Target Fabrication

In the backseat, a scientist keeps one hand pressed flat against a small metal case.

“The other grips the handle above the door.”

He's made this trip before. Hundreds of times. Still, his heart pounds. Not because what he's carrying is dangerous, but because it's fragile. One side, the case, is an object smaller than a pencil eraser, built for science.

And delicate enough that months of work could be undone by a single vibration in the wrong direction. The next step of the journey is the airport. A few people glance at the singular case carried flat in the scientist's arms. Unaware of the significant breakthroughs possible from what's inside.

It leaves his hands given carefully to security. For a moment, there's nothing to do but wait. Because what's inside can't be rushed, can't be jostled, and can't be easily replaced. This tiny object has already crossed continents. Soon it will reach its final destination, Lawrence Livermore National Laboratory.

“It's a capsule filled tube assembly, the most fragile and essential component of a fusion”

target, engineered to sit at the exact center of the most energetic laser system ever built. Designed to experience temperatures hotter than the core of the sun, and fabricated with intolerances, so precise that a flaw smaller than a bacterium could change the outcome of an experiment. Before the laser's fire, before ignition is even possible.

Everything depends on this one small capsule. Welcome to the Big Ideas Lab, your exploration inside Lawrence Livermore National Laboratory. Here 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 Lawrence Livermore National Laboratory is hiring.”

If you're passionate about tackling real-world challenges in science, engineering, business, or skilled trades, there's a place for you at the lab. Right now, positions are open for a senior labor relations advocate, operations cybersecurity manager, and a senior database administrator. These are just a few of the more than 100 exciting roles available.

At Lawrence Livermore, you'll work on projects that matter, from national security to cutting-edge scientific advancements. Join a team that values innovation, collaboration, and professional growth. More opportunities at llnl.gov/careers, where your next career move could make history. The National Ignition Facility at Lawrence Livermore is the most energetic laser system

on the planet.

It generates temperatures of up to 100 million degrees, and pressures more than 100 billion

times Earth's atmosphere. Making the extreme conditions required for nuclear fusion. The process that powers the stars and sun. We don't really run a sun, which does a lot of energy and fusion reactions all the time. It is on non-stop 24 hours a day.

Michael Staterman is the program manager for Target Fabrication at Lawrence Livermore. Here we're able to, for a nanosecond, deliver the amount of power that it takes to drive these fusion reactions, and so we very briefly create this flash of light for the mini sun, and then it's gone. The precision and energy of niff's lasers allow scientists to explore nuclear fusion in

a controlled environment. Work that is vital to ensure the safety, security, and effectiveness of our nation's nuclear deterrent.

The synchronization of these 1952 beams is critical.

Each one must travel over a half mile, amplified along the way before converging on a tiny perfect target that makes it all possible.

It has to be as perfect as possible.

“Adding nuclear fusion, or as Michael put it, a mini sun, requires flawless design, fabrication,”

assembly, and materials. Many niff experiments use inertial confinement fusion targets, or ICF targets, engineered to withstand intense conditions and deliver energy with extraordinary precision. At the center is the capsule which holds the fusion fuel. The capsule is suspended inside a small metal cylinder called a hole.

When the lasers enter the hole room, their energy is converted into x-rays that compress the capsule evenly from all sides. All of that complexity inside a single target measured in millimetres. A fusion ignition target is as big as an eraser head, so the very very small, and that's the largest part that we handle, everything else that goes inside is smaller.

Why so small? Because niff has a finite amount of energy, so a bigger target capsule would require a bigger laser.

“Niff is already three football fields long, with one hundred and ninety-two laser beams”

building up immense energy throughout the facility to converge on a single point. Small, but mighty. An ICF target is designed to be used only once before it's vaporized by a laser. The thing that's most famous that we make are the ignition targets, and that's where we have the Duterteum Tritium-filled fuel capsules that we're trying to compress to really

hide temperatures and densities so that we get a fusion reaction that releases more energy than we put in. But before the fuel can reach those extreme temperatures, it has to start incredibly cold. Inside the capsule is fusion fuel made from two isotopes of hydrogen, doterium and tritium. Uncooled to nearly 437 degrees below zero, just a few degrees above absolute zero.

The fuel becomes dense and uniform, forming a smooth layer ready for even compression. But the outer shell that holds that mixture must be strong, uniform, and predictable under pressure. A material 100 times smoother than a mirror. Lab-grown diamond.

The diamond is the material that we use for ignition experiments because we know it works. Smoothness is critical. Tiny imperfections can impact the experiment. Throw the implosion off balance and make fusion unlikely. One common imperfection is a pit.

A pit is a bit of missing mass on the surface. Imagine the perfectly round sphere, and now there is a hole, it's usually just on the surface.

And identifying those pits isn't always straightforward.

“I believe that's really a divot on the surface that's a pit versus hey, there's some doubt”

as far as this may be a piece of dust or something. We should take a look at that and then potentially reclaim the capsule and make sure that we don't have the feature there. Jared Hunt is the Lawrence Livermore Contract Manager at General Atomics, a company which makes key components of the target and performs detailed inspections of the fuel capsules.

