Images of the gold bubble feature in NIF Gas-Filled Ignition Hohlraums

The ViewFactor experiments at the National Ignition Facility use a truncated hohlraum to allow excellent diagnostic views of the interior of the hohlraum. Time-integrated, hard x-ray (3-5 keV) images show the region where the laser deposits its energy at peak power. These images show a three-dimensional structure in the region where the outer beams deposit their energy (the "gold bubble") which varies with pulse shape and cross beam energy transfer. The images from two-dimensional simulations have similar trends but show some discrepancies.