Nuclear Fusion Breakthrough: Here’s What ‘Ignition’ Really Means at Lawrence Livermore National Laboratory

Nuclear fusion as a power source for electricity is plausible, an experiment at Lawrence Livermore National Laboratory in Northern California has shown. Using 192 lasers, the research enterprise reached the point of fusion experimentation known as “fusion ignition” for the first time.

At a Tuesday morning press conference, Energy Secretary Jennifer M. Granholm called him a “fusional breakthrough that will go down in the history books”.

While that doesn’t mean you can turn on the lights in your home and use fusion energy for at least decades, history will indeed record today as a breakthrough. Here’s what he can say: On December 5, 2022, Lawrence Livermore’s team directed many lasers at some hydrogen atoms, pulled the trigger and, for a split second, the atoms became a plasma that generated a fusion reaction. The lasers emitted 2.05 megajoules of energy, and that energy in turn caused a reaction that heated those atoms to millions of degrees Celsius. Under such solar conditions, these types of atoms fuse and become helium, and in this case, this fusion released 3.15 megajoules of energy.

In other words, this fusion reaction produced about 1.5 times more fusion energy than the lasers gave off with their beams.

You can think of previous fusion experiments a bit like striking matches against the phosphor strip on the matchbox and producing sparks. It was the first time the match head produced a flame. But this flame is still too short and inefficient to light the paper stick and then use to light other things.

Scientists have been working on a demonstration like this for nearly 100 years, since the publication of British physicist Arthur Eddington’s 1926 paper, “The Internal Constitution of Stars.” And researchers have been fusing atoms for decades. You can even do a fusion reactor in your garage if you want (probably don’t).

The challenge was to fuse those atoms together efficiently enough to call it an energy source instead of a big energy drain, and in a way of speaking, that remains the challenge moving forward.

Fusion may well be the queen of all clean energy sources at some point, potentially later in this century. But the fusion development timeline unfortunately means, breakthrough or not, it’s not a realistic solution to the climate crisis. Lawrence Livermore’s latest fusion reaction produced a net energy gain within the limits of the experiment itself, but what it failed to do, crucially, was produce enough energy to power the installation that carried out the experiment with enough leftover to start over, thus becoming an autonomous engine that puts electricity on the electrical network.

blue lasers compressing a fuel capsule

Blue lasers compressing a fuel capsule at the National Ignition Facility.
Credit: LLNL / National Ignition Facility

It’s not a dark secret. Kim Budil, Director of Lawrence Livermore National Laboratory broke this part down at Tuesday’s event (using rounded numbers)“The laser requires approximately 300 megajoules of energy from the wall, to drive two megajoules of laser energy, resulting in three megajoules of fusion yield,” she said, adding, “Our calculations suggest that it is possible with a large-scale laser system to achieve hundreds of megajoules of output, so there is a path to a target that produces enough output, but we are a long way from it at the moment.

At first glance, it’s disappointing that the overall efficiency of this system is less than one percent, given that it’s billed as possibly the greatest fusion breakthrough of all time. But there are other methods that don’t rely on 192 lasers and might have a better chance of generating lattice power. One reliable method uses a magnetic field to contain the aforementioned millions of degrees hot fuel and hold it in place, instead of lasering it into oblivion. Such experiments produced similar breakthroughs in the early 1990s – although nothing as eye-catching as a real ignition.

But, coming in the same year as a doubling of private sector funding for nuclear fusion as a power source, this breakthrough in ignition is timely to redefine fusion in the popular imagination. The merger was also part of recent energy security talks caused by the war in Ukraine. As Russian control over oil and gas supplies jeopardizes Europe’s ability to provide enough energy for heating this winter, and Ukraine and Russia have fought battles near a nuclear exponentially more dangerous fission facilities, the promise of an abundant and relatively safe form of energy has never been so welcomed.

There’s a famous cliche about fusion being “at 30forever. Now we need a new joke, because this timeline is outdated, and we know the merge is really coming. But until then, it would be wise to continue building powerful wind turbinesand do not sell your solar panels.

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