Coating and Mandrel Effects on Fabrication of Glow Discharge Polymer NIF Scale Indirect Drive Capsules

Abstract

Targets for the National Ignition Facility (NIF) need to be about 200 μm 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 mm in diameter, of varying qualities were coated with as much as 125 μm 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.