Burner DEC Collector Interface

Direct energy conversion decelerates escaping ions against biased collector grids; the interface reads per-grid currents and sets grid potentials.

How the burner extracts power

The burner (Aegis / MetroVolt) converts the kinetic energy of ions escaping the mirror directly into electricity rather than through a thermal cycle. Ions stream out the expander, sort by energy, and are decelerated against a stack of biased collector grids — each grid tuned to a slice of the ion energy spectrum. The interface reads per-grid current and sets each grid's potential.

Signal set

# per-grid collection (DEC train)
for g in grids:
    I_g = measure_collector_current(g)
    P_g = I_g * V_grid[g]                # power on grid g
# tune grid potentials to the arriving spectrum
V_grid = dec_controller(spectrum_est, I_grid, V_grid)
P_dec = sum(P_g)

Efficiency depends on matching each grid potential to the arriving ion energy: a mismatch either fails to decelerate the ion (energy lost as heat) or over-decelerates and reflects it. The interface therefore couples tightly to the expander, which sets the spectrum, and to grid modulation, which follows load.

Neutron fraction context

D–³He is chosen partly because only 5.44% of its energy appears as neutrons; the rest is charged-particle energy that direct conversion can collect. This is a design-and-simulation property of the fuel, not a delivered performance number — the machine is not built.

• Owner: L1 for grid-bias regulation and fault ride-through; L3 for spectrum-matched setpoints.
• Sense: per-grid current and voltage, grid temperature, collector vacuum.
• Protection: grid overcurrent and arc detection with fast bias shed.

Calibration ties measured grid current to collected power at known bias. Design-and-simulation specification.