Center-Stack Integration
TF inboard leg, shielding, center-post, and cooling all fight for the same narrow radius — the center stack is where the breeder's hardest trades collide.
One volume, four demands
The center stack of a compact spherical tokamak is the single most contested volume in the machine. Into a narrow inboard radius the design must fit the toroidal-field inboard conductor at 16.84 T, the center-post carrying that current, shielding to protect the magnet, and cooling to remove the heat. None of these can be sacrificed, and there is not enough room for all of them at full comfort.
How the trades collide
More shielding protects the magnet but leaves less room for conductor or coolant. More conductor carries more field but leaves less room for shield, raising magnet dose. More cooling keeps the center-post alive but crowds both. The design resolves this not by winning every trade but by accepting a short, replaceable center-post as the release valve for the whole squeeze.
- TF inboard leg: needs conductor cross-section for 16.84 T.
- Shield: needs thickness to protect magnet dose and heating.
- Center-post: needs conductor and cooling in the same space.
- Resolution: a replaceable, short-life center-post.
Why it defines the breeder
The center-stack squeeze is the engineering signature of a compact high-field breeder. It explains the ~0.01 fpy center-post life, the emphasis on remote replacement, and the coupling between magnet, shield, and cryogenics. Understanding the center stack is understanding why the breeder is designed the way it is.
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.