[HN Gopher] Lawrence Livermore claims a milestone in laser fusion
___________________________________________________________________
Lawrence Livermore claims a milestone in laser fusion
Author : furcyd
Score : 367 points
Date : 2021-08-17 16:30 UTC (6 hours ago)
(HTM) web link (physicstoday.scitation.org)
(TXT) w3m dump (physicstoday.scitation.org)
| Izikiel43 wrote:
| With a tokamak, like SPARC (https://www.psfc.mit.edu/sparc) it's
| clear how energy will be extracted, the vessel will be heated and
| the cooling fluid goes through a heat exchanger to get the
| energy.
|
| How would it work here? I imagine something like spiderman 2
| where a big ball of fire is suspended in a chamber, but how would
| energy be transformed to electricity?
| adnmcq999 wrote:
| Without any googling, wouldn't be the same way as a fission or
| coal power plant? Energy from exothermic reaction heats up
| water which is then used to turn a steam turbine
| api wrote:
| Seems like it could also be mechanical. There are gigantic
| Diesel engines that have pistons capable of each absorbing
| this kind of energy. Have a little bit of gas or water near
| the target and there will be quite an expansion.
|
| Also a "thermonuclear internal combustion engine" is kind of
| retro-futuristic and cool.
| willis936 wrote:
| This is General Fusion's approach.
| skinkestek wrote:
| Wow, cool idea!
| robocat wrote:
| Largest Diesel engine in the world[1] burns 160g (5.6oz) of
| diesel each combustion, within a 960mm (38in) diameter
| cylinder with a 2500mm (8.2ft) stroke. A barrel of oil is
| about 160 litres and contains 6.1E9 Joules[2], so each
| combustion stroke is about 6MJ.
|
| The fusion reaction released 1.3MJ of energy. So a single
| cylinder fusion engine seems realistic!
|
| [1] https://en.wikipedia.org/wiki/Wartsila-Sulzer_RTA96-C
|
| [2] https://www.ocean.washington.edu/courses/envir215/energ
| ynumb...
|
| A Cheeseburger weighs 3.9oz for comparison
| https://cockeyed.com/science/weight/cheeseburger-
| mcdonalds.h...
| beefman wrote:
| The article mentions losses at the hohlraum but doesn't mention
| losses in the laser. "Ignition" means they controled the
| implosion well enough to break (almost) even on laser energy, but
| the laser itself is less than 1% efficient on wall power. Input
| energy to the entire system is over 400 MJ per shot. Even at max
| theoretical fusion yield, it wouldn't come close to breakeven.
|
| There's also a firing rate issue. Even if the system produced net
| power, significant production would require many shots per
| second. Currently, the laser flash lamps are expendable and it
| takes on the order of a day (and lots of money) to prep for each
| shot.
|
| Some of these drawbacks were addressed in the LIFE proposal,
| which would use fusion neutrons to burn fission fuel in a blanket
| around the fusion chamber. You could burn spent reactor fuel
| subcritically (no fission chain reaction), for example. But then
| it's a fission machine, and criticality excursions aren't much of
| an issue in conventional fission reactors. In the end, there are
| many drawbacks and little benefit with such a setup -- even if it
| worked.
|
| I love lasers, and NIF is a marvel. But there really is no
| sensical story about power production in it. Even the machine's
| stated purpose -- stockpile maintenence -- is highly dubious. It
| is really an elaborate welfare machine, given to weapons
| scientists in exchange for their support of testing bans.
| dukoid wrote:
| My money is on stellarators. Just saw Wendelstein in the
| newsfeed here: https://news.ycombinator.com/item?id=28211413
| pfdietz wrote:
| Stellarators face many of the same likely showstoppers as
| tokamaks. Power density, materials, maintainability,
| complexity, cost.
| leephillips wrote:
| I think your take on this is accurate, but it's a little deeper
| than a welfare program. The government needs to maintain a
| population of cleared scientists who know how to calculate
| things like fusion yields, simulated with classified codes.
| These fake fusion energy programs contribute to that; some of
| the most capable scientists don't want to work on weapons, so
| they can kid themselves that they are working on "energy".
|
| There is no reasonably foreseeable future with fusion as part
| of the electricity grid. Even if we got fantastically lucky and
| were able to build a practical (magnetic or inertial) reactor
| in 50 years, by that time improvements in energy storage and
| transmission technologies will have allowed renewable energy to
| dominate, and no government would be crazy enough to permit it
| to be built.
|
| http://progressive.org/op-eds/let-cut-our-losses-on-fusion-e...
| Ericson2314 wrote:
| On the contrary, it will be so much energy it will be like a
| new agrarian revolution. No society outside the be able to
| resist it.
| AlanSE wrote:
| This is deeply fascinating to read.
|
| But what about projects like Iter? There's a lot going on in
| fusion that has no alternative government justification.
| Surely those provide little to no value for weapons programs.
|
| If fusion for grid-scale energy is really accepted to be non-
| viable (and if we're honest... it is) then that has some
| pretty far-reaching consequences.
|
| I don't think that fusion is categorically non-viable, but
| the approaches of the currently funded megaprojects all seem
| to be. More creative and compact approaches could still have
| potential. Of course, there's always PACER, which illustrates
| our cognitive dissonance.
| whatshisface wrote:
| Don't get too fascinated by the takes you hear about on
| Hacker News, as many of these comments are written by
| software engineers as they are by deeply embedded domain
| experts.
| Retric wrote:
| Fusion isn't just about grid power. In terms of covering
| the needs for food, shelter, etc the Hubble telescope,
| cassini probe, large hadron collider etc are useless.
| However, there's plenty of economic capacity to push limits
| simply to explore what's possible and what's out there.
|
| Fusion is likely the energy source of the future and that's
| ok. It's ok to dream of far future deep space colonization,
| and take just one tiny step closer to that dream.
| leephillips wrote:
| There are plenty of true believers working in fusion
| energy. Enough to support big projects like ITER.
|
| But consider this analogous situation. I was working in a
| government physics lab when Star Wars (excuse me--SDI) was
| still a program that you could get money from for all kinds
| of projects. Nobody--I mean nobody--actually doing research
| believed in the program. That we would actually build a
| Star Wars defense shield to make Ronald Reagan proud. But
| they happily sent off grant proposals and were glad to
| accept money to work on various things. You can spin lots
| of pet projects so it sounds like they are all about
| missile defense. But the algorithms I worked on, during my
| brief involvement, would have been more useful for game
| design.
| blablabla123 wrote:
| > These fake fusion energy programs contribute to that; some
| of the most capable scientists don't want to work on weapons,
| so they can kid themselves that they are working on "energy".
