Fusion reactor is held together with tape

https://spectrum.ieee.org/fusion-2662267312

by headalgorithm • 3 years ago

86 63 3 years ago

spectrum.ieee.org

ben_w2• 3 years ago

10,000 km? I wonder how many amps that can carry.

(I have occasional daydreams of a global power grid; four of these reactors would have enough superconductor to go around the equator).

willis93610• 3 years ago

Tens of kiloAmps.

jacquesm8• 3 years ago

But you wouldn't be able to use it in that application because you can't keep it cool enough.

explaininjs• 3 years ago

Take down the world for the low low price of 4 missiles! Sign me up.

RobotToaster• 3 years ago

Wouldn't a superconductor theoretically be able to carry infinite amps? since it has zero resistance? (I=V/R etc)

Sanzig• 3 years ago

There is a critical magnetic field at which superconductors stop being superconductive [1]. Generally, a superconductor carrying a lot of current suddenly becoming conductive is a bad thing. This is directly related to the maximum current density in a particular superconducting wire, so you need larger cross sections to increase the current carrying capability.

[1] https://en.wikipedia.org/wiki/Critical_field

ohazi• 3 years ago

More current produces a stronger magnetic field around the conductor, and superconductors usually have a maximum magnetic field beyond which they stop superconducting.

WJW• 3 years ago

Not really, at a certain amount of current (how much exactly depends of the shape and material of the superconductor in question) it "quenches", where it abruptly goes back to being a material with non-zero resistance. Since there is usually a ton of current already flowing through the material, this usually leads to damage as the former superconductor heats up rapidly.

ben_w2• 3 years ago

Nah, but easy misconception. Rearrange it as V=IR and that formula tells you there’s no voltage drop across the superconducting bit regardless of current.

lambdatronics3• 3 years ago

ReBCO still isn't practical for grid transmission AFAIK. It needs to be cooled to something like 20 K to achieve high current. That's ~4x warmer than traditional superconductors (~4.5 K) but it's still not "high temperature" by anyone else's standards.

archo• 3 years ago

SPARC (tokamak) : https://en.wikipedia.org/wiki/SPARC_(tokamak)

epistasis3• 3 years ago

What a weird let down that this is actually thousands of kilometers of super advanced super conducting tape, and not the more mundane varieties available at my local hardware store.

Great headline.

visarga• 3 years ago

YBCO tape - Yttrium barium copper oxide

ReBCO tape - Rare-earth barium copper oxide

jacquesm8• 3 years ago

You can buy it though:

https://www.bruker.com/zh/products-and-solutions/superconduc...

xyst• 3 years ago

You can buy it but there’s no listed price lol

Probably too much if I have to ask ha

hammock• 3 years ago

The headline relies on our shorthand of “adhesive tape” as “tape.” There is no adhesive in this tape and it’s not holding anything together. “Tape” simply refers to the geometrical shape of the product

epistasis3• 3 years ago

Well there's a second double meaning of the "held together" phrase in the headline too, as it's not adhesive properties of the tape but the electromagenetic properties of the superconducting tape that's doing the "holding."

adhesive_wombat• 3 years ago

Correct. Unidirectional bonding strip is the preferred Star Command terminology for the adhesive material.

ck2• 3 years ago

We can still make our own x-ray machines with mundane scotch tape for giftwrapping

https://google.com/search?q=scotch+tape+x-ray+machine

genewitch• 3 years ago

I knew about this before i saw it on House M.D., but it was still good to see it spread further. It was usually mentioned in the same paragraph as Certs mints making sparks in your mouth.

exabrial• 3 years ago

These are the kind of clickbait headlines I enjoy.

adventured• 3 years ago

Iter will be humiliated in exactly the same way and for exactly the same reasons that the US Governnment's efforts to crack the human genome were humiliated by Venter & Celera moving at a far faster pace. While the smaller, faster, more nimble approaches will race on ahead, Iter will lag badly.

doctorwho42• 3 years ago

Ironically, the US government had the opportunity to fund this project when it comes as still entirely contained at MIT. They didn't, and so the fusion people at MIT spun a startup to be able to receive funding and collaborate with the scientists still at MIT.

So the government (1) could have been at the forefront of this project through funding MIT, (2) its tech and results would be entirely public, (3) we may have already had first plasma with sparc by now because the time it took MIT to accept they were no longer going to receive tokamak levels of funding - and then come up with CFS as a solution to get private funding for work within MITs system

sanxiyn• 3 years ago

Celera used HGP data but not vice versa, so that's not a fair comparison. Celera's use of shotgun sequencing was an inspired choice, but even in retrospect it wasn't obviously superior to HGP's chain termination. It was high risk high return bet that could well have failed, while HGP made a conservative choice.

Sequencing has two parts of reading and assembling. Shotgun sequencing makes reading easier and assembling harder. Computing infrastructure of 1990s was barely enough to assemble shotgun reads of human genome, and Celera was overly optimistic from its success on fruit fly genome. They were saved by miracles and heroics at the end.

