[HN Gopher] MIT-designed project achieves major advance toward f...
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       MIT-designed project achieves major advance toward fusion energy
        
       Author : klintcho
       Score  : 214 points
       Date   : 2021-09-08 19:50 UTC (3 hours ago)
        
 (HTM) web link (news.mit.edu)
 (TXT) w3m dump (news.mit.edu)
        
       | NiceWayToDoIT wrote:
       | I remembered that in 2018 Japanese team manage 1200 T peak power.
       | http://www.sci-news.com/physics/strongest-magnetic-field-ach...
       | 
       | In comparison, 20T does not look much, but again it is, I wonder
       | with the Japanese technique what is the highest continuous
       | magnetic field.
        
       | sbierwagen wrote:
       | Every mass-media article on fusion seems obliged to use "the fuel
       | comes from water" line. I wonder if a "just says in mice" style
       | harassment campaign would get journalists to stop saying this.
        
       | FredPret wrote:
       | It's now only twenty years away!
        
       | dfdx wrote:
       | Plenty of skepticism in these comments. I've been following CFS
       | for a while and can present a point of view for why this time
       | might be different.
       | 
       | Fusion energy was actually making rapid progress in the latter
       | half of the twentieth century, going from almost no power output
       | in the fifties and sixties to a power output equal to 67% of
       | input power with the JET reactor in 1997. By the eighties there
       | was plenty of experimental evidence to describe the relationships
       | between tokamak parameters and power output. Particularly that
       | the gain is proportional to the radius to the power of 1.3 and
       | the magnetic field cubed. The main caveat to this relationship
       | was that we only had magnets that would go up to 5.5 Tesla, which
       | implied we needed a tokamak radius of 6 meters or so in order to
       | produce net energy.
       | 
       | Well that 6 meter tokamak was designed in the eighties and is
       | currently under construction. ITER, being so large, costs tens of
       | billions of dollars and requires international collaboration; the
       | size of the project has led to huge budget overruns and long
       | delays. Recently however, there have been significant advances in
       | high-temperature super conductors that can produce magnetic
       | fields large enough that we (theoretically) only need a tokamak
       | with a major radius of about 1.5 meters to produce net gain. This
       | is where SPARC (the tokamak being built by the company in the
       | article) comes in. The general idea is that since we have
       | stronger magnets now, we can make a smaller, and therefore
       | cheaper tokamak quickly.
       | 
       | Small tokamaks do have downsides, namely that the heat flux
       | through the walls of the device is so large that it will damage
       | the tokamak. There have been breakthroughs with various divertor
       | designs that can mitigate this, but to the best of my knowledge
       | I'm not sure that CFS has specified their divertor configuration.
       | 
       | This was just a short summary of the presentation by Dennis Whyte
       | given here [0]. I do not work in the fusion community.
       | 
       | [0] https://www.youtube.com/watch?v=KkpqA8yG9T4
        
         | zetalyrae wrote:
         | I've always wondered: why exactly is ITER so expensive, and
         | slow? Is the engineering required at such a standard that it
         | should takes decades of planning and construction and tens of
         | billions of dollars? The timeline is so dilated (started in
         | 1988, first plasma planned for 2025!) it feels like the kind of
         | project that's expected to be cancelled from the start.
         | 
         | It just doesn't strike me as obvious that reducing the major
         | radius by a few meters would have such a huge impact on
         | cost/timelines.
        
           | LeegleechN wrote:
           | It's just an absolutely giant construction project. The mass
           | and volume of the construction goes as the cube of the major
           | radius of the reactor. Back of the envelope, SPARC is
           | (6/1.5)^3 = 64 times smaller than ITER. The construction
           | budget for SPARC is ~$500M, so ITER being tens of billions is
           | in line.
        
             | bigyikes wrote:
             | How do projects like LIGO ever get completed? I'm probably
             | totally naive here, but I thought LIGO is physically larger
             | and has many difficult constraints. The LHC comes to mind
             | as well, and that absolutely dwarfs ITER in physical size.
             | What's the difference? Dealing with heat output?
             | Superconductors are really hard maybe?
        
               | sbierwagen wrote:
               | LIGO did take decades to construct, like the LHC.
               | According to LIGO's wikipedia article, it was the most
               | expensive project ever funded by the NSF in 1994.
        
