Fabrication of Overcoated Divinylbenzene (DVB) Shells
Abstract
Target models for the High Average Power Laser Program require a 4 mm diameter capsule with a core of deuterium tritium (DT) vapor, a layer of DT ice, a layer of low density foam filled with DT ice, a full density polymer overcoat, and a high-Z metallic overcoat. Requirements of the foam are a density from 30-140 mg/cm3, cell size less than 5 microns, and possibly only containing carbon and hydrogen. Divinylbenzene was developed as a foam system to meet these requirements as the system can be produced within the density range of interest, has a cell size of 1-4 mm, and contains no oxygen. The shells are formed using a water-oil-water emulsion microencapsulation technique and are agitated during thermal gelation to increase shell concentricity. An interfacial polycondensation technique using poly(vinyl phenol) reacted with an acid chloride was selected to apply the full density overcoat. Research specification goals are as follows: 4 mm diameter, 300 micron foam wall thickness, 100 mg/cm3 foam wall density, <1and overcoat surface roughness <20 nm RMS. Formation, gelation, characterization, overcoating techniques, and methods to further reduce nonconcentricity and surface roughness are presented. Work performed under the auspices of the Naval Research Laboratory under contract N00173-03-C-2023.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 2004
- Bibcode:
- 2004APS..DPPNP1121S