Big Ideas Lab - Fusion Ignition

Episode Date: October 15, 2024

Step inside LLNL’s National Ignition Facility, home to the world’s largest and most powerful laser. It’s a building as vast as three football fields, with beams amplified a million times in strength, all focused on a tiny target no bigger than a centimeter. The scale is immense, but the goal is even bigger: to create the most extreme conditions in the universe and unlock a revolutionary energy source.But what does it really take to reach fusion ignition?Join us as we explore the science, the stakes, and the people behind this incredible pursuit. Tune in to discover how a fleeting moment of triumph could change the future of energy forever.--- Big Ideas Lab is a Mission.org original series. Executive Produced and Written by Lacey Peace. Sound Design, Music Edit and Mix by Daniel Brunelle. Story Editing by Daniel Brunelle. Audio Engineering and Editing by Matthew Powell. Narrated by Matthew Powell. Video Production by Levi Hanusch. Guests featured in this episode (in order of appearance): Kim Budil, Director of LLNLJean-Michel Di Nicola, Program Co-Director for Laser Science and System Engineering at LLNLMichael Stadermann, Program Manager for Target Fabrication at LLNL Richard Town, Associate Program Director for Inertial Confinement Fusion Science at LLNLBrought to you in partnership with Lawrence Livermore National Laboratory. 

It was a moment six decades in the making. On December 5th, 2022, scientists at Lawrence Livermore National Laboratory initiated their most successful experiment yet, using the most energetic laser ever created. It is enormous in scale. The laser facility is 10 stories tall. It's the size of three football fields. Inside it, you have also structures in concrete, steel, and glass. The stage was set, and the destiny of a scientific quest spanning generations was waiting to be realized. Each beam is about a foot by a foot in size. We concentrate all the energy into a little tiny target that's about a centimeter in diameter

and create the most extreme conditions in the universe. In less than a blink of an eye, billionths of a second, the experiment unfolded. In that brief moment, the fate of a decades-long scientific pursuit hung in the balance. Would the impossible finally happen? The teams could only speculate as the raw data began rolling in. But one thing was clear. They stood at the precipice of a potentially historic achievement. Success or failure, the attempt itself marked a milestone in the long scientific trek toward fusion ignition. But the days ahead would determine if this moment would be one for the history books, or fade with the whisper like so many attempts before it. Certainly the story of ignition is a long story of both the thrill of victory and the agony of defeat.

Welcome to the Big Ideas Lab, your weekly exploration inside Lawrence Livermore National Laboratory. Hear untold stories, meet boundary-pushing pioneers, and get unparalleled access inside the gates. From national security challenges to computing revolutions, discover the innovations that are shaping tomorrow, today. Since its inception in 1952, Lawrence Livermore National Laboratory's defining responsibility has been national security. Work in the early days of Lawrence Livermore National Laboratory was centered around splitting the atom, a process known as fission, as well as merging the atom, known as fusion. The science was the backbone of powerful weapons like the atomic and hydrogen bombs. But as scientific understanding of these reactions evolved, so too did the lab's vision for the future.

What if, instead of exploring the process of fusion in detonating weapons, you could create it in the laboratory using lasers. This new direction is all about fusion ignition. It's a mix of hardcore science and a dream of a cleaner future. Ignition refers to the moment when the energy from a controlled fusion reaction produces more energy out than in. It provides unprecedented capabilities to support the U.S. stockpile stewardship program, which keeps our nuclear deterrent safe, secure, and effective in the absence of testing.

It's also a crucial first step in a fusion energy future. Fusion is the process by which two hydrogen atoms fuse together. They create a helium atom and release a neutron, which carries energy. So you get more energy out than you put in if you can create a self-sustaining fusion reaction. So the other nuclear process that creates energy is fission, and nucleus splits apart. And again, you get two fission fragments and you get a neutron, which carries energy away from the reaction. If you can make fusion reactions net energy positive, so more energy out than it took to create the fusion conditions in the target that you're working with, you can create clean