|
| This sounds quite anti-progressive and anti-scientific, I
| have trouble understanding where this sentiment comes from.
| If Fusion reactors could be realized, this would solve all
| energy problems. As you mention, renewables done right
| doesn't stop at production but also includes global
| deployment of Smart Grids and Energy storage capabilities.
| It's nuclear energy done in a reasonable way. Apart from
| that, it's really not clear if production fusion reactors
| will ever be possible so it's clearly a research topic.
| Perhaps better availability of computing power (to engineer
| the confining magnetic fields) and better abilities to
| orchestrate such complex projects will also help if you look
| at the challenges of the ITER project.
| arthurcolle wrote:
| Maybe some vested interests don't want to solve energy
| problems. Didn't the cotton industry kill hemp in the early
| 30s or so? And created the whole Reefer Madness scare?
|
| Why wouldn't the natgas and upstream/downstream petroleum
| industry want to do the same thing with any potential
| competitors? There is already propaganda about windmills
| killing seagulls and windmills being ugly, so why not take
| it an extra step and flash pictures of thalidomide babies
| and then say "wow do you really want this?" with respect to
| nuclear? Seems totally within the realm of possibility.
|
| EDIT: Correction - I think I actually meant the petroleum
| industry when I was referring to cotton in this post. What
| killed the hemp industry in the 50s (I said 30s earlier but
| I made a mistake) apparently was the availability of
| inexpensive, manufactured synthetic fibers.
| leephillips wrote:
| "This sounds quite anti-progressive and anti-scientific, I
| have trouble understanding where this sentiment comes
| from."
|
| It can't be, it was first published in the _Progressive_.
|
| It comes from my scientific knowledge of the field and is
| my factual description of what I personally observed,
| working on-and-off in both magnetic and inertial fusion for
| many years. My motivation is not anti-scientific but in
| defense of real science that is not getting done because of
| the billions wasted on fake energy projects.
| jollybean wrote:
| I read your article here [1] and I've found it a bit
| problematic.
|
| You don't give a real foundation impetus to 'stop' fusion
| research other than the perception not making enough
| progress in general terms, and that the money could be
| used on renewables.
|
| It's a problematic argument because 'a few billion' is a
| very, very small amount of investment for an energy
| potentially which could yield significant results, even
| decades away.
|
| It maybe a 80 year-long project, even then, it would be
| worth it.
|
| Renewables are not suffering from money otherwise
| allocated to Fusion.
|
| I think if you gave some very specific arguments as to
| why some investment will not work - even as an
| experimental vehicle - that would lend more credibility
| to your argument, but then you'd also have to have that
| view corroborated in some way aka 'this experiment does
| not materially advance science, and they know it, here is
| the evidence or logic'.
|
| [1] https://progressive.org/op-eds/let-cut-our-losses-on-
| fusion-...
| wffurr wrote:
| Is NIF even a "fake fusion energy program"? TFA specifically
| mentions their goal of simulating fusion detonations in
| nuclear weapons.
| leephillips wrote:
| Yeah, but they regularly send out press releases gushing
| about the energy application. This helps with Congressional
| funding.
|
| Here is the head of the NNSA, the funding agency for the
| NIF, quoted in the fine article:
|
| "It also offers potential new avenues of research into
| alternative energy sources that could aid economic
| development and help fight climate change"
|
| That's some finely tuned BS right there.
| lallysingh wrote:
| Would they be useful in space?
| pfdietz wrote:
| No DT reactor will be useful in space. The size of the
| reactor will dwarf that of a fission reactor of equal
| output.
| Tossrock wrote:
| I'll take that bet - say, $500 in 2021 dollars, that a fusion
| power plant is selling energy to the grid? I'll even make it
| easier and halve the time you suggested to 25 years, so we
| can settle the bet in 2046.
| jetbooster wrote:
| https://longbets.org ?
| Tossrock wrote:
| That would be my favored platform!
| billiam wrote:
| I like what Tim Bray's doing with his time.
| https://longbets.org/863/
| leephillips wrote:
| I'm interested, but the bet needs another condition, to
| exclude toy demonstration projects. The reactor will have
| to generate at least 100MW (far less than existing coal
| plants) and be in operation for an integrated time of at
| least 90 days over the course of any one year on or before
| 2046. Accept?
| Tossrock wrote:
| 100MW seems like a substantial moving of the goalposts,
| given your earlier statement that "there is no reasonably
| foreseeable future with fusion as part of the electricity
| grid" and that I've already cut the timetable by 25 years
| :) That said, I'll still accept - I'm emailing you at
| your profile address for the details!
| leephillips wrote:
| I didn't mean to move the goalposts. I just want to
| exclude demonstration projects that might produce some
| net energy but not be serious commercial sources of
| electricity. But thanks for accepting anyway.
| Tossrock wrote:
| I've sent an message to the address listed in your
| profile, it's coming from a nonstandard domain though, so
| if you don't see it, it may be in spam. Also, I now
| realize that the longbet page is still under review, so
| you might not be able to see that either until the staff
| approve it.
| kbenson wrote:
| I wonder how many of the bets on the longbets site stem
| from HN discussions. Probably not a significant number,
| but it would be deeply interesting to go back and read
| the discussions that spawned them.
| toomuchtodo wrote:
| Longbets should include a link to the thread in question
| in the bet.
|
| Edit: Would be nice to have a link to refer back to the
| discussion that led to the bet. To my knowledge, most
| bets do not provide such a citation.
| kbenson wrote:
| Is that a prescriptive or descriptive statement? I just
| looked at about 20 and didn't see anything immediately
| obvious, but that was with in page text search, and not
| actually paying attention enough to tell whether it's
| common or encouraged to include a link to online
| discussions in general (and I would happily search for a
| data set or scrape the data if I could expect to find it
| there).
| maxerickson wrote:
| "Practical" is in there.
|
| A price competitive 10 MW generator probably meets that
| standard though (Islands, small towns, isolated mills,
| etc).
| fasdf23967 wrote:
| ...very fast spaceships for the solar system,
| interstellar big ones probably. With continous thrust.
| DennisP wrote:
| Seems like any profitable plant should count. Some
| designs work best at smaller scales, but if they worked
| out they'd be cheap and for more power you just build a
| lot of them. Even in fission, there's a big push now to
| build reactors small enough to mass-produce in factories.
| Maybe say at least 100MW total power?
| jollybean wrote:
| Energy has the most externalized costs of any industry.
|
| The 5th fleet is in the Gulf to protect the flow of Oil.
|
| The USD is backed to some extent by petrodollar, and that
| is a geopolitical hammer the Americans like to use at
| least to some extent.
|
| So what does 'profitable' mean?
