[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)