DEVELOPMENT AND EVALUATION OF FIRST WALL MATERIALS FOR THE NATIONAL-IGNITION-FACILITY

Several low-Z refractory materials are evaluated for use as the NIF fi rst wall in terms of their cost, level of vacuum outgassing, and abili ty to survive laser light, target emissions and debris, and rigorous d econtamination. The best performers contain B, C, or both, with B4C be ing the best overall. It appears possible at this time that plasma-spr ayed B4C can be fabricated with low enough porosity and cost to be pre ferred over hot-pressed B4C, the conservative choice.