[HN Gopher] Radical hydrogen-boron reactor leapfrogs current nuc...
___________________________________________________________________
Radical hydrogen-boron reactor leapfrogs current nuclear fusion
tech
Author : chris_overseas
Score : 565 points
Date : 2020-02-21 12:34 UTC (10 hours ago)
(HTM) web link (newatlas.com)
(TXT) w3m dump (newatlas.com)
| eveningcoffee wrote:
| Cool thing about this is that it will be a direct energy capture
| if I understand it correctly.
|
| _" The hydrogen/boron fusion creates a couple of helium atoms,"
| he continues. "They're naked heliums, they don't have electrons,
| so they have a positive charge. We just have to collect that
| charge. Essentially, the lack of electrons is a product of the
| reaction and it directly creates the current."_
| javajosh wrote:
| Yes it seems like you could generate extreme levels of
| electrostatic force by collecting the Helium nuclei. Do that on
| one side of a capacitor, periodically short it out (producing
| ordinary Helium) to clear both plates, and repeat. So yeah a
| machine which takes hydrogen and boron and emits helium gas and
| electricity. Sounds like it's worth doing, at least for the
| sake of children's birthday parties.
| multiplegeorges wrote:
| Helium is limited on earth and we need it to cool things like
| MRIs and other massive electromagnets.
|
| Apart from literally saving humanity from a climate disaster,
| we can still use our MRIs!
| anonuser123456 wrote:
| You're not going to make an appreciable amount of helium
| with this process.
|
| And MRIs of the future will be constructed with REBCO
| magnets and cooled with liquid nitrogen.
| russfink wrote:
| Start looking for unexplained helium signatures among the
| exoplanets, as evidence of a civilization that applied
| this method successfully.
| hinkley wrote:
| This doesn't sound like it would be more energy-dense than a
| chemical reaction. How much power can you extract -
| electrically - from two alpha particles?
| DennisP wrote:
| Depends on how fast they're going. Fusion generates quite a
| lot of energy per reaction.
|
| According to HB11's papers, each shot would have about 30
| kilojoules input power via laser, consume 14 grams of fuel,
| and produce over a gigajoule output power, or 277 kWh.
|
| They think within a decade the lasers will be capable of one
| shot per second. Right now it's more like one per minute.
| acidburnNSA wrote:
| Presumably the lasers have produced enough energy to ionize
| helium generated in the target. It's quite unclear how a net
| energy gain will be extracted simply by grabbing the moving
| ions electrically. That sounds like a huge extra challenge on
| top of achieving net positive controlled fusion.
|
| There will inevitably be a lot of heat produced that has to be
| cooled. Generally people plan to use the coolant as the working
| fluid in the power cycle.
|
| If there's an innovation here it'd be cool if they put it way
| more up front.
|
| In any case there will still be a coolant.
| andymoe wrote:
| So... what is their Current Q number?
|
| "The fusion energy gain factor, usually expressed with the symbol
| Q, is the ratio of fusion power produced in a nuclear fusion
| reactor to the power required to maintain the plasma in steady
| state." [1]
|
| [1] https://en.m.wikipedia.org/wiki/Fusion_energy_gain_factor
| [deleted]
| DennisP wrote:
| Currently zero, because the necessary lasers are just now
| becoming available.
|
| In theory, they've got a kJ laser to generate the magnetic
| field, a 30kJ laser hitting the fuel, and a GJ energy output,
| for Q over 30,000 minus whatever losses you have in the lasers
| and electricity harvesting.
|
| https://aip.scitation.org/doi/10.1016/j.mre.2017.05.001
| sam wrote:
| If new fusion startups like this one are interesting to folks on
| this thread, here's a list of companies working on fusion energy
| that I've compiled:
|
| https://www.fusionenergybase.com/organizations/
| baddash wrote:
| thanks :D
| kragen wrote:
| I think he's dechirping a convergent laser wavefront to get a
| 10-petawatt pulse with which to accelerate hydrogen into a 11B
| target to run an alphavoltaic battery from an aneutronic p-11B
| fusion avalanche resulting within a plasma sphere contained by
| optical tweezers. Is that right?
| DeusExMachina wrote:
| Can somebody with more understanding tell me if this idea I had
| is stupid or has some merit?
|
| Fusion will deliver an incredible amount of energy, making it
| cheap. Everybody then turns up their energy consumption since it
| costs nothing. Raise heating in houses, use AC everywhere, longer
| showers, more transportation, etc.
|
| All this energy eventually becomes heat. Can it get to a
| threshold where it can influence temperature on a global scale
| even if it lowers carbon emissions? What am I missing?
| DennisP wrote:
| There's waste heat from our power plants today, but it's an
| extremely minor factor compared to carbon emissions. However,
| if we were to continue our current rate of exponential energy
| growth on this planet, we would boil the oceans in 400 years.
|
| https://dothemath.ucsd.edu/2012/04/economist-meets-physicist...
|
| On the other hand, compact fusion power would make for some
| great rockets, so by the time it's common it would probably
| make sense to move most of the growth off planet.
| Vysero wrote:
| No the idea has no merit.
| andys627 wrote:
| Use free energy to sequester infinite carbon!
| Tade0 wrote:
| Orders of magnitude. Total Earth solar irradiance is in the
| order of hundreds of petawatts, while total world installed
| power plant capacity sits in at a few terawatts.
|
| We're simply unable to measurably increase the amount of heat
| on the surface of Earth directly.
| nnq wrote:
| > energy [...] costs nothing. Raise heating in houses, use AC
| everywhere, longer showers, more transportation
|
| Yey, can we get to this future _faster_?! Joking aside, all the
| current eco-friendly tech _diminishes comfort by a loooot_...
| we need low-energy habitats that are actually _comfortable_
| ffs.
|
| For example, traveling around Europe, I see that the new trend
| in the developed/western part is to _shiver you ass out during
| the cold months_ and to _melt your brains out during the hot
| ones_ in _almost all public spaces!_ Like we 're back in the
| pre-AC era! You need to get to Eastern Europe's bigger cities
| to enjoy comfy heating/cooling habits like _proper heating in
| the winter_ (yes, I want my >25 C in winter!) and proper
| cooling in the summer (<18 C please!)... It's wasteful, but
| very much enjoyable! Snow fighting after/before coming out/in
| of a 30+ C heated house is bliss :D Same a blasting through an
| enjoyable heatwave after jumping out of a 15 C office and then
| back in. Life's little pleasures.
|
| _After we invest so much of our lives in developing
| technology, we should at least enjoy the simple comforts and
| pleasures it freaking offers!_
| thescriptkiddie wrote:
| I have never understood this. Why keep indoor temperatures so
| warm in the winter? Everyone is already wearing warm clothes
| when they come in from outside, so why make it like a sauna
| inside? I'm already sweating before I can get my coat off.
| jimbokun wrote:
| > the design is "a largely empty metal sphere, where a modestly
| sized HB11 fuel pellet is held in the center, with apertures on
| different sides for the two lasers. One laser establishes the
| magnetic containment field for the plasma and the second laser
| triggers the 'avalanche' fusion chain reaction. The alpha
| particles generated by the reaction would create an electrical
| flow that can be channeled almost directly into an existing power
| grid with no need for a heat exchanger or steam turbine
| generator."
|
| > HB11 says its generators would be compact, clean and safe
| enough to build in urban environments.
|
| Video: https://www.youtube.com/watch?v=OxEX8UueZ4U
| galangalalgol wrote:
| How do alpha particles get turned into current on a line?
| ycombonator wrote:
| Now that's science
| foreigner wrote:
| As a bonus it produces helium, which we've been running low on
| right? Break out the party balloons!
| StavrosK wrote:
| All fusion produces helium, though. I don't think anyone is
| looking into fusing heavier atoms.
| jabl wrote:
| If you look at the nuclear binding energy curve (e.g. https:/
| /en.wikipedia.org/wiki/Nuclear_binding_energy#/media/... )
| you'll see a nice bump there for He4. So there's no gain in
| fusing heavier stuff.
| logfromblammo wrote:
| Not unless you could somehow bang three of them together at
| once to get to C-12. That seems unlikely with current
| technology. We can't even get C-N-O cycle fusion in the
| dinky little star we live next to.
|
| So that's at least 20 years away from being 20 years away
| from being 20 years away. And you could just make more
| alpha particles, anyway. It's not like the universe is
| short on hydrogen.
| shireboy wrote:
| That shortage is mostly a myth:
| https://www.wired.com/2016/06/dire-helium-shortage-vastly-in...
| homonculus1 wrote:
| So what happens after 117 years?
| DennisP wrote:
| If we get compact working fusion reactors, what probably
| happens is we import as much helium as we want from
| Jupiter.
| Throwaway984332 wrote:
| It's a bit weird to say we're running out of He, not unless
| we're running out of CH4. Which, theoretically we are.
|
| But practically, with CH4, our modern concern is not running
| out of it, but the associated GHG emissions of producing and
| burning it.
