Fusion Experiment Demonstrates Cheaper Stellerator Using Creative Magnet Workaround (pppl.gov) 41
Popular Science reports that early last week, researchers at the U.S. Energy Department's Princeton Plasma Physics Laboratory revealed their new "MUSE" stellarator — "a unique fusion reactor that uses off-the-shelf and 3D-printed materials to contain its superheated plasma."
The researchers' announcement says the technique suggests "a simple way to build future devices for less cost and allow researchers to test new concepts for future fusion power plants." Stellarators typically rely on complicated electromagnets that have complex shapes and create their magnetic fields through the flow of electricity. Those electromagnets must be built precisely with very little room for error, increasing their cost. However, permanent magnets, like the magnets that hold art to refrigerator doors, do not need electric currents to create their fields. They can also be ordered off the shelf from industrial suppliers and then embedded in a 3D-printed shell around the device's vacuum vessel, which holds the plasma.
"MUSE is largely constructed with commercially available parts," said Michael Zarnstorff, a senior research physicist at PPPL. "By working with 3D-printing companies and magnet suppliers, we can shop around and buy the precision we need instead of making it ourselves." The original insight that permanent magnets could be the foundation for a new, more affordable stellarator variety came to Zarnstorff in 2014. "I realized that even if they were situated alongside other magnets, rare-earth permanent magnets could generate and maintain the magnetic fields necessary to confine the plasma so fusion reactions can occur," Zarnstorff said, "and that's the property that makes this technique work." [...]
In addition to being an engineering breakthrough, MUSE also exhibits a theoretical property known as quasisymmetry to a higher degree than any other stellarator has before. It is also the first device completed anywhere in the world that was designed specifically to have a type of quasisymmetry known as quasiaxisymmetry. Conceived by physicist Allen Boozer at PPPL in the early 1980s, quasisymmetry means that although the shape of the magnetic field inside the stellarator may not be the same around the physical shape of the stellarator, the magnetic field's strength is uniform around the device, leading to good plasma confinement and higher likelihood that fusion reactions will occur. "In fact, MUSE's quasisymmetry optimization is at least 100 times better than any existing stellarator," Zarnstorff said.
"The fact that we were able to design and build this stellarator is a real achievement," said Tony Qian, a graduate student in the Princeton Program in Plasma Physics, which is based at PPPL.
Also covered by Gizmodo. Thanks to Slashdot reader christoban for sharing the news.
The researchers' announcement says the technique suggests "a simple way to build future devices for less cost and allow researchers to test new concepts for future fusion power plants." Stellarators typically rely on complicated electromagnets that have complex shapes and create their magnetic fields through the flow of electricity. Those electromagnets must be built precisely with very little room for error, increasing their cost. However, permanent magnets, like the magnets that hold art to refrigerator doors, do not need electric currents to create their fields. They can also be ordered off the shelf from industrial suppliers and then embedded in a 3D-printed shell around the device's vacuum vessel, which holds the plasma.
"MUSE is largely constructed with commercially available parts," said Michael Zarnstorff, a senior research physicist at PPPL. "By working with 3D-printing companies and magnet suppliers, we can shop around and buy the precision we need instead of making it ourselves." The original insight that permanent magnets could be the foundation for a new, more affordable stellarator variety came to Zarnstorff in 2014. "I realized that even if they were situated alongside other magnets, rare-earth permanent magnets could generate and maintain the magnetic fields necessary to confine the plasma so fusion reactions can occur," Zarnstorff said, "and that's the property that makes this technique work." [...]
In addition to being an engineering breakthrough, MUSE also exhibits a theoretical property known as quasisymmetry to a higher degree than any other stellarator has before. It is also the first device completed anywhere in the world that was designed specifically to have a type of quasisymmetry known as quasiaxisymmetry. Conceived by physicist Allen Boozer at PPPL in the early 1980s, quasisymmetry means that although the shape of the magnetic field inside the stellarator may not be the same around the physical shape of the stellarator, the magnetic field's strength is uniform around the device, leading to good plasma confinement and higher likelihood that fusion reactions will occur. "In fact, MUSE's quasisymmetry optimization is at least 100 times better than any existing stellarator," Zarnstorff said.
