Diffraction Set-up to Study Highly Compressed Matter at LCLS and the European XFEL

4th generation light sources, such as the LCLS, have the ability to emit hard X-rays with a pulse length of less than 100 fs and a brilliance of 1031-32 ph/sec/mrad/cm2/0.1% BW. These extremely brilliant, short pulses allow one to collect high-quality diffraction patterns in a single pulse, and hence are ideal to combine with nanosecond dynamic compression techniques to make detailed diffraction studies of highly-compressed matter at extreme conditions. The Matter at Extreme Conditions (MEC) beamline at LCLS, and the High Energy Density (HED) instrument due to come online at the European XFEL in 2016, utilise high-power, long- and short-pulse lasers to access extreme solid and plasma states. Here, we will present an experimental setup, implemented on the MEC in February 2013, which combines long-pulse lasers, capable of compressing solid matter to a megabar, with in situ diffraction and optical velocimetry (VISAR). X-ray diffraction measurements made using a single pulse of the LCLS beam will be compared directly with data obtained from a conventional synchrotron source. Finally, we will present future plans to implement similar setups at the HED instrument within the framework of the Helmholtz International Beamline (HiBEF) beamline at the European XFEL