Ablator dopants
affect the opacity and density, changing the manner
in which energy is absorbed by the ablator.
By
adding mid-Z dopants (like bromine, copper, or germanium) to the plastic or beryllium capsule ablator, we can control the density
and opacity of the ablator. This in turn controls the ablation/compression physics
in the fuel capsule. The dopants
also provide a ‘shield’ against radiation preheat of the fuel, allowing for efficient compression at the lowest entropy
possible.