Chaotic scattering in atomic or molecular systems
(with J.M. Rost)
In atomic and molecular systems, a classical scattering process can -
depending on the interaction potential and the available energy - result in
the temporary trapping of the projectile. The projectile will spend some
time near the target, which will lead to multiple collisions between target
and projectile. The corresponding time delay of such an event as compared to
a direct trajectory is the classical signature of a resonance, i.e. a
temporarily bound state (target+projectile) that will finally decay again.
Classically, this
time delay can become arbitrarily long, leading to an infinite hierarchy of
indirect processes and an infinite sensitivity of the outcome of the
scattering process on the precise initial condition. This scenario has been
termed 'chaotic scattering'. For the special case of an atom-diatom scattering
system with van der Waals forces, we have uncovered the way in which chaotic
scattering arises in a real experimental setting as a function of the
projectile energy [1]. Moreover, we studied the influence of the presence
of indirect (chaotic) scattering events on the fragmentation behavior of
systems. While in a pure Coulomb potential resonances do not exist in an
energy range where complete fragmentation can occur, such a regime can be
present in molecular potentials. For our atom-diatom system, we could show
that chaotic scattering indeed has consequences for the
fragmentation behavior, showing pronounced differences between direct and
indirect events [2].
[1] A route to chaos in classical atom-diatom collisions; T.
Pattard and J.M. Rost, Chem. Phys. Lett. 291 (1998) 360
[Abstract]
[2] Classically chaotic scattering and fragmentation dynamics
in molecular type potentials; T. Pattard and J.M. Rost, unpublished
[Abstract] [Full text]
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last change: 08/16/99