A full characterization of the ICF fuel assembly at stagnation through nuclear imaging

The joint LANL/LLNL nuclear imaging team has transformed the 2D neutron imaging technique for inertial confinement fusion implosions at the National Ignition Facility into a full 3D fuel characterization diagnostic suite over the past decade. With advances in detector technology, as well as sophisticated analysis codes, the nuclear imaging team now delivers physics information on the three-dimensional hot spot shape, cold fuel density, and remaining ablator position. Three neutron imaging lines-of-sight allow for three-dimensional hot spot tomography, and cold fuel density reconstruction – showing performance-limiting shape asymmetries. Applying our three-dimensional limited-view tomography technique to X-ray images visualizes contaminant mix into the hot spot. Gamma imaging interpretation aided by simulations shows the remaining ablator position, and potential jetting of remaining mass into the fuel. A decade of progress has grown the nuclear imaging effort from a single diagnostic into a powerful diagnostic suite that provides comprehensive information on the fuel assembly at stagnation.