Characterizing the impact of material layers on Opacity-on-NIF Samples with Forward Modeling

Measurements taken during the Opacity-on-NIF experiment measure x-ray transmission, and thereby infer an opacity for a material of interest. Some samples for this experiment are built up in layers using a co-deposition method. Due to this fabrication method of the target samples, there can exist regions along the axis of the sample with significantly different material compositions, leading to a non-uniform opacity. Along with being the quantity of interest measured in the experiment, opacities also impact how energy is absorbed in the sample, causing temperature and density gradients in the sample during measurement time. This work details radiation-hydrodynamics simulations of target foils performed using the CASSIO code, and postprocessed using time-resolved methods to determine the impact that layered foils can have on both time-integrated and time-resolved opacity measurements.