[HN Gopher] Laser fusion reactor approaches 'burning plasma' mil...
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Laser fusion reactor approaches 'burning plasma' milestone
Author : rbanffy
Score : 153 points
Date : 2020-11-25 14:40 UTC (8 hours ago)
(HTM) web link (www.sciencemag.org)
(TXT) w3m dump (www.sciencemag.org)
| raziel2701 wrote:
| Oof, energy input is 1.8 MJ, output is 100 kJ. That's still a
| ratio of energy in/out of 0.05.
| jjk166 wrote:
| The goal they are trying to achieve is ignition, which is the
| point where the fusion reactions they directly cause with the
| lasers release enough energy to in turn lead to more fusion
| reactions. It's the same principle as using a spark plug to
| ignite gasoline in an engine: once some of the fuel ignites,
| that will cause the rest to burn. Getting that initial spark to
| light is hard, but going from ignition to net-power out is
| comparatively easy.
| raziel2701 wrote:
| At what ratio of energy out/energy in are they supposed to
| achieve that?
| X6S1x6Okd1st wrote:
| From a layman's perspective it really seems like Fusion is
| getting closer and closer to a reality.
|
| The organization I am most excited about is
| https://www.tokamakenergy.co.uk/
| SiempreViernes wrote:
| Hopefully, but the NIF should really stop pretending it's about
| anything other than developing nuclear weapons. This is after
| all a research project that has publicly failed to reach its
| basic science goal for a solid 45 years across _four_
| generations of experiments (to compare with the 2 and a bit for
| tokamak experiments).
| raziel2701 wrote:
| I think they have the problem that if they come out and admit
| that they're going to invite a lot of protests and negative
| media, which they don't need at the moment since they're
| facing a demographic shift in the lab with a bunch of people
| retiring now. So they need to attract and hire a bunch of
| people.
| colechristensen wrote:
| I'm of the opinion that fusion is already done for classified
| military use. Exclusive availability of small scale fusion
| reactors would be a huge tactical logistical advantage.
| germinalphrase wrote:
| I remember listening to a presentation by a quantum computing
| researcher in which he made a joke about the lab's experience
| of receiving funding from the NSA (paraphrased): 'getting
| funding from the NSA is great. They're the only funding
| source that would say "we would prefer that you fail and this
| technology doesn't exist - but if it does work, we want the
| first one".
|
| I don't see why fusion research couldn't be analogous.
| weregiraffe wrote:
| There already are small scale fission reactors. USSR launched
| satellites powered by them (one even infamously fell on
| Canada). From military use, why would you need fusion?
| colechristensen wrote:
| Those space based reactors would have a hard time powering
| a single house, and the highly enriched fuels in a highly
| mobile platform would be a disaster. Those are about
| kilowatts.
|
| This containerized fusion concept is planned to have the
| capacity for one unit to power a small city or a naval
| ship, many megawatts.
| leetcrew wrote:
| fuel security could be one reason. it's much easier to find
| deuterium and lithium than fissile material.
| SiempreViernes wrote:
| Hydrogen bombs don't really work as a reliable power source,
| you're thinking of fission.
| colechristensen wrote:
| I can't tell if you're joking, but I'm not confused about
| my terms nor do I think they are achieving this with
| thermonuclear bombs.
| hutzlibu wrote:
| And I can't tell, if you are serious by implying the US
| Army has secretly achieved a working fusion reactor.
| colechristensen wrote:
| I mean the DoD and a defense contractor, but yes, I'm
| serious.
| hutzlibu wrote:
| So you imply the DoD did a Manhattan project in peace
| time for years and nobody suspected a thing?
|
| Anythings possible, sure, but that clearly is conspiracy
| theory category.
|
| Unless they found a working cold fusion method by chance,
| it would require a HUGE budget and the best of the best
| scientists avaiable. Who all need to keep their mouth
| shut and pretend fusion is still not working. For years.
| Not likely. Not in peace times.
| colechristensen wrote:
| It would not need be manhattan project size, it's a
| precision engineering problem not a fundamental physics
| problem mixed in with an industrial scale production
| problem.
