Extreme materials environment of the fusion
Commercial fusion energy will require an energy-producing fusion plasma core (the “fire”) surrounded by an integrated engineering system (the “fireplace”). This review focuses on the extreme materials requirements of the fusion “fireplace,” which has the following intertwined functions: (1) a first wall that faces and survives the intense fluxes of energetic particles and photons emanating from the fusion core without overly poisoning the fusion plasma, (2) transferring the heat from the captured particle/photon flux via a coolant medium and heat exchanger toward useful applications (e.g., electricity generation or high-grade heat for industrial processes), and (3) providing a closed fuel cycle, which for deuterium–tritium fusion concepts means breeding, extracting, and separating tritium and re-injecting it back into the fusion core. The review will emphasize key opportunities in fusion materials research for enabling and accelerating the development and demonstration of commercial fusion energy, ranging from plasma-facing materials through the first wall and blanket structural and functional materials and plasma-heating systems to the high-field magnets.