Spectrally Resolved Imaging of X-Ray Self Emission from NIF Implosions

Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide spectrally resolved time-integrated absolute emission images of the imploded core of cryogenic layered targets. By limiting the spectral range of imaging, we can diagnose the hydrodynamic mix of Ge-doped ablator mass within the hot spot, core symmetry without interpenetration mix, shell assembly, and distribution of temperature and hot spot mass. Further, the measured brightness of Ge K-shell emission and bremsstrahlung allows for the inference of burn-weighted electron temperature, hot spot mass, rhoR, density, and pressure. Experimental results and a simple hot spot pressure model will be presented.