               | neltnerb wrote:
               | LIGO's size is also deceptive, the legs are kilometers
               | long but the design is a L with the important bit being
               | to vibrationally isolate things, maintain dimensional
               | stability, and maintain vacuum.
               | 
               | ITER is likely bigger in terms of volume of concrete or
               | actual footprint.
        
           | jvanderbot wrote:
           | Margin?
           | 
           | Akin's law of spacecraft #29 "To get an accurate estimate of
           | final program requirements, multiply the initial time
           | estimates by pi, and slide the decimal point on the cost
           | estimates one place to the right."
        
           | dfdx wrote:
           | Anecdotally, ITER was the largest of few options for a fusion
           | researcher to run their experiment in a new tokamak.
           | Everybody wanted to put their work into it, and as more
           | features were added, the more funding it sucked up, leaving
           | less money for other experiments, leading to more people
           | wanting to put their experiment into ITER. Here's a
           | presentation [0] that goes over why SPARC, being so much
           | smaller and simpler than ITER could be more likely to
           | succeed.
           | 
           | [0] https://library.psfc.mit.edu/catalog/online_pubs/iap/iap2
           | 016...
           | 
           | This quote from the presentation summarizes it well:
           | 
           | "The more money that's involved, the less risk people want to
           | take. The less risk people want to take, the more they put
           | into their designs, to make sure their subsystem is super-
           | reliable. The more things they put in, the more expensive the
           | project gets. The more expensive it gets, the more
           | instruments the scientists want to add, because the cost is
           | getting so high that they're afraid there won't be another
           | opportunity later on- they figure this is the last train out
           | of town. So little by little, the spacecraft becomes gilded.
           | And you have these bad dreams about a spacecraft so bulky and
           | so heavy it won't get off the ground- never mind the
           | overblown cost."
           | 
           | "That boils down to the higher the cost, the more you want to
           | protect your investment, so the more money you put into
           | lowering your risk. It becomes a vicious cycle." - Rob
           | Manning, Chief spacecraft engineer, JPL
        
             | maccam94 wrote:
             | This is also why it's exciting to see the huge drop in
             | satellite launch costs driven by SpaceX. Your satellite
             | design is going to be much different if you have a few
             | chances to launch on a $1B rocket per year, vs launching it
             | for $10M anytime. Rather than one complicated reliable one,
             | you might make 10 simpler ones and buy extra flights to do
             | repairs if necessary.
        
           | sbierwagen wrote:
           | Here's a render of the completed reactor: https://www.iter.or
           | g/doc/all/content/com/gallery/media/7%20-... Note human for
           | size.
           | 
           | It's all completely bespoke scientific equipment hand made
           | for this project only. The cryostat will be the largest
           | stainless steel vacuum vessel ever made-- all welded by hand.
           | 
           | After welding, a substantial number of in-vessel components
           | have to be installed by threading them through access ports,
           | which is also quite a task:
           | https://www.youtube.com/watch?v=pt70mO2nQac
        
             | kwertyoowiyop wrote:
             | That will become a level in an FPS game for sure.
        
         | causality0 wrote:
         | Are those calculations of net gain referring to the total
         | energy generated, or the amount we can realistically capture
         | and put to use?
        
         | yboris wrote:
         | A march 2019 talk by Dr. Dennis Whyte of MIT working on SPARC
         | https://www.psfc.mit.edu/sparc
         | 
         | https://www.youtube.com/watch?v=rY6U4wB-oYM
        
