61st Annual Gaseous Electronics Conference
Volume 53, Number 10
Monday–Friday, October 13–17, 2008;
Dallas, Texas
Session QR2: Electron Impact Ionization of Atoms and Molecules
10:00 AM–12:00 PM,
Thursday, October 16, 2008
Room: Salon A-D
Chair: Klaus Bartschat, Drake University
Abstract ID: BAPS.2008.GEC.QR2.2
Abstract: QR2.00002 : Electron Impact Ionization of the Rare Gases
10:30 AM–11:00 AM
Preview Abstract
Abstract
Author:
Birgit Lohmann
(ARC Centre for Antimatter-Matter Studies, University of Adelaide, 5005, Australia)
Detailed information about the electron impact ionization process
can be obtained from fully differential cross section
measurements, in which the ionized electron is detected in
coincidence with the outgoing scattered projectile electron.
Incident and outgoing electron momenta are completely determined
in these measurements. A considerable body of experimental and
theoretical data exists for H and He targets, and the level of
agreement between theory and experiment for these simple atoms is
exceptional. However, there are still significant discrepancies
between theory and experiment in the case of ionization of more
complex atomic targets such as the heavier rare gas atoms. In
this talk I will present recent measurements and theoretical
predictions of fully differential cross sections for ionization
of a range of rare gas targets: He, Ne, Ar and Xe. The talk will
concentrate primarily on experiments which have been performed
by two experimental groups, our group in Australia [1-3] and that
of Lahmam-Bennani [3-5] in France. The experimental conditions
span two different kinematic regimes, one with intermediate
incident electron energy and low ejected electron energy, and the
other with higher incident electron energy, and ejected electron
energies which correspond to large energy transfer in the
collision process. All experiments have been performed in a
coplanar asymmetric configuration in which the scattered electron
is detected at a small forward scattering angle. The experimental
apparatus used in Australia is of quite different design to that
in France, and I will present the results of an experiment in
which the two groups have collaborated to produce data under
identical kinematic conditions and for the same targets, using
these two very different experimental approaches. This
comprehensive set of experimental data has provided an
interesting challenge to theory, and I will discuss the state of
play with regard to the alignment between curent state-of–the-art
theoretical models and the experimental results.
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[1] Stevenson and Lohmann, Phys. Rev. A 73, 020701R (2006)
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[2] Stevenson and Lohmann, Phys. Rev. A 77, 032708 (2008)
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[3] Naja et al, J. Phys. B: At Mol. Opt. Phys. 41, 085205 (2008)
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[4] Catoire et al, J. Phys. B 39, 2827 (2006)
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[5] Kheifets et al, J. Phys. B 41, 145201 (2008).
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2008.GEC.QR2.2