[HN Gopher] NASA's new shortcut to fusion power
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NASA's new shortcut to fusion power
Author : GordonS
Score : 98 points
Date : 2022-02-28 18:22 UTC (4 hours ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| nynx wrote:
| I really hope this works.
|
| Honestly, there are a number of low-hanging fruits in fusion.
|
| More recent calculations show that, if you include the kinetic
| energy of the muons, Muon-catalyzed fusion may be net positive
| [0]. This LCF stuff is a low-hanging fruit too----ignored for
| many decades because scientists didn't want to hurt their
| reputations.
|
| [0]: https://en.wikipedia.org/wiki/Muon-
| catalyzed_fusion#Alternat...
| was_a_dev wrote:
| Do those revised calculations take into the energy requirements
| for generating the muons?
|
| The wikipedia article doesn't appear to give a clear answer
| smaddox wrote:
| Good to see this field getting some serious investigation. Last I
| looked it was still very hypothetical with only questionable
| characters investigating.
| JackFr wrote:
| > with only questionable characters investigating.
|
| Well the assumption in the physics community is that if you're
| investigating this field you're a questionable character, so
| its surprising that it got investigated at all.
| [deleted]
| willis936 wrote:
| Do the names "Fieschmann" and "Pons" ring any bells? Here is the
| wikipedia article that covers these recent developments. Look in
| the "Later Research" section.
|
| https://en.wikipedia.org/wiki/Cold_fusion
| DennisP wrote:
| The NASA research isn't mentioned there. Differences from cold
| fusion: they're hitting the lattice with gamma rays, and seeing
| 2.45MeV neutrons come out.
|
| Doesn't mean they'll achieve net power this way, or that the
| lattice will survive the neutrons at practical fusion rates,
| but they seem to be seeing D-D fusion reactions.
| ch4s3 wrote:
| Is it real or could there be unaccounted for neutron sources?
| That's been an issue with past metal lattice setups.
| DennisP wrote:
| No idea, but it'd be odd if neutrons from another source
| just happened to have the energy of D-D neutrons.
| danbruc wrote:
| Fusing hydrogen is easy, ionize it and accelerate the
| plasma with a voltage of on the order of 10 to 100 kV,
| hobbyists do this somewhat regularly. Doesn't sound too
| surprising that hitting hydrogen with gamma rays produces
| some fusion. But that's the crucial point, some fusion is
| not useful as an energy source, and not all fusion
| methods can be scaled up.
| DennisP wrote:
| Sure, I'm not denying that at all. It looks like real
| fusion happening, but might not be no more useful than
| fusors. They mentioned their current methods are too
| lossy, but they did have some interesting arguments for
| it being a practical energy source someday.
| fooker wrote:
| I misread lattice as lettuce and was a bit confused for a
| while about the purpose of hitting lettuce with gamma rays!
| riffic wrote:
| https://en.wikipedia.org/wiki/Food_irradiation
| honkycat wrote:
| We need fusion, we need more power YESTERDAY.
|
| Whatever amount we are spending to develop these moonshots it
| needs to be more.
|
| So many "hard things" become that much easier when we remove
| having to power it out of the equation.
|
| A generator for a forklift is probably unrealistic, but for a
| huge, skyscraper building crane? Or for one of those giant
| shipping barges that produce multiple percentage points of our
| carbon emissions? That no longer sound so crazy.
|
| Isn't that how the US powers its aircraft carriers and submarines
| anyway? Only with fission, which clearly is too dangerous to put
| on civilian ships.
| yellow_postit wrote:
| Any good overviews on the different types of fusion and relative
| sense of liklihood to achieve their aims?
|
| I know the throwaway comment is about fussion always being 30
| years away but also does appear from the outside that
| hype/excitement is picking up for some of the recent advances in
| magnetic confinement fusion.
| teeray wrote:
| I'm looking forward to the work Solomon Epstein is doing in this
| area
| DennisP wrote:
| There seems to be an inconsistency in the article. First it says
| the Dynamitron produces gamma rays:
|
| > We can jump-start the fusion process using what is called a
| Dynamitron electron-beam accelerator. The electron beam hits a
| tantalum target and produces gamma rays, which then irradiate
| thumb-size vials containing titanium deuteride or erbium
| deuteride
|
| But later it says:
|
| > producing neutrons from a Dynamitron is energy intensive. There
| are other, lower energy methods of producing neutrons including
| using an isotopic neutron source
|
| Is the input neutrons or gamma rays?
| parksy wrote:
| From what I gather the actual lattice requires neutrons. Their
| current setup uses an electron source (dynamitron) on tantalum
| which generates gamma rays. The gamma rays have the energy
| needed to push neutrons around inside the lattice. It seems
| they're saying it would be more energy efficient just to
| directly generate neutrons without having to go electron ->
| gamma -> neutron.
