New materials for thermal neutron shields in fusion reactors

Aegis Fibretech has presented the results of proof-of-concept testing have shown that materials produced using the company’s innovative electrospinning method are capable of capturing and sequestering the nuclear fusion neutrons produced following thermalisation.

While fusion energy has yet to be produced commercially, it holds vast potential to produce clean energy in quantities that could solve the climate crisis. But a major challenge is to deal with the neutrons produced in the reactor, which are highly efficient at inducing radioactivity and damage in materials they encounter, and novel shielding materials will be a cornerstone for viable fusion energy power plants.

Aegis Fibretech, a spin-out from the University of Birmingham, produces ultra lightweight materials and has already shown that these deliver exceptional thermal insulation, providing an effective heat-shielding barrier for temperatures up to 1000^oC.

Latest updates unveiled at the Fusion Industry Shielding Showcase on 29 April demonstrated a chemically adapted form of these materials can moderate and capture fusion neutrons efficiently, leading to a proposed layered approach to shielding.

The novel neutron shielding materials were delivered through a project supported by the UK Atomic Energy Authority through the Fusion Industry Programme (FIP), which is stimulating the growth of the UK fusion ecosystem and preparing it for future global fusion powerplant market.

Aegis Fibretech was the only early-stage company to be awarded this supplier contract in the 2025 FIP to develop sustainable shielding solutions for fusion environments.

The funding allowed the company to scale from nanofibre structures to functional, cohesive panels called APEX (Advanced Panels for Extreme eXposure). These were tested at the Neutron Irradiation for Local Electronics (NILE) facility, a specialized testing station located on the world-leading Harwell Campus in Oxfordshire, UK.

Dr Gowsihan Poologasundarampillai, Reader in Biomaterials Science at Kings College London, co-founded Aegis Fibretech with Dr Sam Moxon while at the University of Birmingham. He led a consortium of researchers and consultants to rapidly deliver APEX.

He said: “Innovative materials science is critical to unlocking the safe and commercial future of fusion energy. We worked with an incredible team of physicists, material scientists and industry experts to develop a sustainable shielding solution.”

During the FIP, Aegis Fibretech received interest from a UK-based developer and manufacturer of fusion reactors a US based company specialising in radiation shielding for aerospace. The company is now looking for customers and industrial partners to scale and develop in other areas of neutron capture, particularly bioshield and hot cell handling, and explore thermal insulation in fusion.