|
| If Climate Change gets really problematic quickly, then
| guess what, all Nuclear Plants become considerably more
| profitable because the government will socialize the
| losses in case of catastrophic failure meaning owners
| don't pay for massive insurance costs which are a problem
| for profitability today give the possibility of $100B
| payouts in the case of failure.
|
| I'm wary of the commentator's cynicism. If we can make
| demo plants operating at some scale, close to break even
| in 25 years ... then that's a strong hint there's
| material progress, and that those plants could be
| breaking even another 25 years later.
|
| It also easily justifies a number of scientists working
| on it now even if only pans out in 50 years. The long
| term surpluses are potentially ginormous, like, to the
| point where they existentially shape the future, much
| like carbon fuels triggered the industrial revolution.
| ludsan wrote:
| I think this is a safe bet. Between Commonwealth Fusion's
| Arc/Sparc, or General Fusion's spinning glob of hot metal,
| or TAE systems, or any of the others, I think you have a
| better than average chance of settling this bet within 20
| years.
| pfdietz wrote:
| ARC has a power density 40x worse than a LWR's primary
| reactor vessel.
|
| General Fusion abandoned their first scheme because of at
| least three showstoppers (vaporization of the liquid
| metal wall, Richtmyer-Meshkov instability turning the
| implosion into jets of metal, and stochastic magnetic
| field lines in the spheromak causing unacceptable loss of
| energy via electrons to the metal). The new scheme has
| extremely serious engineering problems (the central
| pillar will be in a radiation/thermal environment orders
| of magnitude worse than the walls of ITER, and subject to
| extreme JxB forces). And they've never produced a
| neutron, as far as I know.
|
| Rostoker et al. were told 20+ years ago that their p-11B
| concept couldn't work, for at least eight different
| reasons.
|
| https://www.researchgate.net/publication/235032059_Commen
| ts_...
|
| If I had to bet on any current private fusion effort I'd
| choose either Zap Energy or Helion.
| eloff wrote:
| > no government would be crazy enough to permit it to be
| built
|
| Why? Nuclear fusion doesn't have the meltdown risk or waste
| problems of fission.
| leephillips wrote:
| There is no meltdown risk with modern fission reactor
| designs. But there is the waste problem.
|
| If you follow the links my Op-Ed, you'll find articles
| describing the radioactive waste and proliferation risks
| that will accompany _any_ fusion reactor. Not as great as
| fission, but far from zero. And there is the problem of
| production and transportation of tritium, a very nasty
| substance.
|
| A commercial fusion reactor would be fantastically
| expensive and complex, and require a huge infrastructure to
| support it.
| blablabla123 wrote:
| "Does Fusion produce radioactive nuclear waste the same
| way fission does?
|
| Nuclear fission power plants have the disadvantage of
| generating unstable nuclei; some of these are radioactive
| for millions of years. Fusion on the other hand does not
| create any long-lived radioactive nuclear waste.
|
| Can fusion reactors be used to produce weapons?
|
| No."
|
| https://www.iaea.org/topics/energy/fusion/faqs
| leephillips wrote:
| Right, as other commenters have pointed out, this is low-
| level radioactive waste. It, along with tritium, is great
| for dirty bombs and catnip to terrorists.
|
| A dirty bomb is a weapon. They are talking about "atom
| bombs".
| kortilla wrote:
| > is great for dirty bombs and catnip to terrorists.
|
| This is another variant of "think of the children". How
| many terrorists have built these dirty bombs?
| leephillips wrote:
| I saw it in at least two movies.
|
| They haven't been able to yet, because we don't have any
| fusion reactors out there.
| chongli wrote:
| Fusion still has to deal with waste, just not high-level
| waste. Through the process of neutron activation all of the
| parts exposed to neutrons eventually become radioactive
| enough to be treated as low-level waste. In a reactor large
| enough to produce energy for the grid these parts could be
| very large (and expensive) to deal with (not to mention
| replace).
| bbojan wrote:
| https://en.wikipedia.org/wiki/Aneutronic_fusion
| pfdietz wrote:
| Anything beyond D-3He or D-D is likely impossible. And
| any fuel with deuterium will still make enough neutrons
| to render the reactor inaccessible to hands-on
| maintenance. So there will still be a waste problem (as
| well as a huge reliability and maintenance problem). The
| reactor might not AS MUCH radioactivity, but much of the
| cost of dealing with it will scale with the mass of the
| contaminated material, not its activity. And fusion
| reactors will be very large. The cost of dealing with the
| activated material might end up higher than the cost of
| dealing with spent fission reactor fuel.
| EarlKing wrote:
| ...is even further from breakeven than deuterium+tritium
| fusion.
| tux3 wrote:
| Yes, though the article consists almost entirely of
| reasons why aneutronic fusion is _really hard_ ( "the
| conditions required to harness aneutronic fusion are much
| more extreme than those required for deuterium-tritium
| fusion being investigated in ITER").
|
| Note that the "Candidate fuels" section is not part of
| "Technical Challenges", but it might as well be.
| Helium-3, by far the easiest, is vanishingly rare.
| Deuterium would not really be aneutronic. Then further
| down is a list of worse and worse headaches.
|
| The leading scenario for acquiring the most convenient
| fuel candidate is "mining it on the moon". (The
| alternative scenario being to scale up production of
| tritium by existing heavy-water reactors from the nuclear
| weapons program, which decays into helium-3... and
| defeats the point of researching extremely complex,
| clean, aneutronic fusion reactors)
|
| I want to like aneutronic fusion, but it takes an
| objective that is several breakthroughs away and plays
| the game on nightmare mode.
| wrp wrote:
| The main parts of a commercial tokamak would be huge. I
| read once that due to thermal stresses, replacement might
| be needed annually. I seem to recall that the STARFIRE
| project[1] estimated nearly 60 tons of low-grade
| radioactive waste per year of the operational lifetime.
|
| [1] https://www.sciencedirect.com/science/article/abs/pii
| /002954...
| labawi wrote:
| Power plant waste:
|
| 60T/y for 1200 MWe = 50g / kWe*y = 1.6 mg/MJ
|
| Coal energy density:
|
| 24 MJ/kg = 0.024 MJ/g -> 42 g/MJ
|
| Not perfect, but depending on what the waste is, doesn't
| seem too bad.
| phkahler wrote:
| >> There's also a firing rate issue. Even if the system
| produced net power, significant production would require many
| shots per second. Currently, the laser flash lamps are
| expendable and it takes on the order of a day (and lots of
| money) to prep for each shot.