       | TrainedMonkey wrote:
       | This is exciting. Magnetic field strength is a key component for
       | enabling magnetic confinement fusion. This is because energy gain
       | and power density scales to the 3rd and 4th power with magnetic
       | field strength but only ~linearly with reactor size. See
       | following equations for more details:
       | https://youtu.be/xJ2h3vbOag4?t=306
       | 
       | So, why is this particular announcement exciting? There are 3
       | factors:
       | 
       | 1. This is a high temperature superconductor. I can't find any
       | references, but as far as I remember the substrate they are using
       | needs to be cooled to (WRONG, it was cooled to 20degK, see reply
       | by MauranKilom) 60-70 degK to achieve super conductivity. Compare
       | to magnets used in ITER which need to be cooled to 4degK. This is
       | the difference between using relatively cheap liquid nitrogen vs
       | liquid helium.
       | 
       | 2. Field strength of 20 Tesla is significantly higher than 13
       | Tesla used in ITER. Given that magnetic confinement fusion scales
       | significantly better with field strength vs reactor size, this
       | will enable much smaller reactor to be power positive. See
       | following links for more details on ITERs magnets:
       | https://www.newscientist.com/article/2280763-worlds-most-pow...
       | https://www.iter.org/newsline/-/2700
       | 
       | 3. Finally, the magnet was assembled from 16 identical
       | subassemblies, each of which used mass manufactured magnetic
       | tape. This is significantly cheaper and more scalable than custom
       | magnet design/manufacturing used by ITER.
       | 
       | The kicker is how 3 of the factors above interact with the cost
       | of the project. Stronger magnets allow smaller viable reactors.
       | High temperature superconductors + smaller reactors allow for a
       | much simpler and smaller cooling system. Smaller reactors +
       | scalable magnet design further drives down the cost. Finally,
       | cost of state of art mega projects scales somewhere between 3rd
       | and 4th power with the size of the device. Combining all of the
       | above factors, SPARC should be here significantly sooner than
       | ITER and cost a tiny fraction (I would guesstimate that fraction
       | to be between 1/100 and 1/10,000).
       | 
       | edit: typos + looked at the cost of ITER and refined my cost
       | fraction guesstimate + corrected some stuff based on the reply by
       | MauranKilom.
        
         | MauranKilom wrote:
         | Appreciate the rundown of why this is important!
         | 
         | > This is because energy gain and power density scale
         | exponentially with magnetic field strength but only linearly
         | with reactor size
         | 
         | Nit: It scales polynomially, not exponentially. Specifically
         | (according to those formulas) energy gain scales with the cube
         | of field strength and power density with the fourth power.
         | Still massive scaling indeed, but exponentially would be
         | something else.
         | 
         | > as far as I remember the substrate they are using needs to be
         | cooled to 60-70 degK to achieve super conductivity
         | 
         | The video in the article shows 20 K. Could of course be that
         | higher temperature is feasible and they just played it safe (or
         | the video is wrong).
        
           | TrainedMonkey wrote:
           | You are right on both counts, I will update the comment. 2020
           | paper referenced 7degK magnets. I am not sure where I got
           | 70degK number from...
           | https://www.cambridge.org/core/services/aop-cambridge-
           | core/c...
        
           | zardo wrote:
           | There is a temperature dependent maximum field strength the
           | material can take and keep superconducting. REBCO
           | superconducts at 70k, but it can't take much current at that
           | temperature.
        
       | jcfrei wrote:
       | Lots of negative comments in this thread. I've been following CFS
       | for a few years now and I honestly believe this is an historic
       | event - probably the beginning of the "fusion age".
        
         | hutzlibu wrote:
         | "probably the beginning of the "fusion age"."
         | 
         | I wouldn't call it that, even if there would be a energy gain.
         | 
         | I call it beginning of "fusion age", when we solved fusion ad
         | can build them reliable and reproducible - and if we still need
         | them by that time, for main energy production.
        
         | phscguy wrote:
         | Yeah, any positive news on fusion progress and there always
         | seems to be the same set of comments appear that are
         | overwhelmingly critical of fusion development. Fusion is not
         | well funded and imo has been let down by mismanagement of ITER,
         | and despite this keeps making progress.
         | 
         | I feel that fusion is one of humanity's best shots at actively
         | reversing climate change, and it is disheartening to see such
         | widespread pessimism about it. Yeah it's hard. There are huge
         | hurdles in making it economicly viable, but if we can go from
         | first powered flight to the moon in 70 years, and put billions
         | of transistors on a chip in 50, then maybe we can get fusion
         | going. It's clearly possible.
        
       | john_yaya wrote:
       | The magnets are a problem to solve, but not the biggest problem
       | by far. Solve for neutron embrittlement of the reactor parts, and
       | then you'll start to have some credibility.
        
