Plug-Density Fueling Interface

Sustaining the end-plug density and confining potential drives an operating regime 166-830x beyond any device, on a helium-3 supply 400x short.

What the interface controls

The tandem mirror confines the central cell by maintaining a high-density, high-potential plug at each end. This interface fuels and heats the plug to hold the target density and the ambipolar confining potential. It commands plug fueling (deuterium and helium-3), plug heating, and reads plug density and potential.

Two gates on one interface

This is the interface where two of the four burner gates concentrate. The plug operating regime sits 166–830× beyond any device ever operated, so its behavior is not post-dictable from existing data today. And the helium-3 feed demands ~400× the domestic terrestrial supply per commercial unit — the fuel does not exist at terrestrial scale, which is why breeder-bred and lunar helium-3 matter. Both are physics-and-supply facts, stated without softening.

# plug density/potential control (L3), with honest flags
u = plug_mpc(n_plug, phi_conf, refs, twin)
flag('plug_regime', regime_factor)     # 166-830x beyond any device
flag('he3_supply', he3_cover)          # ~400x short today
plug_fuel(u.d, u.he3); plug_heat(u.P)  # L1 actuation

Signal set and owner

• Sense: plug interferometry/microwave density, emissive-probe potential, heating power.
• Actuate: plug fueling valves, plug heating, coupled to potential electrodes.
• Fuel link: metered helium-3 from the helium-3 handling interface.

Owner: L3 for the plug setpoint on the predictive shadow, L1 for the fueling/heating actuation. Because the regime is un-post-dictable, twin predictions here carry wide uncertainty by construction. Design-and-simulation specification; the burner is not built.