"The fact that we were able to design and build this stellarator is a real achievement," said Tony Qian, a graduate student in the Princeton Program in Plasma Physics, which is based at PPPL.
Also covered by Gizmodo. Thanks to Slashdot reader christoban for sharing the news.
Great news (Score:4, Funny)
I'm glad my fusion powered anti-gravity FTL flying car is still on schedule to arrive at now + 50 years.
Re: (Score:2)
The above comment was a joke btw. It's awesome so much progress is being made with our best minds working on it. Appreciate all the work being done to make it happen. Hope it gets done before its too late.
Re: (Score:2)
But the marketing said 40 and the cup holder is still in beta!
Re:Great news (Score:5, Informative)
That's not the way fusion reactors work. When containment fails, at most you get a small localized explosion, but most likely the reaction just stops. From
https://www.iaea.org/topics/en... [iaea.org] : "Every shift or change of the working configuration in the reactor causes the cooling of plasma or the loss of its containment; in such a case, the reactor would automatically come to a halt within a few seconds, since the process of energy production is arrested, with no effects taking place on the outside. For this reason fusion reactors are considered to be inherently safe."
This, and the different fuel source, make fusion reactors very attractive when compared to fission reactors. In a worst case scenario you'd have some limited localized fallout from the activated materials in the reactor lining getting spread about by a low yield explosion.
I guess that the main reason development is so slow, apart from the fact that getting it to work is really hard, is that it has limited military applications, and that it would compete with already established fission reactor operators.
Weird (Score:3)
Huh, I submitted this same article a week ago, got an email that it was accepted, then it was immediately removed for Slashdot's front page. Now it's back under someone else's name.
Re: (Score:2)
You was robbed!! Demand your money back and call the police.
Re: (Score:2)
You got AI'ed.
Re:Weird (Score:5, Funny)
The two comments were put into a stellerator and fused. That's a new feature of AI powered Office 365.
Re: (Score:3)
Whoops, this one is mine, I was looking at the /. editor's name. Not sure why it disappeared and reappeared... Don't mind me, I'm old and my eyes are near gone...
Re:Do people realize this is nuclear energy? (Score:5, Insightful)
Fuck off. Fusion do not produce HLW (high level radioactive waste) -- so attempting to associate it with fission stigma is just a propaganda move not anything based on fact. Fusion plants structures when replaced would be considered LLW - low level waste "which usually does not require shielding during handling and transport. Most LLW is suitable for shallow land burial and is often compacted or incinerated before disposal to reduce its volume." Also tritium leakage is a non-issue given how little fuel is in the reactor at any given time. But even if you're unnecessarily paranoid, if there's loss of containment the plasma won't have enough energy to melt through anything. There no pressure buildup or runaway heating. If there is a loss of power absolutely NOTHING will happen. Second, any residual radioactivity in the walls will be diminished to zero within a few decades. It's not gonna be a Chernobyl, not even close. By the way, tritium isn't all that dangerous as you make it sound. You can buy lots of stuff with tritium in it, like these watches: https://twobrokewatchsnobs.com... [twobrokewatchsnobs.com]
Re:Do people realize this is nuclear energy? (Score:5, Informative)
Fusion do not produce HLW (high level radioactive waste)
Of course they don't, since those are by definition the waste produced in a fission reactor.
However, neutron activation is a reality, and one that will have to be come to grips with.
Fusion plants structures when replaced would be considered LLW
Low-level radioactive waste (LLW) is defined as any radioactive waste not from the fission process itself.
It can still be highly radioactive.
If there is a loss of power absolutely NOTHING will happen.