|
| There have been plenty of very expensive defense programs
| that were kept quite secret for a very long time.
|
| I've known and worked with people with top secret
| clearances, they just didn't talk about their work, it's
| not that hard.
| lokimedes wrote:
| What have formed your opinion? Do you have any evidence?
| colechristensen wrote:
| Lockheed Martin is openly working on shipping container-
| sized fusion reactors, it does not take a stretch of the
| imagination to think that the results of such a program
| would be kept classified quite a while after success.
|
| It would likewise not be surprising if there were other
| prime contractors working on the same technology.
|
| https://lockheedmartin.com/en-us/products/compact-
| fusion.htm...
| DickingAround wrote:
| I don't think they have the ability to keep a secret like
| that. A couple reasons: 1. The act of keeping the secret
| makes the tech useless. If it's not incorporated into
| equipment that could use it (e.g. a naval vessel, an
| isolated firebase) then what good is it? And if it is
| incorporated and there's a bunch of 20 year old techs
| working on it, it's going to leak. 2. I don't think
| they're that bad of people. If they could save us from
| global warming with fusion tech, not doing so would be a
| great tragedy. And historically at least the US military
| just isn't that selfish. For example, they opened up GPS
| even when they didn't have to. I think they get that a
| richer/stronger public means a richer/stronger military.
| jasonwatkinspdx wrote:
| No, they wouldn't be issuing press releases if this was a
| black program. You're also not just taking Lockhead's
| claims at face value, which themselves have not be
| established with evidence, and going further to imagine
| that they're lying/slow playing their claims and actually
| are even further ahead. None of this is motivated by
| evidence.
| SiempreViernes wrote:
| Making a net energy producing fusion reactor container
| sized is a feat, making your first prototype container
| sized is just starting out. The first tokamak had a
| radius of 0.7m, so could easily fit inside a standard
| shipping container.
| peteradio wrote:
| It's a conspiracy theory so obviously evidence would be
| nigh impossible to present. Doesn't mean he or she is wrong
| though. Doesn't it seem somewhat realistic that some
| technological advances would be kept secret? There is
| shitloads of less valuable information that is kept secret
| (only to be discovered later) so it stands to reason that
| if an extremely valuable advancement was discovered then it
| might be concealed.
| colechristensen wrote:
| I don't know how a basic understanding of how military
| technology is developed fits into "conspiracy theory".
|
| I'm not projecting that a sinister cabal of technologists
| are hiding some great truth, just that the department of
| defense and defense contractors are obviously developing
| this technology and that new military tech is usually
| highly classified. There's no great mystery there.
| peteradio wrote:
| I'm not suggesting a sinister cabal, I'm suggesting there
| is a literal conspiracy, a group coordinating in secret.
| And that group is the government. And the secret would be
| that highly classified information. In my mind we are
| seeing things the same, but I can see how the words I put
| to it might give a different impression.
|
| I really don't like the current "conspiracy theory"
| understanding in modern usage. It completely screws over
| the literal usage of those two words together.
|
| If you wish to, please reread my comment without the
| common connotation of "conspiracy theory" and see if we
| then agree.
| SiempreViernes wrote:
| Indeed there is no mystery: the article even mentions
| that the bulk of the effort at NIF is for testing nuclear
| weapons. Same as it ever was.
| missosoup wrote:
| This is actually the most plausible scenario for if/when
| fusion is achieved by any nation state. There is evidence
| that China is secretly working on fusion reactors and there's
| no reason to assume that the Russian and US militaries
| wouldn't do the same.
|
| The first nation to achieve economically viable fusion will
| have a huge advantage over others. All of these open
| experiments like NIF are the equivalent of public ML research
| which is years behind what happens at secret research labs in
| Goog etc. From a game theory point of view, there is a huge
| incentive to work on fusion alone and in secret, and not tell
| anyone about it until long after the desired result is
| achieved.
|
| Fusion is a similar technological leap to attaining nuclear
| weapons, and we're only now learning about the extreme levels
| of secrecy and investment that the US and other nations
| afforded to those projects.
| [deleted]
| rwdim wrote:
| TL;dr.. they shot a beam at a fuel pellet and it ignited. Story
| at 11.