|
| So we won't run out of He, so much as stop producing it.
| deftnerd wrote:
| CH4, aka Methane, is one Carbon atom and four Hydrogen atoms.
| There is no Helium in Methane, just Hydrogen.
| ncmncm wrote:
| Helium is a byproduct of natural gas extraction. Radon too.
| escape_goat wrote:
| It might be less confusing to refer to 'natural gas' in this
| context, rather than CH4.
| SamBam wrote:
| 'Natural gas' and not 'cow burps'?
| jl6 wrote:
| > First milestone is demonstrating the reactions, which should be
| easy.
|
| They haven't even demonstrated the reaction? What's all the talk
| about results being "billions" of times better than expected?
| willis936 wrote:
| As someone who works on a stellarator: no plasma experiment in
| fusion research is easy to do.
| noselasd wrote:
| Simulations.
| [deleted]
| archeantus wrote:
| Seems like the jury is still out on whether they can reliably
| generate more energy than it takes to initiate the reaction? It
| won't go anywhere if it can't clear that hurdle.
| taneq wrote:
| Indeed, the four elements, like Man alone, are weak, but together
| the form the strong fifth element.
|
| https://youtu.be/2IfCUsBpR-I
| nickik wrote:
| I have long thought this fuel was a far better fit. Really in a
| practical sense, you don't get that much benefit from most
| tritium fusion reactors compared to fission. Meaning that
| compared to what we have now, fusion and fission are so much more
| efficient anyway.
|
| The primary problem for fission is state regulation and large
| cost even if you didn't have to pass regulation. And most fusion
| concepts can't really address that much better.
|
| Directly creating current rather then having a whole heat to
| electricity transformation might allow the whole thing to be much
| cheaper.
| redm wrote:
| " This cascading avalanche of reactions is an essential step
| toward the ultimate goal: reaping far more energy from the
| reaction than you put in. The extraordinary early results lead
| HB11 to believe the company "stands a high chance of reaching the
| goal of net energy gain well ahead of other groups."
|
| Its a great read, but it sounds like its still a net energy
| loss.. one more brick on the road though.
| wefarrell wrote:
| Can someone explain why this is considered fusion? The reaction
| involves shooting a proton (hydrogen) at a boron nuclei and
| outputting 3 alpha particles. That seems more like the nuclei
| being split apart than fused together.
| DennisP wrote:
| The explanation I've heard from a fusion scientist is that as
| far as they're concerned, if you're initiating the reaction by
| colliding nuclei, it's fusion, and if you're initiating it by
| hitting a large nucleus with a neutron, it's fission.
| wefarrell wrote:
| Makes sense, thanks!
| cstross wrote:
| Start here: https://en.wikipedia.org/wiki/Aneutronic_fusion
|
| (TLDR version: proton-boron fusion is a less energetically
| efficient alternative to 3He fusion, but with the howlingly
| significant advantage that boron -- the fuel -- is lying around
| in heaps and drifts on Earth, rather than being so exotic a
| substance that annual global production is measured in single-
| digit kilograms and a significant energy economy would require
| mining it from the Lunar regolith. It's not as well-known as
| 3He fusion, though, because the space cadets don't see the
| point -- there are no Moon colonies required. Advantages of 3He
| or B + p fusion over D-T fusion: it doesn't produce a surplus
| of neutrons, so there's less radioactive waste created as a by-
| product of the process.)
| baq wrote:
| space cadets would love to have that kind of a reactor on a
| deep solar system exploration mission, especially if you
| could make it into a rocket engine by spitting the resulting
| super high energy helium out of the business end without
| negative side effects.
| acidburnNSA wrote:
| I has to do with something called the Binding Energy Per
| Nucleon. If you march up the curve from small numbers to get
| energy you are fusion. If you march down the curve from high
| numbers, you are fission. If you march up the curve from small
| numbers and go all the way to large numbers even though that's
| endothermic, you are a supernova.
|
| https://en.wikipedia.org/wiki/Nuclear_binding_energy#Nuclear...
| ars wrote:
| Because you are fusing a proton to a boron.
|
| After that there is radioactive decay (the splitting).
|
| To be fission you have to actually [actively] break the atom
| apart, which isn't happening here.
| Robotbeat wrote:
| Headline is misleading. Should be "hopes to leapfrog".
| tln wrote:
| It would be awesome to know what experiments they've done, or if
| this is all simulation
| DennisP wrote:
| There have been experiments, but only at lower power than
| required for fusion. From their latest paper:
|
| > A significant case of nonlinear deviation from classical
| linear physics was seen by the measurements, how the laser
| opened the door to the principle of nonlinearity and could be
| seen from the effect measured by Linlor [9] followed by others
| (see [7] p. 31) when irradiating solid targets with laser
| pulses of several ns duration. At less than one MW power, the
| pulses heated the target surface to dozens of thousand degC and
| the emitted ions had energies of few eV as expected in the
| usual way following classically. When the power of the
| nanosecond laser pulses was exceeding a significant threshold
| of few MW, the ions - suddenly - had thousand times higher
| energies. These keV ions were separated with linear increase on
| the ion charge indicating that there was not a thermal
| equilibrium process involved.
|
| Lasers adequate for fusion are just now becoming available.
|
| https://www.hb11.energy/news-and-publications
| penetrarthur wrote:
| > and most rely on a deuterium-tritium thermonuclear fusion
| approach that requires the creation of ludicrously hot
| temperatures, much hotter than the surface of the Sun, at up to
| 15 million degrees Celsius (27 million degrees Fahrenheit).
|
| Surface of the Sun - 6000 C
|
| Center of the Sun - 15000000 C
| dmos62 wrote:
| It's not often that the child in me goes "that's awesome!", but
| this is one of those times.
| SamBam wrote:
| Assuming you're talking about the temperature, it's always
| been a source of human pride to me that the hottest place in
| the entire universe, as far as we are aware, has been created
| at the LHC on Earth.
|
| Barring other species as intelligent as ours elsewhere (which
| is of course possible, but unknown), the very hottest thing
| in the entire unimaginably-large universe full of exotic
| stars and black holes and supernovae, was created by a tiny
| group of apes on a minuscule planet orbiting a smallish,
| boring star on the unfashionable side of a galaxy.
| miscPerson wrote:
| That strikes me as... a strange claim, considering how fast
| the OMG particle whizzed by.
|
| Per Wiki:
|
| > The energy of this particle is some 40 million times that
| of the highest energy protons that have been produced in
| any terrestrial particle accelerator.
|
| Presumably wherever these extreme energy protons are coming
| from is rather warm.
|
| Is there some reason to think the LHC has higher
| temperature?
|
| Not a physicist; could be something like LHC having larger
| bunch sizes... but since we don't know what causes these
| particles, it seems like we don't really know the source
| temperature.
| FredrikMeyer wrote:
| I think they might be thinking of the corona of the sun
|
| > The temperature in the corona is more than a million degrees,
| surprisingly much hotter than the temperature at the Sun's
| surface which is around 5,500deg C
|
| https://scied.ucar.edu/solar-corona
| willis936 wrote:
| Fusion happens in the core of stars but is powered by
| gravity. "Temperature" in this case is individual particle
| speed (in eV) because the particle speed distribution is not
| necessarily Boltzman. Higher particle speeds are needed
| because our confinement fields are weaker than the force of
| gravity inside a star.
| DonHopkins wrote:
| Most SF stories have artificial gravity generators, because
| it simplifies plots and lowers production costs. But is
| there actually a chance in hell that we'll ever have that
| kind of control over gravity?
| willis936 wrote:
| Probably not, but it does help with storytelling. You
| need things like exotic matter and time travel. Space
| magic seems to mostly be all the same thing: negative
| mass.
|
| https://www.youtube.com/watch?v=10AP7tio408
| ekimekim wrote:
| The Expanse offers a more realistic take to the same
| effect:
|
| With sufficiently efficient fuel, the fastest path from A
| to B is by constantly accelerating (more or less) towards
| it until you reach halfway, then flipping and constantly
| decelerating until you arrive.
|
| Under this kind of trajectory, you're under constant
| acceleration of, say, 1g the whole time. This means you
| effectively have gravity for the entire trip, as long as
| you've designed your ship such that the floor is in the
| same direction as you apply thrust - think less
| traditional ship decks and more like a skyscraper.
|
| Another realistic option, of course, is a rotating
| section. But this generally requires massive, "ugly"
| ships to work so it's pretty rare in fiction.
| hajile wrote:
| "Naked Helium" -- What a nice way to say "we output alpha
| radiation"
|
| > "The hydrogen/boron fusion creates a couple of helium atoms,"
| he continues. "They're naked heliums, they don't have electrons,
| so they have a positive charge. We just have to collect that
| charge. Essentially, the lack of electrons is a product of the
| reaction and it directly creates the current."
| andreiklochko wrote:
| To shed a different light on this: think of temperature as
| walking through mud. Your legs lose energy trying to slowly pull
| a lot of mud behind you. Now think about skiing. A lot less snow
| is dragged with you but it flies fast.