That is simply not true.
The amount of heat in the reactor at any moment in time is dependent upon the power capacity of the reactor.
You wouldn't want to be anywhere near a 100GW fusion reactor that lost magnetic confinement.
Smaller reactors would be much safer.
Second, any residual radioactivity in the walls will be diminished to zero within a few decades.
This is true, but you still need to store literal tons of radioactive material that need to be regularly swapped out, replaced, and stored.
Still better than fission, arguably, but to pretend it doesn't have problems is absurd.
By the way, tritium isn't all that dangerous as you make it sound. You can buy lots of stuff with tritium in it, like these watches: https://twobrokewatchsnobs.com... [twobrokewa...obs.com...] [twobrokewatchsnobs.com]
Tritium can be quite dangerous. On your skin though? Not at all. It simply can't penetrate.
Breathe a good bit of it though, and your cancer risks skyrocket.
DD fusion produces incident tritium (they're the primary source of fast neutrons that destroy the containment structure)
Ultimately, tritium would dissipate pretty damn quickly to a safe concentration, so it's probably not too worrisome.
Re: (Score:2)
The fusion reactions are happening basically in high vacuum.
The amount of fuel is extremely low.
It is unlikely we will ever have a fusion reactor, that is so big that a failure in the magnetic field, will have negative consequence s to the reactor.
Re: (Score:2)
The fusion reactions are happening basically in high vacuum.
At room temperature, yes.
At 150 million C, the pressure is high enough to breach the coulomb barrier, obviously.
The amount of fuel is extremely low.
Yes, it is, relatively speaking.
It is unlikely we will ever have a fusion reactor, that is so big that a failure in the magnetic field, will have negative consequence s to the reactor.
You're probably right, if no reason other than the difficulty getting enough fuel to power one.
100GW is a common cited target, and regardless of fuel in the reactor, 100GW of thermal flux is 100GW of thermal flux.
100GW requires around a kilogram of deuterium and tritium (combined) per day.
At any one time, there's enough shit in that reactor at 150 million degree
Re: (Score:2)
At 150 million C, the pressure is high enough to breach the coulomb barrier, obviously.
Oh, I can help you with that!
Just call it what it is: 10 kV or so of electrical potential, a.k.a. about half the voltage from your mom's basement's color TV.
And all of a sudden it doesn't sound that dangerous anymore now, does it?
Re: (Score:2)
Oh, I can help you with that!
Oh, I sincerely doubt that.
Just call it what it is: 10 kV or so of electrical potential, a.k.a. about half the voltage from your mom's basement's color TV.
How are you supposed to help me if you don't know the difference between an electronvolt and a volt?
And all of a sudden it doesn't sound that dangerous anymore now, does it?
Good question. Little physics question for you.
Express the energy in a few grams of 50/50 D/T flying around at 100KeV, in tons of fucking TNT.
Re: (Score:2)
huh? Who is flying around at 100keV .. you mean around 10keV. Let's assume it's a 10 gigajoule reactor .. which is a massive amount .. that's 2 tons of TNT. But the reactor is obviously already designed to handle that much heat because it's a 10GW fucking reactor. What we're saying is that the magnetic field somehow instant collapses and the plasma hits the reactor surface .. that force is not going to hit one spot it'll be spread around. Also how about if it's a 1 GW reactor instead .. hmm.
Re: (Score:2)
The Coulomb barrier for DD fusion is 0.1MeV, or 100KeV.
The only thing that can happen at 10KeV are tunneled fusion reactions, which are inconsequential to the discussion at hand.
Re: Do people realize this is nuclear energy? (Score:2)
First, potential - the word I used - is not eV, it's just V.
Only once you start putting stuff inside, e.g. 'e', it becomes eV.
Second, it's 10 kV, not 100 kV.
