Coating and mandrel effects on fabrication of glow discharge polymer NIF scale indirect drive capsules

Targets for the National Ignition Facility (NIF) need to be about 200 mum thick and 2 mm in diameter. These dimensions are well beyond those currently fabricated on a routine basis. We have investigated fabrication of near NIF scale targets using the depolymerizable mandrel technique. Poly-alpha-methylstyrene (PAMS) mandrels, about 2 nun in diameter, of varying qualities were coated with as much as 125 mum of glow discharge polymer (GDP). The surface finish of the final shells was examined using a variety of techniques. A clear dependence of the modal spectrum of final GDP shell on the quality of the initial PAMS mandrels was observed. Isolated features were found to be the greatest cause for a shell not meeting the NIF standard.