, it is shown that the intrashell dynamics of each atom is strongly modified by the presence of the other. Three characteristic dynamical regimes are identified with separating radii which both scale linearly with principal quantum number n for otherwise constant field parameters. A region of conditional entangled electron dynamics is separated from the outer asymptotic region of independent atom dynamics through a conditional radius, R{sub c}. An inner region, where both atoms becomes locked in their initial state, is again separated from the conditional region by a smaller blocking radius, R{sub b}.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