Neutrons Enable Critical Technologies
Our compact fusion machine generates a steady stream of high-energy neutrons.
All Neutron ApplicationsFusion Neutrons Enable Critical Technologies
Neutron irradiation creates one of the most challenging environments for materials and electronics to survive. Materials that withstand neutron damage are essential for fusion energy, advanced fission reactors, and defense microelectronics. Fusion neutron sources can provide the controlled, high-energy neutron environments needed to develop and qualify these critical technologies.
A key metric of neutron damage is displacements per atom (DPA) or the average number of times each atom in a material is knocked from its lattice position during irradiation. For many nuclear applications the DPA a material experiences is greater than 1. When a high-energy neutron collides with an atom in a crystal lattice, it transfers enough energy to displace that atom from its site. This primary knock-on atom (PKA) then cascades through the lattice, displacing thousands more atoms in its path. These displacement cascades fundamentally alter material properties: strength increases while ductility drops, dimensions swell, and thermal conductivity degrades. Such changes can determine whether a reactor operates safely for decades or fails catastrophically.
Beyond displacement cascades, fusion neutrons transmute nuclei, producing helium and hydrogen inside materials through (n,α) and (n,p) reactions. These gases create additional damage mechanisms: helium migrates to grain boundaries where it forms bubbles that grow under stress, hydrogen embrittles materials, and both gases pin defects in place, preventing the self-healing that might otherwise restore material properties. At 14.1 MeV, fusion neutrons access transmutation cross-sections unavailable to fission neutrons, creating unique damage signatures that must be understood before fusion plants can achieve commercial operation. This makes high-energy fusion neutron sources essential for qualifying materials for fusion energy, extending next-generation fission systems to higher doses, and proving the nuclear survivability of defense microelectronics.
In microelectronics, even a single neutron can trigger catastrophic single-event effects (SEE). When a neutron strikes a silicon nucleus in a transistor, it generates a shower of charged particles that deposit energy along their tracks. This localized charge collection can flip memory bits, causing data corruption in everything from satellite navigation systems to flight computers. More critically, it can trigger latch-up conditions where parasitic thyristors form and create short circuits, potentially destroying the chip entirely. Military and space systems require extensive neutron testing across the entire energy spectrum to ensure survivability in these environments.
Critical Testing Requirements Across Technologies
Neutron damage testing addresses distinct challenges for a number of technologies. Below are some examples of how neutron damage testing fits into fusion, fission, and defense applications:
Application
Neutron Testing Requirements
Fusion: First-Wall & Structural Materials
(tungsten armor; CuCrZr or W-Cu heat sinks; RAFM steels)
Achieve target DPA with fusion-relevant spectra while tracking He/H production per DPA. Map dose-temperature effects, including hardening, Ductile-to-Brittle Transition Temperature (DBTT) shift, swelling, and thermal conductivity degradation.
Fusion: Superconducting Magnets
(REBCO tapes, Nb₃Sn; organic insulators)
Perform cryogenic irradiation to measure critical current (Ic/Jc) degradation vs. neutron fluence, magnetic field, temperature, and strain. 14 MeV neutrons can provide the most prototypic damage. Track radiation-induced conductivity and dielectric breakdown in insulators.
Fusion: Tritium Breeding Systems
(Li₂TiO₃/Li₄SiO₄ ceramics; Be multipliers)
Test coupled DPA and transmutation effects. Directly measure tritium production and release kinetics. Quantify helium bubble formation and swelling. Operate at service temperatures (300-700°C) with multi-DPA/year exposure rates.
Fission: Advanced Reactor Materials
(HT9/T91/Grade 92; ODS steels)
Execute high-dose campaigns to map void swelling and irradiation creep. Measure mechanical property evolution and dimensional stability. Compare spectra to isolate pure displacement from gas-driven effects.
Defense: Radiation-Hardened Electronics
(ICs, FPGAs, memories, flight computers)
Quantify displacement damage using 1 MeV-equivalent fluence (NIEL scaling). Characterize Single Event Effect (SEE) rates across neutron energies. Conduct mixed neutron/gamma testing. Perform radiation lot acceptance testing (RLAT) for production qualification.
The Fusion Neutron Advantage
Multiple neutron sources exist for damage experiments, each with distinct capabilities and limitations. Fusion neutron sources offer unique advantages for materials qualification:
Prototypic 14.1 MeV Spectrum: Only D-T fusion reactions produce the narrow peak 14.1 MeV spectrum neutrons that accurately represent fusion energy spectra. These neutrons can be moderated for applications requiring lower energies.
Scalable Neutron Intensity: As fusion devices advance toward energy production, they will generate the intense neutron fluxes needed for accelerated testing. Future high-gain fusion machines will be able to produce these fluxes more cost-effectively than alternative neutron technologies, enabling practical multi-DPA irradiation campaigns.
Operational Flexibility: Fusion neutron sources avoid the regulatory complexity of fission-based facilities. They can be cycled on demand, located at user facilities, and operated without fuel management constraints. This flexibility enables rapid iteration of test conditions and materials.
Make Neutron Testing More Available: The world faces a critical neutron shortage with limited reactor availability. No fast-spectrum irradiation reactors currently operate in Western-aligned nations, creating a strategic vulnerability. Companies like Radiation Test Solutions and Fifth Gait Technologies already employ compact D-T fusion sources for microelectronics qualification, demonstrating the near-term value of fusion neutrons.
As fusion devices advance toward energy production, their neutron capabilities become increasingly valuable for materials testing. Higher plasma temperatures yield greater neutron production. Improved confinement enables extended irradiation campaigns. Manufacturing scale reduces per-neutron costs. This symbiotic relationship accelerates both fusion energy deployment and the technologies that depend on neutron validation.
Fusion neutron sources can help to eliminate the testing bottlenecks that have constrained progress for decades. They can enable parallel development paths that could deliver transformative technologies years ahead of traditional schedules. The materials that will power fusion reactors, enable advanced fission systems, and protect critical defense infrastructure all require comprehensive neutron validation. With fusion neutron sources, that validation becomes faster, more affordable, and more accessible than ever before unlocking the materials solutions needed for tomorrow's energy and security challenges.
