First Light Fusion Makes Progress Towards an Economical Working Fusion Reactor

First Light Fusion is developing an inertial fusion with a pulsed process. They fire physical projectiles at high speeds like 40 kilometers per second to generate fusion OR they may use high-power lasers to generate the fusion. They are working on methods with the targets and other systems to amplify the pressures generated and increase the power produced.

They have managed to increase the distance the reaction-starting projectile travels by a factor of 10. The projectile can travel at least 10 centimeters without vaporizing. They do not want the physical project to get vaporized when they accelerate it. They want it to stay as a physical object so that it can hit the target from about 3 meters away. This lets them protect key expensive parts of a working reactor. IF the parts were too close to the actual fusion reaction then it would become too expensive to replace parts. The object travelled 10 centimeters instead of less than 1 centimeter. It is likely out of the danger zone and it should be able to travel a few meters. Further tests will confirm if that is the case.

Each target releases a large amount of energy. The power output is the energy per shot multiplied by the frequency. A pulsed approach gives great design flexibility, trading off energy per shot and frequency. Their aim is the lowest risk plant design possible. High energy per shot reduces physics risk, and slower frequency and small overall plant size reduce the engineering risk.

The targets are a key technology in First Light’s approach to fusion and they are nearly all trade secrets. One example uses three cavities, two big and one small. The collapse of the two bigger cavities focuses the pressure onto the small one in between, which is collapsed with a higher pressure and from two sides rather than one. The carefully shaped targets can amplify the impact power. They will model and control the waves of forces so that effects and pressures are amplified.

They will need to work on the drivers to increase the power.

First light Fusion is using gas guns and other systems working to get to the power levels and speeds needed to generate fusion.

In 2023, the UK Atomic Energy Authority (UKAEA) and First Light Fusion (First Light) signed an agreement for the design and construction of a new purpose-built facility to house First Light’s Machine 4 at UKAEA’s Culham Campus in Oxfordshire. First Light’s method leverages the same physics proven by NIF. First Light will fire a projectile at a fuel pellet to force it to fuse and produce energy instead of using powerful lasers. This approach has been validated by UKAEA.

Although the machine itself will not generate power, it will be used to develop the technology needed for future inertial confinement fusion energy powerplants.

Construction should start in 2024 and will begin operating in 2027. The 10,500-square-metre building will house the fusion machine which is expected to be commissioned in 2026. First Light Fusion has raised over $105 million.

There is a large amount of existing engineering that can be reused to make First Light Fusion plant. Fast breeder reactors, a type of nuclear plant, use liquid metal as the coolant, typically sodium or sodium-potassium mixture. The engineering from these plants can be ported over to lithium. After the lithium heat exchanger, the plant is identical to many other already working facilities. Most of the cost is low-risk engineering.

They are aiming for a power plant producing ~150 MW of electricity, firing once every 30 seconds, and costing less than $1 billion.

First Light Machine 4

First Light’s unique “inertial confinement” approach to achieving fusion involves compressing a target containing fusion fuel using a projectile travelling at a tremendous speed.

The Z-machine at Sandia National Labs (https://www.sandia.gov/z-machine/) is currently the largest ‘pulsed power’ machine in the world. It uses high magnetic fields associated with fast, intense electrical currents to produce high temperatures, high pressures, and powerful X-rays for research in high energy density physics.

Machine 4 will have a stored electrical energy of about 100 megajoules with the capability of launching projectiles at 60 kms per second. This speed on impact inside the target will accelerate to about 200kms per second as a result of First Light’s exclusive amplifier technology. The amplifier focuses the energy of the projectile into the fusion fuel, both boosting the pressure from impact to deliver to the fuel and shaping the waves to produce spherical implosions. The National Ignition Facility has given proof of viability for pulsed power to create a brief fusion ignition event. First Light’s current ‘pulsed power’ machine, Machine 3, launches a projectile at about 20kms per second.

First Light is aiming for net energy gain with Machine 4 with fuel gain of 100 or more. This machine is the building block for the pilot power plant, validating First Light’s simulation codes, while de-risking the design of high-gain targets for power production.