Nice thorough overview. A couple small corrections - (15:55) in ICF the lasers are so incredibly vast, and the beam diameters so huge, that we actually can't use neodymium doped yttrium lithium fluoride (or yttrium aluminum garnet) crystals for the lasing medium. The Czochralski pull method of growing single pure crystals of the stuff simply maxes out at a few inches in diameter, and in order to keep the beam intensities lower than the intrinsic laser damage threshold of the material while attaining energies of a couple megajoules on target, we need beam diameters of over a foot (60cm) across! And so we are forced to use Nd doped phosphate glass instead, which can be made into practically arbitrarily large slabs then cut to size. It would be nice if we didn't have to do this of course, because glass is a terrible conductor of heat, while single crystals are great at it; but as it is we have to wait hours between shots for everything to cool down uniformly, lest the next shot suffer wavefront distortions from traveling through nonuniformly still warm amplifier Nd:glass. Also, immediately subsequent to this section you say that "the higher the frequency the deeper into the plasma they penetrate", but I think you meant to say the longer the *wavelength* instead. We like higher frequency in ICF (shorter wavelength) because it selectively heats the ablator shell of the capsule and *doesn't* prematurely heat the electrons in the fuel before maximum compression time, which longer wavelengths do. The final video section is quite good indeed, and in particular the identification of hydro instabilities as a likely show-stopping problem for General Fusion's lead/lithium alloy hybrid magneto-inertial scheme is most welcome, as I rarely see anyone rightly calling this out. One disagreement with this section though, at the very end you mention that a hypothetical future power reactor would have to take the "still unproven direct drive approach", but in fact I would argue that though we haven't achieved as high yields as the indirect method, this is merely a consequence of NIF's beam arrangement being optimized for hohlraum irradiation in two groups of 96 beams and its inability to currently do symmetric direct drive. The direct drive method is actually much more likely to succeed, all else being equal, and most of us think that NIF would have long since ignited its pellets by now if it were doing direct drive, if for no other reason than simply because hohlraum 351nm UV light to soft x-ray conversion is so utterly abysmal at ~10%; ie. they're throwing away 1.8 megajoules of laser energy entering the target chamber and only actually coupling only 0.2 megajoules into the target implosion merely for the sake of x-ray irradiation uniformity (and weapons configuration similarity)! In reality, the non-uniformity issues of direct drive have long been largely solved with things like distributed phase plates, distributed phase rotators, and spectral smoothing by dispersion.
Thanks for the comment. Totally agree about the over-simplified NIF beamline (explaining even a simple beamline like the actual one at 22:34 would have doubled the length of the video). For some reason, I thought there was a Nd:YLF seed pulse (and even re-recorded that bit as you may hear). I also didn't want to go to deep into things like avoiding a pre-pulse and so on. Maybe I will do a "How Lasers Work" video including very intense lasers. With regards to the benefits of higher frequency waves, I was alluding to the various absorption processes at or below the plasma frequency. If I recall correctly, very early research used CO2 lasers which just couldn't penetrate deep enough. Isn't that also a problem now, that the hohlraum closes to 1-omega light too early? I also agree that direct drive ignition should also be easy in principle, but I would urge the same kind of caution as must now be felt for the 2012 Ignition Campaign.