Before capsules can be approved, every surface has to be understood. We basically create a Google Earth of the entire capsule so that we've got a representation you can zoom in on any little square patch and see where any kind of defect or any kind of feature is and provide a histogram to physics and counts of what these features are. And every year we seem to be able to drive those down, fewer and fewer.

We're working right now on understanding systematically what gives rise to the evolution of pits, voids, and inclusions. So hopefully as the request comes into make bigger shells, we're well prepared for it and can adopt quickly. And then figuring out, maybe in the next step, how do we make bigger hull roms, what kind

of hull roms should we be making for those larger energy drives to support those experiments adequately? Scientists create roughly 1500 capsules each year, but only half are perfect enough to use. Each one is built by hand over months and used for a single experiment. The smallest human mistake can end a capsule's journey.

When I first started, I measured some capsules by hand and one day I dropped one.

And so I was on my hands and knees with a piece of paper, sweep in the floor, I found it, but it was trash at that point as far as it had been exposed to the dust and stuff on the floor. That's the level of fine motor control and carefulness you've got to have because if you bump something wrong and it goes flying, it's over and it's a really touchy process.

And the more imperfection you introduce, the harder these become to model.

“The experiment will tell us if the imperfections are a problem or not.”

So we can look from the data that tells us do we need to work on removing more of the pits, or are we at a level that is acceptable? While the inspection is microscopic, the journey of the material is global. Long before it reaches Lawrence Livermore, target fabrication begins halfway across the world.

When a team where expertise makes a difference, Lawrence Livermore National Laboratory is hiring for a nurse practitioner physician assistant, a senior health physicist, and a laser modeling physicist. And the list of open positions doesn't end there.

There are more than 100 job openings across science, engineering, IT, HR, and the skilled

trades. This is more than a job.

“It's an opportunity to help shape the future.”

Explore all open positions and start your next career adventure today at llnl.gov/careers. That's llnl.gov/careers. For Lawrence Livermore, target fabrication for ignition experiments begins with diamond materials in southwestern Germany. Engineers at diamond materials grow thin diamond shells that form the outer layer

of the fuel capsule. Each shell is made to exact specifications with careful control over thickness, shape, and surface quality. From Germany, the shells travel to the US where they arrive at general of latimics in San Diego to be measured and inspected.

A lengthy process. We want the definition, how thick they are, how big they are, we want that eight months in advance.

“So those will be processed, starting with the coding and manufacturing, then they go”

to general atomics, where they get post-processed, characterised, and turned into capsule fill-to-bassemblies, those then come to Livermore and we assemble them into the targets. Transporting capsules comes with its own engineering challenges. Mostly around how much vibration the capsule's experience. We hadn't carry all of these capsule fill-to-bassemblies from llhoia to Livermore.

Transportation is also part of the experiment. Given the movement of human hands becomes data, when the capsules get packed up, the experiment gets turned on, you can see exactly how steady someone's hands are, as they're walking to the car or from the airport, and you can see how rough the car rides are, and you can see how rough the plane ride is, and usually the plane ride, there is a good amount

of underlying vibration because of the engines that are turning all the time, you can see exactly when the plane starts taking off. But the car rides from Oakland to Livermore are actually the worst. While ignition draws the most public attention, nift targets are used for a wide range of national security applications, including ones that draw insights for basic science.

Each target is designed to meet the goals of the experiment, which drives the choices in materials, size, and shape. Besides the ignition experiments, there's a wide range of experiments for national security applications such as the stockpiled stewardship. And then there's a lot of basic science experiments to go on as well.

There is a set aside of, with the call discovery, science shots, they're looking at things that may be some kind of astrophysical phenomenon, or it's some kind of measurement that will help them understand the model of the sun. And experiments require trial and error, especially when so many variables can affect the outcome.

The capsule or the target is only one variable of many as you do an experiment. So for example, the laser performs ever so slightly different between different shots as well, and there might be other external circumstances, fuel age or other things like that that affect the result. And so we really only can learn if we have a good picture of the conditions going in

because then when something goes wrong, you can try to compare that and contrast it with prior experiments and see, what did I do different this time, the last time, why is this one

worse and why is the other one better, and that's ultimately how we're able to make improvements.

Experiments in if last only fractions of a second, but the targets they depend on take months to create. Before fusion can happen, before ignition is even possible. Success begins in perfected diamond shells carried by steady human hands. This is where every beam meets at the center of the national ignition facility.

is hiring for a nuclear facility engineer, systems design and testing engineer, and a senior

“scientific technologist, along with many other roles in science, technology, engineering,”

and beyond.

At the lab, every role contributes to groundbreaking projects in national security, advanced

computing, and scientific research.

“All within a collaborative mission-driven environment.”

Discover open positions at LLNL.gov/careers, where big ideas come to life.

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