       | nielsbot wrote:
       | Update: They have a press release on their website
       | https://cfs.energy/news-and-media/cfs-commercial-fusion-powe...
       | 
       | In case others are wondering, looks like this is for SPARC.
       | 
       | FTA: This "MIT-CFS collaboration...on track to build the world's
       | first fusion device that can create and confine a plasma that
       | produces more energy than it consumes. That demonstration device,
       | called SPARC, is targeted for completion in 2025."
       | 
       | CFS: https://cfs.energy/technology
       | 
       | (edit: clarification)
        
       | noobermin wrote:
       | University press releases need not be peer reviewed so they can
       | get close to saying things that would offend other scientists and
       | get away with it. The key phrase in "the most powerful magnetic
       | field of its kind ever created on Earth" is "of its kind."
       | Creating a many telsa magnetic field has been done in other
       | experiments like with lasers[0], only they are physically smaller
       | in size and last for nanoseconds, it's just of this size,
       | stability and with the high temperature superconductors that
       | makes it special. If the claim is just the magnitude of the field
       | they've already been beat.
       | 
       | [0] https://www.nature.com/articles/s41467-017-02641-7
       | 
       | Just as a note, the max B field here is 600T
        
         | zardo wrote:
         | I think "it's kind" refers specifically to a magnet for plasma
         | containment. As this doesn't set the record for a REBCO magnet.
         | 
         | https://nationalmaglab.org/news-events/news/lbc-project-worl...
        
       | shmageggy wrote:
       | These university press releases are always very positively
       | framed. This one makes the new magnet seem incredibly promising
       | and fusion seem like almost an inevitability now, but decades of
       | failure have us conditioned for skepticism. What's the catch this
       | time?
        
         | anonuser123456 wrote:
         | > What's the catch this time?
         | 
         | This is D-T fusion. Which means you have to have T. Which
         | currently comes from fission reactor and has a half life of 15
         | years.
         | 
         | So the plan is to use a molten salt blanket with Be to breed T.
         | But Be isn't scalable for consumption, so maybe lead
         | eventually. That's probably do-able, it just slows down the
         | rate new reactors can come online since Pb is not as good a
         | neutron multiplier.
         | 
         | Once they breed extra T, they have to capture and refine it.
         | Hydrogen is very corrosive and hard to work with... and T is
         | radioactive hydrogen. Again, probably doable. But guess what?
         | Refining spent nuclear waste in fission reactors is also do-
         | able. It's also super expensive.
         | 
         | And they still need a containment vessel that will withstand
         | the wear and tear from sitting next to a mini hydrogen bomb all
         | day.
         | 
         | These challenges are likely all surmountable. But are they
         | surmountable AND cheaper than existing nuclear or other energy
         | sources? Meh?
        
           | OJFord wrote:
           | > This is D-T fusion. Which means you have to have T.
           | 
           | For the other uninitiated, (or far enough out of secondary
           | school and didn't take it further!) this seems to refer to
           | Deuterium-Tritium fusion, D & T being the isotopes of
           | hydrogen with an atomic mass of 2 (1 neutron, 'heavy' but
           | stable) and 3 (2 neutrons, radioactive) respectively.
        
           | rnhmjoj wrote:
           | > But are they surmountable AND cheaper than existing nuclear
           | or other energy sources?
           | 
           | DT fusion solves the two biggest arguments that are always
           | raised by nuclear energy opponents: storage of nuclear waste
           | (it doesn't produce high-level waste) and safety (it's not
           | perfect but it can't explode). I wouldn't call it a "meh",
           | even if it comes off as much more expensive than fission.
        
             | danans wrote:
             | > I wouldn't call it a "meh", even if it comes off as much
             | more expensive than fission.
             | 
             | It's not competing with fission, though. It's competing
             | with renewables + storage + load shifting + efficiency.
             | Compared to those, it might indeed be "meh".
        
               | rnhmjoj wrote:
               | Agreed, but grid and storage technology that will
               | completely solve the renewable intermittence is probably
               | as far in the future as commercial fusion reactors.
        
               | UnFleshedOne wrote:
               | In the grid this would take role of coal or gas plants
               | for base load, no?
        
             | speed_spread wrote:
             | It sounds like the T production chain might itself be quite
             | messy. Molten isotopes salt and lead? How much of that
             | stuff would you need? What do you do with when it goes bad?
             | It may not go boom Chernobyl-style, but it's still far from
             | the birds-in-the-sky deuterium-from-the-sea fusion dream.
        
