Laser-driven compression experiment at the European X-Ray Free Electron Laser

November/ December 2024

Axel Phelipeau and Christoph Otzen recently participated in a large-scale international experiment at the European X-ray Free-Electron Laser (EuXFEL)—the brightest and fastest X-ray source in the world.

Held over seven days at the High Energy Density (HED) instrument, the experiment brought together more than 100 scientists from 35 institutions across three continents. The ambitious goal:  study materials under the extreme pressure and temperatures found deep with planetary interiors and during impact events.  To achieve this, we coupled the high intensity Dipole-100X optical laser producing shockwaves in the materials with the unique X-ray brightness provided by the EuXFEL. This combination is essential to probe extreme states of matter with X-ray pulses of less than 30 femtoseconds, capable of delivering sufficient photons in a single shot to produce high-quality diffraction patterns. 

Once frequency-doubled and focused on a target, the Dipole-100X generates conditions similar to those in Earth’s core or in the interiors of giant exoplanets. These experiments allow researchers to study the behaviour of matter under extreme conditions, helping answer fundamental questions about how planets form, evolve, and function internally.

Over the course of the campaign, the team studied more than 2,500 samples covering a wide range of compositions and physical states. Each sample provided unique insight into material properties under shock compression and high energy density—data that could reshape our understanding of planetary physics.