| codefreakxff wrote:
| Hmm. It looks more like it exploded with no ignition. But they
| think they are close!
|
| A decade and 3,000 failures and they are probably spinning some
| PR so they don't get defunded
| SiempreViernes wrote:
| Four decades, ICF has been predicted to reach break even at
| one kilojoule (kJ) of energy in 1972, then 5 kJ, 10kJ, 100kJ,
| 200kJ, and finally 1.8 MJ by 1979 and the construction of
| three generation of lasers that all proved the predictions
| wrong.
|
| The NIF is the fourth shot at this, and has a target
| performance about an order of magnitude less power that what
| experimental tests (using nuclear weapons) indicate is needed
| to be _directly_ supplied to the fuel.
| willis936 wrote:
| NIF is funded alright, just not by the DoE. The energy
| research has always been a facade for the facility's actual
| purpose.
| vilhelm_s wrote:
| From the NIF website,
|
| > The facility is funded by the U.S. Department of Energy's
| National Nuclear Security Administration (NNSA) and is a
| key element of NNSA's science-based Stockpile Stewardship
| Program to maintain the reliability and safety of the U.S.
| nuclear deterrent without full-scale testing.
|
| Most of the Department of Energy budget goes towards
| nuclear weapons, although they also do some work on
| civilian nuclear power and pure science. The name was
| always a bit of a euphemism.
| goda90 wrote:
| "I Have Not Failed. I Have Just Found 10,000 Things That Do
| Not Work." - Edison, supposedly.
| bnt wrote:
| Apparently most people think stuff just happens on the
| first run. I write code for a living and in most cases it
| doesn't run as intended on the first run, I can't imagine
| making a fucking fusion reactor "just work" by assembling
| it and pressing "start".
| chadwittman wrote:
| And then your results are published online (either
| because you need funding or someone reports on them) and
| people criticize you for not accomplishing your goals.
| Humans... -\\_(tsu)_/-
| hannasanarion wrote:
| no, it specifically didn't. If it had ignited, it would be
| enourmous news because the age of fusion and clean energy has
| begun. It didn't ignite, it's "close to self-heating", which is
| progress, but not ignition, and they want funds to double their
| laser power to actually make it happen.
| harimau777 wrote:
| Do you know what the challenge in these sorts of thing are?
| For example, do we already know how to double the laser power
| if we just had the resources or would there need to be
| research on how to build the laser itself?
| ThomPete wrote:
| One of the biggest challenges with fusion is to be able to
| contain plasma as far as I understand. Magnets seem to be
| the way they want to do it but I am a layman so take what I
| say with a grain of salt.
| deepnotderp wrote:
| This is inertial confinement fusion, not magnetic
| confinement fusion like you're thinking.
| hannasanarion wrote:
| Magnetic confinement is needed for the continuous-
| reaction donuts like French scientists are building.
|
| The NIF strategy is more like an internal combustion
| engine: load fuel, start reaction, capture energy, remove
| byproducts, start over. The lasers are acting like spark
| plugs, triggering the fuel to release all its energy at
| the top of each cycle.
|
| In other words, the French strategy is "build a miniature
| sun", the American strategy is "build a miniature
| hydrogen bomb". In theory, it should be easier, hydrogen
| bombs already exist after all, but to trigger the
| reaction, you need to find a way to squeeze a lot of
| energy into a really small space to make the hygrogen
| atoms kiss, and you can't use the traditional method of
| "put a plutonium bomb next to it" for obvious reasons.
| ArtWomb wrote:
| Never really considered it before, but a cool by product of this
| research is the high-energy-density beamline development. This
| could have many interesting applications, including deep space
| internet and power transmission ;)
|
| The L4n laser beamline of the P3-installation: Towards high-
| repetition rate high-energy density physics at ELI-Beamlines
|
| https://aip.scitation.org/doi/10.1063/5.0022120
| hedora wrote:
| I wonder if the push to divert funding away from clean energy and
| toward more nukes will continue under the Biden administration.