| orthecreedence wrote:
| > Existing fusion reactors rely on the resulting alpha particles
| --and the energy released in the process of their creation--to
| further heat the plasma. The plasma will then drive more nuclear
| reactions with the end goal of providing a net power gain. But
| there are limits. Even in the hottest plasmas that reactors can
| create, alpha particles will mostly skip past additional
| deuterium nuclei without transferring much energy. For a fusion
| reactor to be successful, it needs to create as many direct hits
| between alpha particles and deuterium nuclei as possible.
|
| This is one of the most clear explanations of fusion power I've
| read so far. Worth a read just for that alone.
|
| > And as the technology matures, it could also find uses here on
| Earth, such as for small power plants for individual buildings
|
| Distributed power generation is the ideal. Why bother with
| transporting energy when you can just generate it where you need
| it?
|
| Really cool article/tech. I've not heard of LCF until now. Seems
| promising.
| vkou wrote:
| > Why bother with transporting energy when you can just
| generate it where you need it?
|
| For the same reason every household no longer grows, harvests
| and threshes its own wheat, bakes its own bread, and why Mao
| Zedong's Great Leap Foward idea of building a blast furnace in
| every village, in order to increase the country's steel output
| was an utter failure.
|
| Power transmission is cheap, and economics greatly favor
| utility-scale deployments. You also get significantly less need
| for wasted peak capacity when multiple power producers can pool
| together into a grid.
| doctor_eval wrote:
| Ive read that creating enough food for a family of 4 from a
| home garden requires something like 8 square meters of land,
| chickens, and loads of labour. It's non trivial, and if you
| make a mistake you go hungry.
|
| Assuming some putative ideal future Mr Fusion, plugging it
| into the wall would be a completely different proposition,
| require relatively little space, and zero household labour.
|
| Considering the massive infrastructure and street furniture
| required to distribute electrons, the unit economics of home
| fusion would need to be terrible in order for centralisation
| to remain competitive against the significant benefits for
| reliability and decentralisation.
| mbrubeck wrote:
| > 8 square meters of land
|
| Pretty sure this is off by a few orders of magnitude.
| camdat wrote:
| Why? Staple crops can be planted very close together and
| there are many crops that can coexist on the same plot.
|
| Crop nutrients are obviously a concern, but if you're
| only trying to survive for a couple of cycles seems
| totally feasible and could be extended artificially.
| mbrubeck wrote:
| Have you actually tested this in any way? How many
| calories/year do you grow in each square meter of your
| garden?
|
| People actually doing this for a living find that they
| need 100 to 1000 times that much land to feed a family of
| four.
| chefkoch wrote:
| > Ive read that creating enough food for a family of 4 from
| a home garden requires something like 8 square meters of
| land, chickens, and loads of labour.
|
| I'm pretty sure you can't feed a family from what you can
| grow on a balcony.
|
| /edit: >Research in the 1970s by John Jeavons and the
| Ecology Action Organisation found that 4000 square feet
| (about 370 square metres) of growing space was enough land
| to sustain one person on a vegetarian diet for a year,
|
| https://www.growveg.com.au/guides/growing-enough-food-to-
| fee...
| shakezula wrote:
| > For the same reason every household no longer grows,
| harvests and threshes its own wheat
|
| This feels like a weird point to make when solar power is as
| popular and growing as it is.
|
| Localized power generation is not only here now, we already
| have programs to tie your localized power generation into the
| existing power grid and you get paid for it. I don't see how
| this system couldn't work the same way.
| BurningFrog wrote:
| Solar power is inherently distributed by the sun shining
| everywhere on Earth.
|
| Other forms of energy, perhaps with the exception of wind
| power, do not work like that.
| vkou wrote:
| It's popular and growing because of credits and subsidies.
| Remove all credits and subsidies, and I can build utility-
| scale solar for less than half the cost per KWH than you
| can install panels on your roof.
|
| There's way too much human labour involved in getting
| someone to drive to your house, climb onto your roof and
| bolt panels to it. In that time, that same worker could set
| up a dozen similarly-sized panels when building out a
| utility solar farm.
|
| And yes, if your time is worthless, and you don't value
| your neck, you could DIY, and save on some of those costs.
|
| ... But you'd still be tied to the grid (and paying grid
| fees), unless you are ready to invest $XY,000 for a massive
| battery bank... That might still leave you without
| electricity during a period of low generation/high
| consumption.
| Kototama wrote:
| > There's way too much human labour involved in getting
| someone to drive to your house, climb onto your roof and
| bolt panels to it. In that time, that same worker could
| set up a dozen similarly-sized panels when building out a
| utility solar farm.
