Instrumentation and Diagnostics
The first-of-a-kind unit is heavily instrumented so that every gate is measured against prediction and every anomaly is understood.
Measuring the machine
A first-of-a-kind machine exists to be measured. Instrumentation and diagnostics let the program observe plasma behavior, magnet performance, neutron production, and tritium inventory in enough detail to compare hardware to prediction and to diagnose whatever the machine does that the design did not expect.
What is measured
- Plasma: current, density, temperature, confinement, and stability
- Magnets: field, temperature margin, strain, and quench signals
- Neutrons: yield and spectrum, tied to fusion power and breeding
- Tritium: inventory and flows through the fuel loop
Diagnostics and the gates
Each physics gate depends on diagnostics: G1 on confinement measurement, G2 on field and margin measurement, G3 on neutron and tritium measurement. Without adequate diagnostics a gate cannot be judged, so diagnostic coverage is part of the gate design, not an afterthought.
Why FOAK is over-instrumented
FOAK carries more instrumentation than a production foundry unit would need, because its job is to learn. Some diagnostics will prove essential and carry forward to NOAK; others will prove unnecessary and be removed. Deciding which is one of FOAK's outputs to the manufacturing plan.
The diagnostic suite is a design for a machine not yet built. It is what turns the first build from a demonstration into a measured, reportable body of evidence against pre-registered predictions.