|
| The article says the White House has recently been pushing to
| reallocate the funds, but that congress keeps blocking it. Is
| "recently" just the Trump administration, or were they pushing
| for the change under Obama?
| SiempreViernes wrote:
| Let's hope Biden reverses out of the nuclear weapons race that
| Trump has tried to start!
| jasonwatkinspdx wrote:
| It's unique to Trump. The only nuke related programs I'm aware
| of that were going during the Obama admin were the new fuse
| research program and the very beginnings of the ground based
| strategic deterrent program, which is going to be the
| replacement of the Minuteman III ICBMs.
|
| On the other hand, Tillerson famously referred to Trump as a
| moron after Trump asked why the US wasn't working to expand our
| nuclear arsenal.
| hannasanarion wrote:
| Am I wrong in thinking that the energy quantities here are
| shockingly small?
|
| The 1.8 MJ laser array that's being used to trigger these
| reactions, that's like 400 calories, less energy than you'd get
| from a ham and cheese sandwich with mayo, and the output they're
| hoping to achieve, 100kJ, that's 2mL of gasoline.
| dredmorbius wrote:
| 1 Hiroshima atomic bomb (15 kt TNT) is 37,500,000 ham
| sandwiches (at 400 kcal/sandwich).
| Someone wrote:
| Such comparisons are almost meaningless. For explosives, its
| not only about how much energy gets released, but also
| (almost more so) about how fast it gets released.
|
| For example, per kilogram, TNT releases less than a tenth of
| the energy that burning gasoline does, and a sandwich stores
| more energy than the equivalent weight in dynamite (but both
| are cheating, as TNT and dynamite both include the oxygen
| needed to 'burn' them, whereas gasoline and sandwiches don't)
| dredmorbius wrote:
| And the forms of energy, deliverable size, etc., etc.
|
| Ham sandwich prompt radiation, thermal pulse, blast, and
| long-term radiation effects are somewhat less than those of
| the Little Boy gadget. The last may depend on how much hot
| sauce is applied.
|
| Both weight and volume exceeded the B-29 and would be
| better suited for a bulk-cargo carrier of about 30' beam,
| 40' depth, and 300' length.
|
| The relationship between promptness and completeness of
| reaction is an interesting one, and not limited to TNT and
| petroleum. The WWII atomic weapons haad a pretty
| remarckably low efficiency --- most of the fissile material
| was dispersed before it could fully react. Nuclear power
| generation is far more efficient. And generally slower.
|
| See related the Beruit 2020 ammonium nitrate explosion:
|
| https://news.ycombinator.com/item?id=25154155
|
| https://news.ycombinator.com/item?id=24064248
| asah wrote:
| .oO( humans... portable mayo powered reactors! #matrix )
| mytailorisrich wrote:
| If I understand correctly how this works, this is a laser pulse
| of 1.8MJ and that pulse's duration is in the 20ns range.
|
| So it's actually massively powerful but very short.
|
| If you were to burn gasoline at a rate of 2mL per 20ns you
| would be burning 100,000 L per second, which is a higher rate
| than Saturn 5 on takeoff so quite a burner...
| leephillips wrote:
| That 1.8 Mj is the energy in the laser output. I haven't looked
| at the numbers for a while, but it probably takes 10x that much
| energy to operate the laser facility. A commercial fusion power
| plant will never exist.
|
| And it's no accident that the article doesn't mention the laser
| efficiency. NIF has a public relations office that has honed
| its game over decades. Their purpose is to influence Congress
| by selective reporting through press releases and by feeding
| propaganda into articles like this.
| aqme28 wrote:
| I mean, for small enough duration in time, any power plant is
| producing a laughably small amount of energy.
|
| How much power it produces is the better question.
| jvanderbot wrote:
| If power in < power out, they've "proven" fusion, and the rest
| is scaling.
| handol wrote:
| 1800 kJ > 100 kJ
|
| Even if they achieve 'burning plasma', it's still like a
| 100hp engine using an 1800hp spark plug.
| colechristensen wrote:
| But is it a ham sandwich every hour or every few nanoseconds?
| 1-6 wrote:
| Wasn't all this effort involved just to prove Fusion is
| possible before going all into the tech? The machines are
| massive today but so were early computers.
