Some Aspects of the Hydrodynamics of the Microencapsulation Route to NIF Mandrels

Spherical plastic shells for use as mandrels for the fabrication of ICF (Inertial Confinement Fusion) target capsules can be produced by solution-based microencapsulation techniques. The specifications for these mandrels in terms of sphericity are extremely rigorous, and it is clear that various aspects of the solution hydrodynamics associated with their production are important in controlling the quality of the final product. This paper explores what we know (and need to know) about the hydrodynamics of the microencapsulation process in order to lay the foundation for process improvements as well as identify inherent limits.