Scientists make breakthrough in understanding how to control intense heat bursts in fusion experiments

March 13, 2015, Princeton Plasma Physics Laboratory
Computer simulation of a cross-section of a DIII-D plasma responding to tiny magnetic fields. The left image models the response thatsuppressed the ELMs while the right image shows a response that was ineffective. Credit: General Atomics

Researchers from General Atomics and the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) have made a major breakthrough in understanding how potentially damaging heat bursts inside a fusion reactor can be controlled. Scientists performed the experiments on the DIII-D National Fusion Facility, a tokamak operated by General Atomics in San Diego. The findings represent a key step in predicting how to control heat bursts in future fusion facilities including ITER, an international experiment under construction in France to demonstrate the feasibility of fusion energy.

The studies build upon previous work pioneered on DIII-D showing that these intense heat bursts - called "ELMs" for short - could be suppressed with tiny magnetic fields. These tiny fields cause the edge of the to smoothly release heat, thereby avoiding the damaging heat bursts. But until now, scientists did not understand how these fields worked. "Many mysteries surrounded how the plasma distorts to suppress these heat bursts," said Carlos Paz-Soldan, a General Atomics scientist and lead author of the first of the two papers that report the seminal findings back-to-back in the same issue of Physical Review Letters this week.

Paz-Soldan and a multi-institutional team of researchers found that tiny magnetic fields applied to the device can create two distinct kinds of response, rather than just one response as previously thought. The new response produces a ripple in the magnetic field near the plasma edge, allowing more heat to leak out at just the right rate to avert the intense heat bursts. Researchers applied the magnetic fields by running electrical current through coils around the plasma. Pickup coils then detected the plasma response, much as the microphone on a guitar picks up string vibrations.

The second result, led by PPPL scientist Raffi Nazikian, who heads the PPPL research team at DIII-D, identified the changes in the plasma that lead to the suppression of the large edge heat bursts or ELMs. The team found clear evidence that the plasma was deforming in just the way needed to allow the heat to slowly leak out. The measured magnetic distortions of the plasma edge indicated that the magnetic field was gently tearing in a narrow layer, a key prediction for how heat bursts can be prevented. "The configuration changes suddenly when the plasma is tapped in a certain way," Nazikian said, "and it is this response that suppresses the ELMs."

The work involved a multi-institutional team of researchers who for years have been working toward an understanding of this process. These researchers included people from General Atomics, PPPL, Oak Ridge National Laboratory, Columbia University, Australian National University, the University of California-San Diego, the University of Wisconsin-Madison, and several others.

The new results suggest further possibilities for tuning the magnetic fields to make ELM-control easier. These findings point the way to overcoming a persistent barrier to sustained fusion reactions. "The identification of the physical processes that lead to ELM suppression when applying a small 3D to the inherently 2D tokamak field provides new confidence that such a technique can be optimized in eliminating ELMs in ITER and future fusion devices," said Mickey Wade, the DIII-D program director.

The results further highlight the value of the long-term multi-institutional collaboration between General Atomics, PPPL and other institutions in DIII-D research. This collaboration, said Wade, "was instrumental in developing the best experiment possible, realizing the significance of the results, and carrying out the analysis that led to publication of these important findings."

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19 comments

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jalmy
1 / 5 (7) Mar 13, 2015
They should try to use sound waves like the in the move "chain-reaction". Seriously scientists stop wasting money trying to figure out problems Hollywood already solved.
reset
3.7 / 5 (3) Mar 13, 2015
They should try to use sound waves like the in the move "chain-reaction". Seriously scientists stop wasting money trying to figure out problems Hollywood already solved.


Why introduce a kinetic mechanism to charged particles? It is almost impossible to isolate the region you wish to affect. These guys are on the right track by adding subtle magnetic fields and configuring them to achieve the goal.
WillieWard
1.4 / 5 (9) Mar 13, 2015
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
And even worse, spending billions upon billions on flawed tokamak concepts while more promising and cheaper fusion approaches remain unfunded.
TheOrphan
1 / 5 (5) Mar 13, 2015
Cold fusion experiment in the UK ...
http://www.wired....-reactor
ubavontuba
1.5 / 5 (8) Mar 14, 2015
Fusion Confusion
by Ubavontuba:

Fusion confusion, infusion and more
Funding required, greenbacks for sure
Hydrogen heated with lasers that cook
Energy forever, if they get it to work

Polywell, Pinch, Tokamak and more
Fusion alternatives they wish to explore
Billions of dollars spent on a whim
"Hurry!" I say, "My bulbs grow dim!"

Consumption presumption, gumption and more
Heat from a source, like from a star's core
"It's coming soon." they assert yet again
Here I'm wondering, will I be here then?

Conflagration fiction, confliction and more
It passes from fact to myth then to lore
"Unlimited energy." I hear them yet say
Just burn the money ...it's cheaper that way

Shabs42
4.6 / 5 (9) Mar 14, 2015
Cold fusion experiment in the UK ...
http://www.wired....-reactor


Was your purpose to show that cold fusion doesn't work? Because that article does a great job illustrating that point.
Dethe
1.5 / 5 (8) Mar 14, 2015
The cold fusion indeed does work - it's documented in thousands of articles, which the mainstream physics ignores intentionally for not to threat its income from another energy research (including the hot fusion). But the failure of cold fusion reactor linked above doesn't prove anything about cold fusion - both in positive, both in negative sense.
Torbjorn_Larsson_OM
4.5 / 5 (8) Mar 14, 2015
@Dethe: OIf course it isn't documented, it doesn't work, and that is the main problem. (A minor problem is that it is used by scam artists to pull money of suckers.)

