X-ray backlighting imaging of mixed imploded targets

The X-ray image of a compressed shell (enhanced by high-Z doping) was used in recent experiments to diagnose the effect of shell-fuel mixing. The emission ring (due to the limb effect) moves toward smaller radii due to mixing. We show here that using backlighting imaging can greatly enhance future imaging experiments. In addition to the emission ring, a backlighting absorption ring can appear around it. The absorption ring is virtually unaffected by mixing. Thus, the relative position of the two rings constitutes a mixing signature. In other words, the absorption ring delineates the colder part of the shell and is a true signature of the compression, whereas the emission ring reflects the shell material motion due to mixing.