Monolithic Fill Tube Target Fabrication

Fielding a cryogenic ICF capsule for near-term ignition shots requires a fill-tube to deliver fuel to the capsule. Polymer capsules (0.9 and 3.1 mm o.d.) with a monolithic fill-tube have been produced. The fill tube is formed on the capsule by plasma polymer coating on a mandrel with a depolymerizable stalk. We report recent advances achieved in monolithic fill-tube capsule production. The micro-assembly station for attaching PAMS stalk to the mandrels was improved to reduce fillet and fill tube diameters and increase throughput. Excimer laser etching is used to micro-machine fill-tube capsules and target components to allow proper mating for assembly. The fill-tube target is attached to the gas source by a flexible polymer fill line and was tested to confirm gas flow and retention. The effect of the mandrel stalk on the uniformity of GDP coating is investigated.