|
| Oh, but then there's this part:
|
| >> Further experiments will require the manufacture of
| additional fuel capsules and hohlraums. These may not be ready
| until at least October, Herrmann says. The nanocrystalline
| diamond-coated capsule that was imploded in this month's event
| took six months to grow at General Atomics, which has long
| worked with LLNL on fabricating capsules. The spheres have to
| be polished and the core's interior etched with tools inserted
| through a 2-micron-diameter hole drilled into it. The tritium-
| deuterium mixture is injected through a tiny fill tube just
| prior to the shot.
| hutzlibu wrote:
| Well, it is aweseom tech. But probably nothing I would bet we
| can rely on, soon.
| val314159 wrote:
| for the love of god, someone please rename these "diluthium
| crystals"!
| MurMan wrote:
| > There's also a firing rate issue ...
|
| The NIF goal was ignition, not continuous power production. The
| original spec was one shot every four hours. Achieving one shot
| per day is close.
| pfdietz wrote:
| > the LIFE proposal, which would use fusion neutrons to burn
| fission fuel in a blanket around the fusion chamber.
|
| This is crazy. If you are going to have fission and fission
| products, you might as well just build a fission reactor. It
| would be vastly simpler, smaller, and cheaper.
| sam0x17 wrote:
| Having toured NIF a few times and worked in one of the
| buildings adjacent to it a few summers ago, I will say the
| energy stuff always seemed more like a way to get funding. The
| main use and aim for NIF is and always has been to re-create
| some of the conditions inside nuclear weapons and similar
| fusion-based reactions.
|
| The whole NIF building has the ability to switch modes between
| classified and unclassified. They wouldn't have gone through
| the trouble of making this a toggleable feature on the building
| if they weren't actively using it for both.
| sleavey wrote:
| > The whole NIF building has the ability to switch modes
| between classified and unclassified.
|
| Interesting, can you explain this more? What gets hidden?
| sam0x17 wrote:
| I don't know the specifics but I imagine most of it is
| waving a magic wand and saying _poof_ now this room is
| classified. But there are logistics that go with that,
| certain door technologies that have to be in place,
| probably some complex security procedure for "switching"
| between modes, (i.e. I would think they need to clear the
| building of uncleared personnel and be 100% sure there
| isn't someone hiding in a bathroom somewhere) etc etc, and
| it's enough of a pain that most buildings are either one or
| the other all the time. The ability to switch on the fly
| for a large facility like that is super rare and indicative
| of there being a real need for switching.
|
| All I know for sure is on the tour they mention they can
| switch the whole building to be unclassified or classified
| and during the tour it is in unclassified mode.
| maxerickson wrote:
| I imagine a big chunk of switching to classified is
| shooing the un-cleared visitors.
| sam0x17 wrote:
| Likewise for going from classified mode to unclassified
| mode they would have to sweep the whole facility for
| sensitive material
| usrusr wrote:
| I'd imagine waste disposal processes and cleaning staff
| to be major headlines in the switching procedures.
| sam0x17 wrote:
| To be clear though, I don't think anything about NIF's
| actual design is classified. Maybe the parameters they use
| on some tests and the angles on some of the lenses and/or
| target design/composition are, but the actual setup is all
| publicly documented AFAIK.
| orbifold wrote:
| The aliens have to go to their cryopods :).
| TheDudeMan wrote:
| Holy shit, they got the power and energy units correct.
| fguerraz wrote:
| What a great distraction from the real problems!
|
| If we had that free limitless renewable energy, and we used it as
| we do now to fuel "growth" building malls and car parks,
| extracting ores from the crust, and produce pesticides, then we
| will have solved no problem at all.
|
| Spieces do not become extinct, they are being exterminated.
| Energy production is but a tiny part of the ecological crisis
| we're in. We need to solve the energy usage problem, not its
| production.
|
| This is madness.
| code4money wrote:
| Releasing more energy is good, but is it enough of a difference
| that the delta can be captured (assuming imperfect capture
| process) + is it able to offset the cost of the expensive laser
| setup (maintenance)?
| m-watson wrote:
| Baby steps, there are any number of issues to address if the
| goal was to create something that is energy producing for
| consumption. However, taking out even any aspect of
| commercialization or scaling this is an important milestone in
| terms of science and engineering. That's not to say don't ask
| those questions, it is just allow the excitement of progress
| while asking future questions.
| modeless wrote:
| The article states that the reaction produced more energy than
| the fuel absorbed, not more energy than it took to run the
| lasers. I expect the efficiency of power transfer to the fuel
| is pretty low.
| jatone wrote:
| also mentioned chain reactions which would be one way to
| generate more energy than input even if your input was high.
| belter wrote:
| Reading the info so far...I would advise a frugal dose of
| moderate optimist toned down with a spice of healthy scepticism:
|
| "The lab hasn't yet reproduced this month's results, and Herrmann
| cautioned that doing so might not be straightforward. "We don't
| know what variability will be in successive shots. It's a
| nonlinear process where alpha heating heats up the fusion fuel
| and creates more fusion, which creates more heat." Herrmann says
| the 3.5 MeV alpha particles, which remain in the plasma, produced
| 20% of the fusion yield, with 14 MeV neutrons accounting for most
| of the energy."
|
| "The lab is still analyzing the results from the shot. It's not
| yet known which or what combination of advances to the targets,
| laser pulse lengths, or other variables led to the leap in
| performance. Some of the instruments were saturated by the
| unexpected yield of the reaction. A few that are used in the
| target chamber for other, non-ignition experiments will need
| repair."
|
| "Herrmann acknowledged that the announcement deviates from the
| standard practice of peer-reviewed publication. But the results,
| he says, were leaking, "so we wanted to put it out so people
| could discuss the facts." "
| peter303 wrote:
| "just around the corner" quote from 1955
| QuadmasterXLII wrote:
| For reference, the hydraulic press channel recently demonstrated
| what the fusion energy released here looks like. 10^6 joules is
| basically one hand grenade. Very exciting!
| https://www.youtube.com/watch?v=eDA7EUDOiwU
| dekhn wrote:
| wow, I remember my friend in grad school working on this.... 20
| years ago? They said it would never work and was just funded to
| keep livermore going.
| brofallon wrote:
| I'm honestly not sure why there seems to be so much interest in
| fusion these days. Wind and solar seem to offer a limitless,
| carbon-free energy supply with relatively cheap, well understood
| technology that is already price competitive with coal and gas.
| By contrast fusion seems super expensive and technologically very
| complex - even fission plants take 10+ years to bring on line.
| Does fusion offer some advantage over wind + solar that I'm
| missing?