@@ImprobableMatter Oh yeah, I'm pretty sure the seed pulse from the pulse generation room is definitely YLF generated on OMEGA, I think they're using ytterbium doped fibers or something in NIF's master oscillator room... Ah I see about the frequency thing now, and keeping in mind we're really approaching the edges of my limited knowledge as a mere non-scientist engineer, my understanding was that the longer wavelengths caused unacceptable electron preheat (because of the high e-field? ....I guess?) before the bang time, but I see the energy absorption also scales favorably with frequency... So you were right about the absorption efficiency relationship to irradiation frequency: Taken from Gordinier et al. 2003: "While carbon dioxide gas lasers can be pulsed and have efficiencies approaching 10%, their wavelength of 10.6 μm is too long for efficient coupling to pellets. The interaction of an electromagnetic wave (laser light) and the ablating plasma at the edge of the pellet can result in total reflection of the incident light at a critical density layer defined as the radial location where the laser light frequency matches the plasma frequency. The plasma frequency is proportional to the square root of the plasma density. Thus, for deep pellet penetration, a high frequency (low wavelength) light source is required. Long-wavelength lasers therefore have a difficult time efficiently coupling to pellets and achieving the compression factors required to initiate a thermonuclear burn." Yes, caution in this field is obviously in a perpetual deficit, and we should always strive for more of it. Though the recent 1.3 MJ yield shot on NIF last August really did surprise everyone I think. There seemed to be a general resignation among many that the R-T hydro instabilities were underestimated (yet again) for NIF scales, and the cross-beam energy transfer, and the laser plasma interactions.... etc. were going to conspire to prohibit ignition from ever being reached. But now, well...it really seems right around the corner at least for indirect ICF. It'll never result in a power reactor of course, but even being able to achieve ignition in the laboratory at all I believe is going to open up a whole new world of ultrahigh flux neutron experiments, among other things, that make the machine itself a valuable new tool in high energy density science. Thanks much again for your videos, they're really excellent.
@@Muonium1 Do you know what the exact reason behind choosing the hohlraum method over direct drive? Was it purely because it was functional in nuclear tests and they didn't want to dedicate NIF to an as-of-yet-unproven method? There must have been some reason for it, seeing as the physics suggests it is a big bite out of the efficiency.
"I will release a follow-up video about stars that mostly fuse heavier elements such as silicon about a trillion years from now when it becomes relevant." 🤣🤣🤣
I came to the comments to see how many others picked up on that one. God I am so happy to find this channel FINALLY some non dumbed down stuff in an understandable format.
@@TheClumsyFairy I feel the same way. It gets so tiresome clicking on videos about fusion that spend the whole time going "The reactor burns hotter than the sun! Wow how cool is that!" when experimental fusion temperatures hotter than the sun haven't been new since the 60s.
Hey mate, I've recently found your channel, and have just got to say, I'm loving it. You've earnt a subscriber for a long, long time to come. Your subject matter understanding and excellent communication combined with simple informative graphics make your videos a powerhouse of knowledge. Keep up the amazing work :D
Been such a treat finding this channel. I won't say I "understand" it now per se, yet undoubtedly I now know how much I didn't understand. Can't thank you enough for the useful explanations & demos, minus pie in the sky rhetoric. Now if only a similar honest & straightforward take was made toward our current best source for energy. Substituting the hype of one with the removal of fear from the other.
The note about tracking pellets and rapid firing reminds me of the type of work that went into semiconductor manufacturing, the EUV machines needs to fire a drop of tin and lasers to vaporise it incredibly rapidly and in such accuracy to ensure a “constant beam of light” for the production of the chips… it’s insane and I wonder if the knowledge can be shared with the nuclear fusion industry too!
I think I've read that the Cymer laser used in ASML's EUV machine fires at something like 30 KHz, with a tin droplet being blasted to plasma by a CO2 laser for each pulse. But the power levels are only a few hundred watts, compared with the much higher levels needed for ICF.
@@tristan7216 Yeah, it's quite small vs what is needed here. Tho, I would say it is an ideal technology demonstrator for something bigger! I do feel like with a lot of modern tech, people forget that there are usually many iterations done before you get to where a "completed" or "presentable" product will be!
Great entry to the series. This really is a useful resource for showing the shape of the problems faced by fusion power research to people who are not fusion power researchers (there are a surprising number of those around). Funny timing with JET's recent nuclear campaign press release a few days ago.
I did read the news about the JET D-T campaign (not in touch with my former colleagues there anymore). I considered doing a text post on here, or a short video about it, but I will probably cover it in the next full video.
