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Future predictive models of materials response under extreme conditions will be increasingly phaseand microstructure-aware. As such, model development and validation will require new types of experimental data that probe responses at lattice-to-mesoscales in real time during dynamic events. High brilliance X-ray light sources coupled to dynamic driver platforms offer tremendous potential for providing new insights into the physics of materials under dynamic conditions. Over the last several years, data from burgeoning facilities are already challenging historical model assumptions in several areas.

Development of robust instrumentation has shown evidence for a multi-μC expulsion of relativistic electrons from a sub-μm-thick foil, laser illuminated with 60–70 J on target at 2 × 10²⁰ W/cm². From previous work and with electron spectroscopy, it is seen that an exponential electron energy distribution is accurate enough to calculate the emitted electron charge and energy content. The 5–10-μC charge for the >100-TW Trident Laser represents the first active measurement of the >50% laser-light-to-electron conversion efficiency. By shorting out the TV/m electric field usually associated with accelerating multi-MeV ions from such targets, one finds that this charge is representativemore » of a multi-MA current of relativistic electrons for diverse applications from electron fast ignition to advanced radiography concepts. Also included with the details of the discoveries of this research, shortcomings of the diagnostics and means of improving their fidelity are discussed.« less