Measuring Dynamic Density Gradients in Warm Dense Matter with 1 µm Spatial Resolution

X-ray phase-contrast imaging of micron-scale objects and features requires high spatial coherence. These highly spatially coherent x-rays can be generated at fourth generation light sources or by passing laser-produced x-rays through a narrow slit. By coupling these sources to an isochoric heating platform, we can measure the dynamic changes in density gradients at the interface between two warm dense matter (WDM) samples with micron-scale spatial resolution. The high spatial coherence gives rise to refractive and diffractive features at the interface 1 , 2 , 3 , allowing for precise measurement of dynamic processes in WDM, including transport properties and measuring the equation of state. We will present an overview of successful experiments at both the Omega Laser Facility and the European XFEL that demonstrate our platform's high efficacy and spatial resolution for characterizing density gradients in dynamically evolving WDM systems.