• Hernandez, J.-A.
• Lefevre, F.
• Sollier, A.
• Brygoo, S.
• Ravasio, A.
• Berlioux, A.
• Vinci, Tommaso
• Duthoit, L.
• Guarguaglini, M.
• Benuzzi-Mounaix, A.
• Denoeud, A.
• Videau, L.
• Loison, Didier
• Brambrink, E.

Abstract

International audience ; An ultrafast x-ray powder diffraction setup for laser-driven dynamic compression has been developed at the LULI2000 laser facility. X-ray diffraction is performed in reflection geometry from a quasi-monochromatic laser-generated plasma x-ray source. In comparison to a transmission geometry setup, this configuration allows us to probe only a small portion of the compressed sample, as well as to shield the detectors against the x-rays generated by the laser-plasma interaction on the front side of the target. Thus, this new platform facilitates probing of spatially and temporarily uniform thermodynamic conditions and enables us to study samples of a large range of atomic numbers, thicknesses, and compression dynamics. As a proof-of-concept, we report direct structural measurements of the bcc-hcp transition both in shock and ramp-compressed polycrystalline iron with diffraction signals recorded between 2θ ∼30° and ∼150°. In parallel, the pressure and temperature history of probed samples is measured by rear-side visible diagnostics (velocimetry and pyrometry).

Topics

• impedance spectroscopy
• x-ray diffraction
• iron