Great video! Waiting for the next on magnetic confinement! Also interested in your take on some of the more unorthodox approaches, like Helion Energies' pulsed FRC tech
Love your informative and structured videos! Are you maybe also planning videos about fission or similar topics? I'm really interested in fusion/fission :D
It's a shame that the caprice of the all-powerful algorithm throws such high quality videos like this to the dogs, with a mere 2 thousand views, simply due to some fickle lack of a face or red arrow in the thumbnail or somesuch, while some "which phone will survive being run over by my car!!??!?!?" garbage gets a thousandfold more hits in an hour. Oh well, maybe they'll randomly suggest this video to everyone 7 years from now...
From my experience, a video needs to have a "click through rate" of above 10% when it reaches 1600 views to start getting recommended widely (not sure if that 1600 is a magic number in the algorithm or not). Technical videos like this one don't get up to the required rate. To be fair, I can see why people don't want to watch anything educational on here. People watch RUclips to relax, so drama and negative videos are easier to digest.
Another great video. Question - Why has tritium-tritium fusion got a lower cross-section compared to D-T fusion? I would have thought that the extra neutron would increase the weak nuclear attraction and help them fuse. Any info to help me understand this would be greatly appreciated!
It is true that D-T appears to be the outlier: adding neutrons seems to help all other hydrogen isotopes to fuse. The simple reason is that there is a resonance in forming Helium-5 which boosts up D-T specifically. For a detailed explanation, you can look up Gamow factors and so on.
It really does need to. The only other way is with fission reactors like the CANDU, but you would need many fission reactors just to supply a single fusion power plant.
@Improbable Matter Would it be possible to use a particle accelerator, or even a power consuming inertial electrostatic confinement fusion device, to breed Tritium?
I love the series of fusion based videos so far, but I have a question. In the nTte equation, would it be possible to substitute frequency and amplitude with Temperature to make up for the temperatures needed? Something like this: n(ω + A)te. It just feels like getting a plasma that hot is very innefficient to me.
@@ImprobableMatter I'm thinking you could replace the temperature with the atomic frequency of the fuel your trying to fuse to 'excite' it and then increase the Amplitude of that frequency to forcefully induce fusion through that excited phase. P.S. Sorry for my Butchered English structuring. I am a native speaker of the language but when I get excited about something, I tend to use the wrong words to try and explain what I'm thinking. Edit: In other words, Couldn't we use frequency and amplitude to mimic the properties of temperature by using the atomic frequency of the fuel and increasing the amplitude to make fusion possible?
Weird request but in case you’ve ever watched the podcast “Well There’s your Problem”, you’d make a great guest and you should get in touch with them! If you haven’t seen it, I recommend it highly
You are quite amazing. Thks for taking the time to explain this geeky subject so-well. However now I'm pessimistic about practical fusion. I wonder if you were king of all fusion research, ?what practical approaches would you try to make fusion practical?
I think the magnetic approach is more practical in the near-term. Going from 1 shot per day to 1 shot per second is tough; making a tokamak like the ones currently, but slightly larger and with a higher magnetic field seems easier.
Kinda funny but with many star, the Q plasma will be around 100-1000 by the time the star dies, but will be less than 2, and in many cases, much less than 1, after that. gravitational collapse releases a bunch more energy that can't be used for fusion and if it produces a white dwarf, the overall energy spent in the process is on the same order of magnitude as the fusion energy. If it produces a neutron star or black hole, there will be far more energy released by the actual crushing of the star into such a small object than ever gets released by fusion. Huh, I guess maybe instead of fusion power, we should find a way to generate energy by dropping things into really extreme gravity wells.
21:11 - the budgeting office wishes for a status report on the KV-2 power plant. How far along are you with training them to shoot ten times a second and would an autoloader help?
8:55 OMG!!! Since when was this known? In the science fiction book "The curents of space" from Isaac Asimov, he talks about how how there are two tipes of fusion, for one of which carbon serves as a catalyst (in the book this results in super novas). On the end of the book he added an addendum later in his life, saying for people not too take his writing about this too seriously, because at the time of writing far less was known about fusion and solar processes. Since I am am pretty sure novas are not caused by this carbon stuff I assumed that this carbon reaction was also wrong. But here it is! In its full beauty! This is hella epic.
