The Neutron-Yield Benchmark

The 14 MeV neutron source rate implied by 85.0 MW of D-T fusion power is cross-checked against first-principles reaction kinematics before any breeding or activation is computed.

From fusion power to neutron rate

The breeder's products — tritium, helium-3, and materials irradiation — all flow from one quantity: the rate of 14.1 MeV neutrons the plasma emits. That rate is fixed by the fusion power once the reaction is specified, so it is the first thing to benchmark. Each D-T reaction releases 17.6 MeV, of which 14.1 MeV is carried by the neutron.

# Neutron source rate from D-T fusion power
E_dt_MeV = 17.6          # energy per D-T reaction
E_n_MeV  = 14.1          # carried by the neutron
P_fus_MW = 85.0          # frozen design fusion power
MeV_to_J = 1.602e-13
reactions_per_s = (P_fus_MW*1e6) / (E_dt_MeV*MeV_to_J)
neutrons_per_s  = reactions_per_s   # one 14.1 MeV n per reaction
# ~3.1e19 neutrons/s -> feeds the breeding and activation analyses

Why benchmark the obvious

The neutron rate looks like a trivial division, and that is exactly why it is worth pinning: every downstream product number multiplies it, so an error here would propagate everywhere. Benchmarking the source rate against reaction kinematics isolates a single, checkable step from the more model-dependent breeding and activation estimates that follow.

What it does not yet include

The source rate is the ceiling, not the yield. How many of those neutrons breed tritium depends on blanket coverage and the tritium breeding ratio, which is where the local-vs-net reconciliation enters. The neutron-yield benchmark deliberately stops at the source term.

This page describes a design-and-simulation study, not a built machine. Construction of the breeder (Hyperion) begins Q2 2027; first-of-a-kind first tritium is targeted near 2030. No hardware net-gain claim is made before FOAK.