Energy

Chinese tokamak keeps plasma 2.6 times as hot as the Sun for 17 minutes

Chinese tokamak keeps plasma 2...
The donut-shaped chamber of China's Experimental Advanced Superconducting Tokamak reactor
The donut-shaped chamber of China's Experimental Advanced Superconducting Tokamak reactor
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The donut-shaped chamber of China's Experimental Advanced Superconducting Tokamak reactor
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The donut-shaped chamber of China's Experimental Advanced Superconducting Tokamak reactor
Team members in the control room of China's Experimental Advanced Superconducting Tokamak facility as a new world record for sustained high-temperature plasma is achieved
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Team members in the control room of China's Experimental Advanced Superconducting Tokamak facility as a new world record for sustained high-temperature plasma is achieved

Good news for fusion energy progress and a new world record for the Chinese Academy of Sciences, as its Experimental Advanced Superconducting Tokamak (EAST), or "artifical sun," maintains 70 million degrees Celsius (126 million °F) for 1,056 seconds.

High-temperature plasma is a critical part of many large-scale fusion energy initiatives, which attempt to replicate some of the conditions that make the Sun a powerful enough fusion reactor to warm our solar system, with the goal of eventually supplying safe, clean energy for humankind.

Heat can be viewed as an energetic vibration of atoms, and this vibration becomes so extreme at ultra-high temperatures that atoms begin to randomly smash into one another with enough speed to jam their nuclei together, fusing them together and creating a new atomic element.

If you're using lightweight atoms from the lower end of the periodic table – like the Sun does, fusing hydrogen into helium – the new atom weighs less than the original two combined, and the difference in mass is ejected as thermal energy. At the core of the Sun, temperatures around 27 million °C (48.6 million °F) fuse about 620 million metric tons of hydrogen into about 616 million metric tons of helium every second, converting some 4 million tons of matter into energy.

A small proportion of this eventually reaches us here on Earth as electromagnetic radiation, supplying us with visible light, ultraviolet light, infra-red, radio waves, X-rays and gamma rays, and without this generous solar gift of energy, life as we know it would never have been possible.

Tokamak-style fusion reactors like the International Thermonuclear Experimental Reactor (ITER) obviously don't have the colossal scale and gravity of the Sun, but they aim to heat up hydrogen atoms – specifically, deuterium and tritium isotopes – to a point where they begin smashing together, fusing and releasing energy that can both be harvested, and sustain the reaction as additional hydrogen atoms are fed in.

ITER's target temperature is 150 million °C (270 million °F). China's EAST facility, which is a key contributor to the ITER project, has hit this mark already, reaching 160 million °C (288 million °F) for 20 seconds, and holding 120 million °C (216 million °F) for 101 seconds in separate experiments announced last May.

Team members in the control room of China's Experimental Advanced Superconducting Tokamak facility as a new world record for sustained high-temperature plasma is achieved
Team members in the control room of China's Experimental Advanced Superconducting Tokamak facility as a new world record for sustained high-temperature plasma is achieved

The latest experiment tested the Chinese tokamak's capability to endure extreme temperatures over longer periods, sustaining a temperature 2.6 times hotter than the Sun's core for some 1,056 seconds, or 17 minutes and 36 seconds. Nobody's ever sustained a high-temperature plasma for 1,000 seconds before, so this is an important milestone.

It's natural to wonder how these insane temperatures can possibly exist on Earth without causing the entire tokamak facility to melt down or burn to a crisp. Essentially, the donut shape of the tokamak's inner chamber is lined with the most heat-resistant materials available – tungsten and carbon, for example. Since even these would be destroyed if exposed to hundreds of millions of degrees, the superheated plasma is squashed right into the middle of the chamber, as far from the walls as possible, using powerful magnetic fields.

Most importantly, though, these extraordinary temperatures are achieved in a tiny amount of plasma relative to the size of the chamber, so the energy dissipates rapidly before it reaches the walls.

It's important to clarify: EAST has not created a fusion reaction here, just a sustained, superheated plasma similar to the kind that will eventually be used to create fusion. So it's a long way from being energy-positive at this point. Tokamak-style fusion is still many years from that lofty goal at this point, and the globe-spanning ITER project has already been described as the most expensive science experiment of all time and the most complicated engineering project in human history, since even when it does generate heat from fusion reactions, it'll vent that heat rather than attempt to capture and use it.

Indeed, we'll likely have to wait for a "DEMO" class successor to the ITER facility, like the one planned by EUROfusion, before we see a large tokamak generating useful amounts of electricity. Where ITER is shooting for a Q value of 10 – putting in 50 MW of thermal energy and generating 500 MW of gross thermal output, the EU's DEMO reactor aims to put in 80 MW and generate some 2 GW for a Q factor of 25.

That's currently planned to begin operation in 2051. Ah well, 29 years away is better than 30.

Source: Institute of Plasma Physics, Chinese Academy of Sciences via China Daily

17 comments
17 comments
paleochocolate
It's always 30 years away. In 2050 they'll say 2080.
vince
We are still 50 to 100 years from commercialization. Probably more like 200 years or never. Who needs it? We already have a far larger fusion reactor in our sun and with photovoltaics and energy storage we have technology NOW to produce amd storage 1000 times more energy than all mankind needs. We just need political will to implement it.
SteveMc
@paleochocolate The way we are 'progressing' as a species, I think we'll be lucky to see 2050, never mind 2080. Fusion reactors would help resolve our pending self-destruction of course, unless our scientists mess up and send everything into nuclear fusion chain reaction. At least we won't die of the cold :)
Suzanne B
I shall be 100 years old in 2050, I hope they succeed before then! HNY.
michael_dowling
I thought the Chinese experimental reactor was a fusion reaction generating energy from hydrogen fusion. The article could be more clear on what they are using to create 17 minute long plasmas. So the next step is creating fusion from hydrogen atoms? That is what ITER is aiming for. At the end of the day, climate change cannot be put on "pause". We need a clean replacement for fossil fuels NOW.
Troublesh00ter
@paleochocolate Oh, yeah. I still remember my Electromagnetic Fields and Energy Conversion professor saying back in the early 70s that practical fusion was roughly 20 years away. I have to laugh when I see that the pattern hasn't changed much in half a century!
guzmanchinky
It seems like there are several other technologies out there easier than the tokomak?
FB36
IMHO, people who think "fusion power will never become reality" are not realizing how long it really took for some other very important tech to become reality!
For example, think about how important computer tech is to humanity today!
& think about how long it really was from Babbage's first computer design/idea to first real/practical computer!
Or, consider how long it took going from first airplane to jet airliners!
Or, going from telegram to telephone to internet, etc!



Producing massive amounts of clean power using fusion is really possible?: Absolutely/obviously yes!
Fusion reactions can really be triggered artificially?: Absolutely/obviously yes!
There is really a lot of steady progress on fusion research?: Absolutely/obviously yes!
Then, let's not listen to the naysayers who think "We are just keep wasting tons of money & should/must give-up!"!
jerryd
The question is what is it good for? It can't compete with home, building, business, EV storage, on demand generation, solar, small wind, CSP, CHP at RETAIL in a couple yrs, long before this becomes viable if ever.
You might want to ask how much it costs to do this before getting excited.
In fact all utility scale generation is at risk as most of the loads become generators with lowest cost/kwh Retail, the only price that counts.
Stretch@StiltWalker.com
Are magnets even needed? https://spectrum.ieee.org/zap-energy-fusion-reactor
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