energy. So energy at the scale that a fission power plant could produce, for example, but without many of the long-term radioactive waste challenges that fission has. That's Kim Budell, director of Lawrence Livermore National Laboratory. She'd be the first to tell you that ignition was long considered by many to be unachievable. The original idea that you could create fusion ignition in the laboratory using lasers was made 60 years ago. And that was shortly after the laser had been invented. So it was really quite an amazing leap of imagination to say, hey, here's this new tool. We don't really know much about it or what it can do, but we think, you know, if it was energetic

enough, it could be used to create x-rays, which could be used to compress this capsule. Turns out it was a little harder than anticipated and required an immense revolution in technology. And so over those 60 years, we've been learning a lot about what it takes to compress a little sphere very uniformly, how precisely it has to be manufactured so that the little imperfections in the capsule don't grow and send cold material into that hot fusion fuel. We've learned a lot about how to make these big lasers that deliver the amount of energy that's required to push hard enough and sustain that push for long enough to get to these conditions. Fundamentally, fusion can generate potentially limitless power because the fuel sources, including something as common as seawater, are available in abundant

quantities on Earth. So as we try to think about a clean energy future, most of the sources we have of producing power at scale that is not variable have significant challenges. Either they use fossil fuels and produce a lot of greenhouse gases, or it's nuclear power, fission power, which is very efficient and generates a lot of power but has long-term nuclear waste challenges associated with it, and safety concerns from the public. Solar and wind are great, but they're intermittent. And in order for them to provide energy at scale consistently, you need long-term storage. So when the sun is shining and you're producing solar power, how do you store enough of it to power the grid when it's dark? Fusion could fill that gap. It generates power like fission. It doesn't have the same kind of safety or long-term waste considerations that fission has.

And it doesn't produce greenhouse gases. So it could be a way to have a very clean, stable, reliable energy system at the kind of scale you would need. And it would work anywhere in the country. Even with decades of research behind us, it could still be decades more before fusion energy is fueling the power grid. Thankfully, fusion ignition has more immediate benefits and applications as well. Most notably, the Stockpile Stewardship Program, which was initiated in the 1990s following the end of the Cold War. Physical testing of nuclear weapons ceased in 1992.

In order to ensure the reliability of the nation's nuclear weapons stockpile, the lab had to get creative with how to learn more about these weapons. One way to understand what happens inside a nuclear reaction is, you guessed it, to achieve fusion ignition. Ever since the 90s, we have a moratorium on nuclear underground testing. And that means if you want to understand how and if a nuclear weapon will work, you have to get to other ways to doing the certification. Michael Staderman is the program manager for target fabrication at the lab.

He's been at the lab. He's been at the lab for 20 years and worked alongside the team studying both fusion ignition and stockpile stewardship. And so we have models that predict how a material will behave and how it will react. But without a way of testing those, those models don't take us very far. And ignition is a nice milestone to reach in this endeavor, but it's not the end point. Richard Town is the lab's associate program director for inertial confinement fusion science, or ICF. Fusion, working backwards, is basically combining light ions together, fusing them, pushing them together to form a new element. So typically, if we use deuterium and tritium, we bang them together to produce helium. That helium is actually lighter than constituent parts, and that releases a bunch of energy. So through me, that's Einstein's famous E equals mc squared.

Let's pause there. For those of us who aren't physicists, here's what Richard means. Imagine you have two gallons of paint, one gallon of blue paint, and one gallon of yellow paint. If you pour both gallons in the same bucket, the two paints mix or fuse to create a new color and you get green paint. In the case of fusion, your blue and yellow cans of paint are deuterium and tritium. When fused together they form helium, your green paint. Simple enough, right? But here's the special thing about fusion. Imagine that in the process of combining the two gallons of blue and yellow paint,

the resulting green paint actually weighed less after mixing than its two original parts. How is that possible? Where did that extra mass go? Here's where, as Richard mentioned, E equals mc squared comes in. In this famous formula, E stands for energy, m stands for mass, and c stands for the speed of light. So, E equals mc squared is saying energy equals mass times the speed of light squared. What does that mean in our story? It means that the little bit of lost mass didn't just vanish. times the speed of light squared. What does that mean in our story?