               | scythe wrote:
               | The bad zone of radioactive byproducts is the half life
               | between 10 and 1000000 years. Shorter and you can wait it
               | out. Longer and the activity is low enough to ignore when
               | it's spread out. When designing a fusion reactor, you can
               | usually choose components that won't generate these
               | undesirable nuclides. But in fission, many products are
               | generated, so persistent contamination is practically
               | impossible to avoid.
        
         | [deleted]
        
         | stormbrew wrote:
         | I'm not sure it's possible for "lay people" (of which I am one)
         | to recognize the difference between a very slow success and
         | "decades of failure".
         | 
         | Very little is invested into fusion power as a project,
         | overall. So advancements seem to come when outside influences
         | cause breakthroughs.
         | 
         | I wonder how different the world would have been if it had for
         | whatever reason been easier to produce fusion power than a
         | fusion bomb. Military investment into the bomb would have
         | probably pushed things forward a lot quicker. As is, the US
         | military built thermonuclear bombs _very_ quickly and then the
         | appetite for advancement just dried up.
        
           | fshbbdssbbgdd wrote:
           | You could say that military investment into fusion and
           | fission bombs was groundwork for everything done since. On
           | the other hand, the fact that nuclear power started with
           | bombs probably contributed to it falling out of favor and
           | being regulated to irrelevance (even though hydrocarbons have
           | been responsible for a lot more deaths and environmental
           | damage).
        
         | phkahler wrote:
         | >> What's the catch this time?
         | 
         | There are a bunch of issues still to be resolved. Higher magnet
         | strength is/was just one of many.
        
         | azalemeth wrote:
         | Agreed. Whilst it may well be the largest, highest-field "only"
         | high Tc superconductor design in the world, it's definitely not
         | the highest-field high Tc superconducting magnet -- I believe
         | that honour belongs to another bit of MIT with a 1.3 GHz NMR
         | machine [1] (but I do remember something about Bruker
         | collaborating with the US's National Magnet Lab and building a
         | 30T machine -- I can't easily find a link).
         | 
         | I really wish that press release would put the link to the
         | paper at the top -- I found it very hard to work out what was
         | actually new!
         | 
         | [1] https://ieeexplore.ieee.org/document/6926794
        
           | bb88 wrote:
           | This was a 32T field created, not sure if it's the same, but
           | similar.
           | 
           | https://english.cas.cn/newsroom/research_news/tech/201912/t2.
           | ..
           | 
           | Googling "30T magnetic field" shows some papers that have
           | apparently "pulsed" 30T.
        
         | apendleton wrote:
         | I think the framing of what's happened so far as "failure" is
         | probably the main thing responsible for this perception. It's
         | true that progress has been slower than many had hoped and the
         | most optimistic had projected, but "failure" sort suggests that
         | the things the research community have been trying haven't
         | represented meaningful progress towards the goal of power
         | production, which isn't the case.
         | 
         | Q (the ratio of energy out to energy in) has improved by about
         | four orders of magnitude since controlled fusion was first
         | achieved, and it's been a slow, at least reasonably steady
         | march since the middle of the 20th century to achieve that
         | progress. The current record-holding Q for magnetic confinement
         | is around 0.67, so we need well under one more order of
         | magnitude to get to the point of "theoretical break-even" (Q>1)
         | -- we're most of the way there. A plant just barely better than
         | break-even probably wouldn't be commercially viable, though,
         | and while estimates vary, that point is probably somewhere in
         | the 10-30 range, so we have maybe another order of magnitude to
         | go after break-even. I don't think there's anything to suggest
         | that after decades of progress we'll suddenly stop being able
         | to make more.
         | 
         | It's true that things have slowed down somewhat in the last
         | 10-15 years, but most of the blame there goes to the need, in
         | order to continue moving forward, to build bigger and bigger
         | reactors, and the need to divert resources to that goal (mostly
         | ITER). To the extent that promises of going faster have turned
         | out to be hot air, it seems like they've mostly been in the
         | form of novel approaches that do fusion in some fundamental new
         | way that avoids the need to build an ITER-like thing. These
         | approaches seem to often involve lots of unknowns, and end up
         | getting bogged down in practical issues once they're actually
         | tried (surprise plasma instabilities and so on).
         | 
         | Recent advances in materials science (mostly REBCO magnets) and
         | computing, though, offer a path to progress on the regular,
         | bog-standard flavor of magnetic confinement fusion (tokamaks)
         | on a smaller scale -- that's what this is. The nice thing about
         | that is that the plasma physics here are very well understood,
         | and have been heavily researched using conventional/not-super-
         | conducting magnets that won't ever achieve break-even, but
         | create identical plasma conditions inside the reactor (MIT
         | Alcator C-Mod is effectively the conventional-magnet
         | predecessor to this project). Up until now, the only real
         | question was whether or not they could build strong-enough
         | REBCO magnets, and now they have, so this is all good news and
         | reason for optimism.
         | 
         | Of course, commercial viability is a whole other question
         | involving lots of questions besides physics. But the physics
         | here seem to not be in serious doubt, unlike some of the
         | proposals from other startups that are more exotic.
        
