Peak Oil is You
Donate Bitcoins ;-) or Paypal :-)
Page added on August 23, 2018
Steady as she goes: Scientists tame damaging plasma instabilities
Before scientists can capture and recreate the fusion process that powers the sun and stars to produce virtually limitless energy on Earth, they must first learn to control the hot plasma gas that fuels fusion reactions. In a set of recent experiments, scientists have tamed a plasma instability in a way that could lead to the efficient and steady state operation of ITER, the international experiment under construction in France to demonstrate the feasibility of fusion power. Such continuous operation will be essential for future fusion devices.
Fusion powers the sun and stars by fusing light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — to produce massive amounts of energy. Scientists are seeking to replicate fusion on Earth for a virtually inexhaustible supply of electricity-generating power.
The most recent findings, developed by a team of researchers led by physicist Raffi Nazikian of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) and Craig Petty of General Atomics, stem from experiments conducted on the DIII-D National Fusion Facility operated by General Atomics for the DOE in San Diego. The results build on earlier work led by DIII-D scientists that demonstrated the conditions needed for steady-state operation of the core of ITER plasmas and established techniques to control these plasma instabilities.
The new research targets instabilities called Edge Localized Modes (ELMs) that develop at the periphery of fusion plasmas. Such instabilities can cause periodic heat bursts that can damage plasma-facing components in a tokamak. “In these results we observe the suppression of large ELMs, leaving small benign ELMs in plasmas that overlap with the conditions required for steady-state ITER operation,” said Nazikian, lead author of a scientific paper in IAEA’s Nuclear Fusion journal that lays out the findings. “These new experiments are a great example of successfully combining two separate advances, in this case 100 percent current drive in the plasma core and large ELM suppression in the edge, in an efficient and effective manner” said Petty, lead author of a prior Nuclear Fusion paper on the DIII-D findings relevant to the steady state core of the ITER plasma.
To keep large ELMs from occurring, researchers produce small magnetic ripples known as resonant magnetic perturbations (RMPs) that distort the smooth doughnut shape of tokamak plasmas. In the recent experiments, the scientists found that increasing the overall pressure of the plasma makes the plasma far more responsive to the ripples to better control ELMs and produce the conditions needed for steady-state ITER operation.
The higher pressure also increases a self-generated current that forms inside tokamak plasmas. This can be combined with particle beams and microwaves to drive and sustain the plasma current indefinitely in a so-called steady state. These higher self-generated currents make this process more efficient, and thus a fusion power plant more attractive.
When researchers projected the recent DIII-D results to ITER, they found that the higher plasma pressure and bootstrap current, together with additional sources of current from particle beams and microwaves, could create a fully sustainable steady-state regime that generates four-to-five times more power than it will take to heat the plasma and drive the current. Support for this work comes from the DOE Office of Science (FES) and the General Atomics Postdoctoral Research Participation Program administered by Oak Ridge Associated Universities (ORAU).
Going forward, physicists seek to create a greater percentage of bootstrap current to increase the fusion power gain and reduce the additional power needed to drive current. These DIII-D experiments produced about 30 percent self-driven current, although the bootstrap current fraction are projected to increase in ITER as its higher field means its ions collide less often, enabling current to be driven more easily.
“What we are currently working on in DIII-D is to develop the basis for fully steady-state high pressure plasma for ITER and beyond,” Nazikian said. “A central goal of the DIII-D program now is to identify ways in which high-pressure plasmas can drive most of the current required for steady-state reactors. We are undertaking major upgrades to the facility to meet this goal while exploring regimes that are free of dangerous ELMs.”
About General Atomics: General Atomics pioneers advanced technologies with world-changing potential. GA has been at the cutting edge of energy innovation since the dawn of the atomic age — for more than 60 years. With scientists and engineers continually advancing the frontier of scientific discovery, GA is serving our growing planet’s needs through safe, sustainable, and economical solutions across a comprehensive array of key energy technologies.
PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.
25 Comments on "Steady as she goes: Scientists tame damaging plasma instabilities"
Antius on Thu, 23rd Aug 2018 9:24 am
“When researchers projected the recent DIII-D results to ITER, they found that the higher plasma pressure and bootstrap current, together with additional sources of current from particle beams and microwaves, could create a fully sustainable steady-state regime that generates four-to-five times more power than it will take to heat the plasma and drive the current.”