Excellent concise presentation! THANK you for reviewing the math! Question: WHY don't we invest in LFTR technology? It has already been proven to work since the middle of last century, it has far less hazardous waste and some of the by-products are useful for medicine and space flight. Further, LFTR reactors are fail-safe and produce no fissile materials that could be misused. WHY IS NO ONE TALKING about that?
Wow, this is a very informavie and intersting video. Looking forward to part 3. What are your thoughts on Helion Energy and their approach. They have recently gotten a lot of attention and billions in investment from VCs.
Watch the first part of this series. Deuterium-Helium3 is a very hard reaction to do. One thing I can say for certain: the reaction releases enough neutrons that a power plant based on their idea would have to be a certified nuclear facility. Logistically difficult.
@@ImprobableMatter I might misunderstand, but I thought their Trena reactor has already been doing D-He3 fusion for over a year during its test run. The next test reactor (Polaris, due date sometime in 2023) is intended to generate larger amounts of He3 and show a proof of concept positive net electricity sometime in 2024. Going to be interesting to see if they actually achieve that.
@@jRoy7 doing anything at all for over a year isn't exactly realistic if the net energy required over that time is to lie exclusively in the future...they must've done fusion over a year ago and hopefully do fusion regularly enough, but remember that at any given time, charging capacitor banks is most likely going to preclude them from doing anything even related to fusion instead
Can you maybe make a video about hb11 energy startup from Australia? It's working on proton boron reaction. They are claiming it becomes possible because of major improvements in laser technology. I just watched some of your videos and in particular about startups being cheeky. Is this hb11 energy startup one of those or do they have some sort of science that backs them up?
@@ImprobableMatter I've seen the one that states we won't have fusion by 2040. The central idea being net energy gain is basically worth nothing outside research communities. But the examples in the video were based on other type of fusion. But I guess the same is true for the proton bor reaction because of the low efficiency of lasers.
"Keepeing the plasma confined long enough....." Xrays are rarely ever mentioned when confinement is mentioned. Fusion gives off tremendous amounts of Xrays. Xrays can accelerate electrons and protons to tremendous velocities according to Compton scattering. But electrons are two and three thousand times lighter than D and T so one might expect electrons to be accelerated much easier. They refer to electron volts when talking about Xrays as if they are a voltage source. If a fusion plasma can be somewhat confined by voltages as low as 10,000 volts in a Farnsworth Fusor then the zillions of Xrays and Gamma rays coming from a fusion plasma would be a real problem. One Xray or Gamma Ray can deliver hundreds or thousands of volts to an electron or proton. Xrays might also be used for confinement. A book I found in a public library said that Xrays are used to confine the plasma because otherwise a hydrogen bomb would have to be much larger like the first bomb that was many times bigger than the little warheads that they can fit into a cruise missile warhead. One might suspect that if it is in a book at the public library then it is no longer classified. But the author said that when he wrote the book decades ago it was still classified. He went around to hydrogen bomb manufacturing facilities on the public tours that they give and asked a lot of questions. He found out that they made Uranium foils at one factory. He asked a leading question about the foils to the tour guide and the use of uranium foils to reflect Xrays to help confine the bomb plasma. The tour guide suddenly asked him how he found that out because it is classified information. He was just guessing but the tour guide confirmed his suspicion. If a big sphere of DT was heated at the center by lasers to the point that the plasma began to emit Xrays near the center then the Xrays might be used to confine a small plasma at the center. The concentric convergence of the lasers would tend to generate Xrays with the same convergence. If Xrays accelerate electrons much more easily than ions because of the weight difference, one might suspect that a buildup of negative voltage at the center might be very useful for confining a plasma as in a Farnsworth Fusor.
