Fusion energy is basically just smashing things together to make energy. Grossly oversimplified? Yes, but still accurate. First Light Fusion in the UK has a unique approach to fusion energy that takes that “smashing things together” to another level. I had a chance to see their facility first hand and talk to them about their current progress, as well as what’s to come at their new demonstrator plant. Are privately funded companies, like First Light Fusion, the path towards our fusion energy future?

This is the second video in my “UK nuclear tour.” In my first video, I visited the UK Atomic Energy Authority’s (UKAEA) Culham Science Center, which is the hub of the UK government’s fusion research. That’s where you find the JET and MAST-U tokamaks, but what’s interesting is that the UKAEA isn’t just about publicly funded research. They’re also working with private companies, like First Light Fusion, to offer support to accelerate all kinds of approaches towards fusion energy. First Light just recently announced that they’re building Machine 4 at the Culham Science Center, but I’ll get to more on that in a bit.1

What’s crazy to me is just how much private money is fueling the current growth we’re seeing in fusion research. According to the “The Global Fusion Industry in 2022” report from the Fusion Industry Association, there was a massive spike in funding between 2021 and 2022 — a whopping $2.8 billion dollars. $4.74 billion in private funding and $117 million in public funding make up the grand total for 2022’s fusion investment.2 That sounds like a lot, and it is, but it’s a drop in the bucket compared to the rest of the energy industry. According to a 2023 report from the International Renewable Energy Agency (IRENA),3 about $0.5 trillion was invested in renewable energy in 2022. So if you’re concerned that research and interest into fusion is going to slow down adoption of existing technologies, like solar and wind, don’t be.

What is First Light Fusion Doing?

But what exactly is First Light Fusion doing that sets them apart? First Light4 is harnessing a different weapon…literally. Their novel pulsed ignition is called projectile fusion, and it shoots off an old concept known as inertial confinement fusion (ICF).5 Put simply, after triggering a sort of railgun, a copper disk-shaped projectile will fly at about 7 km/s6 towards a target that’s encapsulating the fuel (ideally deuterium + tritium). It’s about 1-3 millimeters in size and is uniquely designed to amplify and direct the effects of the impact, which gives rise to a pressure wave that collapses the fuel. This then turns into plasma, sparking fusion. First Light Fusion successfully demonstrated fusion in November of 2021, so this is a proven concept. The crazy bit is where the inspiration for this idea comes from: a shrimp.

A pistol shrimp snaps its claw together so fast that it rips the water apart, creating a low pressure zone. Bubbles collect in this area and rapidly expand. The outside pressure of the surrounding water pushes back and collapses the bubbles.7 The vapor inside that low pressure zone is compressed to the point that plasma actually forms and reaches temperatures over 4,700 °C. That idea spurred First Light Fusion’s founder, Nick Hawker, to research and simulate the phenomena.

“We were trying to distill that into something you could study on the computer. I kind of describe it as the start of the inventive journey because what we’re doing now is nothing to do with the shrimp. It looks completely different. The great thing about simulations is if you have an idea, you can test it out so quickly, you know, so you can iterate really, really fast. And 10 years later we have a completely new way of doing inertial fusion that came from that sort of starting point.” -Nick Hawker

Nick took it a step further to help me wrap my head around the concept and described it like an internal combustion engine. The high velocity projectile is the spark plug, the target is the fuel, and the entire system will pulse at a certain cadence to produce the right amount of heat and power needed.

They’ve got several test machines that I got to see while I was there. The first is a giant rail gun where you shoot off a projectile using explosives and then amplify the speed of the projectile before it hits the target.

“At that end we put in three kilograms of gunpowder that launches the first projectile, which compresses hydrogen ahead of it. And the hydrogen gets compressed into this central piece here, where it then launches the second projectile, which gets a much higher velocity. So this, the first stage, gets to normal gun velocity of about one kilometer per second. The second stage gets up to seven kilometers per second. And what that does is it delivers a shock wave to our target and allows us to do the target physics testing that we need to do.” -Nick Hawker

While this is great for testing the physics of the projectile design and other effects, it’s not capable of achieving the speeds they need. They can get projectiles up to about 7 km/s, but need something around 50-60 km/s. Basically, this is a very cool piece of lab equipment they can use to test out ideas before scaling up.