| sbierwagen wrote:
| As stronglikedan said, spaceflight propulsion/institutional
| inertia. (Stationary space facilities will use solar, just like
| on Earth. Space transport, unlike Earth transport, will be an
| awful combo of slow and expensive. Space stations will need to
| be _simple._ One type of computer. One type of microcontroller
| board. Maybe three sizes of screw. Solar panels are simple,
| identical, and interchangeable. And not radioactive! (Fun fact:
| every bolt on the outside of the ISS uses the exact same head
| size: 7 /16" hex))
|
| Seasonal variation with solar is a bit of a bummer. If we need
| to fully electrify everything, (Transport and heating) then
| winter will be a problem. Either we massively overprovision
| solar in order to still have heat on the shortest day of the
| year, or we run thousand mile cross-country transmission lines
| and _enormous_ battery banks.
|
| Even so, the economics are such that heavy industry might
| become a seasonal job. Right now we run aluminum smelters 24/7
| because baseload power is fairly consistent, but if solar power
| is free in July but dear in January you might see multi-month
| shutdowns. This gives headaches to central planners, and makes
| them inclined to pour billions into fusion if it can preserve
| some of the status quo.
| stronglikedan wrote:
| My best guess? Space.
| joak wrote:
| Solar+wind(+energy storage) needs a lot more materials and land
| to produce the same amount of energy.
|
| So the footprint of fusion would be a lot smaller.
|
| Also for the same reason deployment would be faster allowing a
| faster phase out of fossil fuels.
| Roboprog wrote:
| More 9s. Closer to 24x7.
| djrogers wrote:
| > Herrmann noted that in previous experiments, neutrons exiting
| the capsule on one side of the implosion arrived a few
| picoseconds earlier than did those flying off the opposite way
|
| Let's all just take a step back here and marvel at this
| statement. We (science-humans) are capable of building a machine
| that can detect _and quantify_ picosecond level variances in
| neutrons traveling in an enclosure. We can do amazing things.
|
| Side note - the lab is just down the road from me, I'm proud of
| my fellow Livermorons, and continue to hope they keep all those
| megajoules contained.
| molyss wrote:
| While everyone is focusing on the picosend part of this, I'm
| more impressed by the neutron detection. Electrically charged
| particles sound much easier to detect, let alone with any kind
| of temporal precision
| CobaltFire wrote:
| For those questioning the "Livermorons": I can't speak directly
| to that but can say that Naval Aviation uses a similar term for
| those who elect to stay at NAS Lemoore: "Leemorons". It's not a
| perjorative; the people I've talked to use the term
| affectionately.
| ezekiel68 wrote:
| In a large enough community, these two (perjorative and
| affectionate) are not mutually exclusive. c.f. Yankee Doodle,
| etc
| dredmorbius wrote:
| A considerable number of post-1960 Nobel prizes in physics and
| chemistry, as well as a fair bit of the medicine ones, come
| from sensor-related discoveries.
|
| Either they're directly applicable to sensing phenomena, or
| they form a substantial part of a sensor technology.
|
| Contrast with the pre-1960 period which was dominated by
| discovery of fundamental particals, elements, and laws or
| principles.
|
| Disclaimers: this is based on a somewhat casual review of
| awards, and even if my own assessment is reliable, the Nobel
| award process itself has numerous opportunities for bias and
| trend-based behaviours.
| HPsquared wrote:
| A nice rule of thumb for these kind of timescales (courtesy of
| a lecture by Grace Hopper) is to consider the speed of light: 1
| nanosecond at the speed of light is about 1 foot (300 mm). A
| picosecond is then 0.3 mm.
| _Microft wrote:
| Which is also a method to shift light pulses by the shortest
| of durations! Insert an optical delay line into the setup and
| by varying the path length, you can delay a light pulse by a
| tiny amount of time, e.g. for a pump-probe experiment (a
| pump-probe experiment works like this: first pulse does
| something to the system ("pump"), second pulse comes a short
| time later and reads out ("probes") the state of the system
| at that time. Changing the time delay gives an idea of the
| dynamics).
|
| Here is a drawing of an optical delay line: https://www.thorl
| abs.com/images/TabImages/Delay_Line_Kit_D1-...
|
| The part labelled "V-Block" can move along the "translation
| stage" which changes the length of the optical path by twice
| this amount. Use the speed of light to calculate which delay
| the pulse incurred over the distance. You can now send pulse
| after pulse through your setup while changing the delay by
| tiny amounts to see how things (e.g. chemical processes)
| happen on these time scales.
| CobaltFire wrote:
| Relevant video for those who haven't seen the lecture:
|
| https://www.youtube.com/watch?v=9eyFDBPk4Yw
| blueprint wrote:
| We can do so much and yet so little. All of this progress may
| amount to nothing if we cannot overcome our internal obstacles
| to our collective survival.
|
| Awaiting the downvotes but it's true.
| blueprint wrote:
| lol yeah y'all aren't in denial, sure....
| Florin_Andrei wrote:
| > _I'm proud of my fellow..._
|
| The part after that, was it a typo? :)
| WookieRushing wrote:
| Nope, looks legit: https://www.google.com/search?q=livermoron
| s+site:www.reddit....
| credit_guy wrote:
| To be honest, Livermorans sounds a bit more natural to me
| than Livermorons. And it does appear that some people from
| Livermore call themselves Livermorans, like "Cheryl is a
| native Livermoran" [1].
|
| [1] https://www.lvwine.org/blog/winemakers-talk-harvest-
| favorite...
| CobaltFire wrote:
| I think you miss the point: it's a friendly in-joke that
| the people who stay in that area are "morons".
|
| You see this in places where there isn't much to keep you
| there except your profession, typically government. I'm
| aware of Livermore and Lemoore, but I'm sure there are
| others.
| philwelch wrote:
| And to completely explain the joke to death, it's also
| ironic to self-deprecatingly call yourselves "morons"
| when you work at a scientific laboratory.
| djrogers wrote:
| No, this has nothing to do with those of us that choose
| to live here being stuck because of our professions, what
| the heck gave you that idea?
|
| Everyone I know who lives here LOVES Livermore. It's
| decent commute distance to most places in the Bay Area,
| is surrounded by beautiful hills, 40+ wineries, an award
| winning downtown, and the friendliest people of any
| biggish California city I've lived in.
|
| It's a joke, but related to the awkward sounding and
| looking term Livermoran.
|
| There is a LOT more keeping the 100k of us in Livermore
| than our professions.
| CobaltFire wrote:
| My apologies; I grew up half and half between Marin and
| Fresno and that's what I recall for both.
|
| If I mistook where the term up north came from then I do
| apologize.
|
| Edit: I think an issue was with my explanation. The
| people I know in both areas actually love it; people
| outside the area think they are stupid for living there.
| Therefore there is some appropriation of the pejorative.
|
| Once again, if that's mistaken in reference to Livermore
| then I apologize.
