Fabrication of Low-Density Aerogels for IFE Applications

Low-density GA-CH and GA-CD aerogels (<50 mg/cc) have quite promising properties for use in Inertial Confinement Fusion (ICF) targets at NIF and OMEGA; the low density and low Z make it a prime candidate for foam liners. Materials like resorcinol formaldehyde (RF) and divinylbenzene (DVB) that have been previously fabricated in the droplet generator can only be fabricated at higher densities. Physical properties of GA-CH and the required fabrication process conditions have been a major hurdle in making GA-CH shells and beads in the droplet generator, an approach that can mass-produce capsules for possible applications in Inertial Fusion Energy (IFE). This paper will look at two ways of making foam beads and shells from GA-CH: machining and droplet generator. To date, GA-CH shells have never been fabricated, and beads have only been machined individually. This work describes the first attempts at making beads and shells in the droplet generator, including modifications made to the droplet generator and the quality of shells made from the process. Shells made with separate machining and leaching process will also be discussed, including optical quality and foam shrinkage. Ultimately, we will compare the benefits of each method of production.