\textbf{Hot-Spot Flow Velocity in Laser-Direct-Drive Inertial Confinement Fusion Implosions}

Multidimensional effects on the hot-spot formation of laser-direct-drive inertial confinement fusion implosions can lead to an anisotropic hot-spot flow velocity and incomplete stagnation. The first and second moments of the primary DT fusion neutron peak, recorded with four neutron time-of-flight detectors positioned around the target chamber in quasi-orthogonal diagnostic lines of sight, are analyzed to infer the hot-spot flow velocity and the ion temperature of implosions on the 60-beam, 30-kJ, 351-nm OMEGA laser. The possible physical degradation mechanisms (e.g., initial target offset, target stalk orientation, and nonuniformities in the target and the laser drive) leading to a hot-spot flow velocity in implosions of DT cryogenic targets and DT gas-filled plastic shells will be presented. Correlations of the hot-spot flow velocity with gated x-ray images of the hot spot recorded along multiple lines of sight and of in-flight asymmetries of the imploding shell will be examined. A hot-spot flow velocity of 50 to 150 km/s is observed to point in the direction of the maximum inferred ion temperature. This material is based upon work supported by the DOE National Nuclear Security Administration under Award Number DE-NA0003856.