White Dwarfs in the Laboratory at European XFEL - 15.02.2024

A subgroup of the team performing the first experiment with the DiPOLE laser at the European XFEL.

 

White dwarfs represent the final state for most stars and can act as "standard candles" for astronomy when exploding in type Ia supernovae. However, the high-energy-density states that exist in white dwarfs are extremely difficult to reach and to measure in the laboratory, so theoretical predictions are largely untested at these conditions.

At European XFEL, we led an international team using the ReLaX laser to produce conditions similar to those in the envelopes of white dwarf and probe this extreme state of matter with the X-ray Free Electron Laser using X-ray Thomson scattering. The aim was to identify important plasma parameters like temperature, density, and ionization. We could obtain a large data set of very high quality that will provide unprecedented insights into the equation of state for extreme astrophysical states of matter. At the same time, we will use the data to benchmark models for the complex physics of intense laser-matter interaction, which is relevant for many applications: from laser machining to fusion energy.

For these experiments, our team from University of Rostock was joined by scientists and students from Stanford University, SLAC National Accelerator Laboratory, École Polytechnique, Queens University of Belfast, Lawrence Livermore National Laboratory, Helmholtz-Zentrum Dresden-Rossendorf, European XFEL, and GSI Helmholtzzentrum für Schwerionenforschung.