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On February 9th, scientists working at the UK Atomic Energy Authority’s
Joint European Torus facility in Oxford made a pretty cool announcement.
They announced that they had more than doubled the previously held record
for sustained nuclear fusion energy.
And what is really exciting is that, in a few years, scientists will
essentially get to repeat the same experiment, but at a much larger scale.
Which could finally put us on the road to a powerful source of clean energy
we’ve been pursuing for the better part of a century.
Nuclear fusion is a potential source of energy scientists
have been investigating since the ‘40’s and ‘50’s.
It is powerful and it is clean, low on greenhouse gas emissions and other waste.
Potentially, that is.
The problem with fusion power so far is that it’s never broken even.
We’ve been able to do it, but it always took more energy to run the reaction
than we actually got out of it.
And the JET reaction didn’t change that.
It simply couldn’t run long enough.
But it wasn’t necessarily meant to.
That’s because this is a test run for a larger experiment
that is scheduled to happen fairly soon.
Which makes this announcement an incremental step, but an important one.
A hypothetical fusion plant would use heat to boil water and spin steam turbines,
just like a coal or nuclear fission power plant does.
But that heat would be generated by the same forces that occur in the heart of the sun.
Our sun fuses together atomic nuclei to sustain itself.
Because of complicated physics stuff related to how atomic nuclei stay stable,
some portion of the total mass of those two nuclei is transformed
into an amount of energy following Einstein’s famous E=mc squared equation.
This is only possible under extreme conditions because the nuclei,
which contain protons, are both positively charged.
Like putting the north poles of two magnets together, they naturally repel each other.
The only way to reliably overcome this is by essentially brute-forcing it
with super high temperatures and pressures.
The sun, with a mass of roughly two billion, billion, billion metric tons,
has no problem putting on the pressure.
On Earth, however, we cannot match that.
So, we can’t hit the pressure, but, remarkably, we can go hotter.
To do this, scientists use a device called a tokamak, which is essentially
a big, hollow, donut-shaped device equipped with really powerful magnets.
In this giant hollow donut, scientists first suck the air out to create a vacuum,
then inject the fusion material and hold it in place with powerful magnetic fields.
This reactor, called JET for short,
uses a mix of two specific isotopes of hydrogen called deuterium and tritium.
Isotopes are versions of elements with a different number of neutrons.
The most common version of hydrogen just has one particle,
a proton with no neutrons.
Deuterium has one proton and one neutron.
Tritium has two neutrons and a proton.
Scientists can technically fuse other elements as well,
but this mix is especially interesting, since it releases more energy
than most fusion reactions and can be done at relatively low temperatures.
“Relatively” being the important word here.
By bombarding the material using particle accelerators, as well as electromagnetic
waves in a process somewhat akin to what you would find in a microwave oven,
scientists can heat it up to 10 times what we would find the center of the sun.
Now, even if the magnetic field failed, the reaction would immediately fizzle out.
So there’s no risk of a meltdown with fusion energy.
So that is how fusion works and how it’s working in this particular reactor.
The latest test is mainly impressive because of how much energy it yielded.
The previous record was 22 megajoules of heat energy, set way back in 1997.
But the JET scientists announced they got 59 megajoules,
more than doubling the old record.
In this experiment, JET ran for five seconds before its magnets got too hot.
Now, we use time to measure energy output,
so running the numbers we get 11 megawatts of energy.
Now, that is honestly not a ton of energy.
It’s about the same as the energy a household uses in a day.
And they didn’t even break even.
It still took more energy to run than they got out of it.
But this is just the little baby experiment.
The big boss is just around the corner.
JET is located in Oxford, England, but in southern France, scientists are preparing
the ITER, which is both larger and more advanced than JET.
And while JET is likely to be decommissioned soon,
ITER is scheduled to begin experiments in 2025.
ITER is exciting because it has different guts that would allow it to run longer.
And scientists seem confident that if they can get JET to run for five seconds,
they can do it for longer at ITER.
Researchers estimate that if everything works with the same with the bigger ITER,
the reaction will more than break even and actually produce net energy.
Meaning, the breakthrough with JET is the pre-breakthrough
to actually making fusion viable.
Hopefully, anyway.
And even if they do produce net energy, it’s safe to say there’s still a lot to figure out.
But this is exciting because if we can get fusion energy to work,
it represents a lot of energy.
A ton of deuterium, fused with tritium,
would produce as much energy as 29 billion tons of coal.
And deuterium is relatively abundant and can be harvested from ocean water.
Tritium is harder to get, but we can make it from lithium.
And fusion would produce no greenhouse gases.
There would be small amounts of radioactive waste, but they should be short-lived.
Unfortunately, fusion almost certainly is not going to happen soon enough
to help us transition away from fossil fuels.
We need to address the climate crisis with current technology kind of now.
But fusion could be the way we power things in the future.
We will just have to wait and see how things go with ITER!
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