|
| Here, what is interesting is if one fusion reaction does happen,
| then the alpha (helium) particles leave at 2.9 MeV. After two
| collisions with protons, if the second proton they have hit hits
| in turn a boron nucleus, then it will have exactly the right
| energy (612 keV) to have maximum chances at initiating a second
| fusion reaction.
|
| 612 keV is like almost 7 billion degrees degC if considered as
| thermal energy, and no experiment anywhere will get that hot for
| long. But compared to the energy of the exiting helium nuclei,
| it's still much lower (0.612 MeV vs 2.9 MeV).
|
| In other words, instead of cascading all the energy down and
| hoping the sea of particles rises to a few billion degrees so
| enough particles do fusion to keep the sea of other particles
| hot, here, the energy is preempted by proton atoms after just 2
| collisions and used immediately to start a second reaction, which
| yields more helium nuclei at 2.9 MeV, essentially producing an
| "avalanche" effect.
|
| Finally, yes, they seem to have devised a way to obtain at least
| a small part of the energy electrically, without relying on
| thermal energy, via direct electric field deceleration of very
| fast charged particles.
|
| This is like "the ultra rich (very fast particles) manage to
| create value among themselves without having to cascade their
| wealth down to the crowd (cold particles), and then upload that
| value to hyperspace (the electric field from the electrodes),
| without ever interacting with the mass of the crowd (the mass of
| the target), until a sufficient amount of fusion reactions have
| been realized"
|
| The avalanche process is explained in Hora's 2016 publication,
| with a schematic page 9:
| https://aip.scitation.org/doi/10.1016/j.mre.2017.05.001
|
| And yes, a petawatt (the energy of present day ultra-fast lasers)
| is a lot of power. It was just chance that there was very little
| practical use to this kind of power - until now.
|
| That being said, I am not a true expert myself of this topic, so
| the true barriers laying in front of this concept might be better
| explained by the other comments here.
| pas wrote:
| Is there any description of how the "hit a capacity coil with a
| laser to generate a magnetic field" thing works?
|
| https://www.cambridge.org/core/services/aop-cambridge-core/c...
| I found this overview a bit confusing and sort of low quality,
| but at least it references a lot of papers. (But haven't
| started hunting down any of them.)
| UnFleshedOne wrote:
| "the ultra rich (very fast particles) manage to create value
| among themselves without having to cascade their wealth down to
| the crowd (cold particles), and then upload that value to
| hyperspace (the electric field from the electrodes), without
| ever interacting with the mass of the crowd (the mass of the
| target)"
|
| Are you saying this kind of fusion is anti social justice? We
| should ban this immediately!
| nkrisc wrote:
| > This is like "the ultra rich (very fast particles) manage to
| create value among themselves without having to cascade their
| wealth down to the crowd (cold particles), and then upload that
| value to hyperspace (the electric field from the electrodes),
| without ever interacting with the mass of the crowd (the mass
| of the target), until a sufficient amount of fusion reactions
| have been realized"
|
| This was actually a helpful analogy for me. I'll have to take
| your word on the accuracy of it, though.
| ChuckMcM wrote:
| Sigh: _Second milestone is getting enough reactions to
| demonstrate an energy gain by counting the amount of helium that
| comes out of a fuel pellet when we have those two lasers working
| together. That 'll give us all the science we need to engineer a
| reactor._
|
| I love the work, I love that they have exploited the fact that we
| can build things (lasers) now that we could not economically
| build before. But the fact is that so many many things die on the
| aforementioned step from the article.
|
| That is the step wherein the science doesn't give you a way to
| engineer a reactor, instead it illuminates something you didn't
| know before and so that you now realize you can't ever build a
| reactor that way.
|
| So when I read these papers and the science isn't all figured
| out, I temper my enthusiasm. High hopes, low expectations, that's
| a good motto here. Unlike the stellerator where all the science
| is "known" and they are engineering an implementation step by
| step by step.
|
| I've added it to my fusion project collection under "interesting
| long shots", check back in 5 years to see what the science taught
| them.
| pfdietz wrote:
| I am very skeptical of this approach.
|
| The big problem I have is the direct conversion approach being
| suggested. The idea, as I understand it, was that the target is
| placed at the center of a large sphere, and is negatively
| charged, so the alpha particles from fusion slow down as they go
| up the potential to the surrounding spherical collector.
|
| You see the problem with this, I hope. The violent and energetic
| event at the target will produce gas and plasma, and lots of free
| electrons. What is stopping that from shorting out this megavolt
| vacuum capacitor?
| annoyingnoob wrote:
| I hope they get their voodoo to work. The world could sure use
| it.
| hnewsshadowbans wrote:
| I'll believe it when I see it. Radical new technology is always
| leapfrogging conventional fusion and has been overtaking and
| rendering it 'obsolete' for the past 30-40 years.
| moneytide1 wrote:
| Straight from fusion to electricity without a steam turbine with
| helium to harvest?
|
| I've seen it said here on HN that the amount of helium out of a
| deuterium/tritium is so small it is negligible.
|
| From article: "My question is: Would that setup produce a
| continuous fusion for some period with positive net energy
| generation?
|
| Here is my argument why I think it would: Since Boron is solid at
| room temperature, it's density is high, so I think the fusion
| rate per nucleon would be quite high. As far as I know 100keV is
| the energy needed for Hydrogen-1 and Boron-11 to fuse, while the
| resultant three He-4 nuclei should have about 8MeV of energy. So
| indeed if all accelerated protons fuse then the energy produced
| should be quite higher than the input. The problem that
| immediately comes to mind is that as the container starts to
| rapidly heat up as a result of the reactions the Boron inside
| would no longer be solid and may even start to leak through the
| opening. But before that happens, would there be at least a brief
| period where an efficient fusion can be sustained?"
| acidburnNSA wrote:
| Always happy to see people doing new and interesting stuff with
| fusion. I got into nuclear technology because of ITER back in the
| early 2000s. Worked on it continuously (mostly in advanced
| fission) ever since.
|
| > "The timeline question is a tricky one," he says. "I don't want
| to be a laughing stock by promising we can deliver something in
| 10 years, and then not getting there. First step is setting up
| camp as a company and getting started. First milestone is
| demonstrating the reactions, which should be easy. Second
| milestone is getting enough reactions to demonstrate an energy
| gain by counting the amount of helium that comes out of a fuel
| pellet when we have those two lasers working together. That'll
| give us all the science we need to engineer a reactor. So the
| third milestone is bringing that all together and demonstrating a
| reactor concept that works."
|
| The fourth step is to deliver the reactor concept as promising
| machine. The fifth step is to attach it to power generating
| equipment and demonstrate the power plant. The sixth step is to
| scale up a supply chain capable of delivering multiple units that
| compete with other sources of commodity electricity (or other
| energy products). The seventh step is to scale to large scale
| without being unduly burdened by either supply chain (raw
| material, skilled labor) or regulatory impact/public concern that
| inevitably scales with any large fleet of any new tech.
|
| Fission made it to step 7 and then faltered and is now teetering
| depending on where you look. It never scaled past 5% of total
| world primary energy.
|
| The promise of fusion is to deliver nuclear energy with less
| public concern than fission because it makes less radiologically
| hazardous material. The challenge is to go through the physical,
| engineering, and commercial viability phases as a power plant.
| Accujack wrote:
| Love the user name. I always thought that movie was amusing,
| and so is the NSA :)
| acidburnNSA wrote:
| Ha thanks. I kind of made it before I knew Hacker News was
| more or less a serious place. And snowden was in the news at
| the time.
| anonuser123456 wrote:
| >I got into nuclear technology because of ITER back in the
| early 2000s. Worked on it continuously (mostly in advanced
| fission) ever since.
|
| What is your opinion on SPARC and tokamak energy?
| acidburnNSA wrote:
| High temperature superconductors are absolutely an
| interesting pathway to make magnetic confinement fusion
| significantly easier than the big tokamaks like ITER. I have
| friends working at Commonwealth Fusion who are good people
| and I wish them much success. That said there are still a lot
| of phases to go through, from physical viability at stage 1
| to scaled commercial fleet at stage 7, and that pathway is
| impossible to predict without getting on the ground and going
| through the stages. I certainly think it's worth running
| through the stages.
| njarboe wrote:
| I really hope that fusion power can become a major power
| source in the future and humanity really needs it to expand
| off planet, but like you said above, nuclear fission power
| got to stage 7 and then stalled. I think the nuclear fusion
| community should drop the word nuclear completely from
| their vocabulary or they are likely to end up with the same
| fate, if they ever get to stage 7.
| freeopinion wrote:
| How about "Smart Plant"(c)(tm)?
| smolder wrote:
| If we can figure out fusion as a power source, maybe we
| can also figure out how to improve the quality of
| people's information exposure too, leading to a smarter
| population. Currently we try to hide the best information
| behind paywalls or in private knowledgebases, we neglect
| schools or profiteer through them (US in particular), and
| we inundate people with stupefying advertisements and
| misinformation.