The authors do not tell us whether this is thermal power generated within the plasma and within the walls of the Tokamak, or electrical power, after conversion losses.
The distinction is quite important, as it takes about 2.5 units of high quality heat in the lithium blankets to produce one unit of electric power. If the second is true, then this is an exciting development, although it still suggests that about a quarter of the power generated by a reactor will be needed just to maintain the reaction – a significant economic penalty.
An increase in operating pressure is a step in the right direction, as volumetric power production in fusing plasma is proportional to the square of ion density, and density is directly proportional to pressure.
Still, a fusion Tokamak can be expected to achieve a decade lower power density than a bog standard pressurised water reactor, using a lot more technology, exotic materials and general complexity. Given that nearly all energy is harvested from hard neutron radiation in the blankets, it will also be more maintenance intensive and may have a shorter lifetime. All things considered, a working fusion reactor would be a technological triumph, but economically it would be a turkey.
The smart money for the future is in more sustainable forms of nuclear fission.
makati1 on Fri, 24th Aug 2018 5:12 am
I would not want my name on the list of “scientists/engineers working on this boondoggle. History will list them as huge failures, wait and see. “…could lead to…” “…seeking to…” How many decades and Billion$ now?
peakyeast on Fri, 24th Aug 2018 7:03 am
As mentioned so many times before:
The creators of the universe has already constructed the best fusion reactors – using the fuels gravity to compress and ignite the reaction and with great efficiency and very little maintenance.
All we need to do is to collect the power produced. Even this very simple task is obviously beyond us.
onlooker on Fri, 24th Aug 2018 7:20 am
Yeah, nuclear fusion perpetually 20-30 years away
Antius on Fri, 24th Aug 2018 8:04 am
Has anyone else had the issue of submitting comments that then fail to appear? This seems to happen a lot.
Sissyfuss on Fri, 24th Aug 2018 8:11 am
And what would humanity do with an abundant clean source of energy? It would accelerate its wanton destruction of the natural world until all that’s left is dust and dreams.
onlooker on Fri, 24th Aug 2018 8:21 am
Yes, the problem is human nature and not wanting or being able to accept/conform to limits to growth
Antius on Fri, 24th Aug 2018 8:49 am
So long as our civilisation is confined to this dinky, finite ball of rock, barely 8000 miles across; even our greatest successes begin to look like failures. Using any resource of any kind, for even the most noble purpose, has to be seen as a tax of future generations.
The solution to this cannot be found in any sort of powerdown scenario, because that would limit resource availability even more and the sort of high-grade, localised resources that our ancestors has access to are now depleted. A complete industrial reversion would not be a retreat to simpler times; it would be a return to the stone age.
Antius on Fri, 24th Aug 2018 8:52 am
My repeated point regarding nuclear fusion is that the challenge is not about building a reactor that works and produces energy in a technical sense. That can almost certainly be done today. The challenge is in building a device that produces affordable energy – one that is compact and has high power density. Tokamak fusion is fundamentally unsuited to this goal, because energy is produced in very diffuse plasmas that have inherently low density because of their enormous temperature. To make matters worse, any energy that is released is released as very high energy neutrons, which makes a fusion reactor a radiological hazard comparable to a fission reactor.
To illustrate my point, ITER is projected to generate some 500MW of thermal power within a containment vessel of 800 cubic metres. That is a power density of 0.6MW per cubic metre. That is about 1% of the power density of a pressurised water reactor and about 0.1% of the power density of a sodium fast breeder reactor. This is unlikely to improve because Tokomak power density is a function of plasma pressure, which is limited by the field strength achievable using superconducting magnets.
Improvements in plasma physics, allow instabilities to be better understood and plasma pressure can modestly increase. But the physicists involve are basically trying to polish a turd, as plasma pressure would need to increase by an order of magnitude to close the gap with the fission reactor. This in itself is uneconomic under the regulatory regimes that govern nuclear applications in most Western countries.
onlooker on Fri, 24th Aug 2018 9:17 am
A complete industrial reversion would not be a retreat to simpler times; it would be a return to the stone age.— And that is where, we are headed due to not attempting moderation, instead headlong into technology , economic and population growth. and so depleting finite resources. But worse managing in the process to do the unthinkable. Destabilizing the living conditions of this planet. Mind boggling really
GregT on Fri, 24th Aug 2018 9:34 am
“Has anyone else had the issue of submitting comments that then fail to appear?”
Yes, that has happened to me before a couple of times. Once for two days. No idea why.
