Lithium-6 Enrichment

Natural lithium is only about 7.5% lithium-6; enriching it raises tritium breeding but adds a materials-supply requirement.

Why enrichment matters

The reaction that dominates tritium production captures neutrons in lithium-6, but natural lithium is only about 7.5% lithium-6 and about 92.5% lithium-7. Enriching the lithium-6 fraction raises the tritium breeding ratio for a given blanket, or lets a thinner blanket hit the same target — valuable in a compact machine short on radial space.

The trade

Higher enrichment improves breeding and saves space, but enriched lithium-6 is a specialized material with its own supply constraints. The breeder treats enrichment as one of the levers that, together with multiplier and coverage, moves the tritium breeding ratio between 1.1, 1.5, and 1.8. It is a materials-supply commitment, not a free parameter.

• Li-6 capture dominates tritium production.
• Natural abundance of Li-6 is only ~7.5%.
• Enrichment raises TBR or shrinks blanket thickness.
• Enriched Li-6 supply is a materials-program requirement.

Honest coupling

Enrichment interacts with the open TBR reconciliation: reaching a local TBR of 1.8 leans on high enrichment and near-complete coverage, both of which are harder in a compact machine with many penetrations. The breeder states the target and the gap between target and realistic net breeding openly.

Depletion over life

As lithium-6 is consumed producing tritium, the blanket's local lithium-6 fraction depletes, gradually lowering breeding unless the inventory is managed or replaced. Enrichment therefore sets not only the starting breeding ratio but how it evolves over a blanket's life, adding a time dimension to the enrichment decision that the design accounts for.

This page documents a design and simulation study, not a built machine. Construction begins Q2 2027; first-of-a-kind first tritium is targeted near 2030. Figures are computed, reproducible targets, not measurements.