Third, I have no idea of TNT, nor do I care. The energy is a lot, that's why we're building fusion reactors. But it isn't escalating. The heat is already being handled, mostly, the worst thing it'll happen is melt a few expensive components that would otherwise be protected by the magnetic fields. The pressure is in a tiny, tiny volume, and once you br
Re: (Score:2)
First, potential - the word I used - is not eV, it's just V.
The coulomb barrier can't be broken by any amount of potential. That's not how it works.
It takes energy.
Can you achieve that much energy with a potential of that magnitude?
Still not enough variables.
Only once you start putting stuff inside, e.g. 'e', it becomes eV.
Yes, only once you have stuff inside can fusion happen. That's kind of how it works.
Second, it's 10 kV, not 100 kV.
No, it's 0.1MeV.
That's 100 KeV.
Stop using volts. It is wrong.
Third, I have no idea of TNT, nor do I care. The energy is a lot, that's why we're building fusion reactors. But it isn't escalating. The heat is already being handled, mostly
That heat is being handled by the now missing electromagnetic field, beyond which is a fucking vacuum.
the worst thing it'll happen is melt a few expensive components that would otherwise be protected by the magnetic fields.
Among those expensive components are human beings working in
Re: Do people realize this is nuclear energy? (Score:2)
The coulomb barrier can't be broken by any amount of potential. That's not how it works.
That's exactly how it works.
The "Coulomb barrier" is a potential. You can break it any day of the week with an uncharged particle - only once you put a charged particle inside the field does it require energy. The more energy the more charge your particle has.
No, it's 0.1MeV.
No, it's not. It's 3 to 10 kV [wikipedia.org].
That heat is being handled by the now missing electromagnetic field, beyond which is a fucking vacuum.
The magnetic field handles containment, not heat. Vacuum will prevent convection, but not radiation.
This is hand-wavy bullshit. The energy in the volume is known.
It's not an enegy, it's a (kind of) energy density (i.e. per-particle, not total).
To illustrate the difference: I work wit
Re: (Score:2)
That's exactly how it works.
No, it isn't.
The "Coulomb barrier" is a potential. You can break it any day of the week with an uncharged particle - only once you put a charged particle inside the field does it require energy. The more energy the more charge your particle has.
No, it's not. And no, you cannot.
The coulomb barrier cannot be broken by any uncharged particle, because it by definition is the energy required for two nuclei- always and invariably charged- to react.
That energy requirement is higher or lower depending on the number of protons in the nucleus.
No, it's not. It's 3 to 10 kV [wikipedia.org].
1) you misquoted. It's KeV, not KV.
Repeat after me: They are not the same fucking thing.
However, the wiki page is misleading.
The coulomb barrier for deuterium-deuterium fusion is 100KeV.
You can howe
Re: (Score:2)
The particles that are at 150 million C are spread out all around the reactor in the plasma. If the reactor is producing a gigajoule and the magnetic containment instantly collapses, that's only the equivalent a couple hundred kilograms of TNT. That's not enough to do damage to anything outside the reactor's building. It may cause an expensive reactor shutdown and repair process, but nobody's dying from that unless there were next to it inside the building. For comparison the Oklahoma city bombing in 1995 w
Re: (Score:2)
That's not enough to do damage to anything outside the reactor's building.
Oh absolutely. I wasn't trying to imply it was going to cause damage outside of the building.
You just wouldn't want to be anywhere near that thing when it popped.
Re: (Score:2)
You wouldn't want to be anywhere near a 100GW fusion reactor that lost magnetic confinement.
Or what? Say, if you were on the parking lot, a mile or so out?
Yes, the heat trapped in the reactor will essentially fuck up all the devices, melt a few components together, and maybe, maybe, the escaping steam and/or hot plasma will blow a roof or two off.
That's it.
You're likely to hear a loud *boom* and an earth-shattering event on the parking lot, and survive if you're inside your car (so you don't get incidental debris falling on your head).