| akiselev wrote:
| Nuclear arsenal maintenance drove this effort.
| raziel2701 wrote:
| Yeah, that's what's so incredibly powerful about nuclear
| energy, e=mc^2 of a grain of sand is a huge amount of energy.
| jjk166 wrote:
| 1 MJ is the optimal energy scale for inertial confinement
| fusion. Going larger makes the fuel harder to compress, going
| smaller means there is less fuel that gets compressed; either
| way your ratio of input energy to output energy goes down.
|
| Also while these energies are low, they are also for very short
| durations. 1.8 MJ in 1 ns is 1.8 PW.
| fuoqi wrote:
| As far as I know laser fusion is not a practical technology for
| energy production due to the plasma instability effects, high
| pellets cost (several orders of magnitude more than necessary for
| economic viability), huge reliance on a very precise calibration,
| and low power capacity even in optimistic scenarios. Most of the
| funding this field receives is motivated by checking models and
| constants for thermonuclear weapons. Since nuclear tests are
| banned, it's the easiest way to study plasma in conditions
| similar to those of a detonated thermonuclear bomb.
| noobermin wrote:
| >due to the plasma instability effects
|
| All fusion experiments are not reaching ignition due to plasma
| instabilities. Not exaggerating, all of them.
|
| The funding from NNSA is actually in this very article.
| leephillips wrote:
| You are correct on all points. The public story is energy, the
| real story is more about stockpile stewardship. Since we will
| never derive commercial power from fusion, it would be foolish
| of Congress to continue to fund this sector with that in mind:
|
| http://progressive.org/op-eds/let-cut-our-losses-on-fusion-e...
| falseprofit wrote:
| The comment you're replying to is talking about laser fusion.
| It would be foolish to give up on the tokamak at this
| point...
| leephillips wrote:
| Quite. I'm sure that commercial fusion power from tokomaks
| is only five years away, as it has been since 1949.
| jvanderbot wrote:
| I think you just repeated most of TFA, but I appreciate the
| summary.
| hannasanarion wrote:
| The NIF's reactor model doesn't need plasma stability, right?
| The article points out they're intending to use a similar
| principle to an internal combustion engine: put in a tiny
| amount of fuel, blow it up, capture the energy, repeat.
| fuoqi wrote:
| No, it very much does. Laser fusion relies on creation of a
| spherically symmetric shock wave, which in turn momentarily
| creates huge pressure and temperature in the center of a
| pellet, thus igniting the fusion reaction. Any asymmetry
| (caused either by miscalibration, setup design, pellet flaw
| or even simple thermal noise) gets amplified by plasma
| instability effects and results in huge energy losses. The
| wiki article [0] briefly covers some of such effects.
|
| [0]: https://en.wikipedia.org/wiki/Inertial_confinement_fusio
| n#Is...
| alexpotato wrote:
| How does the level of precision here compare to the
| precision needed to design LIGO?
|
| I remember reading the precision requirements for LIGO and
| then reading about the efforts needed to achieve that
| precision and it seemed like magic. e.g. IIRC LIGO has a
| precision of PORTIONS of a wavelength of light at the end
| of arms that are kilometers long.
|
| Is the precision for plasma stability that much higher?
|
| (I understand that these are very different systems so
| asking more from an overall "what can we currently achieve"
| perspective).
| raziel2701 wrote:
| It's kind of hard to compare, especially since I don't
| know what you mean by precision: the metrics on both
| projects are very different.
|
| LIGO is all about minimizing losses as the laser light
| bounces back and forth the two mirrors. The losses here
| arise from the stack of materials that the mirrors are
| made out of, which are multilayers of different oxides
| plus/minus Si or Ge, I forget. So one metric of course is
| the surface roughness of the material, but then there are
| also energetic defects called two-level systems in which
| atoms can absorb a little bit of light to tunnel into
| another location and thus contribute to the losses by
| having absorbed laser energy. There's coefficients of
| thermal expansion, stresses, that all have to be taken
| into account and tested as you layer all these dissimilar
| materials that may behave ok at room temperature but not
| at cryogenic ones for instance.