| njarboe wrote:
| Although both things are very difficult, the knowledge
| needed to create a commercial fusion reactor is very
| different to educating a whole populous not to be so
| afraid of radiation (which is natural and found
| everywhere all the time).
| ncmncm wrote:
| There is no actual expectation of ever getting useful power
| generation from magnetic confinement fusion (ITER, Tokamak):
| it has always been, instead, a jobs program for high-neutron
| flux physicists, to maintain a population to draw on for
| weapons work.
|
| p-boron fusion is interesting as a possibly practical energy
| source. The hurdles are a matter of engineering and finance,
| not fundamental design flaws. But it's useless as a jobs
| program for weapon experts, so must rely on commercial
| investment.
| philipkglass wrote:
| I think that you have that backwards. It's the laser driven
| inertial confinement fusion approach that is useful for
| weapons insights. The very low density and slow kinetics of
| fusion in a tokamak are much less like weapon fusion
| reactions.
|
| Lawrence Livermore -- a nuclear weapons lab -- has studied
| inertial confinement fusion for decades. They don't have a
| tokamak.
|
| https://en.wikipedia.org/wiki/National_Ignition_Facility
| anonuser123456 wrote:
| SPARC is not ITER.
|
| It's seems bizarre to ignore the impact HTS tape would have
| on the plausible operation of MCF.
| sf_rob wrote:
| Tangent, but assuming fusion energy generation will be a
| reality in the next 30 years, what do you believe the price/KWH
| will be? I am not knowledgeable enough to parse the estimates
| I've seen and want to believe in the post-energy-scarcity
| future.
| malux85 wrote:
| I doubt we are even anywhere near close to being able to
| calculate that because there's still too many unknowns with
| regards to materials required to build, their rate of
| depreciation, and other things we discover in the
| scaling/commercialisation phases, and also exactly how much
| net energy will be produced!
| joshvm wrote:
| Price per kwh is not solely about generation efficiency, it's
| also about distribution and infrastructure. There will always
| be a cost associated with that which will rise with
| inflation. Even if we went totally renewable and all your
| electricity was "free" then you'd still have to account for
| on demand storage and infrastructure costs.
|
| The main benefit of nuclear is its _relatively_ low carbon
| footprint and in theory less risk of spiking fuel costs
| because we run out of raw materials. That 's the dream of
| fusion anyway.
|
| Nuclear power infra is not cheap and even fusion will have
| security and decommissioning costs.
|
| Forget cost as the main factor, grid power will never be
| free. That's a fantasy - even publicly owned utilities
| will/are funded by taxation. You're paying for price and
| power stability. Domestic fusion means you don't need to rely
| on foreign resources (eg Russia cutting off the gas).
|
| Putting renewable generators in your home has a high capital
| cost, but people forget that you're also cushioning yourself
| against grid outages. It's insurance more than anything else.
| freeopinion wrote:
| What's the fun of tech forecasting if you don't over-
| promise?
|
| A fusion reactor the size of a shipping container? Plop one
| down between my neighbor's house and my house. Right where
| our backup generators now sit. It's about the same
| footprint.
|
| No more distribution costs. Well, except for Amazon's fees
| to drop off the uranium now and then. :)
| DennisP wrote:
| Uranium is for fission, not fusion. Fuel for this fusion
| reactor would be some compound of hydrogen and the most
| common boron isotope. There's plenty of that in a regular
| box of Borax.
| DennisP wrote:
| D-T fusion would have security and decommissioning costs,
| but neither would be an issue for aneutronic fusion.
| 1024core wrote:
| Apparently Step 5 is not needed?
|
| > The alpha particles generated by the reaction would create an
| electrical flow that can be channeled almost directly into an
| existing power grid with no need for a heat exchanger or steam
| turbine generator."
| sandworm101 wrote:
| It isn't that simple. This thing will be DC, and at some
| random voltage. They will need huge bits of kit to convert
| the output into some sort of usable power. It is electricity
| yes, but not clean useful power.
| dfsegoat wrote:
| FWIW as an aside: I always scan comments on nuke-related HN
| posts to find yours first. Super informative and easy to
| digest. Thanks again.
| ccleve wrote:
| A number of these steps become easier if the reactor is
| physically small. A plant that fits in a shipping container has
| a way easier path to commercial viability.
|
| Small plants require less capital. They're easier to
| manufacture. They can iterate faster. They have less
| environmental impact, and therefore fewer regulatory hurdles.
| They require less labor to build and a smaller supply chain.
|
| I expect that the engineering is harder, because scale can
| bring efficiencies. But still, I think the winner is going to
| be a small device, not a behemoth, if only because a small
| device can come online years earlier.
| throwaway894345 wrote:
| I expect that you lose efficiencies with respect to security.
| I.e., it's not easy to secure one large nuclear reactor
| (fission or fusion), but it's a lot easier than securing
| dozens of small reactors.
| goda90 wrote:
| Nuclear fission reactors need more security than other
| power plants because of the implications of stolen
| fuel/waste, or fallout from sabotage. A fusion reactor like
| the one this group is working on probably doesn't have as
| high as security concerns. In fact the only concern might
| be that it is critical infrastructure(like our entire power
| grid), and a distribution of smaller reactors would be
| better for reliability anyway.
| LeifCarrotson wrote:
| Traditional fusion reactors do produce fast neutron
| radiation, which, in addition to causing problems like
| weakening the structure (which can be mitigated with
| better materials, better engineering, and by replacing
| subcomponents over time) is able to irradiate U238 into
| PU239.
|
| Drop a chunk of U238 in/near the fusion reactor
| somewhere, let it absorb stray neutrons, and you'll soon
| have some plutonium. That's bad for control of nuclear
| weapons proliferation, which relies on high-energy
| neutron sources like breeder reactors being difficult to
| build and expensive.
|
| Not sure about the radiation profile from this system
| though.
| goda90 wrote:
| I'm not very knowledgeable about fusion, but it looks
| like this system is aneutronic fusion, so those concerns
| would be lessened too.
| https://en.wikipedia.org/wiki/Aneutronic_fusion#Boron
| [deleted]
| Someone wrote:
| If that's a problem, you can locate hundreds of small
| reactors together.
| lallysingh wrote:
| If these reactors are low heat, not radioactive, and use
| plentiful fuel, what's the threat model? Is it just worried
| about availability of power?
| microtherion wrote:
| According to the article, the energy is generated by
| alpha particles, which are in principle a very dangerous
| form of radiation. It's not clear to me, though, whether
| the radiation stops as soon as the fusion does or not.
| DennisP wrote:
| Substances which continuously emit alpha particles are
| dangerous.
|
| This is something different. With every laser shot there
| will be a burst of alpha particles. Then they'll slow
| down and just be plain old helium. If the direct energy
| conversion works, they'll get slowed down very quickly.
| jandrese wrote:
| "Not Radioactive" is the trick. Even if the fuel isn't
| hazardous you have lots of radiation being kicked off by
| the reaction that irradiates the surrounding equipment
| and the waste products.
| DennisP wrote:
| The HB11 reaction doesn't produce neutron radiation. I've
| seen claims that there would be side reactions,
| generating neutron radiation totaling under 1% of the
| energy output, but the only source of that I can think of
| is if deuterium isn't removed from the hydrogen, and we
| could do that if necessary. It might not be, since
| neutrons from deuterium fusion are a lot less energetic
| than D-T neutrons.
|
| The energy output of HB11 consists of fast-moving alpha
| particles, which is good because that's the energy you
| capture, along with x-rays. None of this would activate
| reactor components. The waste product is non-radioactive
| helium.
| Retric wrote:
| It's not that simple. 1% of even 1MW is a _lot_ of
| radiation so it comes down to what the walls are made of
| more than the total neutron flux. ITER style lithium
| blankets would be recycled for tritium without producing
| much net waste. Light water nuclear reactors have several
| feet of water to absorb fast neutrons, which makes a huge
| difference. The walls of this are a more open question.
| DennisP wrote:
| So I looked it up, and found there actually are two side
| reactions from the primary fuels, no deuterium required.
| In a thermal plasma the resulting neutrons would carry
| less than 0.2% of the energy output. I don't know what
| the percentage would be for this reactor, since the fuel
| isn't a thermal plasma while fusion is happening.
|
| https://en.wikipedia.org/wiki/Aneutronic_fusion#Boron
|
| Neutron energy would be a bit under 3 MeV, comparable to
| fast fission neutrons but in much lower quantity for the
| power output.
|
| https://en.wikipedia.org/wiki/Neutron_temperature
|
| Interestingly, that page says the thermal neutrons in a
| conventional nuclear reactor are better at activating
| materials than fast neutrons.
|
| According to a presentation I saw by the leader of MIT's
| fusion program, the inner wall of a D-T tokamak would be
| activated by the neutrons, but would only need to be
| stored for a few decades. D-T releases 80% of its energy
| as 14 MeV neutrons.
