Potential Impact of Inner Shell Plug Characteristics on Double Shell Capsule Implosions

Double shell capsules were first conceptualized almost four decades ago [4] as an alternative approach to inertial confinement fusion experiments. The double shell target consists of a low-Z outer ablator surrounding a high-Z inner shell [5,4,2]. Two potential mechanisms can be used to fill the inner shell with fuel: a fill tube, or a drill hole and plug. Simulations with fill tubes have shown unwanted contamination early on in the implosion process [1]. Two plug concepts have been considered: a pyrofuze plug made of an aluminum and palladium alloy, and autogenous welding of a plug composed of the same high-Z material as the inner shell.

This study uses 2D simulations from xRAGE [3] to analyze the potential impact of inner shell plug parameters on double shell implosion performance. In our study, we seek to understand how plug geometry impacts yield, how the impact of the plug would compare to that of a fill tube, how the geometry and materials affect its impact on the implosion, and whether it is possible to mitigate this impact.