@ImprobableMatter You said for the laser approach "the input energy is usually DEFINED as beam energy" however, that definition is irrelevant and misleading. The input energy is the total energy into the system which is the 20 MJ of electricity required to produce the laser + the beam energy. Total input energy = 22 MJ and if we consider the 40% loss from the fusion = 20 MJ then we can represent the total energy of the system. The total output = 30 MJ however the total loss = input energy + conversion loss = 20 MJ + 22 MJ = 44 MJ. 44 MJ (input + losses) > 30 MJ (output) so there is no net energy gain. Therefore, it is impossible to have net energy gain from this process without either (1) improving the conversion efficiency of the laser (which is theoretically possible) or (2) improving the thermal conversion efficiency which is impossible. Thus, the only way to get net energy gain from this method is to improve the beam conversion efficiency. Thus the claim by the US Department of net energy gain is false and misleading. The numbers don't lie. Thanks for this series it was very informative
"Hot things drive a turbine" is the only way. Most of the energy is carried by neutrons, and the only way to extract that is by allowing them to collide with a solid blanket and deposit their energy as heat. Then a turbine is as good as it gets.
@@ImprobableMatter Thanks! I had seen a video a while ago where the creators claimed that their fusion generator was powered by the expansion of the plasma directly inducing a current in the electromagnets containing it. Which seemed very interesting. But even if that works, if most of the energy is in the neutrons that seems ridiculously inefficient.
I have seen these kinds of claims for aneutronic fusion, but you can watch the first part of this series to see why that would be very hard to make work.
Can you do a vidio abut what to bild your tokamk out of? How do scientist know that the things they bild the reactor out of wont be canged by the Nutron radiation the plasma gives of?
15:30 So... does that violate the Nuclear Test Ban Treaty? The treaty does not specify a size and it is technically structured like a nuke and could be interpreted as the world's smallest nuke. I'm being sarcastic of course but the thought popped up the first time I heard about what the NIF was doing and how the fuel capsules were structured.
People overlook the fact that the sun has a near-infinite amount of energy to generate fusion with: its own gravity There is no way to achieve such a reaction without emulating this system, and current efforts don't produce as much as they spend trying to artificially create and maintain the pressures and heat. Gravity is the answer.
Listened to a couple of your videos and now feel thoroughly parasocially bonded now. Looking forward to more of your stuff but gonna have to ration the back catalogue.
I am curious about how fusion works, if a thermonuclear bomb (say 500 megatons) is detonated deep under ocean, since water doesn't compress the resulting hot water plasma would be under immense pressure, would that cause fusion of water plasma? could it cause chain reaction of water up to the water surface?
In short: no. As you will see from part (1) of this video, Hydrogen itself is less reactive than the Deuterium-Tritium mix in modern bombs by a factor of 10^25 = 1 followed by 25 zeros; it takes an average of 9 billion years for a given Hydrogen atom in the sun to fuse. Deuterium on its own, which is not common, is much more reactive, but still less than a 50:50 D-T mix. Water does compress when you're dealing with the sorts of pressures described here. It would be squeezed until the electrons are stripped from atoms and it becomes a plasma. However, it would not be compressed or heated nearly enough to achieve the necessary triple product even if you had D-T surrounding the bomb instead of seawater.
@@ImprobableMatterI was very curious about water plasma properties and how much of that water plasma would be fused in such extreme situation when a 500 MT bomb was detonated at ocean floor. Since deuterium is 0.05% of sea water, would the deuterium and whatever else is in water plasma be easier to fuse than protons? Would deuterium + helium 3 fusion occur? This part is confusing for me -"However, it would not be compressed or heated nearly enough to achieve the necessary triple product even if you had D-T surrounding the bomb instead of seawater." If fission reaction can set of fusion in surrounding D-T, why can't first stage fusion be used to start second stage D-T fusion surrounding the first stage? Or D-T fusion is not fist stage, but second or later stage? I read that in theory it would be possible to endlessly add fusion stages, and only reason it is not practical is because of the size and mass of such a device/bomb.
As you can see from this video, the primary fission explosion must be set off so that the x-rays precisely compress the secondary fusion bomb. If you just let x-rays expand in all directions, the compression would not be enough. In order to add another fusion stage, the device would have to be engineered to cause the x-rays to work in a similar way (not just randomly expanding in all directions). Now, let's say you replaced the secondary with seawater so that it does indeed reach the density and even temperature necessary. Whenever two Deuterium atoms collide (there is very little Helium 3 in seawater), they might fuse, less frequently than D-T. However, because, Deuterium is uncommon in seawater, only a tiny tiny fraction of the collisions would lead to exactly two Deuterium atoms colliding and then fusing. So a secondary made of seawater would add almost no additional energy.
