Speaker
Thomas Robert Preston
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/O4.206.pdf
High resolution measurement
of the momentum-dependent plasmonic excitations of 1 Mbar matter
T. R. Preston1, P. Sperling2,3, K. Appel1, B. Chen4, L. B. Fletcher3, S. H. Glenzer3, S.
Göde1, Z. Konôpková1, H. J. Lee3, H. Marquardt5, E. E. McBride1, 3, B. Nagler3, M.
1
Nakatsutsumi ,
B. B. L. Witte2,3, and U. Zastrau1
1 European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
2 Institut für Physik, Universität Rostock, 18051 Rostock, Germany
3 Stanford Linear Accelerator Center (SLAC), Menlo Park, CA 94025, USA
4 China Academy of Engineering Physics (CAEP), Mianyang, China
5 Bayerisches Geoinstitut, University of Bayreuth, 95440 Bayreuth, Germany
The modelling of astrophysical objects such as the interiors of giant planets, low mass stars
and brown dwarfs is heavily reliant on the understanding of matter at temperatures of a few
eV and pressures around 1 Mbar. The creation and diagnosis of these plasmas is challenging
requiring controlled laser shock compression in order to keep the temperature low and
simultaneous probing through inelastic X-ray scattering. Seeded operation at the Linac
Coherent Light Source (LCLS) [1] gives us access to ultrafast, bright, highly monochromatic
X-ray probes allowing the determination of highly resolved dynamic structure factor data [2].
We present here repeatable measurements of the plasmon dispersion in Aluminium both at
ambient conditions and at compressed conditions around 1 Mbar pressure, and make
estimates of the pressure, density and temperature using X-ray diffraction and optical VISAR
measurements. We compare the plasmon dispersion with that expected from density-
functional-theory molecular-dynamics calculations and explore the validity of various models
at temperatures below 1 eV. Finally, we look forward to future measurements at the European
XFEL’s HED instrument.
[1] S H Glenzer et al., J. Phys. B: At. Mol. Opt. Phys. 49, 092001 (2016),
[2] L. Fletcher et al., Nature Photonics 9, 274 (2015).
