12 research outputs found
Electron Impact Ionization Close to the Threshold: Classical Calculations
In this paper we present Classical Trajectory Monte Carlo (CTMC) calculations
for single and multiple electron ionization of Argon atoms and ions in the
threshold region. We are able to recover the Wannier exponents a for the
power-law behavior of the cross section s versus excess energy: the exact value
of the exponent as well as the existence of its saturation for multiple
ionization appear to be related to how the total binding energy is shared
between target electrons.Comment: 9 pages. To be published in Journal of Physics
Charge transfer dynamics in Ar+ + CO
Differential cross sections for the charge transfer reaction between Ar(+)and CO have been measured using three-dimensional velocity map imaging in a crossed beam setup at the two relative collision energies 0.55 and 0.74 eV. We find dominant forward scattering with CO(+)product ions predominantly in the vibrational levels=6,7 of the electronic ground state X. This is indicative of a direct resonant mechanism for the two argon spin-orbit states. At both collision energies also an isotropic distribution with product ions exhibiting high internal excitation is observed. This is more pronounced at the higher collision energy, where the first electronically excited state Abecomes accessible. We conclude that the A-state is partially populated by the product ions at 0.74 eV collision energy and suggest that the isotropic distribution stems from the formation of a charge-transfer complex, in concurrence with previously performed studies. [GRAPHICS]