Phase Contrast Imaging of Inertial Confinement Fusion Capsules Using a Compact X-pinch

The baseline NIF cryo-ignition fusion target contains a 100~$\mu$m thick layer of DT ice inside a cu-doped Be shell. X-ray phase contrast radiography is currently the only known method for verifying the presence and uniformity of this ice layer, but presently available sources require minutes-long exposure, which results in a blurred image due to shell vibrations. A compact x-pinch generator is an excellent source of bright and energetic x-rays, and has the unique advantage of pulsed exposure ($<$1~ns) while being small enough to fit on a tabletop. Initial results from experiments performed to characterize Be coated, Al coated, and plain CH capsules (various diameters and wall thicknesses) are presented. A compact x-pinch device capable of producing 80~kA of current with a rise time of 40~ns was used. X-pinches of various wire materials including W, Mo, and Al were used. The rough spectrum with Ross filter pairs shows x-rays in 1-10~keV range. The phase contrast images of CH capsules reveal a source size of 2-3~$\mu$m.