RESUMEN
We report on the ultraviolet excitation of Na(3s)+CF(4) collision pairs in a crossed molecular beam experiment. We observe Na(3d) collision products originating from the process Na(3s)+CF(4)(nu(3)=0)+hnu-->Na(3d)+CF(4)(nu(3)=1). The spectral intensity distribution of the collision products and the prevailing small angle scattering confirm a previously proposed long range dipole-dipole mechanism. We report velocity-resolved spectra and a comparison to preliminary numerical results based on collisional broadening theory. Polarization experiments suggest future potential for the observation of collision geometries.
RESUMEN
We study optical collisions of Na atoms with N(2), CO, C(2)H(2), and CO(2) molecules in a crossed-beam experiment. Excited electronic states of the collision complex are selectively populated during the collision. We measure the relative population of the Na(3p) fine-structure levels after the collision and observe in this way the nonadiabatic transitions occuring in the final phase of the collision process. For the NaCO, NaC(2)H(2), and NaCO(2) systems new ab initio potential surfaces were generated. The theoretical analysis of the nonadiabatic electron dynamics on the excited potential surfaces is made within the classical-path formalism. The results are in good qualitative agreement with the experimental data and provide insight into the nonadiabatic mechanisms prevailing during the evolution in the upper 3p manifold. The differences between the different collisional systems are related to the presence and system-specific locations of conical intersections and avoided crossing seams in the excited potential surfaces.
RESUMEN
Experimental differential cross sections for the collision process Na(3s)2S+Ne+hnu-->Na(3p)2P+Ne are reported. By comparison with calculated cross sections, we are able to discriminate between different spectroscopic and quantum chemical A2Pi potentials with cm(-1) sensitivity.
RESUMEN
We report differential scattering experiments on the laser excitation of Na + M collision pairs with M = N(2), CO, C(2)H(2), and CO(2). The collision event is probed by the laser polarization revealing geometric and electronic properties of the collision pair. The experimental data are compared to the results of a Monte Carlo trajectory simulation using ab initio quantum chemical data.
RESUMEN
Atomic collision pairs in a light field form a microscopic interferometer. The light acts as the beam splitter and controls at the same time the amplitudes and phases of the interfering waves. We demonstrate the complete tunability using linear and elliptic polarization.
RESUMEN
We study Na+N(2) collisions by laser excitation of the collision complex in a differential scattering experiment. The measured relative population of the Na(3p) fine-structure levels reflects the nonadiabatic transitions occurring in the exit channel of the collision. Theoretical results obtained with a classical-path formalism and accurate quantum chemical data for NaN(2) are found to be in good agreement. The presence of a conical intersection for the T-shaped geometry has a profound influence on the observed fine-structure branching.
