Fusion reactor is held together with tape
spectrum.ieee.org
spectrum.ieee.org
Great headline.
ReBCO tape - Rare-earth barium copper oxide
https://www.bruker.com/zh/products-and-solutions/superconduc...
Probably too much if I have to ask ha
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.
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.
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.
thank you for asking, I will answer to the best of my ability to explain how the two differ in the english language for someone who is genuinely curious and asking in good faith:
the answer is that a thing can be priced correctly for some, but still not affordable to everyone who wants one
for example, a superyacht for sale requires asking for the price, and it might be priced well, perhaps at half the going rate for superyachts, but still unaffordable to me and most people – the same goes for giant mansions, private planes, solid gold toilets, compete dinosaur skeletons, etc.
in essence, me not being able to afford a thing, is a description of me, whereas a thing being "too much" is a description of that thing, and applies to everyone buying it, not just me
the saying obviously doesn't apply to the few people rich enough to buy any thing they want
If anything, in english, it is shorthand for "too much for the value it presents", since a superyacht still has value, and thus a million dollars might not be "too much", but I still can't afford one.
Indeed, both this example and the originating one help illustrate both the difference between the two and the utility of the difference: if there was no difference, the saying wouldn't make sense, as you pointed out. But it does make sense, hence why it's a saying, so the two terms must be different, and that difference is that one term applies to the thing as it relates to the payer, and the other term applies to the thing in isolation
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+.
By the time they're making 10,000 km a year, it'll be even cheaper.
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
(I have occasional daydreams of a global power grid; four of these reactors would have enough superconductor to go around the equator).
See also https://en.wikipedia.org/wiki/Superconducting_magnet#Magnet_...
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.
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
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.
Experiments like DIII-D have spent the last 20-30 years trying to eek out a few dozen percent more performance by fine-tuning the shape of the plasma & the current distribution inside it, etc. Some of the configurations they've tested are right on the edge of instability, requiring high-speed control systems to walk up to (but not over!) the edge of an invisible cliff in parameter space. If we learned anything from Three-Mile-Island and Chernobyl, we do not want that kind of twitchiness in a nuclear context. Sure, the worst-case fallout isn't as bad, but the multi-billion dollar reactor could be crippled for months/years, depending on how things play out. Boring is good, in a nuclear context.
The downside to the use of brute force is literally the forces involved. The original design (a class project) estimated that the structural steel required to hold the coils of a reactor together would run almost $5 billion & account for ~80% of the total cost of the core. (See Table 11 of [0]) This is for a power plant that would deliver ~ 250MW of electricity. The total plant cost would probably be $10-15B, which is not economical. However, they say "there likely exists a better economic optimization of magnetic field strength versus mass for a full power plant." Most likely, that involves reduced field but larger size reactors, which might be slightly more expensive but significantly more powerful. (IIRC, the latest designs for ARC are inching up toward 4 meters major radius.)
I doubt this approach can reach economic breakeven, but I think they have a good shot at exceeding energy breakeven. OTOH, I'm a physicist rather than an engineer, and I work for a competitor, so take my opinion with a grain of salt.
[0] https://library.psfc.mit.edu/catalog/reports/2010/15ja/15ja0...
Technically, grabbing a massive object at 20-77K will result in burns.
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.
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
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.