| taf2 wrote:
| It still amazing how much of the periodic table we owe to this
| place. https://www.llnl.gov/news/tags/periodic-table
| choeger wrote:
| Livermorons? Really?
| AlotOfReading wrote:
| It's the correct demonym for people from Livermore and also a
| bit funny. One of the breweries in the area even named a
| drink after it.
| wolverine876 wrote:
| Maybe they have a sense of humor about themselves.
| hijinks wrote:
| you need to with the heat there in the summer
| k0stas wrote:
| For context, in wired chip-to-chip communication electronics,
| femtosecond variations are (statistically) measurable.
| Picoseconds are rather pedestrian. A 56 Gbaud signal has a
| single-symbol duration of about 18 picoseconds and
| perturbations on the order of 1 picosecond are rather large
| 5.6%.
|
| Not to downplay the achievement of the article or the
| innovation in fusion physics and engineering in general, just a
| bit of context for the timescales.
| aDfbrtVt wrote:
| For further context, the fastest oscilioscopes commercially
| available (Keysight UXR) samples at 256G with 20fs (rms) of
| jitter. Modern coherent optics runs at over 100GBaud, a
| picosecond is 1/10th of a symbol period.
| typon wrote:
| Used a similar scope during my grad school tenure for
| measuring 200GS/s ADCs. RF electronics is a wonderful
| field.
| jhallenworld wrote:
| MSRP of $1.3 Million US dollars
|
| https://www.eevblog.com/forum/testgear/something-
| amazing!-ke...
| lizknope wrote:
| In a 5nm semiconductor chip a standard cell inverter (like
| combinational AND / OR gates) can switch in 5 picoseconds.
| These things are characterized with at least 2 more
| significant digits so we feel we know how they respond at the
| 10's of femtosecond level of precision.
| jjk166 wrote:
| And it's important to note that these developments in sensor
| technologies can be carried forward to future experiments even
| if the NIF is ultimately incapable of being improved much
| further. The quest for fusion is not simply achieved or failed,
| working on tough problems like this leads to technological
| progress at every step along the way.
| [deleted]
| programmer_dude wrote:
| Probably need to use more fuel for a sustained reaction?
| bufferoverflow wrote:
| There's no sustained reaction in this setup, it will be dropped
| targets and lasers pulsing at the right time.
| programmer_dude wrote:
| I am sorry I did not mean indefinitely sustained. Surely not
| all of the fuel "ignites" at the same time? Shouldn't a
| larger mass of fuel increase the energy output (there's more
| of it to "burn")?
| newman555 wrote:
| is there somewhere a summary of "basic science" problems that
| need to be solved to make fusion feasible? And - would throwing
| more money at the problem?
| apendleton wrote:
| This book: https://www.simonandschuster.com/books/The-Star-
| Builders/Art... just came out and is a very accessible
| explainer.
|
| The maybe-tldr version: we can make fusion occur, but it
| currently (well, until today) takes more energy to make it
| happen than we get out. We have good models that predict this
| relationship, and it mostly boils down to maximizing the
| "triple product": temperature times plasma density times
| confinement time. The two most popular broad approaches are
| "magnetic confinement" (holding a plasma for awhile with
| magnetic fields) and "inertial confinement" (taking a capsule
| and rapidly mechanically compressing it, with lasers or a
| railgun or something, which is what this NIF thing is), and
| each chooses to maximize the triple product by leaning on
| different multiplicands -- inertial confinement is much shorter
| time, but higher density as compared to magnetic. For both, the
| other factor is plasma instabilities: plasmas don't like to
| behave, and like to leak out of their enclosures or not
| maintain the shapes you want them to, and lots of research
| seems to be about controlling those.
|
| Beyond that, what the challenges are depend on the approach you
| choose. For inertial, bumping up the triple product seems to be
| mostly about building bigger and more powerful systems, and
| managing plasma instabilities. NIF also uses an "indirect"
| approach where the lasers get (inefficiently) turned into
| X-rays which then compress the plasma, and "direct" inertial
| fusion has even bigger plasma instability problems to solve.
|
| For magnetic, the most mature technologies, tokamaks, have
| well-understood properties in terms of plasma management, and
| the main still-to-do work had been thought to just be making
| the machines bigger, which is what ITER is doing, but the
| recent change is the development of high-temperature
| superconducting magnets, which might allow for much higher-
| strength magnetic fields, which would allow for success with
| smaller machines (that's what, e.g., Commonwealth Fusion, is
| pursuing). In either case, the goal is just bumping up the
| triple product until we get to net gain. Other magnetic
| approaches (stellarators, etc.) are probably at a somewhat-
| earlier stage of understanding plasma behavior.
|
| For both inertial and magnetic, there will also be development
| needed after net energy gain to get enough of a gain factor
| that the economics actually make sense and things can be mass-
| produced (current thinking is that to actually be economical,
| we need to get to ~30x energy out compared to what went in),
| and also likely some materials-science innovations needed to
| keep the reactor from wearing out due to high neutron flux, and
| possibly some work producing tritium, the likely fuel, from
| lithium.
|
| Beyond those MCF and ICF, there are also a bunch of other less-
| mature technologies that startups are exploring that might also
| produce good results, and (the founders think) might do so more
| efficiently than the big approaches, but they're not as far
| along, and the work still to do is more basic-science-ish. This
| would be things like Z-pinch, fuel cycles other than deuterium-
| tritium, etc. etc.
| apendleton wrote:
| Also, realizing I didn't answer the "money" question. Fusion
| enthusiasts definitely think so, and personally (just random
| interested lay-person) it seems like for tokamaks in
| particular, the physics are now well-enough understand that
| it's probably just a matter of money/time, but it's hard to
| say for sure.
| evanb wrote:
| https://www.nytimes.com/2021/08/17/science/lasers-fusion-pow...
| [deleted]
| sb1752 wrote:
| There's a long history of fraud and misleading / sensational
| claims made my companies in the fusion space. The industry is
| nowhere near break-even (total energy into system == total energy
| out). ITER is a great example today. This is covered well with
| in-depth research by journalist Steven B. Krivit. He's put
| together a documentary exposing ITER's many false and dubious
| claims that I recommend watching:
| https://www.youtube.com/watch?v=xnikAFWDhNw&t=8s
| mensetmanusman wrote:
| I remember a talk ten years by the director of LL describing how
| a power plant would potentially need something like liquid
| lithium walls to absorb the energy and transfer heat to steam.
| That sounded amazing.
|
| Also, ASML did commercialize EUV which relies on blasting a
| steady drip stream of molten tin, and people 10 years ago said it
| would never be useful for industry...