A block or two away you'll maybe hear the explosion, but not ev
Re: (Score:3)
Or what? Say, if you were on the parking lot, a mile or so out?
Ya, you'd be fine. What's your point?
Yes, the heat trapped in the reactor will essentially fuck up all the devices, melt a few components together, and maybe, maybe, the escaping steam and/or hot plasma will blow a roof or two off.
If the reactor is large enough, it will cause catastrophic failure of the containment vessel, nearly instantly.
You're right, fuck up all the devices, melt a few components together, and fuck the next part- but more importantly- fucking kill people who work in that building.
This isn't FUD or scaremongering, it's just a fact. The reactor is dangerous if it loses power.
You're likely to hear a loud *boom* and an earth-shattering event on the parking lot, and survive if you're inside your car (so you don't get incidental debris falling on your head).
Absolutely. What's your point?
The most likely source of blast would be a nitrogen tank or two that got ruptured because... reasons.
That and the several hundred pounds of TNT worth of energy suddenly expan
Re: Do people realize this is nuclear energy? (Score:2)
People die at their workplace all the time.
That's something to be dealt with, surely, but it's not potentially a planet-posioning Chernobyl or Fukushima event, of which we can't, as a species, afford more than a dozen or so.
Re: (Score:1)
Equating all nuclear fission power plants with Chernobyl is like equating all passenger jets with the 737 MAX. Only the Soviets were so uncaring for public safety to build a nuclear power plant like that, and once that accident happened all reactors like it were decommissioned or underwent considerable modifications. Nobody is going to build another power plant like Chernobyl so bringing it up shows ignorance on the matter. It is fear of most anything nuclear like you've demonstrated that causes me to be
Re: (Score:2)
> Only the Soviets were so uncaring for public safety to build a nuclear power plant like that,
Years ago a commenter here claimed to have been involved with Chernobyl and the way it went down is that a grad student in nuclear engineering wanted to run his pet theory experiment on the Chernobyl reactor.
Everybody said no up and down the chain.
Bu his father was high up in the Politburo and ordered it.
Soviets do what they're told.
It sounds plausible enough that a smart researcher could probably find the fath
Re: (Score:2)
That sounds interesting, do you recall more specific details or the comment itself?
Re: (Score:1)
Depends on the kind of fusion process.
The neutron radiation will indeed everything around the reactor highly radioactive.
So your "waste handling idea" is complete nonsense.
However when the current questions how to properly fusion are answered, we likely jump to a process that produces a low amount of neutrons, which in turn can be used to breed tritium instead of killing gthe reactor walls :P
Re: (Score:2)
Why are you lying??
Re: (Score:2)
Why are you lying??
First time reading one of his posts, huh? I don't know whether to envy you or feel sorry for you.
Re: Do people realize this is nuclear energy? (Score:2)
Send STL files (Score:2)
My electric bill is too damn high.
Computational Modelling Threshold Crossed (Score:5, Informative)
But Does It Work? (Score:4, Interesting)
I didn't see anything in the article to suggest that the reactor has actually successfully produced a fusion reaction. I'm not talking about net power gain. I mean I didn't read anything to suggest that they've even induced fusion in the reactor at all. The off the shelf permanent magnets don't seem to have enough power to actually confine plasma to fusion temperatures. I'm pretty sure the only thing this "reactor" has done is show that the magnetic field they've generated is actually consistent with with their mathematical models, meaning it's not actually a reactor at all as there is no reaction taking place inside it.
The reason electromagnets, usually superconducting magnets, are used in fusion devices is that permanent magnets simply can't generate enough Teslas of magnetic flux to confine a plasma of fusion temperatures. Proving that you can make a quasisymetrical field with permanent magnets for a fusion reactor is pointless if you can't make permanent magnets with enough strength to hit net energy gain in a fusion reaction. This is maybe an interesting theoretical paper and a good thesis project for some grad students or post-docs, but it's not really advancing fusion power research.