It means that the little bit of lost mass didn't just vanish. It had to go somewhere. It was converted into energy and released. At this point, you may be wondering, if it's as simple as mixing two gallons of paint, then what's all the fuss about? What makes achieving fusion power and fusion ignition so challenging? Why have researchers spent 60 plus years trying to figure it out without success? Well, it turns out that combining the deuterium and tritium needed for achieving ignition

requires near ideal circumstances and a heck of a lot of energy. It's very hard to force together two positively charged particles. They want to repel each other. They don't want to bind together. So you have to overcome that repulsion. The way the sun creates fusion and fusion ignition is through gravity. So there's a lot of deuterium and tritium, which are heavy isotopes of hydrogen. And the immense gravity of the sun pushes them together and causes them to fuse.

And that drives this energy process. The sun does it by being massive and big, and it uses gravity to keep the fusion fuel and compress it together. So we have a tiny little capsule that's filled with deuterium and tritium and we squeeze that capsule using the x-rays we create with our laser. You make it very hot and start super dense and particles circulate around and they collide. The approach that we use at Livermore is inertial confinement fusion. And we use basically lasers to compress the fuel to extremely high pressures and actually the fuel together. It's inertial because it's just the capsule that contains the fusion fuel.

It's just using that inertia of that capsule to keep the implosion together just for long enough to enable this fusion reaction to occur. That capsule compressed enough, so to a high enough density, fast enough, and hold it together long enough that we can create that same self-sustaining fusion reaction that you see in the sun. So all we have to do is simulate the force of gravity at the center of the sun here on Earth, an object which is 100 times wider and 300,000 times heavier than our planet.

How hard could that be? John Nichols, who pioneered ICF research, had this idea back in the 60s. Why, hey, I can generate fusion yield, but he didn't have a driver. He didn't know, you know, he's done, he's high explosives or whatever, right? How could you get this to work?

With the invention of the laser, he put two and two together, said, I can use the laser to provide the driver to be able to compress the fuel to the conditions I need to get fusion energy out. And he published this paper back in 1972, when I was not even at high school, right? But he published that paper, and that really kick-started, I would say, ICF research in the U.S. and around the world. At the time that John Knuckles was sharing his research, it wasn't clear if ignition could be achieved.

But what was clear was that in order to try, it would take technology and a facility that didn't yet exist. When we started building the laser, there were seven core technologies that were required to make it work that didn't exist. So the team set out on this incredible journey to build this multibillion-dollar laser facility while still trying to invent the components that would have to go into the building. So there were many moments during that journey where people were really pressing hard to find a technology breakthrough to make something possible.

Over the next three decades, the lab manufactured a series of increasingly more powerful laser systems. And in 1997, this work eventually culminated in the construction of the National Ignition Facility, or NIF, a state-of-the-art 192-beam laser facility designed to achieve fusion ignition. In spring 2009, the building was completed, becoming the world's largest and highest energy laser system. It's actually a very impressive building. Inside it, you have also structures in concrete, steel, and glass. It's literally a marvel of engineering. Jean-Michel DiNicola is the lab's program co-director for laser science and system engineering.

Some part of the building is buried under the ground. Laser bays are about 120 meters in length. And the beam traverses four times this amount of length to get amplified through stimulated emission and bringing their energy to a huge amount. Each beam is about a foot by a foot in size. It's very massive, but it needs to be also extremely precise. But building the facility was just the first step of an even greater hill to climb. When we finally turned the laser on at full scale in 2009,

we started what was called the National Ignition Campaign. So we'd been doing models and simulations throughout this whole time, designing our capsule and our little target assembly and really getting ready, fully anticipating that within the first two years of running the facility, we would get ignition. And we did not. And we did not even get close. And so there was tremendous anxiety in the system

because everything we tried netted the same result. The same result again. And again. And again. And again. Was it even possible to achieve ignition? What would it take to tip the scales? In our next episode of Big Ideas Lab, you'll meet more of the visionaries challenging the boundaries of the possible

and learn about the fascinating tools they are employing along the way. Stay tuned for a journey into the heart of scientific innovation, where the impossible becomes reality. Lawrence Livermore National Laboratory invites you to join our diverse team of professionals where opportunities abound for engineers, scientists, IT experts, welders, administrative and business professionals, and more. At Lawrence Livermore National Laboratory, your contributions are not just jobs. They're a chance to make an impact from strengthening U.S. security to leading the charge in revolutionary energy solutions and expanding the boundaries of scientific knowledge. Our culture

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