L3 for the Burner: Direct Energy Conversion
The burner extracts electricity directly from its end-loss plasma; L3 governs the multi-modal DEC train and its coupling back to confinement.
Converting streaming energy directly
The tandem-mirror burner does not rely on a thermal cycle for its primary conversion: energy leaving the ends as streaming charged particles is captured directly by a multi-modal DEC train, traveling-wave direct conversion (TWDEC), ultra-high-field MHD conversion, and thermionics. Each modality suits a different part of the end-loss energy spectrum, and L3 coordinates them and their collector potentials.
The control coupling
DEC control is a two-sided problem. On the extraction side, collector potentials and power-electronics setpoints are tuned for conversion efficiency across the end-loss spectrum. On the confinement side, the end-collector potentials are the boundary condition on the ambipolar potential, so a change made to extract more power perturbs the confinement the plug-density controller manages. L3 solves the two with shared state so they cooperate rather than fight over the same actuators.
- TWDEC: decelerates and captures fast ion streams via traveling waves
- Ultra-high-field MHD conversion: extracts from the flowing conducting plasma
- Thermionics: captures the residual thermal fraction
- Coupling: end-collector potential = ambipolar boundary condition
Downstream of conversion, the Power Systems module handles grid synchronization: keeping the output phase- and frequency-locked to the interconnect and ramping within limits for a MetroVolt data-center load or an Aegis fixed installation. This is described purely as dispatch and timing, when and how much power is delivered, with no economic content, which has no place in the control stack.
DEC control operates inside a certified envelope (electrode, thermal, and interconnect limits) and above the hardware protection layer that guards against over-voltage and electrode faults. Pre-FOAK it is validated against DEC and end-loss models; the burner is a later program stage than the breeder, and no net electrical output is claimed before hardware.