The Gate Program
Three physics gates, confinement, magnet, and fuel loop, structure how the breeder retires its largest risks before claiming its design point.
Why gates
The breeder program organizes risk retirement into discrete gates. Each gate is a defined demonstration with a pre-registered prediction and a pass criterion. A gate is passed when measured hardware performance meets the prediction, not when a model says it should. This keeps claims tied to evidence.
The three physics gates
- G1 Confinement: the plasma holds energy long enough to reach the design gain point
- G2 Magnet: the high-field magnet system reaches and holds 16.84 T peak field under load
- G3 Fuel loop: neutrons breed tritium and the fuel cycle recovers and accounts for it
How gates relate to the schedule
The gates are sequenced with commissioning. Magnet energization (toward G2) precedes plasma; confinement (G1) is demonstrated once plasma operation begins; the fuel loop (G3) is proven at first tritium. Passing all three is what turns the first-of-a-kind unit from an assembled machine into a demonstrated foundry.
Pre-registration
Each gate has predictions registered before the test, covering the quantities the gate is meant to prove: energy confinement time, achieved field, neutron yield, and breeding ratio. Reporting measured against predicted, rather than reporting the measurement alone, is how the program distinguishes a genuine demonstration from a retrofit explanation.
The gates apply to a machine that is not yet built. They are the acceptance structure for the first build, and every design-point number cited elsewhere on this site remains a simulation value until the relevant gate is passed.