[HN Gopher] Fusion reactor is held together with tape
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Fusion reactor is held together with tape
Author : headalgorithm
Score : 77 points
Date : 2023-07-15 15:57 UTC (7 hours ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| p0w3n3d wrote:
| 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 wrote:
| You may mean "lede"?
| p0w3n3d wrote:
| Either I don't understand the reference, or I'm not
| understood. The "lead" is the first paragraph of the
| publication.
| trobertson wrote:
| That's what they're saying. It's spelled "lede":
| https://www.merriam-webster.com/dictionary/lede
| adventured wrote:
| 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 wrote:
| 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 wrote:
| 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.
| archo wrote:
| SPARC (tokamak) : https://en.wikipedia.org/wiki/SPARC_(tokamak)
| godelski wrote:
| 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.
| willis936 wrote:
| 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.
| Ekaros wrote:
| 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.
| ipcress_file wrote:
| Damn. I was hoping for a Red Green-designed Mr. Fusion.
| 1letterunixname wrote:
| 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 wrote:
| 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.
| epistasis wrote:
| 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 wrote:
| YBCO tape - Yttrium barium copper oxide
|
| ReBCO tape - Rare-earth barium copper oxide
| hammock wrote:
| 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
| adhesive_wombat wrote:
| Correct. Unidirectional bonding strip is the preferred Star
| Command terminology for the adhesive material.
| epistasis wrote:
| 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."
| codeflo wrote:
| That doesn't work for me. It's not really holding together
| the reactor as the headline would imply, it's holding the
| plasma.
| epistasis wrote:
| The tape is not holding the reactor together either, the
| entire headline must be taking with sliding meaning.
| jacquesm wrote:
| You _can_ buy it though:
|
| https://www.bruker.com/zh/products-and-solutions/superconduc...
| xyst wrote:
| You can buy it but there's no listed price lol
|
| Probably too much if I have to ask ha
| jacquesm wrote:
| If you need it badly enough I'm sure the price is
| reasonable. As my old boss used to say: better expensive
| than not for sale.
| [deleted]
| willis936 wrote:
| I've always heard this but when I'm spending millions is
| when I ask about price the most.
| jacquesm wrote:
| That makes good sense, but if there is no competing
| product and/or if there is an urgent need the price may
| not be all that elastic.
|
| For a commodity (say, server hardware or mechanical gear
| with well understood production processes) you'll
| probably be able to negotiate to some degree. But for a
| niche item such as this I'm not sure it would be nearly
| as effective. It would be interesting to know how many
| manufacturers of such tape there are and what the spread
| in pricing is. But usually they are not listed, it's
| 'call us for pricing' aka we'll see how much we can
| fleece you for.
| willis936 wrote:
| There are half a dozen companies making and selling REBCO
| commercially, so there is competition.
|
| In my personal experience with I&C equipment the number
| is much higher. When the market isn't making sense I make
| it myself or pay someone to make it. Knowing the price
| matters a lot.
| jacquesm wrote:
| Can you give a rough indication of what stuff like that
| costs?
| willis936 wrote:
| It depends on the specs. If you have very lenient needs
| then you can skirt by with STM32s and pay a few bucks per
| channel. Networked, higher sample rate, higher dynamic
| range, and industrial spec rating compound for costs up
| to $1000 per channel. How local high quality I/O is to
| fast and reliable compute is often a relevant factor not
| serviced by existing markets. Cabling, connector, panels,
| cabinet, power supplies, and power distribution costs are
| also priced for the application. There are very few
| surprises except when having weird combinations of
| requirements (as is often the case in interesting
| applications).
|
| My original point is that "if you have to ask it's too
| much" is never true. What is true is "if you have to ask
| then it is a high price, low volume market and there is
| an expectation of a discussion between the seller and
| buyer". It's also true that "the price is too much when
| it's too much", but that isn't a witty adage.
| jacquesm wrote:
| Ah, sorry, I meant the superconducting tape. But another
| commenter has already given an indication. I interpreted
| your original comment as spending millions on such tape.
| willis936 wrote:
| More than $10 / m, less than $100 / m.
| jacquesm wrote:
| Thank you!
| ImPostingOnHN wrote:
| that is probably why the actual adage is "if you have to
| ask, you can't afford it", which is usually true for most
| consumers
| willis936 wrote:
| How is "if you have to ask it's too much" different than
| "if you have to ask, you can't afford it"? The ability to
| afford something is independent from having to ask.
| Having to ask is a result of being in the market as a
| buyer and the seller not publicly stating the price. Most
| people in market likely know they can afford it. So the
| saying isn't marginally wrong, it's very wrong.
| akiselev wrote:
| The price isn't listed because everything is made custom to
| order. Nobody orders generic HTS tape.
|
| I've heard prices ranging from $500 to $1,500 per kiloAmp-
| meter depending on order volume and geometry, so a meter of
| tape with current carrying capacity of 10,000 amps would
| cost $5,000-15,000.
|
| I have no idea what CFS uses but some fusion designs
| require current carrying capacity exceeding 150 kA so it
| gets expensive really fast when a meter of tape costs
| $75,000+.
| jacquesm wrote:
| That puts the 10000 km at the upper range of
| 'astronomical'.
| willis936 wrote:
| Astronomical indeed. How would CFS convince investors to
| give then 1.8 Bn USD to build a machine it one of the raw
| components cost 750 Bn USD? It's safe to say that
| estimate is wrong.
| akiselev wrote:
| My info is years old so I wouldn't be surprised if all
| the fusion companies are paying an order of magnitude
| less.
|
| By the time they're making 10,000 km a year, it'll be
| even cheaper.
| ck2 wrote:
| 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 wrote:
| 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.
| ben_w wrote:
| 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).
| RobotToaster wrote:
| Wouldn't a superconductor theoretically be able to carry
| infinite amps? since it has zero resistance? (I=V/R etc)
| Sanzig wrote:
| 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 wrote:
| More current produces a stronger magnetic field around the
| conductor, and superconductors usually have a maximum
| magnetic field beyond which they stop superconducting.
| WJW wrote:
| 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.
|
| See also https://en.wikipedia.org/wiki/Superconducting_magnet
| #Magnet_...
| ben_w wrote:
| 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.
| jacquesm wrote:
| But you wouldn't be able to use it in that application because
| you can't keep it cool enough.
| willis936 wrote:
| Tens of kiloAmps.
| explaininjs wrote:
| Take down the world for the low low price of 4 missiles! Sign
| me up.
| Animats wrote:
| 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 wrote:
| 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
| Animats wrote:
| > 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 1mm 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.
| willis936 wrote:
| 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
| exabrial wrote:
| These are the kind of clickbait headlines I enjoy.
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