|
| According to LPP, which is working on a different boron
| fusion design, a 20MW reactor would activate the walls
| with short-lived radiation, but it could be safely opened
| for maintenance after about twelve hours (iirc).
| kbenson wrote:
| There might also be less security needed if you have dozens
| of smaller reactors. You have to secure the one because
| losing it affects so much. If losing a couple is not as big
| a problem, you an rely more on the redundancy of the system
| than on the redundancy of the component.
|
| This depends on the threat model to some degree, but
| there's security in knowing that it's vastly harder for a
| threat to affect multiple targets at once, no matter the
| threat.
| jacobedawson wrote:
| Isn't this just the same scenario as we currently have,
| just with different underlying technology? Do coal-
| powered plants have additional security outside of a few
| private guards?
| naiveprogrammer wrote:
| I don't know whether this is a legit breakthrouhg. But
| technological progress is often a sigmoid (S-shaped) growth
| curve, it may take a while to get past certain steps but once
| you are through, money flows and more people devote time to
| that technology which accelerates the process. It is not hard
| to imagine, say, 20 years from now, we have power plants
| running on fusion given the interest we have in solving the
| climate crisis.
| wtracy wrote:
| > The fifth step is to attach it to power generating equipment
|
| The part that jumped out at me as strange is that they claim
| their process generates electricity "directly" without having
| to drive a turbine. Supposedly they produce helium cations, and
| that can drive a circuit.
|
| Can anybody comment on whether that makes sense?
| frankus wrote:
| Huge if true.
|
| Most fission plants throw away about two-thirds of their
| energy output as waste heat (according to: https://www.answer
| s.com/Q/How_much_of_the_heat_generated_in_...), and their
| cooling towers are so much bigger than the reactor itself
| that they've become a symbol of the plants as a whole.
| graycat wrote:
| Sorry to get away from some really nice physics and
| suggestion of some really good news for some of relevant
| reality:
|
| The cooling towers? The photographs in the news commonly
| show huge clouds of water vapor escaping from the tops of
| the towers with a picture caption about "nuclear" power or
| some such.
|
| So, the suggestion is that nuke plants generate huge clouds
| of dangerous radioactive byproducts.
|
| Such news content is easy: (1) Suggest that the cooling
| towers are the nuclear reactors and (2) don't mention that
| what is coming out is just water vapor, from water recently
| in some river or lake. Now the news people have their
| audience by their eyeballs for ad revenue and/or politics
| as in
|
| https://www.peakprosperity.com/2019-year-in-review-
| part-1/#c...
|
| "The whole aim of practical politics is to keep the
| populace alarmed (and hence clamorous to be led to safety)
| by an endless series of hobgoblins, most of them
| imaginary."
|
| ~ H.L. Mencken
| Rhinobird wrote:
| The main Proton-Boron reaction produces charged particles
| instead of neutrons. You can capture the charged particles
| directly as a source of voltage with no intermediate step.
| Just stick a piece of metal in the way and hook up wires.
|
| Conventionally, neutrons are used to generate heat which is
| then used to drive steam turbines.
| NortySpock wrote:
| Wouldn't it produce high-velocity charged particles?
|
| Thus you would capture the energy with a "reverse coilgun",
| "regeneratively braking" the particles down to a non-
| relativistic speed, rather than just using them to charge a
| capacitor plate.
| rklaehn wrote:
| Once the capacitor plate has a voltage in the range of
| the kinetic energy of the particles, this is exactly what
| will happen. The particles convert their kinetic energy
| into electrical energy by rolling "uphill" against the
| electric potential.
| Zardoz84 wrote:
| Interesting... I remember reading about fusion on the high
| school, and I thought that must be a way to collect the
| energy directly.
| ChuckMcM wrote:
| Spot on analysis. There is one loophole which is Total Cost of
| Ownership (TCO).
|
| If you energy production solution can achieve a lower TCO in an
| existing market segment, steps six and seven (production and
| supply chain) take care of themselves. The poster child for
| this was 'on premise PV generation.'
|
| Once a nuclear technology demonstrates a lower TCO for baseline
| power generation, its game on.
| tinco wrote:
| Off-topic question: is there some software part in nuclear
| energy systems that is restricting plants or research? I'd like
| to contribute to the industry as a non-physicist, but it's hard
| for me to imagine what kind of software might be missing or is
| being sold by too expensive specialist companies.
|
| I imagine most software is tied to the specific devices they
| run on, but perhaps there's coupling or analytical software
| that could be better geared towards the problem domain. Is
| there any fundamental issue that is waiting for a good software
| solution?
| jxy wrote:
| All kinds of simulations. For example: https://journals.sagep
| ub.com/doi/full/10.1177/10943420177120...
| acidburnNSA wrote:
| It just so happens that a nuclear fission reactor analysis
| framework recently emerged on github partially with hopes
| that people like you would be interested in contributing. It
| hasn't been widely publicized and is pretty esoteric but is
| there.
|
| https://github.com/terrapower/armi
|
| Some more open source things in the domain can be found here:
| https://github.com/paulromano/awesome-
| nuclear/blob/master/RE...
| ttul wrote:
| I'm not an expert at all, but I follow news about fusion
| energy with keen interest. Getting to conditions where fusion
| reactions can take place requires modeling the physics with
| supercomputers. I think the physicists have a handle on the
| software required to do that modeling; they also have access
| to the computers.
|
| I think if you have a software background and want to
| contribute, you should consider applying for a job with one
| of the projects themselves. General Atomics lists 135
| software jobs (https://www.ga-careers.com/search-
| jobs/software/499/1) for instance.
| LaMarseillaise wrote:
| I think it must be mentioned that in addition to fission
| and fusion (ITER) work, General Atomics is the creator of
| the MQ-9 Reaper, which is commonly used for drone strikes.
| A software job at this company may involve work on these
| aircraft.
| JoeAltmaier wrote:
| Why a pellet? Why not a gas of boron and hydrogen? Easier to feed
| continuously.
| kamesstory wrote:
| Probably had to do with density, if the target is cascading
| reactions by nuclei to nuclei contact. Solids have a higher
| chance of contact.
| ncmncm wrote:
| Better yet, a wire feed.
| teilo wrote:
| This article reads like a press release for a startup.
| thinkcontext wrote:
| The title is profoundly misleading. Fusion has not been achieved
| using this method, the "leapfrog" results are from simulations.
| tartoran wrote:
| This proves once again what could happen if one is not to follow
| the herd.
| melling wrote:
| "He called this in the 70s, he said this would be possible.
| It's only possible now because these brand new lasers are
| capable of doing it."
|
| He knew it would work 50 years ago.
|
| I imagine there are ideas being discussed today that will come
| to fruition 50 years from now.
|
| ... or 30 years. Our choice.
| dlsso wrote:
| Yes. This was my favorite quote. With slightly more context:
|
| You know what's amazing? Heinrich is old, he's 84 or so. He
| called this in the 70s, he said this would be possible. It's
| only possible now because these brand new lasers are capable
| of doing it. That, in my mind, is awesome.
| jsilence wrote:
| Ada Lovelace and Charles Babbage come to mind.
| wokkel wrote:
| What i find disturbing is when I start looking for other sources,
| google gives me a news item on
| https://newsroom.unsw.edu.au/news/science-tech/pioneering-te...
| but there the article has been retracted? Also another one that
| is behind a paywall it seems (cannot tell as the paywall is
| broken). So I have 1 story on 1 website and the company website
| itself. The news-site claims on their about page that they value
| old-school journalistic values (I assume they mean, they
| investigate a story before publishing) but it's hard to take that
| claim seriously without more credible sources. For me this is
| interesting technology to keep an eye on, but without more
| confirmation and research, this is cold-fusion for now.
| DennisP wrote:
| For the credible sources look at their publications in
| scientific journals. They might be wrong but this is nothing
| like cold fusion.
| yufeng66 wrote:
| There is a warning sign. Without actually running the number, I
| believe the energy generated by the proposed HB11 fusion should
| be several order of magnitude higher compared to the electric
| energy alpha particle can carry. So extreme hot temperature will
| be created regardless.
|
| Edit: actually read the paper :) From the paper: H + 11B = 3 x
| 4He + 8.7 MeV
|
| when alpha particle absorb the electron to become helium, it can
| carry about 50 eV energy. So vast majority of the energy
| generated will be kinetic energy or photon energy which translate
| into very hot temperature at macro level.
| steerablesafe wrote:
| I think the idea is to capture the kinetic energy of the Helium
| ions not through cooling but slowing them down with
| electromagnets. The high-speed Helium ions carry a large
| current, it's not about the ionization energy.
| bbojan wrote:
| Actually, converting kinetic energy of fast moving ions to
| electricity is a very efficient process. See
| https://en.wikipedia.org/wiki/Direct_energy_conversion.
| danmaz74 wrote:
| I suppose the idea is that most of the energy will be expelled
| as kinetic energy of the alpha particles, that then can be
| converted into electric potential energy?