Of course shotgun sequencing is much better now because we have much better computing infrastructure.

ipcress_file• 3 years ago

Damn. I was hoping for a Red Green-designed Mr. Fusion.

1letterunixname• 3 years ago

Riding high on a 1985 Ford LTD station wagon piloted by Doc Brown with Harold pointing out some obvious omission at just the moment of catastrophic failure.

dale_glass• 3 years ago

I think this is very cool research, but I'm almost certainly neither fusion nor fission will be a significant part of the solution.

Fission has already lost the competition, being far too expensive, and not getting any better.

Fusion will take decades to get to production, let alone to being competitive.

Meanwhile, renewables are extremely amenable towards mass manufacturing, mass deployment, and quick iteration, something neither fusion nor fission are good at. We'll ultimately solve the problem by inelegant brute force rather than by a small number of amazingly engineered wonders.

Animats2• 3 years ago

How promising is the physics of this thing? The basic claim here is that that, with a better magnet, tokomaks can produce useful power. Is that a valid claim?

How does energy come out? As neutrons? Something with a charge? What's the first wall, the thing the emitted particles hit?

These are the standard fusion reactor questions, and the article avoids all of them. Seeing an article this dumbed down from the IEEE is disappointing.

DennisP• 3 years ago

Yes it's valid. Tokamak scaling is very well established: the output scales with the square of reactor size but the fourth power of magnetic field strength. Double the field, 16X the output. That's why CFS can build reactors much smaller than ITER to achieve basically the same thing.

80% of the energy from D-T fusion is neutron radiation. The CFS plan to deal with it is this:

- Surround the inner war with molten FLiBe salt which functions as both coolant and tritium breeding blanket.

- The inner wall is 3D-printed and replaced annually.

- The magnetic coils are hinged so they can be opened up to replace the inner wall. MIT proved several years ago that they could do this in REBCO tape without adding significant electrical resistance.

This old presentation from MIT's Dennis Whyte goes into more detail: https://www.youtube.com/watch?v=KkpqA8yG9T4

Animats2• 3 years ago

This old presentation from MIT's Dennis Whyte goes into more detail: https://www.youtube.com/watch?v=KkpqA8yG9T4

Oh, that's fascinating. The tape has fantastic properties. The superconductive layer is only 1μm thick. The superconductor itself doesn't quench at high magnetic field strengths, which is different from most other superconductors. The insulator is stainless steel! Compared to a superconductor, anything with more resistance is an insulator.

His key points are 1) now we can have much stronger magnetic fields, and 2) with stronger magnetic fields, some of the other hard problems, such as plasma instability, go away. Also, this tape is much easier to work with than other superconductors. Not brittle, less damaged by radiation, not too hard to terminate, superconducts below 43K. So some expensive engineering problems also go away.

All this is very encouraging.

willis93610• 3 years ago

Empirically derived scaling laws here (5 minute mark for the spark notes, but the whole video is worth watching). This is a lay-consumable presentation. You could spend a grad program reading the papers to build up this understanding from first principles.

https://youtu.be/xJ2h3vbOag4

godelski• 3 years ago

The title here implies hacky, but this definitely isn't. But next chance you get, go visit a physics or chemistry lab at a top university. I think a lot of people would be surprised by how hacky things often are in academic labs. You'll find nuclear reactors that are built by students as well as equipment built by them. Then remember that physicists and chemists aren't engineers; mechanical, electrical, nor software. I wouldn't be surprised if you found a fusion reactor in an academic lab held together by tape, metaphorical or literal.

Ekaros• 3 years ago

I would actually guess that Engineering in Universities would also be only marginally better. In research and such good enough really does get quite far. Even if you could fabricate the perfect part. Re-using or jury rigging something likely is still done to save time, money and effort.

willis93610• 3 years ago

I worked at a university magnetic confinement research lab for a few years. It was certainly scrappy but no literal duct tape. What university labs can accomplish on a tight budget is impressive. Literally plucking vacuum pumps out of the trash. I'd do it again if it could pay the bills.

p0w3n3d3• 3 years ago

Title: "Fusion reactor is held together with tape" Lead: Fusion reactor requires 10000 kilometers of this superconducting tape

Title: "spacex rocket is glued with bubblegum" Lead: 16 thousands of elves must chew resin from the Yggdrasil for 100 years to create a bubblegum that will hold spacex rocket together

bcraven• 3 years ago

You may mean "lede"?

p0w3n3d3• 3 years ago

Either I don't understand the reference, or I'm not understood. The "lead" is the first paragraph of the publication.

klyrs• 3 years ago

Although “high temperature” might suggest something that could burn you, HTS materials operate in a range of 20 to 77 kelvins (around –200 to –250 °C).

Technically, grabbing a massive object at 20-77K will result in burns.

joshspankit• 3 years ago

I wish I could flag ieee.org for clickbaiting.

lambdatronics3• 3 years ago

I toured a multi-million-dollar electron microscope at ORNL. They had a piece of tissue paper taped to the side. I asked about it, and they said that it was an airflow monitor. It turned out to be more sensitive than some very expensive sensors, according to the tour guide.

Fusion reactor is held together with tape

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