|
| Where do you put the solar farm?
| peteradio wrote:
| Unproductive farm fields.
| vkou wrote:
| Literally anywhere that's not prime real estate. There's
| three orders of magnitude more of that kind of surface
| area on this planet than there are single-family home
| roofs. [1] I think we can figure something out.
|
| [1] 2 billion 'single-family' homes, 800 square feet of
| roof/average [2], ~50,000 square miles of roof space.
| Total land area of the Earth is 57 million square miles.
| You can take your pick of which 50,000 of it can be used
| for utility solar...
|
| [2] This is a large over-estimate, reality is much
| smaller than that.
| zrm wrote:
| The interesting question is what happens if battery
| prices continue to decline so that $XY,000 becomes $X000
| and thereby less than grid fees.
|
| Low generation can be solved with an inexpensive gas
| generator for use in emergencies the likes of which might
| see three days use in a year.
| vkou wrote:
| If battery fees get lower than peaker plant-related grid
| fees, then grids will shut down peaker plants and instead
| buy warehouses full of batteries.
| s1artibartfast wrote:
| I don't think the grid can ever go away. Regional solar
| is just too variable. You might get backup for a day, but
| storage costs scale linearly with duration.
| dylan604 wrote:
| >And yes, if your time is worthless, and you don't value
| your neck, you could DIY, and save on some of those
| costs.
|
| This is such a cop out. How I spend my time is up to me.
| If it's a DIY weekend project being worked on a weekend
| that I had no other plans, then it's not really a cost to
| me. Sure, professionally, I have my hourly rate that
| determines my "worth". However, I do not get to bill
| those hours 24/7/365. Even playing along with your
| premise, if I'm playing weekend electrician, I'm not a
| master electrician making the same rates as my other job
| so a 1:1 correlation is just a lame argument.
| orthecreedence wrote:
| Tell that to my septic system!
|
| If the cost of generating power drops, then distribution is a
| more viable model. Especially if you get extremely high fuel
| density. Also as we've found in California, power delivery
| can be very expensive.
| 7952 wrote:
| > Distributed power generation is the ideal. Why bother with
| transporting energy when you can just generate it where you
| need it?
|
| You need to be able to throttle the power output up and down.
| That is harder to design and harder to make efficient. Or you
| need lots of batteries, which is expensive. And it all has to
| be sized for peak demand rather than being able to benefit from
| flows across the grid.
| dd36 wrote:
| Produce at double max and use the excess power to remove
| carbon from the atmosphere?
| saiya-jin wrote:
| or desalinate & clean water, or store the excess for next
| peak use in ie high & low connected dams, or... that's
| really a nice problem to have
| willis936 wrote:
| The reason to use MCF (and why IEC can't work) is that it's
| okay if particles don't collide often if they are confined for
| sufficiently long. So what if the fast alpha doesn't collide?
| It's charged and thus well confined. It will transfer its
| energy to other particles eventually.
| PaulHoule wrote:
| Inertial confinement fusion works just fine if you are
| building a 1 megaton device driven by a fission bomb. You
| probably can't make it work if you're driving with a laser
| because the wallplug efficiency of a laser is terrible, but
| at least you can build a failing facility which is only huge
| as opposed to gargantuan. Real breakeven might be possible
| with heavy ion beam ignition but the minimum size facility to
| make an attempt is gargantuan.
| willis936 wrote:
| IEC is inertial electrostatic confinement: fusors and
| polywells. Conduction through the confinement/accelerator
| coils being immersed in the plasma reduces the confinement
| time lengths far too short for a reactor.
| PaulHoule wrote:
| ... like Philo Farnsworth's Fusor
|
| https://en.wikipedia.org/wiki/Fusor
| nonrandomstring wrote:
| High energy Gamma sources don't sound like a fun and easy place
| to get started. Maybe that's why this is a NASA project for deep
| space, rather than something you'll be able to buy at Tesco.
| was_a_dev wrote:
| It can be done the same way x-rays can be generated. Accelerate
| electrons in a magnetic field using a syncrotron.
| perihelions wrote:
| - _" One promising alternative is lattice confinement fusion
| (LCF), a type of fusion in which the nuclear fuel is bound in a
| metal lattice. The confinement encourages positively charged
| nuclei to fuse because the high electron density of the
| conductive metal reduces the likelihood that two nuclei will
| repel each other as they get closer together."_
|
| Isn't this just cold fusion? The end paragraph even credits an
| "International Conference on Cold Fusion".
| DennisP wrote:
| No, because of the gamma ray input.
| simonh wrote:
| As many physicists pointed out at the time of the Fleischmann
| and Pons controversy, fusion at room temperatures may well be
| possible. If fact we know it's possible because we have Fusors,
| and then there's muon catalysed fusion. The problem wasn't with
| the temperature range, it was with the not working and not
| being fusion.
