Berlin 2005 – wissenschaftliches Programm
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P: Plasmaphysik
P 25: Dichte Plasmen 2
P 25.4: Vortrag
Mittwoch, 9. März 2005, 12:00–12:15, HU 3059
Thomson scattering using the VUV-FEL at DESY Hamburg — •Robert Thiele1, Eckhart Förster2, Ronald Redmer1, Heidi Reinholz1, Gerd Röpke1, and Thomas Tschentscher3 — 1Universität Rostock — 2Friedrich-Schiller-Universität Jena — 3DESY Hamburg
The scattering of photons in plasmas is an important diagnostic tool.
The region of solid-density plasmas can be probed by x-ray
Thomson scattering. The scattering cross section is related to the
dynamic structure factor S(k,ω). We improve the standard
treatment of the scattering on free electrons within the random phase
approximation (RPA) by including collisions [1].
S(k,ω) is calculated via the dielectric function at finite
wavenumbers
which can be obtained by using a generalized Mermin ansatz
[2].
The dynamic collision frequency is treated in Born and Lenard-Balescu
approximation [3].
We show that theoretical description beyond the RPA is crucial to
obtain reliable results for the plasma parameters.
Experimental investigation at experimental parameters where
a treatment beyond RPA is required are under preparation for
the VUV-FEL at DESY, Hamburg.
[1] A. Höll, R. Redmer, G. Röpke and H.
Reinholz, Eur. Phys. J. D 29, 159-162 (2004)
[2] A. Selchow at al., Phys. Rev. E 64, 056410
(2001)
[3] H. Reinholz, R. Redmer, G. Röpke, A. Wierling, Phys.
Rev. E 62, 5648 (2000)