DEC Collector-Grid Voltage Modulation
Direct energy conversion recovers charged-particle energy on biased collector grids; L1 modulates grid voltages to match the escaping-ion spectrum.
Converting particle energy directly
The burner recovers energy not only as heat but directly: charged fusion products and escaping ions are decelerated against biased collector grids, depositing their kinetic energy as they climb the potential, so their energy is captured electrically. The collector-grid voltages are the actuator — setting them to match the particle energy spectrum maximizes recovery. L1 modulates them in real time.
Spectrum matching
Escaping ions arrive with a distribution of energies. A grid biased to a voltage V recovers particles whose energy exceeds eV as they are decelerated; multiple grid stages at graded voltages capture successive energy bands. L1 sets the stage voltages to track the instantaneous spectrum, which shifts with plasma conditions, so the collector array stays matched as operation varies.
The modulation loop
- Estimate the escaping-ion energy spectrum from fast-ion and current diagnostics.
- Compute per-stage grid voltage setpoints to match the bands.
- Drive the grid supplies via deterministic drivers, staged and gated.
- Protect against grid faults with fast ride-through.
This is the burner's analogue of the breeder's shaping loop: a coordinated, multi-element voltage set that must move together, released on synchronized gates so the graded collector operates coherently. Mis-timed stages would distort the effective collector characteristic and lose recovery.
Part of the multi-modal DEC train
Grid modulation is one mode of Kronos's multi-modal DEC train, which also includes traveling-wave direct energy conversion (TWDEC), ultra-high-field MHD conversion, and thermionics for the neutron-carried and thermalized fraction. L1 coordinates the modes; the grid modulation loop and fault ride-through pages detail the electrostatic mode.