Asymmetry study from the hot-spot self-emission imaging of inertial confinement fusion implosion driven by high-power laser facilities

Implosion asymmetry is a crucial problem quenching ignition in the field of inertial confinement fusion. A forward-calculation method based on 1D and 2D hydrodynamic simulations has been developed to generate and to study the x-ray images of hot-spot self-emission, indicating asymmetry integrated over the entire drive pulse. It is shown that the x-ray imaging photon energy should be higher to avoid the influence of remaining shell. The contour level (percentage of the maximum emission intensity) and spatial resolution should be as low as possible, optimally less than 20% and 3 microns, for characterization of higher-mode signatures such as P8 to P12 by x-ray self-emission images. On the contrary, signatures of lower-mode such as P2 remain clear at all contour levels and spatial resolutions. These key results can help determine the optimal diagnostics, laser and target parameters for implosion experiments. Recent typical hot-spot asymmetry measurements and applications on Shenguang 100kJ-class laser facility are also reported.