A THERMAL COMPOSITE PLASMA FACING MATERIAL

MATERIALS EROSION IN THE HIGH TEMPERATURE RADIATIVE ENVIRONMENT OF THERMONUCLEAR REACTORS SEVERELY LIMITS DESIGN OPTIONS. LOWER SURFACE TEMPERATURES AND REDUCED EROSION OF OF THE PLASMA FACING MATERIALS MAY BE ACHIEVED WITH COMPOSITE MATERIALS DESIGNED TO HAVE ENHANCED HEAT CAPACITY AS WELL AS HIGH THERMAL CONDUCTIVITY. EXISTING DESIGNS ARE BASED ON GRAPHITIC MATERIALS THAT HAVE GOOD THERMAL CONDUCTIVITY AND SHOCK RESISTANCE BUT WHOSE VOLUMETRIC HEAT CAPACITY IS LOW. INCREASED HEAT CAPACITY OFFERS SIGNIFICANT BENEFITS DURING TRANSIENT HEATING EVENTS RANGING FROM MILLISECOND DISRUPTIONS TO THE MULTISECOND TIME SCALE OF FUSION EXPERIMENTS. THIS PROJECT INVESTIGATES COMPOSITE MATERIALS THAT INCORPORATE A HIGH CAPACITY PHASE-CHANGE COMPONENT DISPERSED IN A HIGH CONDUCTIVITY PYROLYTIC GRAPHITE STRUCTURE. PHASE I EFFORTS ARE DETERMINING OPTIMUM COMPOSITE PROPORTIONS FOR TOKAMAK DIVERTOR APPLICATIONS BASED ON TRANSIENT THERMAL ANALYSIS. THERMAL COMPOSITE SAMPLES WILL BE PREPARED AND CHARACTERIZED IN HIGH FLUX TRANSIENT THERMAL TESTING. PHASE II DEVELOPMENT WOULD INCLUDE PROCESS OPTIMIZATION, FABRICATION OF PROTOTYPE PLASMA FACING TILES, AND EXPOSURE TESTING IN A REACTOR ENVIRONMENT.