Our Gain demonstrator

Machine 4 (M4) will be our ‘gain demonstrator’. The successor to Machine 3, M4 will be the world’s largest pulsed power driver at approximately 75 metres diameter – equivalent to the size of the Royal Albert Hall. We will use the machine to create ‘ignition’ – a critical step towards self-sustaining fusion energy – using our unique target technology and projectile approach.

With a storage capacity of around 100 mega joules of electrical energy, M4 will have the capability of launching projectiles at over 60 kilometres per second – three times faster than M3. Coupled with our proprietary amplifier and target technology, we will achieve ignition with M4.

Demonstrating ignition is a crucial milestone in the strategy to commercialising fusion energy. So far, inertial confinement fusion has achieved ignition and gain (more energy out than in) at the National Ignition Facility in 2021 and 2022 respectively. Ignition is the point at which the plasma created from a fusion reaction burns, creating a fusion reaction that becomes self-sustaining. This occurs when the heated plasma releases secondary alpha particles, which then means the energy from the reaction heats the fuel mass before the implosion cools.

Once developed, we are aiming for fuel gain of 100 or more on Machine 4, but with the core principle of de-risking the physics of self-heating. We are strategically focusing on the physics of the burning plasma, rather than the efficiency of the drivers or equipment.

In January 2023, First Light announced its plans to develop M4 at the UK Atomic Energy Authority’s Culham Campus in Oxfordshire. With construction anticipated to begin in 2024, operations will likely commence in 2027.

Dr Nick Hawker | First Light Fusion's Gain Demonstrator | Royal Society 2022

Next step to a First Light pilot plant

Demonstrating ignition is the fundamental milestone for developing a pilot power plant that is based on First Light’s unique target technology and corresponding projectile approach, significantly de-risking the physics of self-heating and further validating the design of its high-gain targets for commercial power production.

Machine 4 is the building block for a First Light pilot plant, allowing us to demonstrate ignition, while we continue to develop plans for a pilot commercial fusion power plant.

A world-class facility for High-Energy Density science

Once operational later this decade, M4 will become a world-class research platform not only for First Light’s projectile fusion programme, but provide a new capability in the UK for other High-Energy Density science applications, further benefiting the UK’s science and technology research needs.

This high-voltage, fast current rise time machine will access multi Gbar regimes on millimetre-spatial-scale lengths, where fundamental science questions on lab-astrophysics, planetary science, materials, radiation, and nuclear fusion can be explored.