Physics

Under pressure: New world record set on path to nuclear fusion

Under pressure: New world reco...
A look inside the Alcator C-Mod t MIT
A look inside the Alcator C-Mod t MIT
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A look inside the Alcator C-Mod t MIT
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A look inside the Alcator C-Mod t MIT

While there is a lot of attention on non-fossil-fuel sources these days such as solar and hydrogen, the true Holy Grail of alternative energy is nuclear fusion, which theoretically could produce an endless source of clean power. Because scientists would have to basically reproduce the conditions at the core of the sun to bring this atom-mashing technology to fruition though, it's been a bit slow to evolve. Researchers at MIT however, have just passed an important milestone on the long path to a fusion future, placing plasma under what they say is the most pressure ever created in a fusion device.

In nuclear fusion, the nuclei of atoms are basically forced to join together despite their natural repellency. When they fuse, they release a tremendous amount of energy. How much? Well, it's the process that keeps our sun churning, where molecules of hydrogen are fused together in its core to create helium.

To recreate controlled nuclear fusion on Earth (unlike the uncontrolled version involved in a hydrogen bomb), gas is first heated to super-hot temperatures to form plasma. The plasma is simultaneously placed under intense pressure with the goal of keeping it stable, and is contained by an electromagnetic field.

While machines known as tokamaks, such as China's Experimental Advanced Superconducting Tokamak (EAST), have created the intense temperatures needed for fusion reactors before, MIT is claiming first place in having created pressures never before attained. Using a tokamak called the Alcator C-Mod, which has been in operation at MIT for 23 years, researchers were able to place plasma under pressure equaling 2.05 atmospheres, a 15 percent leap over the previous C-Mod record of 1.77 atmospheres that was set in 2005. The university says it expects the new record to hold for 15 years as long as a new device – such as the one proposed by MIT itself – isn't built before then.

MIT says that the Alcator C-Mod can create a magnetic field up to 8 tesla strong, which is 160,000 times the Earth's magnetic field. In this particular record-smashing experiment, the machine reached 5.7 tesla. It also was heated to more than 35 million degrees Celsius (about twice the temperature at the core of the sun), produced 300 trillion fusion reactions per second, and carried 1.4 million watts of power. All of that took place in a chamber of about 1 cubic meter, which MIT says is not much larger than a coat closet.

Due to defunding by the US government, the Alcator C-Mod has now been deactivated; it reached its new record on its final day of operation.

This video provides a 360-degree tour of the device, as well as more information on how it works.

Source: MIT

Alcator C-Mod 360 degree tour

12 comments
Nairda
"Due to defunding by the US government, the Alcator C-Mod has now been deactivated" Things like this boil my blood. So much potential in fusion
LarCharWelsh
"We have this handy fusion reactor in the sky called the sun, you don't have to do anything, it just works. It shows up ... And it's wireless! " Elon Musk
ThomasStandfield
You fail to mention that more energy was put into the device than was gotten out. Perhaps that's why it was discontinued.
PhilTaylor
I'd love to know how this is filmed and what type of glass is used to make it possible to film.
LarCharWelsh
There is a very large Fusion Reactor at the center of our solar system delivering energy wirelessly around the globe which can be harvested with solar arrays and wind farms. Tough to meter, thogh.
ec5bef1eb7234d96ab8bd5d13ab93871
See the ITER project https://www.iter.org/ for information on the long-term multi-national cooperative project to provide practical fusion energy.
StWils
All of my life fusion has been seen as the energy source of the future. It was described a being just twenty years in the future, where it has remained "twenty" years away. Maybe defunding is the best immediate answer, maybe not. I would however hope that this machine has simply been mothballed so it can be rapidly turned back on when better systems or components become available. And, yes solar, wind, and ocean sourced energy is available now.
Douglas Bennett Rogers
ITER should produce 500 MW of fusion power for about a half hour a day when activated. It is the first machine of power plant scale but won't have steam turbines or run around the clock. DEMO is supposed to be the first grid connected fusion plant, contingent on ITER producing favorable data for around ten years.
rpark
...360 degree tour notwithstanding, we've heard this all before- let us know when they actually have an operational electricity producing generator. Zero-point technologies and other renewables will be entrenched before fusion, rendering the Tokamak irrelevant.
RonVanWegen
Meanwhile, Thorium-based Molten Salt Reactors can do it all NOW!