Plasma-Facing Component Design
First wall, divertor, and their attachments form one system that must join a refractory surface to a cooled, replaceable structure.
Surface plus structure
A plasma-facing component is more than its surface material. It is a refractory armor bonded or attached to a cooled heat sink, mounted so it can be removed and replaced remotely. The hard problem is the join: connecting a brittle, high-temperature carbide to a cooled metallic structure that expands differently when heated.
The bond is the risk
Differential thermal expansion between a carbide armor and a metal heat sink concentrates stress at the interface. Under cycling this is a fatigue-and-delamination risk. Interlayers, graded joints, and mechanical attachment are all studied to manage it. A component that survives steady state can still fail at the bond under thermal cycling.
- Armor: hafnium-carbide-class refractory facing the plasma.
- Heat sink: actively cooled to carry away steady flux.
- Interface: the fatigue-critical join between the two.
- Mount: designed for remote removal and replacement.
Designed to be replaced
Because armor erodes and neutron damage accumulates, plasma-facing components are consumables on a maintenance schedule. Their design is inseparable from the remote-handling system that will replace them, which is why component design and maintenance are treated as one program.
Standardized interfaces
So they can be replaced remotely, plasma-facing components share standardized mechanical, coolant, and mounting interfaces that a manipulator can disconnect and remake. Standardization trades some per-component optimization for maintainability, and it is decided early because a bespoke component that cannot be handled remotely is unserviceable once the machine is activated.
This page documents a design and simulation study, not a built machine. Construction begins Q2 2027; first-of-a-kind first tritium is targeted near 2030. Figures are computed, reproducible targets, not measurements.