Abstract
The advent of hard x-ray free-electron lasers (XFELs) has opened up a variety of scientific opportunities in areas as diverse as atomic physics, plasma physics, nonlinear optics in the x-ray range, and protein crystallography. In this article, we access a new field of science by measuring quantitatively the local bulk properties and dynamics of matter under extreme conditions, in this case by using the short XFEL pulse to image an elastic compression wave in diamond. The elastic wave was initiated by an intense optical laser pulse and was imaged at different delay times after the optical pump pulse using magnified x-ray phase-contrast imaging. The temporal evolution of the shock wave can be monitored, yielding detailed information on shock dynamics, such as the shock velocity, the shock front width, and the local compression of the material. The method provides a quantitative perspective on the state of matter in extreme conditions.
Highlights
The advent of hard x-ray free-electron lasers (XFELs) has opened up a variety of scientific opportunities in areas as diverse as atomic physics, plasma physics, nonlinear optics in the x-ray range, and protein crystallography
Whilst many of the advances afforded by x-ray free-electron lasers (XFELs)[1,2,3] are completely new[4,5,6], several key results have been obtained by exploiting established static techniques and transporting them to the femtosecond time-domain made possible by the short duration of the XFEL pulses[7,8]
We make use of the very short but intense XFEL pulses to image the propagation of an elastic compression wave in diamond with both high temporal (~50 fs pulse duration) and spatial resolution (~500 nm)
Summary
Andreas Schropp[1], Robert Hoppe[2], Vivienne Meier2,*, Jens Patommel[2], Frank Seiboth[2], Yuan Ping[3], Damien G. We conclude that this is a purely elastic wave, as the pressures are well below the Hugoniot elastic limit (HEL) of diamond[18] In this first approach to quantitatively analyze the phase-contrast images we determined a wave curvature of R = 440 μ m at the time delay of Δ t = 1.2 ns, which scales linearly up to R = 476 μ m at Δ t = 3.0 ns. With this example, we demonstrated that fast dynamic processes inside matter can be visualized in situ with both high temporal and high spatial resolution by magnified x-ray phase-contrast imaging at an XFEL. The elastic compression wave here was atomic in front width, the direct observation of the evolution of the width of the front in a shock for a material subjected to pressures above the HEL would provide significant insight into the time scales for plastic flow under high strain-rate conditions well in excess of 109 s−1
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
