Progress in X-ray imaging and spectroscopy of ultraintense laser matter interactions

Energetics of ultraintense laser-matter interactions are strongly characterized by production of large currents of high energy electrons. We describe recent progress in diagnostics of such electrons and related processes. We use an Energy Encoded Pin-Hole Camera, a novel X-ray imaging technique based on single photon detection to investigate generation and transport of such high energy electrons following the interaction of femtosecond laser pulses with solids at intensities exceeding 5 x 10(19)W/cm(2). The imaging system was configured to work in a single-photon detection regime to identify the energy of the X-ray photons and to discriminate among different X-ray emission processes.