| blisterpeanuts wrote:
| Slightly tangential, but this amazing scientific work makes me
| wonder how much more we could have achieved over the last 30-40
| years, had we diverted even a small fraction of military funding
| to science and space research. Say, $100B/year.
|
| LLNL's budget is $2.5 billion. The entire Nasa budget is around
| $25B/year; NSF is $8.5B. It's true that there's also military R&D
| and of course the majority of R&D is private sector[1], but just
| saying, what a shame that there isn't more of a national focus.
|
| Not only should we be spending more on civil R&D, but what did we
| gain from that military expenditure, for example the couple of
| trillion we poured into Afghan for 20 years?
|
| 1. https://ncses.nsf.gov/pubs/nsb20203/cross-national-
| compariso...
| ttraub wrote:
| Raising budgets don't intrinsically guarantee better results.
| Would a larger staff of physicists etc. lead to more
| breakthroughs or quicker results? Or would it just be piddled
| away in frivolous experiments, nicer Aeron chairs and the like?
|
| A physicist friend from NSF told me once that $50 billion would
| be about right.
| jatone wrote:
| depends on where the bottle necks in the research are. I
| doubt its man power. its most likely production of the
| various parts.
|
| generally speaking you don't get great returns on increasing
| the number of scientists. you do get great returns by
| speeding up the production of data.
| binarymax wrote:
| This is amazing! But then...
|
| _"It gives the US a lab capability to study burning plasmas and
| high-energy physics relevant for [nuclear weapons] stewardship,"_
|
| Are you freaking kidding me? How about solving the energy crisis
| required to reverse climate change? Nope. More bombs :(
| laurent92 wrote:
| AND to solve the provisioning of fissile-capable material in
| third world country by having tech that can work on fissiON-
| capable material, ie non-radioactive. Which makes carrying
| those to Africa a progress rather than war material. Which
| means we might need less bombs.
| leephillips wrote:
| It's not more bombs so much as maintaining our existing nuclear
| deterrent without actually testing warheads by blowing them up,
| something that, thankfully, is behind us. Warheads deteriorate
| over time; you can't just keep them on the shelf and claim that
| they will still work if used. And our adversaries know this.
| parhamn wrote:
| Don't get too alarmed by this. It's how a good portion
| scientific progress in America has always worked (especially if
| the project needs military scale funding). The tech eventually
| makes it out to civilian space.
| credit_guy wrote:
| The US gives about the same amount of money to the National
| Ignition Facility as to the ITER project, roughly half a billion
| dollars per year (a bit more for NIF, a bit less for ITER). Of
| course, the main objective of the NIF is to assist in the
| stewardship of the nuclear stockpile, not to seek economic
| nuclear fusion. Still, it's great that they achieved this
| milestone. Congrats to all involved. And good luck in the future.
| topspin wrote:
| "the main objective of the NIF is to assist in the stewardship
| of the nuclear stockpile"
|
| I suspect that's always been a funding fig leaf. The nuclear
| stockpile stewardship claim is highly dubious.
|
| Not that I mind. There are worse things diverted DOD money has
| been squandered on.
| vajrabum wrote:
| This isn't diverted and it isn't DOD money. It's DOE money.
| If it's a figleaf then what's it covering?
| willis936 wrote:
| Department of Energy wasn't made when the grid came online;
| it was made when nuclear bombs were invented. The DoE isn't
| the department of electrical power security; it is the
| department of nuclear weapons security. The fusion energy
| research has been painfully underfunded because there isn't
| a political motivation to solve the problem. How does
| solving the energy crisis benefit the countries that
| benefit the most from it? Put another way: when you are on
| top of the hill, why would you flatten the landscape?
| willis936 wrote:
| MCF faces a few engineering hurdles. ICF faces several times
| more. Investing in a facility on the scale of NIF for ICF
| doesn't make much sense if the goal is economic fusion power
| on the grid. There are much lower hanging fruits where that
| money could be spent: such as on new MCF machines or a wider
| and shallower mix of ICF machines. Ask non-US fusion
| researchers how they feel about ICF if you want a proper
| outside perspective.
| Robotbeat wrote:
| Magnetic confinement fusion like ITER is no less of a
| boondoggle. Maybe even more so because the progress is
| intentionally slow in spite of not having a dual-role for
| "stockpile stewardship." ITER is being funded not just by
| the US but by many countries, started development in 1985,
| detailed design in 2001, and construction in 2013, but it's
| not even PLANNED to get full fusion until 2035. _2035_!
|
| Plus, it won't even generate electricity at all. That's
| planned for the DEMO reactor that won't start operation
| until 2051 at earliest. It is depressingly slow if you
| think one of the main reasons we should be developing
| alternative energy sources is to address climate change.
| It's so bad as to qualify as a waste and maybe even a
| negative investment as it's pulling a bunch of researchers
| toward a project that literally has no hope of being
| relevant to fighting climate change (as its first possible
| kilowatt-hour of electricity won't start until 30 years
| from now, well after we've exhausted our carbon budget for
| 2 degrees C of warming).
| sjburt wrote:
| The problem is that ITER is funded as a science project,
| and the researchers want to get as much research as
| possible.
|
| So they are going to spend a lot of time studying plasma
| before they irradiate the vessel with fusion byproducts
| and it's no longer safe to take apart (for example, to
| add new sensors).
|
| It's the only facility of this size so the research
| program is completely sequential.
|
| We could have fusion, we just need to spend $20 billion a
| year for 10 years. Not $1 billion a year for 200 years.
| pfdietz wrote:
| The first job of ITER is to show that disruptions can be
| controlled. This is absolutely necessary, and requires
| access to the machine to repair it when disruptions
| occur. So this had better be done without tritium (or
| possibly even deuterium). And if they can't do it, they
| will never be allowed to operate the machine with
| tritium.
| Robotbeat wrote:
| They could spend the same amount per year and get results
| in 5-10 years if it were being run competently.
|
| There's no point in babying a facility if it means taking
| decades too long to get useful results!
| pstuart wrote:
| What about "magnetic mirrors"?
| https://www.llnl.gov/archives/1980s/mirror-fusion-test-
| facil...
|
| I recall hearing a scientist from the lab say that was
| the way to go and they mothballed it because they wanted
| to focus on weapons research.
| willis936 wrote:
| Mirrors are interesting. They hit very high performance
| metrics in a small budget. However they have this pesky
| issue of requiring an electrostatic field. Conduction
| losses are a killer, scale up in nasty ways, and ablate
| material quickly.
|
| In terms of inexpensive neutron sources: they're perhaps
| some of the best we have.
