X-ray imaging of and phase transformation kinetics in shocked Silicon at LCLS

We report on first results of a new X-ray imaging diagnostic at the Matter in Extreme Conditions endstation at the Linac Cohorent Light source.

The diagnostic uses the sub-100 fs pulse duration of the X-ray beam at photon energies between 6 and 17 keV to obtain real density snapshots of material dynamics under extreme conditions at better than 600 nm spatial resolution and over larger than 100micron field of view.

We have used the diagnostic to image shock waves in single crystal Si, investigating the two elastic waves and the related kinetically inhibited phase transition to Si-V and Si-XI. In addition we see for the first time in situ the banding associated with this phase transition which has been predicted by MD simulation but never been recorded during a shock before.