@@ImprobableMatter I wasn't thinking seawater as secondary, more like quaternary after primary fission that sets of secondary fusion that sets of tertiary fusion, I was just thinking how would one make biggest bomb possible. When Soviet scientists were making Tsar Bomba in 50s they were worried about setting of a fusion chain reaction, later it was proven to be impossible in the air, I was think what would be the situation deep under water with much higher density and pressure, also no need for chain reactor, adding let's say 50% energy to initial bomb would be a huge improvement Why can Helium-3 fuse in the Sun at 10-15 million degrees, but ITER needs 600 million degrees, is it the difference in pressure?
Has asml helped with confinement fusion? They have figured out how to shoot tin droplets with big lasers for EUV lithography. Based off the insane engineering, holding the semiconductor industry hostage and they are billions making I'm assuming they figured out a lot of the problem.
Sun's core is assumed to be very dense and hot. The current solar model suggests the density at the core's outer edge be 20 g/cc, heavier than the uranium, while the hydrogen is in plasma state. We don't even have an agreed upon phase diagram for hydrogen for such density and temperature, but let's assume it's plasma there. Then, what prevents the entire core of the sun from imploding and become helium or heavier element instantly? When hydrogen bomb explodes, it will keep fusion reaction until the pressure/temperature get removed or lowered. In the solar core, gravity holds the pressure, and more fusion means hotter temperature, so more fusion should lead more and more fusion. What's acting as a so-called "control rod" in the sun's core, which prevents further fusion reaction?
If you watch the video, you will see that the peak density in the sun is 200 g/cc while inertial fusion reaches up to 900 g/cc (sometimes even greater) as shown at 18:21 in the referenced figure. The temperature is also higher than the center of the sun. The phase diagram, equation of state and so on for hydrogen at even greater extremes than the center of the sun is achieved every day at the National Ignition facility, among other experiments. The state of matter is very well understood. The temperature and density in the sun is a balanced and stable equilibrium. If the temperature increased, so would the pressure; the plasma would expand until its density dropped; lower density would lower the fusion rate until the temperature dropped back down. The system is therefore self-regulating. This is in contrast to fission reactions which would grow exponentially if the control rods as you put it are not there.
@@ImprobableMatter "The state of matter is very well understood." -> I don't think they actually "measured" any properties of the "plasma" state when the fusion is taking place. Viscosity, conductivity, impossible to measure. "If the temperature increased, so would the pressure; the plasma would expand until its density dropped; lower density would lower the fusion rate until the temperature dropped back down." 1. In the Sun, because the gravity is holding the entire core together, if density gets lowered for any reason, the core will expand, temperature lowered, fusion rate lowered, and the density and temperature lowered further, and then the fusion would stop entirely. 2. Instead, if fusion did "ever" take place inside the sun, one helium atom is much smaller than four hydrogen atoms, so the density gets denser, and due to fusion, it's hotter, so more fusion should take place, and denser helium will further make the core more compact, core gets smaller, denser, and hotter, encouraging more and more fusion. The current solar model is an unstable system, not self regulating stable fusion reactor. The Sun's core should have become helium or heavier atom almost instantly 4 billion years ago, as soon as fusion started. Solar fusion is an unstable model. The entire Sun's core is a fusion pallet firmly held by the gravity pressure, no escaping from it.
You are mistaken. Numerous experiments, including the NIF, have directly measured plasma properties at high temperatures and densities. Your point 1 is logically incorrect: when the temperature is lowered, the pressure will lower and the core will contract again. It is therefore a stable system. Your point 2 is also misinformed, since most of the hydrogen has not yet fused and therefore the effect of having fewer particles is not significant. Will it be in the future? You bet, and models of the late stages of the sun's life take this into account. They agree with astronomical observations of red giants in our galaxy. Anyway, I am leaving this comment mostly for the benefit of anyone else reading this, not because I hope to change the mind of anyone who believes the Earth is hollow or some other nonsense.