| tsimionescu wrote:
| I also understand that fusion in general is unlikely to
| be an economically-viable energy source anyway, since the
| reactor and any surrounding material will be relatively
| quickly (~few years) be made brittle by the neutron
| bombardment, while also becoming radioactive - meaning
| any fusion plant will have to be carefully and constantly
| torn down and rebuilt, and materials from the old plant
| securely stored for large amounts of time (not as large
| as fission waste, but still in the order of decades or
| centuries). There are other concerns with hydrogen escape
| etc, but this one seems completely fundamental.
| Robotbeat wrote:
| Some methods of fusion solve this in varying ways, with
| liquid metal blankets, etc, or using non-neutron is
| fusion fuels. But that's missing the point. There's no
| path to these more viable methods of economically
| producing power that don't run through the path of
| generating more fusion energy than it absorbs, so we
| start with the easier fuels first to prove we can do
| sustained fusion before worrying too much about neutron
| embrittlement.
| pfdietz wrote:
| Even if we had unobtainium that was free of radiation
| degradation, fusion reactors would still be unlikely to
| be competitive -- they're just too large and complex, and
| hence expensive.
| topspin wrote:
| I don't buy this view. You can see from the quotes these
| physicists don't really understand why they got this
| result. We don't actually know enough about what is
| happening with ICF of MCF or any other xF to rule out
| approaches. And why should I need to seek foreign opinions
| to confirm your view? NIF detractors grow on trees in the
| US. You never, ever get a story about NIF without one
| chiming in.
| hppb wrote:
| Fusion using lasers is an off-shoot of H-Bomb development,
| and advances by John Nuckolls from early laser-based fusion
| research in the 1960s(!) were fed back into H-Bomb research.
|
| These fields are surprisingly related. For details, see Alex
| Wellerstein's book "Restricted Data", chapter 7.
| _Microft wrote:
| Here is your daily bit of useless knowledge: the energy released
| by fusion from this single, microscopic target is roughly the
| caloric value of a McDonald's cheeseburger (~300kCal).
| QuadmasterXLII wrote:
| For intuition about what it's like to release the energy
| instantly, it's also ~ one hand grenade.
| colechristensen wrote:
| A cheeseburger's worth of energy actually extracted from
| something the size of a spec of dust. It's a good way to make
| numbers real.
|
| Alternatively it's about the amount of energy to raise 4 L of
| water from room temperature to boiling.
| jonplackett wrote:
| For some reason I'm surprised a cheese burger has enough
| energy to boil my kettle multiple times.
| stickfigure wrote:
| A cheeseburger has enough energy to power _you_ for most of
| a day. Possibly doing a lot of heavy lifting, and
| continuously running the largest and most sophisticated
| neural network hardware on the planet.
| eloff wrote:
| That'd be a very large cheeseburger. I burn more calories
| in a typical 50 min workout (weights, not cardio, it's
| easier with cardio.)
| stickfigure wrote:
| Looking up burgers I've eaten recently:
|
| * A bacon cheeseburger from Five Guys is 1060 kcal
|
| * A double-double from In-N-Out is 670 kcal, and that's
| before you make it animal style
|
| But yeah, not a McDonald's cheeseburger. I'm somewhat
| offended that they're allowed to call those "burgers".
| aaaaaaaaaaab wrote:
| A 300 kcal cheeseburger? I don't think so. The baseline
| metabolic rate of an adult is ~1700 kcal/day.
| furyofantares wrote:
| Yeah, I mean, it's just generally astounding that the food
| I eat is enough to power even a sedentary lifestyle, let
| alone one with a bunch of running and other exercise.
| dralley wrote:
| The definition of a dietary calorie (kilo-calorie) is the
| amount of energy needed to raise the temperature of 1kg of
| water by 1 degree Celcius.
|
| So the kettle math is actually quite straightforwards.
| thereddaikon wrote:
| Since any practical reactor will use steam turbines to
| translate heat to useable energy that last one is actually a
| good way to think of it.
| PaulHoule wrote:
| Not steam turbines, closed-cycle gas turbines.
| crispyambulance wrote:
| Yes, the energy equivalent of McDonald's Cheeseburger dietary
| calories.
|
| From a blob of matter about 100 microns across and over a
| timespan of less than a nanosecond.
|
| Obviously, once (or IF) they get this thing to be repeatable
| and then scalable, it will become a big deal.
| [deleted]
| lolc wrote:
| I like how they didn't expect it:
|
| "The lab is still analyzing the results from the shot. It's not
| yet known which or what combination of advances to the targets,
| laser pulse lengths, or other variables led to the leap in
| performance. Some of the instruments were saturated by the
| unexpected yield of the reaction. A few that are used in the
| target chamber for other, non-ignition experiments will need
| repair."
| Robotbeat wrote:
| This is fantastic. And I agree with the fellow mentioning direct
| drive as better. If you can get the same results using direct
| drive, you'll have a sizable energy gain above what the input
| energy was, perhaps enough to drive a (multiple stage) heat
| engine and produce net electricity.
|
| Anyway, I also want to point out that laser inertial confinement
| fusion bears a not-coincidental (some of the same codes and
| plasma physics techniques developed for laser fusion were used by
| Lawrence Livermore and others to develop EUV) resemblance to the
| extreme UV light sources sold by ASML and used for the highest
| end computer chips today. Compare the LIFE fusion reactor concept
| (based on an evolution of the NIF) with the EUV light source of
| droplets of tin being hit with a pulsed laser:
|
| https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy
|
| EUV light source: https://youtu.be/IattxYrc9Go
|
| (The Hohlrahm of the National Ignition Facility, surrounding the
| tritium deuterium fuel pellet, is acting like the tin droplet of
| the EUV light source, converting longer wavelength pulsed laser
| light to (near) X-Rays.)
| jeffbee wrote:
| NIF isn't supposed to achieve net power generation. It's a
| defense research facility which is intended to test nuclear
| weapons technology without violating weapons testing bans.
| Robotbeat wrote:
| That is not quite correct. Yes, its primary purpose is
| "stockpile management," but it's not _exclusively_ that. It
| was ALSO sold as a facility to study fusion power generation,
| hence this announcement.
|
| LIFE was a proposed follow-on project to NIF that would be
| focused on power generation demonstration (high repetition
| rates, etc). It never went anywhere and work on it
| effectively stopped around 2013 or so.
| leephillips wrote:
| But the comment you're replying to is exactly correct. NIF
| is not LIFE. Ignition is far from net power generation, by
| a few orders of magnitude.
| Roboprog wrote:
| I picked up on that angle as well.
|
| "Ignition" isn't about generating electricity. It's about
| making fusion bombs which don't emit neutrons or other
| radiation (from a fission trigger) while the device is in
| storage.
|
| So, not primarily a power generation design like a tokamak
| would be.
___________________________________________________________________
(page generated 2021-08-17 23:00 UTC)