DEVELOPMENT OF FOAM SHELL WITH PLASTIC ABLATOR FOR CRYOGENIC LASER FUSION TARGET

A low density, low Z foam shell overcoated with a plastic ablation lay er was developed for use as a cryogenic laser fusion target in which m ain liquid or solid fuel is sustained by the uniformly thick foam laye r. The high quality ablator with thickness of 1-10 mum, uniformity of > 95%, and surface smoothness of <0.2 mum was coated on the foam shell by the interfacial polycondensation method using hydroxyethylcellulos e or poly(p-vinyl phenol) (PVP) and isophthaloyl chloride. The tensile strength of the crosslinked PVP at low temperature and its permeabili ty to deuterium at room temperature are comparable with those for poly styrene. In this reaction, we found that the existence of surfactant i n the emulsion was essential to form an ablation layer which adhered t o the foam layer.