@@ImprobableMatter "They agree with astronomical observations of red giants in our galaxy." Give me a break. We don't even have an agreement what the calm Jupiter is made of, what state it is in, after sending probes after probes with High Definition Photos. We don't have real working models for any star, let alone the Sun. Just check out wikipedia, or any astronomy books, like "Universe" from Smithsonian, p 178, or any astronomy college level text books, and take a look at the cut-away diagram of Jupiter. The "GAS GIANT", has gas layer only at the very top, like the earth or venus. The rest is supposed to be liquid metallic hydrogen, liquid hydrogen, helium rain, and at the core, very small rocky ball. Add them up in density, and try to come up with 1.3 g/cc for the overall density of Jupiter. Let me help you. The density of liquid metallic hydrogen is 0.7 g/cc. Liquid or solid hydrogens are 0.06 - 0.07 g/cc. The rocky core is less than 1% of the whole volume. How can you average up 0.06 - 0.7 g/cc thing, which is 99% of the volume, and come up with 1.3 g/cc density? Thus, according to wikipedia, Smithsonian, Gas Giant has definite surface -> "not gas giant". According to their cutaway views, Jupiter is a hydrogen ball, but the basic math, density, doesn't add up. Self contradicting. aka Wrong. If you can solve this puzzle, I will pay you $300 USD, Zelle or whatever. So go on. Oh, and logically, think about this. We don't know what Jupiter is made of... let alone its internal structures.... with all the pictures and videos in details.... But you believe the claim that we know the Sun, its interior, how it makes energy? Furthermore, we know anything about Red giant, Blue giant, white dwarf, the birth of galaxy and the universe? You must be kidding....
@@ImprobableMatter "Your point 1 is logically incorrect: when the temperature is lowered, the pressure will lower and the core will contract again. It is therefore a stable system. " Why temperature is lowered? Because fusion rate is lowered? Ok, let's start from there then. You are wrong anyway. 1. Temperature is lowered "SOMEHOW". 2. Fusion slows down. 3. Pressure lowered 4. Core contracts 5. Density increase 6. Temperature increase 7. Fusion occurs more # 8. 4 hydrogens become 1 helium -> lot mode dense. 9. Core contracts, temperature increase, 10. Pressure decrease by factor of 4 (H -> He) & Pressure increase by factor of temperature (not much change) => net less pressure. 11. More contraction 12. More fusion. -> Go back to #8. Unstable? You Bet. Did I get anything wrong here? If so, tell me where.
I heard it was only 10 year away... 30 years ago. It seems like a lot of effort for something that might not even work at the end. Wouldn't doing new nuclear fission reactors be a better way to go.
Or you could initiate an extremely confined column of lithium dueteride creating a jet of neutrons up through a building turning thousands of tons of steel into dust and making the rest as brittle as glass.... for a short period of time.
I have designed an entirely successful fusion power plant. The solution lied in the creation of a z-pinched stellerating spherical tokamak. I am unable to release the full design to the public at this time because a portion of my design may infringe upon currently valid patents, and also because I must complete my prototype power reactor for safety testing. The test bed reactor will have to wait another month though because the primary coil of the reactor is needed by my lawn mower until such time as the grass stops growing - and I also need to get my electricity reconnected. It is frustrating when your local utility blocks the advance of civilization.
Perhaps with neutrons , which have 150 T and Protons. Photons have only 0,03 T as UV light. Light lasers tend not to be inertial fusion lasers at 0.03 Tesla (for momentum-balancing particles with UV) Neutrons have 150 T . Nucleons become per charge and field strengths brought to mutual resonance paths up to the right fusion. in the core they continue to circle the nucleons in between. (not the laser electrons) from the projector or LCD screen 😁. They're probably somewhere else. The halogen lamp would probably be 100 times stronger when shined in from the Mono - Laser side? (More like a joke) Cheap LED advertising from China keeps popping up! Of course, the sun doesn't shine like limone when it comes to nuclear fusion on earth. Also, limone light does not increase nuclear fusion on Earth! Cleavage of borisotopes alone and Laser moon light - as nuclear f i s s i o n became the first time in the world ? No No. some disco - jokes either more ! Not light makes ignition , but f u s i o n ignition makes some little light too but more gamma. how media works i will not say . What is imaginative nuclear bomb power and what is good joule ?
