(Left) Cross section of the spherical capsule used at NIF. The capsule is encased in a cavity (hohlraum) and ablated by x rays during a laser pulse. Its core consists of a gas of deuterium and tritium, surrounded by a layer of deuterium-tritium ice. The casing consists of plastic doped with silicon. (Right) The intensity of the laser pulse delivered to the hohlraum changes with time. Previous experiments used a “low-foot” drive (dotted yellow line), in which the first stage of the pulse (the “foot”) delivered a relatively low power. Park et al. showed that using a high-foot drive (solid yellow line) instead delivered a higher neutron yield that was more consistent with simulations. The radiation temperature, which characterizes the radiation field in the hohlraum that drives the implosion, is plotted against time.