           | zardo wrote:
           | Would stellarators see the same benefits as tokomaks from
           | higher field strength magnets?
        
             | apendleton wrote:
             | Potentially yes, though stellarator research in general
             | seems to be somewhat less mature than tokamak research.
             | There's an outfit called Type One Energy, though, that
             | looks to me like they're essentially CFS but for
             | stellarators (i.e., take established stellarator designs
             | but do them with HTS magnets):
             | https://www.typeoneenergy.com/ . Their academic heritage
             | seems to come out of the University of Wisconsin instead of
             | MIT.
        
       | xqcgrek2 wrote:
       | Ah, a university press release.
       | 
       | Nah.
        
       | sdeyerle wrote:
       | In the original proposal for the ARC reactor, they were proposing
       | making the magnet separable so the top and bottom of the reactor
       | could be separated and the vacuum vessel removed. (See pg. 5 of
       | https://library.psfc.mit.edu/catalog/reports/2010/15ja/15ja0...)
       | 
       | It doesn't look like they are targeting that here. Does anyone
       | know if that is ARC (not SPARC) specific, or if that has been
       | abandoned?
        
         | nielsbot wrote:
         | The article says this is from an "MIT-CFS collaboration" which
         | is "on track to build the world's first fusion device that can
         | create and confine a plasma that produces more energy than it
         | consumes. That demonstration device, called SPARC, is targeted
         | for completion in 2025."
         | 
         | So, sounds like it's for SPARC.
        
           | sdeyerle wrote:
           | Yeah, they are definitely building SPARC. I had just been
           | under the impression they were trying to do the separable
           | magnets in SPARC, and was curious if I misunderstood their
           | plan or if their plan had changed.
        
             | nielsbot wrote:
             | Yeah--I misread your question. :)
        
         | [deleted]
        
       | dfdz wrote:
       | The thumbnail of the youtube video made me laugh
       | 
       | Smaller. Smarter. Sooner. 2018
       | 
       | Currently 2021 where is my fusion energy? But this time must be
       | different, after this advance we are only a few years away from
       | fusion energy?
        
         | bwestergard wrote:
         | They seem to have made two claims. First, that they have a
         | qualitatively different design that requires a significantly
         | stronger magnetic field. Second, that they could build a magnet
         | that produces such a field.
         | 
         | They are now claiming to have done the latter. Are you
         | skeptical of the new design? Or do you think it does not
         | represent as significant a departure from earlier designs as
         | they claim?
        
         | ChrisMarshallNY wrote:
         | The running joke has always been that "Fusion is 20 years
         | away," and has been, for the last 50 years.
         | 
         | I really want this to work. I am a bit concerned, with how "the
         | old guard" will react, once we have successful, productive,
         | fusion.
         | 
         | I foresee an astroturf NIMBY campaign against construction of
         | fusion plants.
        
           | phicoh wrote:
           | At the moment it is very far for clear that fusion will be
           | cost effective. The article says this about the fuel of
           | fusion: "The fuel used to create fusion energy comes from
           | water, and "the Earth is full of water -- it's a nearly
           | unlimited resource. [...]"
           | 
           | They forgot to say that it is not the H2O that comes out of
           | your tap. The earth is especially not full of tritium.
        
             | apendleton wrote:
             | The plan is for them to breed their own tritium, though, so
             | the consumables coming in the front door would just be
             | deuterium and lithium, both of which (while less common
             | than tap water) are not rare.
        
             | rory wrote:
             | The fuel for fission comes from rocks. The Earth is full of
             | rocks!
        
             | hutzlibu wrote:
             | It's like saying the ocean is full of gold for anyone to
             | pick up. It is. But not worth picking up with the very low
             | concentration.
        