|
| So LIGO is a game of minimizing losses, because you're
| after detecting the faintest of signals: a gravitational
| wave. Their game is all about increasing the signal to
| noise ratio.
|
| NIF is a monster of energy. There's the whole steering of
| an enormous laser pulse which is the addition of 192
| beams that have to converge into a tiny area the size of
| a pencil eraser. There's the containment of all this
| energy into a steel capsule that looks like something out
| of a sci-fi piece. There's the manufacture of the 2 mm
| diameter capsule that starts as plastic but is then
| coated with diamond, beryllium or more plastic and that
| leads to inherent asymmetries because it's not easy to
| coat a non-planar geometry. Already this coating
| assymmetry is very likely to lead to the hydrodynamic
| instabilities (https://en.wikipedia.org/wiki/Rayleigh%E2%
| 80%93Taylor_instab...) that are obstructing the path
| forward. The hole with which you fill up the capsule with
| DT is still a problem, but they try to sweep it under the
| rug. The surface roughness of the capsule is a problem,
| contaminants in the diamond or plastic is a problem, a
| few atomic percent is enough to significantly dampen the
| amount of X-ray absorption/transmission. Control of the
| material's density is another one. The work that goes on
| all of this is tricky because you can solve all of these
| and control them very well on a planar geometry, but the
| moment you want to take this onto a sphere it doesn't
| work as well, we cannot suspend something in Earth's
| gravity without using a string, which then introduces an
| asymmetry. So the best we use is we roll the sphere
| around, and it's not very good for the tolerances that
| the scientists think we need.
|
| And NIF has a history of escalation. We are currently
| shooting 1.6 - 1.8 MJ, but the scientists' simulations
| had predicted kJ range shots in the beginning, and the
| estimate has continued to climb. You see it in the
| article itself that they're hoping to get funding to go
| to 3 MJ. But there are some studies (Halite-Centurion
| IIRC) from the 50s that showed you needed like 100 MJ to
| get inertial confinement fusion on a capsule, and I think
| we've been happily disregarding those results, because,
| well, politics, job-protection etc. It's a complicated
| story, shrouded in a lot of secrecy, so I'm glad to read
| that the NNSA is reviewing it.
|
| So, precision in LIGO, I don't think translates to
| precision in NIF. LIGO feels more like golf, NIF feels,
| like some beasts fighting it out. Very different set of
| challenges, very different resource pools they can draw
| from (I would argue that NIF can draw more money but less
| talent because of security clearance requirements
| restricting employees to be US citizens).
| treeman79 wrote:
| Put a rock tumbler on top of the sensors. Probably
| similar added difficulty.
| Hizonner wrote:
| "Capture the energy". They haven't even looked at that step.
|
| Laser fusion is about the least promising, most impractical
| possible approach to building a power reactor, even if you do
| manage to get ignition. Since at least the early 1980s, the
| word on the street has been that the talk about power is just
| a politically palatable wrapper for the weapons application.
| And let's just say that some of the people I heard that from,
| back in the 1980s, were in enough of a position to know that
| they probably shouldn't have said anything to some random kid
| like me.
|
| Not to say that there aren't a few benighted souls working on
| it who've managed to convince themselves it's a power source,
| but notice that nobody but Livermore has ever bothered to put
| much into inertial confinement... and Livermore is a weapons
| lab?
| cbkeller wrote:
| That's fair enough from a political perspective (after all,
| as they say in the article, >70% of NIF shots are going to
| [nuclear] stockpile stewardship now) -- but just to give
| NIF a bit of credit on the "basic science" front, it has
| turned out to be quite good for studying the properties of
| matter under extreme compression more generally.
|
| Some mineral physicists I know have used this to write some
| cool papers about the properties of natural materials at
| conditions replicating those expected in the cores of giant
| exoplanets [1-3], for example.
|
| [1] https://www.nature.com/articles/s41550-018-0437-9
|
| [2] https://doi.org/10.3389/feart.2019.00023
|
| [3] https://advances.sciencemag.org/content/4/4/eaao5864
| SiempreViernes wrote:
| You might enjoy this report on the NIF from 2000 when it was
| being reviewed because of delays and cost growth:
|
| https://web.archive.org/web/20010209102303/http://www.nrdc.o...