| phkahler wrote:
| Yeah, I thought the electrical output seemed fishy too. Why are
| the electrons stripped from the helium? And is that actually
| due to the energy of the fusion reaction? And how much of the
| fusion energy is left after?
|
| These are IMO the fundamental questions.
| rcollyer wrote:
| Only the helium nucleus is formed as part of the fusion
| reaction, so it starts off being positively charged, and not
| later stripped of its electrons. That, in principle, creates
| a current which can be used almost directly.
| willis936 wrote:
| Well, it creates a region in space with a high charge
| density that can be accelerated to a plate that has a
| voltage applied to it which it bumps into which then causes
| a current.
|
| Importantly, this doesn't have to happen in the reactor
| vessel. The charged gas can be pumped somewhere else.
| DennisP wrote:
| It does have to happen in the reactor vessel. It's not
| just that it's a charged gas. It's that it's a charged
| gas which is exploding with almost 300 kWh of energy per
| shot.
| skykooler wrote:
| Much of the difficulty with fusion is getting the fuel to the
| temperatures needed to sustain fusion - so that's actually a
| good thing.
| londons_explore wrote:
| The whole "electrical energy directly so no steam generators
| necessary" part of the discussion is fairly irrelevant.
|
| Steam generators might have fairly low efficiency, but if
| hydrogen fusion works _at all_ it 'll use so little fuel and
| have such a low marginal cost that we can just do more of it to
| make up for any efficiency losses.
| DennisP wrote:
| It's not so much about efficiency as capital cost.
| londons_explore wrote:
| Except steam generators are pretty cheap - they're off the
| shelf, and will be a drop in the ocean compared to the
| total costs of the first fusion plants.
| steve19 wrote:
| The waste heat from the inefficieny is an environmental
| issue if cooling with sea, lake or river water.
|
| The article talks about the advantage of not needing
| steam cooling apparatus. The stations could be located in
| urban areas.
| DennisP wrote:
| Well, that depends. ITER is tens of billions. The most
| expensive part of this reactor would probably be the
| petawatt laser, which is tens of millions for one-off
| experimental devices. A turbine and generator is about a
| million dollars per megawatt, so it could be a
| significant percentage of total reactor cost, especially
| in mass production.
| excalibur wrote:
| > a swag of patents
|
| Is this the correct term for a group of wild patents? What do you
| call a group of wild patent trolls?
| TomMarius wrote:
| My nuclear fusion physicist friend is very sceptical.
| throwaway9d0291 wrote:
| On its own, this isn't a very substantial comment. Can you
| elaborate on why your friend is sceptical and what effort they
| put in to come to that conclusion?
| crusso wrote:
| Here's a video explaining the reaction:
| https://www.youtube.com/watch?v=Dy0kHQASsX8
| dctoedt wrote:
| Upvoted -- the first minute or so of the video is very helpful;
| it shows (what looks like) PowerPoint slides with drawings of a
| proton (1H nucleus) hitting a boron nucleus (5B11); the proton
| fuses into the boron nucleus to create what presumably is a
| single carbon nucleus (6C12), which then splits into three
| helium nuclei (each 2He4) without emitting free neutrons.
|
| (The very-crude video technique was fascinating to this non-
| artistic person: Create PowerPoint slides, add subtitles for
| "narration" that float in and out, and finally add stock music
| for background. That might be useful for flipped-classroom
| courses.)
| jobseeker990 wrote:
| Why would the carbon split? Why not stay carbon? And wouldn't
| this technically be fission energy then?
| dctoedt wrote:
| > _Why would the carbon split? Why not stay carbon?_
|
| Don't know -- I'm not knowledgeable enough in this area to
| do more than take WAGs about it. The sequence might be
| different: For example, the 1H proton might not ever fuse
| with the 5B11 to form 6C12; instead, the fusion reaction
| might be that the 5B11 fissions into two 2He4 and one
| tritium 1H3, after which the 1H proton fuses to the tritium
| to form the third 2He4.
|
| > _And wouldn 't this technically be fission energy then?_
|
| See the explanation in this thread at
| https://news.ycombinator.com/item?id=22383199 -- it makes
| as much sense as anything.
| gautamcgoel wrote:
| Not to be a downer, but if you say your technology is working a
| billion times better than expected, one of two things is probably
| true: you are trying to stir up media hype, or you don't really
| understand the underlying technology to begin with.
| pier25 wrote:
| Is fusion capable of replacing all our energy systems?
|
| If it works, is it the energy miracle humanity needs?
| LaMarseillaise wrote:
| 1. Yes.
|
| 2. No, because we already have fission reactors. How many
| miracles do we need?
| pier25 wrote:
| > _How many miracles do we need?_
|
| Right, but humanity won't scale up fission to power
| everything.
| LaMarseillaise wrote:
| Why not?
| phaemon wrote:
| Because fission is insanely expensive. The nuclear
| fanboys like to try and divert the conversation to safety
| as they think they can argue that point, but the fact is
| that nuclear is overpriced garbage.
| pier25 wrote:
| I don't know why, but AFAIK there are no countries
| investing heavily in fission to make that happen.
| LaMarseillaise wrote:
| Thank you for your honest reply.
|
| I have heard of efforts in India and China to develop and
| build out nuclear fission plants, though I do not know
| the scale of these plans. However, even ITER (the largest
| fusion project right now) has a budget of only $10-20
| billion. I have high hopes for ITER, but even that has
| been protested by anti-nuclear organizations such as
| Greenpeace. I worry that fusion, despite its many
| advantages, may be stalled or stopped in the same way
| fission has been. If we cannot solve this issue with a
| currently-available zero-emission power source, I just
| cannot see how a new one based on the same principles can
| succeed.
| DennisP wrote:
| It's hard to imagine anyone successfully protesting a
| power source which is non-polluting, very close to non-
| radioactive, dispatchable, and likely cheaper than any
| other system with those properties. However, if the U.S.
| does turn out to be that silly, we'll likely get over it
| when we find ourselves being outcompeted by China, which
| will certainly have no qualms.
| acidburnNSA wrote:
| There certainly is enough fusion fuel on earth to power
| humanity at 10 or 100x current consumption until the sun
| explodes without emitting any CO2.
|
| Same can be said for fission, but it only powers 5% of the
| world due to what can be called complications (even though many
| scientists insist that it's safe and responsible).
|
| Fusion is expected to have fewer complications, but we won't
| know until we scale up a fleet of fusion power plants and
| understand all the nuance.
|
| How's that for an answer?
| pier25 wrote:
| Good answer!
|
| > _Same can be said for fission, but it only powers 5% of the
| world due to what can be called complications_
|
| But weren't these complications obvious before deciding to
| scale up fission power plants?
|
| The ones I know about:
|
| - Radioactive waste
|
| - Risk of failure
|
| - Unavoidable EOL
| acidburnNSA wrote:
| Certainly the generation of radioactive material in fission
| plants was considered potentially fatal all the way back to
| Fermi, who said way back when:
|
| > It is not clear that the public will accept an energy
| source that produces this much radioactivity and that can
| be subject to diversion of material for bombs.
|
| However, the nuclear fission industry has arguably shown
| that it can technically manage radioactive wastes without
| undue harm to the populace. Fission plants have killed up
| to 4000 people while producing 5% of the world's energy.
| Fossil kills 4.2M people/year at 84% total energy. The math
| suggests that nuclear fission has been highly successful.
| But the public largely still doesn't like it.
|
| Fusion indeed has a better going-in position. Potential
| complications involve how hard/complex/expensive it is to
| realize the engineering challenges.
|
| Aneutronic fusion plants, like fossil plants, will likely
| also have an EOL from a thermal creep, corrosion, cracking,
| etc. POV. Normal fusion plants will definitely have a EOL
| from neutron doses to structural materials.
| pier25 wrote:
| Thank you for your comments. It's great to have someone
| knowledgeable about these topics give some ELI5 answers.
|
| > _Fossil kills 4.2M people /year_
|
| Where does this number come from?
| acidburnNSA wrote:
| You're welcome!
|
| That number comes from the WHO:
| https://www.who.int/airpollution/ambient/health-
| impacts/en/
| 1958325146 wrote:
| I am just learning about this reaction, but can anyone explain
| what is wrong with the following naive idea?
|
| - Fire a stream of hydrogen ions with a particle accelerator at a
| chunk of Boron 11. - The hydrogen and boron combine and release
| heat and helium. - Use the heat from that to run a turbine and
| keep running your particle accelerator.
|
| It seems like you would be ending up with lower-energy collection
| of atoms. Does that work but it is just not efficient enough to
| keep running the accelerator, or what?
| Accujack wrote:
| >fire a stream of hydrogen ions with a particle accelerator at
| a chunk of Boron 11.
|
| This is what's wrong. The energy required to accelerate the
| ions is much higher than the energy which can be harvested this
| way.
|
| The concept under discussion substitutes a simpler setup that
| accelerates particles using laser induced plasmas from a very
| small table top laser. The thing could "almost" be battery
| powered.