           | Krasnol wrote:
           | You don't need an astroturf.
           | 
           | Nuclear ruined it's own reputation for generations though
           | hopeful not as long as they'll have to care for the waste we
           | already have.
        
           | soperj wrote:
           | It wasn't a joke, it was always based on an adequate level of
           | funding. Everything is always off in the future if it never
           | gets funded.
        
             | JackFr wrote:
             | Ah yes, and how much money? The answer always seems to be
             | "More".
        
               | MauranKilom wrote:
               | Please consult this graphic from 1976 if you are actually
               | interested in the answer.
               | 
               | https://i.imgur.com/3vYLQmm.png
        
               | drdeca wrote:
               | Could you clarify how to read this chart? The y axis is,
               | funding given different plans? Or.. I got the impression
               | that this is meant to depict a relationship between when
               | practical fusion would be developed and how much funding
               | it receives, but I don't see how to get that from the
               | chart.
               | 
               | Also, not sure why imgur has that image marked as adult
               | content.
        
               | apendleton wrote:
               | I mean, yes, obviously if the criticism is that they're
               | getting too little money, clearly they want more. Some
               | technologies are fundamentally expensive to develop (the
               | Apollo program, the Manhattan project, etc.). That
               | doesn't mean the people saying so are automatically
               | charlatans, especially given that they've never gotten
               | what they've asked for -- it's not like some bomber
               | development project where they get what they want and
               | then keep coming back for more. The relatively paltry
               | amounts the US has been devoting to fusion energy
               | research are lower than any of the scenarios laid out in
               | a 1976 DOE planning document[1] about what it would take
               | to achieve fusion power, and lower even than just
               | continuing at 1970s levels (a plan they labeled in that
               | document as "fusion never").
               | 
               | [1] https://books.google.com/books?id=KSA_AAAAQBAJ&lpg=PA
               | 234&ots...
        
           | AnimalMuppet wrote:
           | Per a comment by nielsbot, they're saying 2025. So, four
           | years away, not 20. That's progress...
        
           | MisterBastahrd wrote:
           | Fusion is the Linux Desktop of energy projects.
        
       | Seanambers wrote:
       | If anyone have not seen it i recommend this video as a primer for
       | fusion technology, it's from MIT.
       | https://www.youtube.com/watch?v=L0KuAx1COEk
       | 
       | The video thouches upon magnetic fields and its relevance at this
       | time mark ; https://youtu.be/L0KuAx1COEk?t=2880
        
       | freeopinion wrote:
       | Let me know when the advance comes from Elizabethtown Community
       | and Technical College. That would probably be affordable to put
       | in production.
        
       | kgarten wrote:
       | Better title: Startup builds strong magnet that might be useful
       | for a fusion plant.
        
       | criticaltinker wrote:
       | The advances enable a magnetic field strength that would
       | otherwise require 40x more volume using conventional technology -
       | doesn't the reduced volume imply the plasma temperature would
       | also increase significantly? Or is the magnetic field strong
       | enough to protect the walls of the chamber?
        
         | tppiotrowski wrote:
         | My understanding is that the volume of the magnet is smaller
         | and thus the entire reactor size goes down significantly
         | leading to lower cost.
         | 
         | ITER was designed to use weaker electromagnets and therefore
         | needs a massive building and tons of cranes and a massive
         | budget.
        
           | pfdietz wrote:
           | The ARC reactor design has 10x the volumetric power density
           | of ITER.
           | 
           | Unfortunately, the ARC design also had 40x worse power
           | density than a PWR primary reactor vessel.
        
             | apendleton wrote:
             | Is that the right metric? You wouldn't need to build a huge
             | containment structure around it like you would for a PWR,
             | so I'd imagine the power density of the plant as a whole
             | wouldn't be anywhere near 40x worse. Why focus just on the
             | primary reactor vessel?
        
       | mzs wrote:
       | SPARC yttrium barium copper oxide (YBCO) high temp (10-70K)
       | superconducting magnets
        
       | pcj-github wrote:
       | If we had "an inexhaustible, carbon-free source of energy that
       | you can deploy anywhere and at any time" we'd wreck the planet
       | faster than we already are... I guess at least a few could escape
       | though.
        
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       (page generated 2021-09-08 23:00 UTC)