Scientists do not at all ignore it, because it would be both fame and money if it works. Instead they have put a lot of effort in it:

"Cold fusion is a hypothetical type of nuclear reaction ...

Many scientists tried to replicate the experiment with the few details available. Hopes fell with the large number of negative replications, the withdrawal of many positive replications, the discovery of flaws and sources of experimental error in the original experiment, ...

By late 1989, most scientists considered cold fusion claims dead,[6][7] and cold fusion subsequently gained a reputation as pathological science.[8][9]"

[ http://en.wikiped...d_fusion ]

Please remember that this is a science site, and claims should be referenced back to peer review. A crackpot organisation isn't such a reference.
Dethe
1 / 5 (4) Mar 14, 2015
You may read about cold fusion in peer-reviewed journals too. Which objection will you bring next time?
Vietvet
3.7 / 5 (3) Mar 14, 2015
You may read about cold fusion in http://www.curren...?splid=2 too. Which objection will you bring next time?


Can't you do better than an impact factor of 0.833?
TheOrphan
1 / 5 (1) Mar 14, 2015
@Shabs42

No , if you watch the video in the article, it looks like containment is the issue they have.

It was a relatively low cost experiment (a replication of other experiments), that had promising results right before it exploded.
PeakSpecies
2.5 / 5 (2) Mar 15, 2015
Good! Another breakthrough. I've been reading about them, in the fusion energy field, since the 1970s and that practical power production is just a decade, or two, away. Would anyone care to guess why these intense heat burst "ELM" difficulties were not mentioned in the last two fusion energy announcements, from the University of Washington and Lockheed Martin Skunk Works, about five months ago?
nkalanaga
5 / 5 (1) Mar 15, 2015
Different type of reactor, possibly. This article is on tokamaks, which use magnetic confinement to hold plasma for relatively long periods, in a stable, self sustaining reaction. A tokamak, and other magnetic confinement systems, want a relatively constant temperature and pressure.

Other researchers are using inertial confinement, collapsing fuel pellets to produce periodic explosions, with no attempts to confine the plasma for longer than needed to extract the energy from it. "Extreme heat bursts" are the desired product in inertial confinement systems, so they wouldn't try to suppress them.
jalmy
not rated yet Mar 16, 2015
They should try to use sound waves like the in the move "chain-reaction". Seriously scientists stop wasting money trying to figure out problems Hollywood already solved.


Why introduce a kinetic mechanism to charged particles? It is almost impossible to isolate the region you wish to affect. These guys are on the right track by adding subtle magnetic fields and configuring them to achieve the goal.


They can move objects around inside a space using 3d interference of sound waves. So no, it is in fact not that hard to "isolate the region you wish to effect." They are using magnetism to produce a ripple. This could very well be achieved with sound as well. Just as in the movie I mentioned, it's about the frequency.
gculpex
not rated yet Mar 16, 2015
So, More ripples on the sides are reducing the thermal leaks?
Dethe
1 / 5 (4) Mar 16, 2015
Can't you do better than an impact factor of 0.833
The better impacted journals don't accept the cold fusion reports at all. As the result, we have a megawatt plant based on phenomena, which officially doesn't exist according to mainstream physics. This is an example what the money can do with objectiveness of science.
reset
1 / 5 (1) Mar 16, 2015
They should try to use sound waves like the in the move "chain-reaction". Seriously scientists stop wasting money trying to figure out problems Hollywood already solved.


Why introduce a kinetic mechanism to charged particles? It is almost impossible to isolate the region you wish to affect. These guys are on the right track by adding subtle magnetic fields and configuring them to achieve the goal.


They can move objects around inside a space using 3d interference of sound waves. So no, it is in fact not that hard to "isolate the region you wish to effect." They are using magnetism to produce a ripple. This could very well be achieved with sound as well. Just as in the movie I mentioned, it's about the frequency.


Where does the soundwave originate (as in where is your emitter?)? How do you control the kinetic transfer of energy in a current? The movie was called "Chain reaction" for a reason....
Captain Stumpy
3.7 / 5 (3) Mar 21, 2015
The cold fusion indeed does work - it's documented in thousands of articles, which the mainstream physics ignores intentionally for not to threat its income from another energy research (including the hot fusion)
@the idiot ZEPHIR
articles are NOT evidence, nor proof of concept

that would be a working cold fusion prototype... and THAT has NEVER been shown, demonstrated, revealed nor does one exist

the simple proof of that is the fact that there are NONE being used or manufactured

want to prove me wrong?
mail me a working prototype
there should be thousands around your house by now... or are they illegal in prague?

there are also more than a million articles and links about faeries, or leprechauns, or ghosts... none of which have ever been proven to exist either
last point: the bulk of the human race believes in some invisible sky faerie deity or another and talk or write about that on line

epic fail for zeph
Captain Stumpy
3.7 / 5 (3) Mar 21, 2015
As the result, we have a http://andrea-ros...w-plant/ based on phenomena, which officially doesn't exist according to mainstream physics. This is an example what the money can do with objectiveness of science.
@the idiot zephir CONT'D
rossi has also NEVER been able to submit a working prototype that has been externally validated and proven to the world or the scientific community

if you want to believe in hoaxes and put your money on con-men, then by all means, start emptying your bank account and put your money where your mouth is

maybe you will get rich

it is FAR more likely that you will lose everything

case in point: your post
JUST BECAUSE SOMEONE WRITES A PDF OR A BLOG DOESN"T MEAN IT IS LEGITIMATE SCIENCE

want to prove me wrong?
send me a working prototype
something that will support my house using cf, per your claims and rossi's link

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