Ultrafast laser-driven x-pinches

X-pinches driven by pulsed power devices can provide a bright x-ray source with small spatial size (~10 μm) and relatively short duration (~100 ps) that enables high-resolution radiography, diffraction, and Talbot-Lau deflectometry measurements. Systems driven by a high-intensity laser pulse can potentially produce stronger currents with shorter rise times. Recent LaserNetUS experiments at the Titan facility aimed to demonstrate x-pinch dynamics using the strong return current generated by picosecond (ps) laser-solid interactions. The x-shaped targets were either laser-cut aluminum or electroformed copper. Current-driven dynamics, including instability growth along the ‘x’ feature, were observed using a frequency-doubled, ps-duration optical probe. Time-integrated x-ray emission, imaged with a slit aperture, suggests a second emitting spot forms at the ‘x’ location. Electron and proton energy spectra were measured using a magnetic spectrometer, and the spatial profile of proton self-emission was captured on radiochromic film. Significant changes in the proton beam shape were observed from the “x” targets compared to solid foils.