Bounce Coating Induced Domes on Glow Discharge Polymer Coated Shells

Abstract

Plasma polymer coating of larger (1 mm or greater in diameter) Inertial Confinement Fusion (ICF) targets in a piezo electric based bounce pan results in surfaces which contain numerous domes of various sizes for coating thicknesses greater than about 3 μm. The density of domes increases with the size of the shells, number of shells coated at once, the strength of bouncing, and the coating thickness. The same problem is encountered when bounce coating large numbers of smaller Nova shells as well. The domes appear to grow from seeds produced by chips of the brittle plasma polymer coating itself produced in shell-to-shell collisions. A tilted spinning pan has been shown to produce smooth dome free coating while providing sufficient agitation to obtain uniform coatings.