| sam wrote:
| The problem with firing a stream of hydrogen ions at a chunk of
| Boron 11 is that most of the collisions between the hydrogen
| and the Boron are glancing blows that will dissipate the energy
| very quickly. Only a small fraction of the collisions result in
| a fusion reaction.
|
| This is the reason why most fusion approaches rely on thermal
| systems. In a thermal system, the ions have a bell-shaped
| distribution of energies and undergo many collisions before
| they leave the region in which they are confined and their
| energy leaves the system.
|
| To achieve net gain, the temperature, density and energy
| confinement time must be above a certain threshold. If the
| system is non thermal, like a stream of hydrogen ions where the
| distribution of energies is a spike, the energy in the hydrogen
| ions that are deflected by glancing blows must be recaptured
| somehow.
| 1958325146 wrote:
| Thank you!
| willis936 wrote:
| 27 comments and not one hit of the word "inertial"! The line
| about not being thermonuclear and the description of the device
| in question (a sphere with lasers) points towards an inertial
| confinement fusion (ICF) device. Most of the fusion research eggs
| are in the thermonuclear basket, specifically magnetic
| confinement fusion. It is good to research a diverse set of
| approaches, but there are more engineering challenges to ICF
| reactors than there are to MCF reactors. Pulses on the order of
| 1-2 Hz requires a mechanical system that can cycle out the
| exhaust and replace the pellet in that time. Going to reactor
| scales also requires high load thermal cycles. MCF ain't easy,
| and brings it's own engineering challenges. The ones I always
| hear are things like wall materials and fuel recycling, but these
| are largely solved or in the process of being solved. The
| engineering challenge I see as the most difficult for MCF are
| related to steady state operation. Tokamaks have no way of being
| steady state. Stellarators do, but now the next problem is wall
| conditioning. Wall materials outgas in hot plasma. A lot. Like
| more than the fuel puffed in. The way this is handled in science
| machines is with glow discharges of various species: plasma just
| below the temperature to cause wall sputtering, coating the wall
| with carbon and boron for their absorptive properties, etc. No
| one's run a steady state hot plasma before, so no one knows if
| these will be a non issue in reactors. Keeping the plasma clean
| may be a challenge to keep the plasma from terminating. Aside
| from that MCF is ready for prime time. It needs a big reactor for
| scaling laws to make it energy profitable (and potentially money
| profitable). We just need some very expensive test reactors to
| smooth out these issues.
| derefr wrote:
| Complete layman to this, but are these approaches fundamentally
| incompatible with one-another, or is it just that each one on
| its own seems to be "enough" to get a reactor to work? Could
| you have a reactor that just combines all these confinement
| approaches at once?
| wolfram74 wrote:
| They're not incompatible in the sense that they assume
| different physics, but they are very different strategies.
|
| The fusion triple product is the go to figure of merit for
| napkin calculations, it's temperature X confinement time X
| ion density
|
| MCF strategies go in on maximizing confinement time, while
| ICF jack up temperature and ion density. This particular ICF
| approach, (if I'm understanding their paper correctly) is
| going so high on both that they're leaving the thermal regime
| behind and doing an honest to glob nuclear chain reaction
| with having the alpha products prompt other boron nuclei to
| accelerate up to fusion speed causing more reactions, which
| is pretty exciting.
| willis936 wrote:
| Laser inertial confinement causing a nonthermal chain
| reaction has been making headlines since 2015. I don't
| think that aspect of this approach is the exciting part.
| It's how promising their simulated performance improvement
| is from the use of a laser that causes additional magnetic
| confinement (I'm a little iffy on how that exactly
| happens).
| DennisP wrote:
| In a way, this new design does combine the approaches, since
| it combines a laser that hits the fuel directly with an
| extreme magnetic field.
| pxhb wrote:
| One reason you might not find 'inertial' is because the only
| thing they have in common is a laser.
|
| For ICF, a long-pulse laser is used like a hammer to heat and
| compress the material to fusion conditions.
|
| This scheme, as far as I can tell, uses the large EM fields of
| a short-pulse laser to accelerate a 'beam' of ions into cold
| material to induce fusion.
| anonsivalley652 wrote:
| It seems easy to conflate any or all approaches as fringe when
| no one's done it yet, and especially if there are political and
| program-$ecurity concerns overriding doing what's best, but
| some approaches scream magical thinking with unexplained
| reasoning more than others (like one or more cold fusion
| proposals in the early 1980's). OTOH, it seems like ICF and
| tokamak are the officially-sanctioned dogma and all other
| approaches are discounted automatically.
|
| Q0: Without bias from my opinion, how fringe or potentially
| legitimate does IEC seem?
|
| Q1: Props to the article's team that they invented some awesome
| lasers. Is there enough experimental data yet on their novel
| approach to backup their claims to justify funding a prototype?
| Would such a team be able to test this on a shoestring budget
| without spending millions?
| DennisP wrote:
| IEC is a different fusion scheme.
|
| "Millions" is pretty much a shoestring budget for fusion
| projects. There is some experimental data, but without actual
| fusion since the lasers weren't powerful enough yet.
|
| This team didn't invent the lasers. They've been waiting for
| the lasers to get sufficiently powerful to attempt fusion
| with them. Those lasers are finally becoming available for
| researchers to use, so it should be quite inexpensive to test
| this idea. Worst case, they have to build one for tens of
| millions, which is comparable to other private fusion
| projects, but hopefully they can run the experiment on other
| people's lasers.
| willis936 wrote:
| Personally, without drawing from rigorous empirical proof
| that doesn't exit, I don't think things like unique IEC
| approaches are based in fairy tales. Fusion science used to
| be very tribal and dogma was important. That era has largely
| passed. Tokamak, stellarator, ps laser, steam machine,
| whatever. If you can find the money to make it and do the
| science to show its performance, great. Everyone wants you to
| do that. This idea of pulling resources away is tricky to
| navigate, because there is finite resources spent on research
| and getting any one design to work takes significant effort.
| That's why so much is being poured into ITER instead of other
| promising leads. Humans are ready to see a machine work. It's
| painful to get there. It's not my first pick on a machine.
| But in order to keep progress moving a real reactor needs to
| be made of some kind.
| wolfram74 wrote:
| The 2015 paper cites 3 other groups with experimental
| results supporting their claims though.
| willis936 wrote:
| You misinterpreted what I said. I said that I don't have
| evidence that inertial electrostatic confinement is _not_
| based in fairy tales. As in, they are a reasonable route
| to explore.
| zgramana wrote:
| There's been a lot of promising work done on IEC by a startup
| called EMC2. Their reactor/fusor design is called Polywell.
|
| * https://en.m.wikipedia.org/wiki/Polywell
| Dumblydorr wrote:
| Just a writing critique. I think your post could use paragraph
| breaks, it's hard to discern the logical structure without
| breaks.
| missosoup wrote:
| So is there a way to invest in this?
| DennisP wrote:
| It's a private company in Australia that likely needs more
| funding, so probably so, if you meet your government's
| requirements for investing in that sort of thing.
| RandomWorker wrote:
| Google polywell the US military has been funding this for the
| past 20 years. There are some issues that might be solved with
| scaling the device. A company called emc2 was spun off this US
| military project.
| DennisP wrote:
| Polywell is a completely different method.
| cfv wrote:
| On paper, this sounds absolutely awesome and a huge game changer.
|
| I'm super concerned about the military applications tho. Giving
| functionally endless, mostly free power to warmonger countries
| with the ability to field drones is something extremely
| concerning for me.
| foobiekr wrote:
| they basically already have endless, mostly free power in the
| sense you are getting at. that it isn't clean is irrelevant to
| their use case.
|
| china, iran, the united states, etc. militaries are not hurting
| for energy and already make heavy use of small nuclear reactors
| where just hauling fuel is not an easier choice.
| detritus wrote:
| This seems.. too good to be true?
|
| I don't have the Physics chops to untangle the likelihood of this
| tech and the credibility of the process and its authors, so I'm
| hoping the HN crowd will be able to pad out the story behind
| this.
|
| Certainly, from my layperson's perspective, their website isn't
| exactly encouraging... https://www.hb11.energy/
|
| - ed re: last line - "books and covers, and all that"
| saagarjha wrote:
| Not a physicist, but I thought it seemed fishy as well. I'm
| curious how they plan to sustain a reaction, since their setup
| didn't seem to be useful for more than a single shot...
| lab-notes wrote:
| This reads like a type of ICF which normally has a stream of
| pellets being fed in after the initial pellet has reached a
| hot enough temperature to sustain the fusion reaction.
| londons_explore wrote:
| I don't think the goal is to sustain the reaction here... I
| think the goal is to make a pulsed reactor, where you start
| the reaction on each pellet in turn. You could imagine a
| laser firing at 1000 pulses per second, and firing a stream
| of 1000 pellets per second into the reaction vessel that
| each pulse hits.
|
| Pellets could turn out to be the size of a grain of sand.