MASTERMIND on Fri, 24th Aug 2018 9:51 am
Antius
Its the cookies of the site..They fuck up some time and block comments..Clean your cache out..
I swear people on this board are all uneducated morons..
GregT on Fri, 24th Aug 2018 10:10 am
” A complete industrial reversion would not be a retreat to simpler times; it would be a return to the stone age.”
I have plenty of handtools, some that are even over 100 years old. No doubt they will last for generations, at least, if they are taken care of properly. Most, if not all electronics, would be useless within a few decades, and even steel reenforced concrete structures won’t likely be around too many generations from now. Modern industrial society is for the most part temporary. Without fossil fuels, much of what we take for granted today, will no longer exist.
The big difference between mankind’s future, and the Stone Age, will depend solely on how much destruction we manage to do to the Earth’s natural ecosystems, before we finally come to the realization that life on Earth is far more important for our survival than technology is. And, IMA, Stone Age man very likely did not miss the conveniences of modern industrial society.
Antius on Fri, 24th Aug 2018 10:11 am
MM wrote: “I swear people on this board are all uneducated morons..”
Well we can’t all be blessed like you 🙂
JuanP on Fri, 24th Aug 2018 10:18 am
“Has anyone else had the issue of submitting comments that then fail to appear?”
Yes, that has happened to me before a couple of times. Once for two days. No idea why.”
Same here. It happened to me a couple of times, I cleared my history and cookies and it stopped. Now I copy my comments before submitting them, just in case.
GregT on Fri, 24th Aug 2018 10:21 am
“Its the cookies of the site..They fuck up some time and block comments..Clean your cache out..
I swear people on this board are all uneducated morons..”
When it happened to me for two days, I couldn’t post on either my Mac, or my IPad. I have never cleared my cache because of this site, and sometimes I only have problems posting on individual threads, which has always fixed itself if I simply wait for a while and try again.
MASTERMIND on Fri, 24th Aug 2018 10:23 am
Greg
You are in a “Deep State” of paranoia..Better watch out for those black helicopters..
GregT on Fri, 24th Aug 2018 10:27 am
And yes, I also copy any longer comments that I’ve made before posting them. I’ve lost enough over the years to know better. Oh, and every once and a while when I try to post, I get the captcha screen telling me that my post is awaiting moderation.
Antius on Fri, 24th Aug 2018 10:30 am
“You are in a “Deep State” of paranoia..Better watch out for those black helicopters..”
In my country, thousands of people are arrested and imprisoned every year for comments they post on Facebook!
Just because you are paranoid, doesn’t mean that they aren’t out to get you.
GregT on Fri, 24th Aug 2018 10:30 am
MM,
The last black helicopter that I saw here was months ago.
MASTERMIND on Fri, 24th Aug 2018 12:50 pm
Russian Central Bank building goes up in flames
https://www.rt.com/news/436786-central-bank-moscow-fire/?utm_source=browser&utm_medium=push_notifications&utm_campaign=push_notifications
Take that Putin!
HAHAH!
MASTERMIND on Fri, 24th Aug 2018 12:58 pm
If Trump wanted to get Hillary locked up..He should have put her in his cabinet..
https://imgur.com/a/P7qVamU
Anonymous on Fri, 24th Aug 2018 3:27 pm
More vaporware.
Fusion research is dramatically overpromised. for Decades now. If you buy into it, you are Charlie Brown trying to kick the ball while Lucy holds it.
In addition, to just the basic technical issues, ITER is a MESS. Vast cost overruns, lots of featherbedding. And way too much cross country “collaboration” (setasides). And then the whole thing makes it 2-3 times as expansive and time consuming as if one country just did the project on their own.
Dredd on Sat, 25th Aug 2018 7:43 am
“Scientists tame damaging plasma instabilities”
Ah, the “look over there” gang.
Stay focused or there will be no need for fusion (Antarctica 2.0 – 7).
Pharmacycenter on Thu, 30th Aug 2018 1:22 am
Before scientists can capture and recreate the fusion process that powers the sun and stars to produce virtually limitless energy on Earth, they must first learn to control the hot plasma gas that fuels fusion reactions. In a set of recent experiments at the DIII-D National Fusion Facility, operated by General Atomics for the DOE, scientists have tamed a plasma instability in a way that could lead to the efficient and steady state operation of ITER, the international experiment under construction in France to demonstrate the feasibility of fusion power.