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Comparison
Fusion Generations: D–T, D–³He, p–¹¹B
Fusion fuels form a progression from easy-but-neutron-heavy D–T, through low-neutron D–³He, to aneutronic p–¹¹B. Kronos stages up this ladder toward ever-cleaner reactions.
- Gen 1 — D–T
- Easiest; ~80% neutrons
- Gen 2 — D–³He
- Low-neutron (Kronos baseline)
- Gen 3 — p–¹¹B
- Aneutronic; hardest (endpoint)
- Kronos
- Stages up the ladder
It's useful to think of fusion fuels as generations, trading ease of ignition for cleanliness:
| Generation | Fuel / character |
|---|---|
| First | D–T — easiest to ignite, but ~80% neutrons |
| Second | D–³He — low-neutron, directly convertible (Kronos baseline) |
| Third | p–¹¹B — truly aneutronic, hardest |
Most of the field is working on the first generation. Kronos commits to the second from the start and stages toward the third — using D–T only for commissioning, running D–³He commercially, and holding p–¹¹B as a gated endpoint. Each step up the ladder trades more physics difficulty for fewer neutrons. See why Kronos skips D–T-first.