What “Design Stage” Means
Design stage means the machine is fully specified in physics and engineering models and reproduced in simulation, but not yet fabricated or operated.
From equations to a machine
A fusion generator passes through distinct maturity phases: concept, design, integrated test, and commercial build. MetroVolt is in the design phase. The plasma physics, magnet requirements, and direct-energy-conversion chain are specified as a self-consistent design point, checked in code, and documented so others can reproduce the numbers.
Design stage is not a sketch. It means a chosen operating point — 26.49 T plug field, 17 T throat, D-³He fuel, a neutron fraction near 5.44% — with each figure traced to a model. What it is not is a built machine: no MetroVolt plasma has been struck, and no direct-conversion module has produced grid power.
Why the distinction matters
Calling a design a demonstration is how fusion loses trust. MetroVolt figures are design and simulation values. The test unit near 2032 is where those values first meet hardware, and where the design either holds or is revised.
- Specified: operating point, magnets, fuel cycle, DEC chain.
- Simulated: plasma, power balance, thermal and neutron loads.
- Not yet done: fabrication, integrated operation, net-power demonstration.
The rest of this section walks the path from this design stage to a commercial fleet, and names the gates that must be cleared along the way.