High-Yield Implosions via Radiation Trapping and High rhoR

A thin layer of mid- or high-Z material (Mo or W) at the inner surface of the ablator can be used to reduce the implosion velocity and hotspot temperature thresholds for ignition. This is because this thin layer can reduce Bremsstrahlung radiation lost from the hotspot as well as improve the confinement by increasing the rhoR. The problem with the thin layer is that it forms an unstable interface and this is the paramount concern for this type of implosion configuration. However, recent advances in target fabrication enable the blending of the inner region of Be ablators with mid- or high-Z material with a graded concentration that decreases gradually toward the outer region of the ablator. This substantially reduces Rayleigh-Taylor growth during the acceleration phase and gives high yield based on 2D simulations. Two types of capsule configurations, with DT gas only and with a DT ice layer, will be presented. The yield of DT-gas only capsules can be considerably higher than gas-only capsules using conventional low-Z ablator configurations.