The component surrounding a fusion plasma that captures neutron energy as heat, breeds tritium fuel from lithium, and shields the superconducting magnets — one of the most challenging engineering systems in a fusion power plant.
In a D–T fusion reactor, the blanket serves three critical functions: (1) converting the kinetic energy of 14.1 MeV neutrons into heat for electricity generation; (2) breeding tritium by capturing neutrons in lithium-containing materials; and (3) shielding the superconducting magnets and other components from neutron damage.[1]
Major blanket concepts include: solid breeder blankets using lithium ceramics (Li4SiO4 or Li2TiO3) with helium coolant; liquid metal blankets using lithium or lead-lithium (PbLi) eutectic; and dual-coolant designs combining helium and PbLi. ITER will test six different test blanket modules (TBMs) from its member parties.[2]
The blanket must withstand extreme neutron fluence (~10 MW/m² wall loading), temperatures up to 500–1100°C, and cumulative radiation damage of 50–150 displacements per atom (dpa) over its lifetime. No existing material has been tested under prototypic fusion neutron conditions. A dedicated fusion neutron source (such as IFMIF-DONES) is needed to qualify blanket materials.[3]