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Direct Energy Conversion & Power Handling

The Dominant Loss: Synchrotron Radiation at Half the Fusion Power

The single largest energy loss in the burner is not the end leak — it is the light the electrons emit.

The burner's biggest loss channel is synchrotron radiation: at the reference point it carries 100 MW, 50.8% of the fusion power, as electrons spiraling in the strong field radiate. It is the loss that dominates the ledger and, therefore, the design's largest single uncertainty.

The science

Electrons at ~92 keV gyrating in a multi-tesla field emit synchrotron radiation strongly. At the reference point this is 100.1 MW — more than the directed end loss, more than bremsstrahlung, more than the neutron power combined. It is the term the engineering gain is most sensitive to, and it grows with electron temperature and field.

Why it matters

Because synchrotron dominates the loss ledger, the accuracy of the synchrotron model largely decides whether the design closes. That is why the burner brackets it across published treatments rather than trusting a single formula — the honesty is in the uncertainty band.

The numbers

Synchrotron loss100.1 MW (reference)
Share of fusion power50.8%
Larger thandirected loss, brems, neutrons
Grows withelectron temperature, field
Roledominant loss, largest uncertainty
Straight answersSynchrotron is the dominant loss and the decisive uncertainty; the burner's survival depends on reabsorption of that radiation, which is treated separately and flagged as the design's most consequential open question.
Kronos is the fusion company that shows its work. Every figure here traces to the openly deposited Kronos simulation programme and design-point records (CC BY 4.0). Read the series, run the code, check us. — All whitepapers
Conceptual design and simulation study; no machine has been built. Quantitative values are simulation-derived and carry the feasibility gates named in the text; superseded values are kept in the record with era labels. This document is informational and is not an offer of securities. © 2026 Kronos Fusion Energy, Inc. · Los Angeles, California.
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