Recent experiments to constrain opacity and heat capacity of gold

In radiation-hydrodynamic simulations of indirect-drive inertial confinement fusion (ICF) targets, laser power multipliers are routinely employed to tune the simulations to experimental observables like x-ray flux and capsule bang-time. Since the laser power is measured to accuracy well below the needed multipliers, this suggests that the simulated partition of energy in the hohlraum is incorrect. One possible reason for this is that the amount of energy absorbed by the gold wall is larger than predicted. Greater wall loss could occur if the gold opacities or heat capacities used in the simulations are sufficiently incorrect. Here, we report on modeling of a recent gold burn-through experiment which constrains the product of multipliers on both the heat capacity and opacity. We then apply these constrained multipliers to a series of vacuum hohlraum experiments to illustrate the degree to which such an approach can be used to reduce the need for laser power multipliers.