Electronic excitation by atomic collisions

Scott T. Sullivan, Wade G. Rellergert, Svetlana Kotochigova +1 more

The role of electronic excitation in inelastic collisions between ultracold Ca atoms and Ba(+) ions, confined in a hybrid trap, is studied for the first time. Unlike previous investigations, this system is energetically precluded from undergoing inelastic collisions in its ground state, allowing a relatively simple experimental determination and interpretation of the influence of electronic excitation. It is found that while the electronic state of the ion can critically influence the inelastic collision rate, the polarizability mismatch of the neutral atom electronic states suppresses short-range collisions, and thus inelastic processes, involving electronically excited neutral atoms. As a result of these features, it is experimentally demonstrated that it is possible to mitigate inelastic collision loss mechanisms in these systems, marking an important step toward long-lived hybrid atom-ion devices.

Boris Michailovich Smirnov

V D Dandawate, Radheshyam Rai

The technique of collision-induced non-radiative transitions has been used to study the excitation transfer in neon brought about by electron-atom collision processes. The experimental results are in agreement with the selection rules suggested by a theoretical analysis for excitation transfer by this process. These selection rules are: (i) the core configuration is conserved and (ii) N+N'>or approximately=K>or approximately= mod N-N' mod , where N=l, j, J. Here, l and j, respectively, refer to the orbital and total angular momentum quantum numbers of the running electron and J is the total angular momentum quantum number for the atom. N' refers to the similar quantum numbers for the final state involved in the excitation transfer and K=1 for dipolar interactions and 2 for quadrupole interactions. The electron-atom collision process seems to be a more efficient mechanism of excitation transfer than atom-atom collision processes.

R. F. Stebbings

H. J. Beyer, Karl Blum, R. Hippler +1 more

1 Electron Scattering from Heavy Atoms.- 2 Spin Polarization in Electron-Atom Scattering.- 3 Electron Scattering from Chiral Molecules.- 4 Applications of Lasers in Atomic Collision Physics.- 5 Excitation and Ionization in Atomic Collisions.- 6 Inner-shell Vacancy Creation: Perturbative Approximations and Beyond.- 7 Excitation in Ion-Atom Collisions.- 8 Coherence in Grazing Ion-Surface Collisions.- 9 The Two-Photon Decay of Atomic Hydrogen and Tests of Bell's Inequality.

J. Pedersen