So how are they going to get up to that 50-60 km/s speed? Instead of explosives, they’re going with an electromagnetic launch system, which brings us to Machine 2. It’s a pulse power machine that they use to test launching their projectiles with electromagnetic pulses. In fact, this machine is actually two pulse power machines because, much like the two-stage light-gas gun, it’s a piece of lab equipment where they need to measure the effectiveness of their designs.

“So this was a really important platform for us when we were first getting into electromagnetic launch. First understanding of how the process works and getting some experiments to check the predictions against. But we’re still using it. So what we’re actually seeing right now is there’s actually two pulse power machines here. There’s the machine, which is launching the projectile, which is behind. And then this in front is actually a second pulse power machine, which is an X-ray source. So we’re actually using this to make a really bright, really short, fast pulse of X-rays. And then we’re using that to X-ray the projectile in flight because we need to have a solid projectile so that it can fly the distance we need in the power plant. How are you gonna measure that? It’s solid. We hit it into a block of other stuff when it produces the shock wave, which is consistent with it being solid, but is that really measuring that it’s solid?” -Nick Hawker

And that brings us to their most current machine, Machine 3, which is a lot to take in when you first see it.

In the center of the machine is a giant vacuum chamber that houses the projectile and target. Surrounding that chamber are a total of 192 capacitors. The top layer is charged up to +100 kilovolts and the bottom layer is -100 kilovolts. The flow of energy is controlled by 96 switches.

“It’ll have a hundred kilovolts here and zero here. We’ve got a triggered cable through here. Pass the signal through here and it disrupts the electric fields and you get a cascade of different arcs through all the different balls. So it’s a really low inducting form of switch.” -Nick Hawker

But the part that I found kind of crazy was how they wire everything up. We’re talking about an incredible amount of energy flowing through all these capacitors into the vacuum chamber in order to fire off the electromagnetically propelled projectile. That current doesn’t flow through wires and cables, it flows through the structure itself. The walkways we stepped on to get to the top of the vacuum chamber are basically gigantic aluminum tabs.

“What we literally walked on is the wire, which connects the capacitors to the central machine. There’s so much current it can’t be a little wire, so the wire is actually plates of aluminum 10 millimeters thick. And that’s how we carry the current from the capacitors and into the vacuum chamber.” -Nick Hawker

“You said something about it moving?” -Matt Ferrell

“Yes. And so on top of the aluminum we have these big, huge steel plates, which the aluminum plates want to push apart because of the force involved. So we have to stamp that down.” -Nick Hawker

That power that gets funneled into the vacuum chamber is used to create about 500 Tesla of magnetic force to shoot the projectile forward.

“So this is what a projectile looks like, or rather, this is what we call the load. So this is where it connects into the machine, so it’s bolted into the machine of this, of this radius, right? And then the current flows in from all sides here, and it comes round to this, it’s what we call the pier.”

“So there’s a little sticky outfit, like a, you know, seaside pier jutting out. And the current comes in through there and then down, and then underneath. There’s a mirror image, another one of these below, right? So the current flow’s in, then down, and then back. And in that tiny, tiny gap, we get the incredible magnetic fields, which I talked about, right? 500 Tesla.”

“And the projectile is actually part of this whole piece. The little square at the bottom there … that becomes the projectile. The forces are so high it’s literally torn out from the assembly, and this little piece is launched upwards at incredible velocity. So that little postage stamp is the projectile.”

“I deliberately picked up this one because of the size, and shape, and thickness of this. This is the optimum design for machine three, which took us, you know, tens of thousands of simulations and hundreds of shots to find that this is the optimum design. The design for the gain demonstrator turns out the optimum design is nearly identical to this.”

“It’s within half a millimeter of the dimensions. It’s just that machine 3 launches this to 15 kilometers per second. Machine four will launch it to 60 kilometers per second. That’s what makes a difference. And then after the shot, this is what it looks like after it’s been cleaned up.”

