Compact nuclear fusion reactor is ‘work to very like to work’ study suggestions


Scientists who have developed a compact version of a nuclear fusion reactor have shown in a series of research papers that it should work, renewing hopes that the long-elusive goal of achieving the way the sun produces energy Can be achieved and ultimately contribute to the fight with the climate. Change.

Researchers and company officials said the construction of a reactor called Spark, which is being developed by researchers at the Massachusetts Institute of Technology and a spinoff company, Commonwealth Fusion Systems, is expected to begin next spring and take three or four years. .

While many significant challenges remain, the company said that testing the construction and, if successful, building a power plant that could use fusion energy to generate electricity, would begin in the next decade.

This ambitious timetable is far faster than the world’s largest fusion-power project, a multinational effort called ITER in southern France for an international thermonuclear experimental reactor. This reactor has been under construction since 2013 and, although it is not built to generate electricity, is expected to produce a fusion reaction by 2035.

Bob Mumgard, chief executive officer of Commonwealth Fusion and one of the company’s founders, said one of the goals of the Spark project was to develop the fusion in time to play a role in reducing global warming. “We’ve really focused on where you can get fusion power as soon as possible,” he said.

Fusion, in which light atoms are brought together at temperatures of millions of degrees to release energy, has been organized as a way of addressing the climate-change effects of electricity generation for the world.

Like a conventional nuclear fission power plant that splits atoms, a fusion plant will not burn fossil fuels and will not produce greenhouse-gas emissions. But its fuel, usually isotropic of hydrogen, is far more plentiful than uranium used in most nuclear plants, and less fusion, and less hazardous than fission plants, producing radioactivity and waste Will do.

But the barriers to building a machine that can create and control a fusion plasma – a rotating ultrashot cloud of atoms that will damage or destroy anything it touches – are huge.

Some scientists working on Fusion Energy for decades say that when they are excited about the potential of sparks, the timetable may be unrealistic.

“Reading these letters makes sense to me that they are controlled thermonuclear fusion plasma that we all dream of,” said physicist Carrie Forrest of the University of Wisconsin, who is not involved in the project. “But if I think where they’re going to be, I’ll give them a factor of two that I give to all my graduate students when they say how long it’s going to take.”

Spark will be much smaller than ITER – about the size of a tennis court, compared with a football field, dr. Mumgaard said – and much less expensive than the international effort, which is officially estimated to cost around $ 22 billion but may be too expensive. Commonwealth Fusion, which was established in 2018 and has about 100 employees, has raised $ 200 million so far, the company said.

Since experiments on fusion began nearly a century ago, the promise of a practical fusion device that can generate more energy than its use remains elusive. Fusion power has always seemed “just decades” away.

This may also be true in this case. But in seven special peer-review papers published on Tuesday in a special issue of The Journal of Plasma Physics, researchers testified that the spark would succeed and produce 10 times as much energy as it would consume.

The research “confirms that the design we’re working on is very likely to work,” said Martin Greenwald, deputy director of MIT’s Plasma Science and Fusion Center, and one of the project’s key scientists. Dr. Greenwold is the founder of the Commonwealth Fusion, but he has no current relationship with the company.

Spark employs the same type of device as ITER: a tokamak, or donut-shaped chamber within which the fusion reaction occurs. Because the plasma cloud is much warmer than the sun – it must be limited by magnetic forces.

The IERT does this using an electromagnetic coil consisting of superconducting wires that must be cooled by liquid helium.

Dr. Greenwald said that Spark takes advantage of a new electromagnet technology, which uses so-called high-temperature superconductors, which can produce high magnetic fields. As a result, the plasma is very small.

Dr. Greenwald said the papers “make this high-level path still look feasible”. “If we can overcome engineering challenges, this machine will perform as we anticipated.”

Commonwealth Fusion said it would announce a location for Spark in a few months.

It is one of several companies working to develop and commercialize Fusion Power in partnership with research institutes, backed by hundreds of million dollars of investment money.

For example, TAE Technologies, based in Southern California, is working on a design that uses a linear device that shoots two clouds of plasma at each other to produce fusion. First Light Fusion, a spinoff from the University of Oxford in England, uses energy to compress and collapse fusion fuel.

Dr. Forrest said that by using strong magnetic fields, Spark finished with a “conservative” design. “This completely differentiates it from all start-ups, which are more nuanced and in the definition of high risk,” he said.

William Dorland, a physicist at the University of Maryland and editor of The Journal of Plasma Physics, said the magazine asked some of these fusion projects to “give us their physics basis.” He said that MIT and the Commonwealth Fusion Group quickly said yes.

“From my point of view, this is the first of these groups that have private money that is actually very clearly saying what they are doing,” Dr. Dorland said.

“Reasonable people disagree on whether it works,” he said. “I’m just happy that they made the move and are telling us in general science what’s going on.”

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