Amazing magnets can unleash a wealth of power


Dr. Greg Brittles is excited and shining when explaining the project he is working on.

“Creating a technically rewarding project is the dream of every engineer. We need to develop new technologies and solutions to difficult problems, but at the same time it’s important to the world.”

Since completing his research at Oxford University five years ago, he has worked for Tokamak Energy, a British startup planning to build a fusion reactor.

Nuclear fusion is a reaction that gives power to the sun and stars. If that power could be used on Earth, it would provide a rich source of energy from a very small amount of fuel without producing carbon dioxide. What should I not love?

The principle is easy to understand. If you take two hydrogen atoms and apply enough heat and pressure, they will fuse to form helium. In the process, some of the hydrogen is converted to heat and can be used to make electricity.

In order for fusion to occur here, it is necessary to heat the hydrogen isotope to hundreds of millions of degrees until it becomes very energetic and swirls in a substance called plasma.

The challenge was always to contain the plasma. Stars do it by gravity, but the most common way on Earth is to use a strong magnetic field to keep the plasma trapped.

Many of the engineering challenges are in the construction of magnets. They must be insanely hot and powerful enough to contain a swirling mass of matter, but not so much power that the reactor uses more power than it produces. ..

Later this year, Dr Bob Mumgaard of Commonwealth Fusion Systems (CFS) and his team will test the breakthrough magnets they say can take that leap forward.

The 10-ton D-shaped magnet is large enough for a person to pass through. A very special electromagnetic tape of about 300km is wrapped around the D shape.

The tape itself is an engineering feat that took decades to develop. A thin layer of superconducting rare earth barium copper oxide (ReBCO) is deposited on the metal tape. When cooled, the bundle of tape can conduct electricity very efficiently. This is essential for 40,000 amps to pass and is enough power to power a small town.

When the fusion industry says it has cooled, it means that the tape has been cooled to minus 253 ° C. This may sound ridiculous and cold to you, but it’s actually pretty warm in the world of superconducting materials.

“The refrigerator we use is like a refrigerator that fits in your kitchen,” says Dr. Mumgaard, co-founder and CEO of CFS.

“The same thing as previous generation technology … you’ll need a refrigerator the size of your home.”

Dr. Bob Mumgaard, CFS Co-Founder and CEO

Magnets are no longer a “toy scale,” says Dr. Bob Mangard of CFS.

CFS is planning a reactor (a device called a tokamak) with 18 of these magnets arranged in a ring, and recently chose the location of the reactor in Massachusetts.

“We were the first to actually get this magnet beyond just desktop, research and development. [reseach and development] The scale that people have done in some small businesses and some national laboratories.

“We are all on the scale we need to build a fusion machine. We don’t have to go from something like a toy scale to something like a fusion scale,” says Dr. Mumgaard.

Illustration of CFS magnet

Approximately 300km of superconducting tape enters the CFS magnet

The leap in magnet technology is also at the heart of a fusion project at Tokamak Energy in the United Kingdom.

Dr. Brittles has spent the last five years developing the technology and is now helping build a demonstrator with a series of powerful magnets working together.

“It’s an assembly of many coils where everything interacts and pulls together to form a balanced set. You need to control this, or the forces will be disproportionate. It could be, “he explains.

The magnet uses a tightly wound superconducting tape

Tokamak Energy had to come up with a way to coil delicate superconducting tape.

The forces that such a magnetic field can generate are daunting. When operating at full power, Dr. Brittles likens the force generated by his magnets to doubling the pressure at the bottom of the deepest trench.

When those magnets are ready, they enter a spherical tokamak (an apple-shaped fusion reactor).

Studies show that such a design produces more energy per unit of power used than the more commonly used donut-shaped tokamak, which is the design used by CFS and others. ..

“The real challenge is commercial fusion. That’s why we’re driving us. We’re focusing on spherical tokamak for long-term commercial benefits,” said one of the founders of Tokamak Energy. According to Dr. David Kingham, who is currently Executive Vice President. President.

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“We believe our technology will be deployable in fusion pilot plants in the early 2030s,” he says. “I think it will be a global race. There are interesting private ventures in the United States, and we race with them.”

The promise that fusion reactors will work has been around for decades (and will always be, so the old joke goes).

The largest project is underway in Southern France. A national consortium is building ITERSo far, a huge reactor that has cost billions of pounds to build and is operating many years behind its original schedule.

However, more compact designs, such as those planned by Tokamak Energy and CFS, attract individual investors who are confident that they will be a viable commercial proposal.

Dr. Wal van Rierop

Dr. Wal van Lierop’s investment company has invested tens of millions of dollars in fusion technology

Dr. Wal van Lierop founded venture capital firm Chrysalix 20 years ago and has invested tens of millions of dollars in the Canadian company General Fusion since 2008.

Historically, the fusion industry has struggled to raise money, he says. This is due to the large amount of money invested in ITER, which is all changing.

“I see more money invested and more interested, and people see this as a very large platform technology that may or may not work by 2050. I’m starting to realize that it’s gone. “

Dr. van Lierop points out that the potential prizes are enormous. The global electricity market is worth about $ 3 trillion (£ 2.15 trillion) annually and could grow even larger.

“If this is the case [fusion] If successful, this will open up the largest industry transition we have ever seen. “

Returning to the coal side (or perhaps the plasma side), Dr. Brittles confesses that there is still a lot of engineering work to do, but he is confident.

“We are always working hard to tackle many of the challenges that can stumble us, but from where we sit, it gets in the way of what I think is a shortper. Is nothing. “

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