Materials and Components — Open Questions
An honest register of the breeder's unresolved materials issues: magnet stress at full field, net tritium breeding, 14 MeV qualification, and center-post life.
What is not yet proven
The breeder is a design and simulation study. Several materials-and-components questions are genuinely open, and this page collects them in one place rather than scattering them. Publishing the open list is deliberate: it is how an on-the-record machine states its status honestly.
The register
- Magnet stress at 16.84 T: demonstrating the coil structure holds REBCO within strain at full field is a named FOAK gate.
- Net tritium breeding: the gap between a local TBR target of 1.8 and realistic net breeding after coverage gaps and losses is unresolved; self-sufficiency is not yet proven.
- 14 MeV qualification: no facility reproduces the full fusion neutron spectrum at fluence, so material lifetimes are extrapolated.
- Center-post life: the ~0.01 fpy working figure must be confirmed against real high-dpa damage data.
How they are handled
Each open question has an engineered response: the magnet gate paces the FOAK build, blanket coverage and extraction target the breeding gap, the qualification program addresses the 14 MeV spectrum, and remote replacement manages the short center-post life. Stating the questions and the responses together is the point.
Why publishing the list matters
Keeping the open-question register public and current is part of the breeder's method: it invites external scrutiny of the design at its weakest points and prevents quiet overclaiming. As data arrive from the FOAK build and the qualification program, entries are expected to tighten or close, and the register is updated to reflect the real state.
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.