Schlieren Refraction Measurements of Implosion Density Profiles

In inertial confinement fusion implosions, the plasma density profile on the inner side of the driven shell is important to the performance of the design. If the profile is of higher density or longer scale length than that predicted by hydrodynamic simulations, the mass increase in the hot spot can decrease its compressibility and reduce performance compared to what is expected from the simulations. The density profile inside the imploding shell is largely shadowed in radiography caused by the large integrated absorption through the dense shell twice. We propose measuring the refraction of an x-ray probe through schlieren imaging. Because of the dependence of the signal on the gradient of density as opposed to density itself, this measurement has the capability of uncovering more information about the density profile inside the shell. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0003856.