Planned experiments to determine the cause of the drive deficit

The drive-deficit is a long-standing problem present in laser-driven hohlraums used in inertial confinement fusion (ICF) and high-energy density (HED) experiments. These platforms routinely have simulated x-ray fluxes that exceed measurements and simulated capsule bang-times that occur earlier than observed. Determining the source of the drive-deficit is difficult due to the highly integrated nature of these experiments and the complexity of the physics involved. Here, we report on focused experiments that have been proposed to help better determine the source of the drive-deficit. The first is an x-ray burn-through experiment that seeks to constrain the opacity and heat capacity of gold and quantify the discrepancy with existing models. The second is a series of experiments that will begin with a simple vacuum hohlraum, adding incremental complexity to quantify the drive-deficit at each step. The goal of these efforts is to provide measurements that will focus attention on possible hypotheses that can solve this long-standing problem.