| tic_tac wrote:
| At https://www.hb11.energy/our-technology they list a number
| of papers they've published supporting their approach.
|
| On ignoring the H B-11 reaction with high intensity lasers:
| https://www.nature.com/articles/ncomms3506
|
| On the reaction avalanche:
| https://www.cambridge.org/core/journals/laser-and-
| particle-b...
|
| On the conversion of alpha particles to electricity:
| https://www.cambridge.org/core/journals/laser-and-
| particle-b...
| [deleted]
| randallsquared wrote:
| The Hydrogen Boron reaction is real and well-known to be a way
| to do fusion without lots of stray neutrons. The sticking point
| has always been that it's more difficult to cause that reaction
| than deuterium/tritium or deuterium/deuterium.
| jwbwater wrote:
| So the fusion here is where two protons form an alpha
| particle? They show a proton hitting B11 and generating two
| alpha particles and another proton.
|
| 1 proton + (5 protons, 6 neutrons) -> 3 * (2 protons, 2
| neutrons)
|
| https://www.hb11.energy/our-technology
| DennisP wrote:
| Check the publications page for the encouraging part. They
| might be wrong but they're doing real science. I've personally
| spoken to a fusion scientist who thought they might be on to
| something.
|
| Exponential progress does sometimes have results that seem too
| good to be true. In this case the progress has been in
| picosecond lasers, which for a while have been getting ten
| times more powerful every three years or so.
|
| What's great about this is it should be pretty cheap to test.
| The petawatt lasers only cost tens of millions in the first
| place, and China is finishing up a 30PW laser which they plan
| to let other researchers use. If Hora is right then that should
| be powerful enough. Even more powerful lasers are being planned
| elsewhere.
|
| HB11 isn't the only company working on aneutronic fusion. The
| largest is TAE (formerly Tri Alpha), with about $700 million
| invested. There's also Helion and LPP.
| scythe wrote:
| >Check the publications page for the encouraging part. They
| might be wrong but they're doing real science. I've
| personally spoken to a fusion scientist who thought they
| might be on to something.
|
| I checked the publications page and so far I'm not seeing any
| real theory here. That doesn't mean it's wrong, but it
| certainly _feels_ weird. The most in-depth equation I saw in
| any of their linked papers is the definition of the
| electromagnetic field tensor.
|
| I'm not saying you _couldn 't_ develop a fusion reactor by
| doing purely experimental work with bleeding-edge laser
| technology. But I'd feel a _lot_ more confident if they were
| to produce, for example, some kind of prediction of their net
| power, or a relation between e.g. laser power and fusion
| yield, or some other quantitative prediction about something.
|
| For example, I'm not sure _what_ prediction they exceeded by
| a factor of a billion in TFA. Shouldn 't you mention that
| somewhere?
|
| Another poster mention's Todd Rider's thesis, a famous
| barrier to creative fusion. In this particular case I think
| the way they evade Rider is by using higher laser powers and
| shorter reaction times than Rider considered to be possible.
| One of the important exceptions Rider acknowledges (and that
| I remember) is ultradense fusion; ultrafast fusion seems to
| be at least similar in principle.
| Wildgoose wrote:
| One of the reasons that it is difficult to predict power
| output exactly is not knowing exactly how much will be lost
| down to Bremsstrahlung, (ELectromgnetic Braking Radiation).
|
| In any event, ultimately practical proven results will
| always trump whatever the current theory may suggest.
| DennisP wrote:
| I think the factor of a billion relates to the expectation
| for boron fuel with spherical compression. See for example
| their latest paper, page three, right column.
|
| They do seem to be making quantitative predictions based on
| simulations. I don't think I've seen them boil it down to a
| simple scaling law though.
| detritus wrote:
| Thanks to yourself and randallsquared below for your
| responses - I'd since posting read the following Abstract by
| the authors, which hinted that the underlying science was
| viable: https://www.cambridge.org/core/journals/laser-and-
| particle-b... , however my only awareness of existing 'laser
| fusion facilities' was the American National Ignition
| Facility
| (https://en.wikipedia.org/wiki/National_Ignition_Facility) ,
| which I think I'd always written off as a covert testing
| facility for weapons that skirted Nuclear Testing limitation
| treaties.
| dragonshed wrote:
| The science is difficult for a layperson (such as myself)
| to pick apart, but the above-mentioned publications page[0]
| links directly to at least one paper[1] which contains some
| promising detail.
|
| [0] https://www.hb11.energy/news-and-publications [1] https
| ://aca3d9dd-3b9c-446b-8797-0ba1cdb49ccb.filesusr.com/ug...
| leecarraher wrote:
| That purpose isn't covert, it is funded by the National
| Nuclear Security Administration(NNSA) under the Stockpile
| Stewardship Program, which built the facility to mimic
| fusion conditions to assure the viable of the US nuclear
| weapon stockpile. From time to time other scientist get to
| use it for other fusion experimentation.
| moneytide1 wrote:
| Yeah I've become wary of "scientific breakthrough" articles
| that never seem to materialize into anything.
|
| But ITER uses huge tower cranes and trucks in the thousands of
| tons of material required to sustain a temperature hotter than
| the surface of Sol because of their fuel selection.
|
| It seems the small player with a new approach that perhaps
| demands less complexity in their scaled up commercial reactor
| could win a commissioning contract with a lower bid during late
| 2020s early 2030s international bidding.
|
| "First milestone is demonstrating the reactions, which should
| be easy."
|
| And "chirped pulse laser amplification" is the recent discovery
| Hora says will make it possible.
| EthanHeilman wrote:
| As a researcher I really like 'scientific breakthrough"
| articles where the impact never seems to materialize. It
| reminds me that technology development works very differently
| on earth than it does in my imagination.
|
| Breakthroughs happen everyday but the road to real impact is
| longer and more failure prone after you make the breakthrough
| than before it _.
|
| _ - with some exceptions
| Accujack wrote:
| Do a google search for "laser induced fission". Generating
| plasmas with CPA lasers is becoming more common, but isn't
| widespread yet because the technology is very new.
|
| These plasmas can be the source for all kinds of particles and
| energy in particular forms, so they may have lots and lots of
| uses.
|
| One person in particular is proposing to use a CPA laser to
| accelerate nuclear decay, to allow radioactive waste to decay
| faster and become less toxic more quickly.
|
| Of course, my own concern would be that being able to induce
| fission with a table top laser means that the tech may
| eventually exist to create a fission or fusion bomb without a
| nuclear trigger....
| [deleted]
| jabl wrote:
| The big problem with H-B11 and other heavier fusion processes
| is that the energy radiated away as brehmsstrahlung is greater
| that the energy gain from the fusion. This was worked out by
| Todd Rider in his 1995 PhD thesis.
|
| Yeah, in theory it might be possible to capture the
| brehmsstrahlung and pump it back into the reactor with
| sufficiently high efficiency, but we're pretty far away from
| that.
|
| That being said, all these fancy fusion reactor schemes are
| interesting. Just make them work on boring old D-T fuel first,
| then lets see if these other fuels are usable, no?
| DennisP wrote:
| Yes, but Rider based that on various assumptions, and
| included an appendix on various ways those assumptions might
| be violated to achieve net power with aneutronic fuels. I
| think this reactor would qualify, since it doesn't rely on
| thermal heating.
| strbean wrote:
| Wait... Todd Rider the DRACO guy?
| pfdietz wrote:
| Yes, he moved away from fusion after basically showing the
| whole non-Maxwellian approach for aneutronic fusion
| couldn't work.
| Lev1a wrote:
| > brehmsstrahlung
|
| Bremsstrahlung
|
| FTFY
| moron4hire wrote:
| I don't know. I think a really flashy website would be more
| concerning. This is a serviceable website that gets it's point
| across without consuming a gig of bandwidth on a video in the
| header background.
| jwbwater wrote:
| Agreed, I do not see their "budget" website as sign they lack
| credibility, I see it as a sign that they are focused on
| their work.
| pxhb wrote:
| I can't tell for sure from the article but I think they are
| accelerating protons with TNSA (target normal sheath
| acceleration). I worked in a lab in undergrad that was doing
| something similar, except with lithium instead of boron. The
| main challenges that I recall from a decade ago with TNSA are
| (WARNING: there almost certainly has been progress since a
| decade ago):
|
| -Conversion efficiency of laser energy into ion (proton)
| kinetic energy
|
| -TNSA accelerates mainly the contaminated layer on the back of
| targets, which may not be a big deal if you are interested in
| accelerating protons
|
| -TNSA protons are not beam like. They do not have a uniform
| kinetic energy, and they have a wide angular divergence.
|
| -Various laser related issues (prepulse, focal spot
| size/shape).
|
| I also anticipate that it will have the same engineering
| problem as ICF/NIF, in that it will need to continuously
| replenish targets.
| DennisP wrote:
| Here's their publications page, if you're interested in
| looking into it further.
|
| https://www.hb11.energy/news-and-publications
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