X-ray backlit imaging measurement of in-flight pusher density for an indirect drive capsule implosion

Abstract

Both the efficiency of an implosion and the growth rate of hydrodynamic instability increase with the aspect ratio of an implosion. In order to study the physics of implosions with high Rayleigh–Taylor growth factors, we use doped ablators which should minimize x-ray preheat and shell decompression, and hence increase in-flight aspect ratio. We use x-ray backlighting techniques to image the indirectly driven capsules. We record backlit 4.7 keV images of the full capsule throughout the implosion phase with 55 ps and 15 μm resolution. We use these images to measure the in-flight aspect ratios for doped ablators, and we infer the radial density profile as a function of time by Abel inverting the x-ray transmission profiles.