Energy

KSTAR fusion device maintains 100 million degrees for record 20 seconds

KSTAR fusion device maintains ...
KSTAR, the so-called "Korean artificial sun," has set a record for maintaining plasma at temperatures over 100 million °C
KSTAR, the so-called "Korean artificial sun," has set a record for maintaining plasma at temperatures over 100 million °C
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KSTAR, the so-called "Korean artificial sun," has set a record for maintaining plasma at temperatures over 100 million °C
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KSTAR, the so-called "Korean artificial sun," has set a record for maintaining plasma at temperatures over 100 million °C

While harnessing the power of the Sun has progressed in leaps and bounds in recent years, harnessing the process that powers the Sun is proving a tough nut to crack. However, progress continues to be made on the various approaches to practical nuclear fusion being pursued, of which tokamak reactors remain a frontrunner. In another promising development for the technology, the Korea Superconducting Tokamak Advanced Research (KSTAR) fusion device has set a world record by maintaining plasma at over 100 million °C (180 million °F) for 20 seconds.

Completed in 2007 and achieving first plasma in 2008, in 2016 KSTAR set a world record for the longest operation in high-confinement mode by successfully maintaining a high-temperature hydrogen plasma at about 50 million °C (90 million °F) for 70 seconds. China subsequently claimed a new record in 2017 with its Experimental Advanced Superconducting Tokamak (EAST), managing to maintain plasma at a similar temperature for 102 seconds.

But although 50 million °C might sound plenty toasty, when you're talking about the process that powers the Sun you need to get to at least double that to give the ions the kinetic energy to overcome the repulsive electrostatic force, known as the Coulomb barrier, that stops them from fusing together. You also need to successfully confine the ions close enough to each other for long enough to avoid plasma cooling, and ensure the ions are confined at a high enough density to maintain a suitable reaction rate.

KSTAR managed to achieve an important piece of the puzzle for the first time in 2018, maintaining high-temperature plasma at over 100 million °C, but only for about 1.5 seconds. In 2019, it managed to up the retention time to eight seconds, and now it has claimed a new world record, this time by maintaining high-temperature plasma with an ion temperature of over 100 million °C in continuous operation for 20 seconds.

This is an important step towards the ultimate goal of maintaining plasma with an ion temperature of over 100 million °C for five minutes by 2025.

"The technologies required for long operations of 100 million- plasma are the key to the realization of fusion energy, and the KSTAR's success in maintaining the high-temperature plasma for 20 seconds will be an important turning point in the race for securing the technologies for the long high-performance plasma operation, a critical component of a commercial nuclear fusion reactor in the future," says Si-Woo Yoon, Director of the KSTAR Research Center at the Korea Institute of Fusion Energy (KFE).

The significant jump in retention time from eight to 20 seconds was largely due to improvements to the performance of the Internal Transport Barrier (ITB) mode that aids in confinement and stabilization of the plasma.

"The success of the KSTAR experiment in the long, high-temperature operation by overcoming some drawbacks of the ITB modes brings us a step closer to the development of technologies for realization of nuclear fusion energy," says Yong-Su Na, professor at the department of Nuclear Engineering at Seoul National University (SNU).

KSTAR is part of Korea's contribution to the International Thermonuclear Experimental Reactor (ITER) nuclear fusion research project, and as such the results from the various experiments conducted there will help inform the development of ITER, which is currently being built in southern France. Key KSTAR experiment findings from 2020 will also be shared at the IAEA Fusion Energy Conference scheduled for May, 2021.

Source: National Research Council of Science & Technology via Phys.Org

11 comments
11 comments
HuckinFarley
Unfortunately, this tech is already "light years" ahead. https://youtu.be/vmVdPgkudC8
los_kiosk
I'd hate to be the technician who stupidly left a gas cylinder casually leaning against the reactor case! A slight leakage could send the whole thing sky high !!
Chris Coles
Everyone needs to turn back the clock to when we were running a, (for example), coal fired generating station . . . 365 days of the year . . . year in year out. For that is the design threshold that we need for any generator. Fact! . . . We do not have ANY idea of the long term viability of ANY container that holds a fire of 100 million degrees C; moreover, designed to be separated, by a single layer of material such as steel, from a coolant such as water at, say, 700 degrees C and the corresponding pressure . . . designed to transfer that pressurised steam to drive a revolving turbine to deliver . . . constantly . . . say, 500MW of electricity to the surrounding communities. In 1960, 60 years ago, as an apprentice, I came into contact with people working on the first designs for such an apparatus, if I remember correctly called ZETA. Now it has taken 60 years to reach 20 seconds. How many more lifetimes to reach, say, one hour?
sidmehta
Fingers crossed...almost free energy will bring new prosperity to our planet.
FB36
A lot of money is spent for fusion research but it is for an extremely worthy goal for whole humanity!
Keep in mind the problem is not just clean energy!
Fusion power can take humanity to a whole new level, which can never be done using solar & wind power etc!
(Because they would be too weak! Imagine trying to run an electric car using a toy car battery!)
For example, imagine humanity doing seawater desalinization at global scale & pumping plenty of water everywhere needed!
(All deserts could be turned to forests or agricultural fields, for example!)

Surely the progress is slow but it just means there are still a lot to learn about fusion before it can become a practical energy source!
Complain when nothing new is learned & progress is truly stuck!

Keep in mind many other important tech took a lot of time to truly become common/practical!
Compare first cars to cars of today or first airplanes to airplanes of today or first computers to computers of today, etc (& consider how long it took for each)!
michael_dowling
For god's sake,fusion reactors of the magnetically confined type are never going to bring us an energy utopia,and even if they could be made to work,it would be far too late to stop climate change,while also being economical: https://thebulletin.org/2017/04/fusion-reactors-not-what-theyre-cracked-up-to-be/
Kpar
Big deal. Nowhere near break-even.

Besides, there is no mention of how to convert the plasma energy into a useful form (electricity).

Current proposals use fast neutrons to heat a stainless steel cooling jacket, which then powers a steam turbine- just like our current generating systems.

Problem one: Fast neutrons will blister and ablate the stainless steel jackets, requiring replacement every few years.

Problem Two: How does one dispose of the now highly radioactive steel? Lots of it. You can't recycle it, like with most iron products.
bwana4swahili
"harnessing the power of the Sun has progressed in leaps and bounds in recent years"

How about in the past 50 years!? With yet another 50+ years to produce net energy, if ever!
Douglas Bennett Rogers
This is a small machine. The Q of a tokomak varies as r**4. As such, this machine gives very promising results. The Q of ITER is about 10.
drBill
Nice and wow