Subproject 7: Dynamic compression experiments of rock material at free electron lasers

PIs: K. Appel and T. Tschentscher, PhD: M. Schölmerich

With the discovery of 3200 exoplanets (by June 2016) in the past few years, the understanding of basic compositions, structure, and the dynamics of rocky planets has gained tremendous importance. In this subproject, we experimentally study rock material at conditions relevant for planetary sciences. To reach and densely cover the P-T space of up to 1 TPa and several 1000 K, we apply dynamic laser compression techniques. We make use of a new experimental facility, the High-Energy Density Science instrument at the Eu- ropean XFEL and realize the required experimental set-up. In the first phase, this research unit subproject as well as the two other subprojects using experimental techniques, study MgO as a model material. Doing so, experimental results obtained by diamond anvil cell compression techniques are validated against those obtained from dynamic laser compres- sion. In addition, this research unit provides a platform to quantitatively compare the experimental results with results obtained on the same model systems by ab initio simulations. This benchmarking enables to experimentally study key phases in rocky planets at relevant conditions. We propose to first obtain equation-of-state data for MgO including its melting curve. In the course of the project, we work on the more complex MgSiO3. Once these model systems are well understood, we focus on solid solutions which are more comparable to natural systems.

Accessible P-T regimes with experimental apparatuses (left, from [Liermann (2014)]) and reachable P-T regions based on laser compression methods (right, from [Benuzzi-Mounaix (2014)]).
Model of the composition of a super-Earth with 10 mass units showing calculated density variations for the pyrolitic mineral assemblage [Tsuchiya (2011)] along an assumed mantle adiabat. The arrows indicate silicate breakdown. A corresponding super-Earth’s cross section is also shown [Valencia (2006)].

Contact PIs

Dr. Karen Appel, European XFEL GmbH
Holzkoppel 4, 22869 Schenefeld (XFEL)
T: +49 (0)40 899 82 930, Email

Dr. Thomas Tschentscher, European XFEL GmbH
Holzkoppel 4, 22869 Schenefeld (XFEL)
T: +49 (0)40 899 83 904, Email