|
| Has nice quotes like:
|
| "Putting aside for a moment the vexing question of whether a
| "big science" machine well into the construction phase should
| still be plagued with numerous unresolved technology
| development issues, there is considerable evidence that both
| the science and technology underlying the NIF are not sound."
|
| and
|
| "While a large majority of ICFAC voted in May 1994 to support
| proceeding with engineering design of the NIF, [20] their
| decision was once again based on non-peer-reviewed LASNEX code
| predictions that had been hastily generated in the weeks
| immediately prior to the meeting. These calculations purported
| to demonstrate ignition with novel gas-filled hohlraum targets
| -- predictions that were subsequently not borne out by actual
| experiments conducted after the meeting."
| lumost wrote:
| These big projects are great at eating budget from
| committees. Tons of meetings, delayed results for decades
| resulting in limited accountability, opportunities for
| everyone to be part of the picture and not point fingers at
| each other. Not to mention bragging rights for "leading" such
| large projects.
|
| We often bemoan the state of the research job market on HN. I
| can't help but wonder what moving funding from these
| facilities to smaller experiments and research labs would do.
| cbkeller wrote:
| Well I think the catch is that, to use the US as an
| example, "big science" projects such as the NIF, particle
| accelerators, synchrotron light sources, and supercomputers
| are generally all funded by the DOE, while small individual
| research labs are generally funded by NSF or (if
| biomedical) NIH.
|
| Critically, the only reason that DOE can support the cost
| of these "big science" projects is that they are generally
| "dual use" so to speak, with both basic science and
| national security applications. A similar dynamic is
| arguably at play in the funding of the largest projects in
| other countries as well.
|
| So it is not clear that cutting such "big science" projects
| would in practice actually open up more funding for small
| basic science grants, lacking the same national security
| applications.
| jjk166 wrote:
| The NIF was never intended to produce power, but it serves as a
| good science experiment for understanding the challenges of
| inertial confinement fusion. You need to make something that
| works before you can make something that works better.
|
| The only fusion devices humanity has yet gotten to produce net
| power are thermonuclear bombs. Laser fusion tries to replicate
| those conditions as best as possible without detonating a
| fission primary. Yes, this means laser fusion is good for
| validating nuclear bomb models, but it's also the only route to
| fusion where we know for a fact that every issue is strictly an
| engineering problem.
| BryanBigs wrote:
| Its a little strange that an article mentioning funding running
| out a few times never gets around to mentioning just how much
| funding this experiment has gotten over the years. Feels like a
| key piece of data that could help inform the reader. In any case,
| hope they eventually get this to be net energy-positive.
| SiempreViernes wrote:
| I imagine the fact that it is a facility mostly for nuclear
| weapons research at a site that does mostly nuclear weapon work
| means the exact budget is somewhat opaque.
| pontifier wrote:
| Aha! Another opportunity to plug my fusion reactor!
|
| http://www.DDproFusion.com
|
| The design has a lot of similarities to NIF in some respects. I
| aim to create an ultra dense implosion of deuterium ions.
|
| Thats where the similarity ends though. The key to viability in
| my eyes is to recover the energy of the ions that don't fuse to
| create another implosion.
|
| In my device, ions leaving the focus are curved by a weak,
| uniform, magnetic field. Each ion travels along it's cyclotron
| trajectory to circle back to the focus at the right time for the
| next implosion.
| pmayrgundter wrote:
| Is it similar to the Bussard reactor? Looks like a cylindrical
| variant of its sphere mechanism.
|
| https://www.kickstarter.com/projects/1992078142/building-the...
| yummypaint wrote:
| What provides confinement in the direction parallel to the
| field?
| pontifier wrote:
| Positively charged electrodes provide a restoring force. The
| system effectively becomes a Penning trap.
|
| I'm trying to target 15kev ion energies with my prototype so
| I was going to aim for 60kv on the end electrodes, and 0.35T
| for the magnet.
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