Dresden 2011 – scientific programme
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A: Fachverband Atomphysik
A 26: Poster III
A 26.81: Poster
Thursday, March 17, 2011, 16:00–18:30, P2
Ion acoustic waves in strongly correlated ultracold neutral plasmas — •Cornelia Lechner, Christian Knapp, and Alexander Kendl — Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, A-6020 Innsbruck, Austria
Recent experiments on ultracold neutral plasmas (UNPs) report on the creation and observation of ion acoustic waves, which belong to the class of low-frequency, electrostatic plasma waves [1]. Surprisingly, despite significant deviations from standard plasma parameters, e.g. the strong coupling regime of the ions and the expansion into vacuum, the observed density oscillations seem to be well described by the standard dispersion relation of ion acoustic waves.
We study the influence of strong Coulomb-coupling on ion acoustic waves in UNPs. By taking into account ionic correlations, we obtain the modified dispersion relation. Deviations from the standard dispersive behavior are expected with an increasing degree of correlations. Ion acoustic waves are usually affected by Landau damping, unless the ion temperature satisfies Ti≪ Te. Since the latter is true for UNPs, a different kind of damping behavior might be expected.
[1] J. Castro, P. McQuillen, and T. C. Killian, Phys. Rev. Lett. 105, 065004 (2010)