“So you can kind of, can almost see where the currents flow in and then round. And that pier has disappeared basically. You get all this sort of interesting patterns happening.” – Nick Hawker

“That’s incredible.” -Matt Ferrell

Just let that sink in a bit. The two-stage light-gas gun shoots a projectile at about 7 km/s, but this machine, machine 3, shoots at about 15 km/s. And their demonstrator that they’re going to be building at the Culham Science Center will be shooting at about 60 km/s. So just how big is that machine going to be?

“This is absolutely massive. But you were also describing that machine four is how many capacitors?” -Matt Ferrell

“So this machine has 192 capacitors, but four will be more like 8,000 capacitors. This one is 12 meters in diameter. Four’s probably going to be something like 75 meters in diameter. So it’s an absolute monster. It’s huge. But it’s not very expensive. Cause again, it comes to that number of joules of energy delivered to the target. Machine 4 will be $2 per joule of energy, whereas the Nuclear Ignition Facility is $2,000 per joule of energy.” -Nick Hawker

And that brings me to some of the economics and supply chain issues with almost all fusion development into full fledged power plants. Tritium is exceedingly rare and expensive. There’s not enough tritium in the world today to run a single fusion power plant for days or weeks. This is a key issue that always comes up in every conversation I have with people who work in fusion research. As I mentioned in my last video, the UKAEA has just built out a tritium research facility. But at the same time most fusion startups and privately funded companies have this on their radar too. First Light Fusion is no different. In fact, they claim that their process will produce excess tritium, so they’ll be able to create their own supply.

“You have to go right into the nuclear physics of how you produce tritium to understand why it’s a big engineering challenge. And the answer that you get basically is that you use one tritium to produce one neutron in the fusion reaction. No matter what you do, you can’t get more than two tritium from that one neutron.”

“So if you think about the total amount of area you have around the vessel in the power plant…if more than 50% of that area is taken up with stuff that doesn’t produce tritium, like laser optics or magnets, then you can’t close your fuel cycle. Right? And this comes in as a design constraint. So meeting that design constraint means tokamaks have to be bigger, for example.”

“So it’s totally possible to make your own tritium and have self-sufficiency, but it’s a constraint, right? For us and with our approach we can use 99% of the solid angle for making tritium, so we can easily close the fuel cycle. And that means we can easily have a self-sufficient technology.”

“It also means in the early days for the pilot plant we can deliberately overproduce tritium, which then unlocks the scaling to the first kind of commercial fleet of power plants.” -Nick Hawker

It’s going to be really interesting to see the results of Machine 4, which is supposed to be in operation around 2027. But again, this all comes back to just smashing things together to make energy. In fact, one of my favorite moments from my visit at First Light Fusion was this…

“What I really love about the, kind of the, what I really love about our approach is the juxtaposition. Our approach relies on this incredibly intricate finesse design within the hub that focuses the shock waves just so … just the right way. And our targets are getting to the point of complexity where you can’t look at them as a human scientist and say, oh, A happens, then B, then C, then D. And that’s how it works. You just see the dynamics happening and it all works. You can’t isolate exactly what’s happening. Finesse in one part, but then ultimately we just smash it in the face with something massive. You know, so it’s really simple, stupid on the outside. But it’s really sophisticated on the inside.” -Nick Hawker

Fusion … smash it in the face with something massive. I love that. From my time at the UK Atomic Energy Authority and talking to the folks at First Light Fusion, it’s really clear to me that each company and group is racing to get to net positive energy generation first, but at the same time there’s a recognition and respect amongst everyone. I heard it again and again … that there isn’t going to be one winning form of fusion energy production, there’s going to be multiple solutions and companies that can all win. With First Light Fusion aiming for the end of this decade for their demonstrator, we’re looking at the 2030’s for an initial power plant.

But we don’t have to wait that long for other uses for fusion. In fact, stay tuned for the last video in my UK nuclear fusion tour series because it’s about a company doing something with fusion that isn’t about creating electricity … and it’s something that can impact our lives today. Be sure to subscribe and turn on notifications to not miss that one.

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