Optimizing neutron imaging system design for the National Ignition Facility using synthetic imaging data

The Los Alamos National Laboratory Advanced Imaging team has been providing neutron imaging of inertial confinement fusion implosions at the National Ignition Facility (NIF) since 2011. Now, the team is designing two additional active detector systems adding two more lines-of-sight to allow three-dimensional reconstruction of the fuel assembly. Together these systems will deliver shape information on the burning hot spot, surrounding cold fuel, and the remaining ablator by adding gamma imaging capabilities. The design of the new detectors is optimized using synthetic neutron imaging data from simulations in the Chimera rad-hydro code together with a detailed forward model of the complete neutron imaging system including the pinhole aperture array. The simulation results will not only inform the design requirements for the new systems, but also improve future physics interpretation of NIF imaging data from both the existing and the planned imaging systems.