| JackFr wrote:
| > The problem wasn't with the temperature range, it was with
| the not working and not being fusion.
|
| And them being chemists not physicists.
|
| And the University of Utah issuing a press release before the
| anything was peer reviewed.
|
| The whole episode is is an example of what can go wrong with
| science. This article shows what clearly could have been a
| useful and productive field of investigation became poisoned
| to the extent that no significant research could go on for a
| quarter century and still the authors have to go to great
| pains to distance themselves from Fleischman and Pons.
| willis936 wrote:
| Nothing about fusors are room temperature.
| pdonis wrote:
| _> Isn 't this just cold fusion?_
|
| No. You still have to heat the fuel. The claim of cold fusion
| was tnat the fuel could just sit there at room temperature and
| fuse.
| WithinReason wrote:
| So cold fusion is viable after all, you just have make sure you
| call it something else so you're not laughed at. They are very
| careful to avoid the label:
|
| "LCF isn't cold fusion--it still requires energetic deuterons and
| can use neutrons to heat them."
| pdonis wrote:
| _> So cold fusion is viable after all_
|
| No, it isn't. There is more than just a change of name involved
| with LCF: the statement "it still requires energetic deuterons"
| means the deuterons still have to be hot. They can't be at room
| temperature.
| mpreda wrote:
| From the article: _Electron screening makes it seem as though
| the deuterons are fusing at a temperature of 11 million degC.
| In reality, the metal lattice remains much cooler than that,
| although it heats up somewhat from room temperature as the
| deuterons fuse._
|
| Sounds pretty much the same as room temperature to me. Also
| the pictures with the experimental setup suggest that the
| glass does not melt, which is pretty cool.
| gus_massa wrote:
| The part about "electron screening" makes no sense at all.
| The deuterium nuclei are in the slots between the erbium
| nuclei. Most of the electrons are very close to the erbium
| nuclei, so the slots where the deuterium nuclei are have a
| low electron density. Approximately the same density of an
| isolated deuterium atom, perhaps the double, but I doubt
| it's 10x higher.
|
| The orbitals of the electrons of deuterium are like 1000x
| bigger than the size of the nuclei. So once the incoming
| deuterium nuclei approach, it will be much closer to the
| target deuterium nuclei and it will not see the electrons.
| Note that most of the energy of the repulsion is when the
| nuclei are close, not when they are far away.
|
| The erbium are useful to keep a lot of deuterium together,
| but the electrons shelling is probably very small.
|
| The trick they use is to use a very energetic gamma rays
| that colides (indirectly) with one deuterium, and this
| deuterium is very fast that is the same effect you get when
| you have a very hot deuterium.
| adrian_b wrote:
| Much the same as room temperature is only the _average_
| temperature of the metal.
|
| The few irradiated deuterons and the products of their
| collisions have speeds (kinetic energies) many millions
| times higher than those corresponding to the room
| temperature.
|
| The average temperature remains low only because few nuclei
| take part in fusion.
|
| If they would succeed to make enough nuclei to take part in
| fusion reactions to produce more energy than consumed, it
| is not clear how great the average temperature of the metal
| would become.
|
| If the temperature of the metal would not increase
| excessively, that could happen only if most of the energy
| produced by fusion would be carried away by neutrons, which
| would be absorbed somewhere else, generating useful heat,
| but also creating undesirable radioactive waste.
|
| This approach is indeed very promising, but there are many
| problems that must be solved, so there is still no chance
| for a fusion reactor in only a few years.
| trhway wrote:
| > There is more than just a change of name involved with LCF:
| the statement "it still requires energetic deuterons" means
| the deuterons still have to be hot.
|
| the original cold fusion experiments explanation was lattice
| confinement in heavy metal (i.e. large electron clouds) like
| Pt/Pd plus energetic deuterons. What was very unclear is
| where those deuterons got their energy. It was theorized
| something along the lines that high electrostatic charges in
| the metal cracks accelerate the deuterons, etc.
|
| Unfortunately pseudo-scientificity got somehow attached to
| that research, and that for decades prevented any meaningful
| research into the source of those deuterons and how to
| efficiently increase their number and/or how to efficiently
| add another source. Only passage of time and the name change
| to LCF - marketing, yea! - has allowed to restart the
| research, though still without due credit to the original
| research.
| itslennysfault wrote:
| How about we call it "Cool Fusion " as a compromise??
| scrumbledober wrote:
| it's really more of a tepid fusion
| rasz wrote:
| Speaking of cold fusion, what happened to that Italian scam
| from few years back?
|
| ah yes https://en.wikipedia.org/wiki/Energy_Catalyzer still a
| scam
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