The only fusion power plant that will ever be built is already in operation, and it is generating power "today". We named it long ago, using various appellations, but to us, it is called the Sun.
Which intermediate technology is developed to justify such investment when the math shows that is not practical? A collateral technology needs to get out during the endeavor to justify the continuous pursuit of the great goal
Something like a CANDU fission reactor produces far less Tritium than a fusion reactor would use. There would need to be a network of multiple fission reactors for a single fusion power plant, which makes the latter rather pointless.
Nice thorough overview. A couple small corrections - (15:55) in ICF the lasers are so incredibly vast, and the beam diameters so huge, that we actually can't use neodymium doped yttrium lithium fluoride (or yttrium aluminum garnet) crystals for the lasing medium. The Czochralski pull method of growing single pure crystals of the stuff simply maxes out at a few inches in diameter, and in order to keep the beam intensities lower than the intrinsic laser damage threshold of the material while attaining energies of a couple megajoules on target, we need beam diameters of over a foot (60cm) across! And so we are forced to use Nd doped phosphate glass instead, which can be made into practically arbitrarily large slabs then cut to size. It would be nice if we didn't have to do this of course, because glass is a terrible conductor of heat, while single crystals are great at it; but as it is we have to wait hours between shots for everything to cool down uniformly, lest the next shot suffer wavefront distortions from traveling through nonuniformly still warm amplifier Nd:glass.
Also, immediately subsequent to this section you say that "the higher the frequency the deeper into the plasma they penetrate", but I think you meant to say the longer the *wavelength* instead. We like higher frequency in ICF (shorter wavelength) because it selectively heats the ablator shell of the capsule and *doesn't* prematurely heat the electrons in the fuel before maximum compression time, which longer wavelengths do.
The final video section is quite good indeed, and in particular the identification of hydro instabilities as a likely show-stopping problem for General Fusion's lead/lithium alloy hybrid magneto-inertial scheme is most welcome, as I rarely see anyone rightly calling this out. One disagreement with this section though, at the very end you mention that a hypothetical future power reactor would have to take the "still unproven direct drive approach", but in fact I would argue that though we haven't achieved as high yields as the indirect method, this is merely a consequence of NIF's beam arrangement being optimized for hohlraum irradiation in two groups of 96 beams and its inability to currently do symmetric direct drive. The direct drive method is actually much more likely to succeed, all else being equal, and most of us think that NIF would have long since ignited its pellets by now if it were doing direct drive, if for no other reason than simply because hohlraum 351nm UV light to soft x-ray conversion is so utterly abysmal at ~10%; ie. they're throwing away 1.8 megajoules of laser energy entering the target chamber and only actually coupling only 0.2 megajoules into the target implosion merely for the sake of x-ray irradiation uniformity (and weapons configuration similarity)! In reality, the non-uniformity issues of direct drive have long been largely solved with things like distributed phase plates, distributed phase rotators, and spectral smoothing by dispersion.
Well hot diggidy daym! What a high quality comment! Thank you for sharing and taking the time!
@@morkovija you may view more historical documentaries about fusion on my channel if you enjoy this particular kind of masochism....
Thanks for the comment. Totally agree about the over-simplified NIF beamline (explaining even a simple beamline like the actual one at 22:34 would have doubled the length of the video). For some reason, I thought there was a Nd:YLF seed pulse (and even re-recorded that bit as you may hear). I also didn't want to go to deep into things like avoiding a pre-pulse and so on. Maybe I will do a "How Lasers Work" video including very intense lasers.
With regards to the benefits of higher frequency waves, I was alluding to the various absorption processes at or below the plasma frequency. If I recall correctly, very early research used CO2 lasers which just couldn't penetrate deep enough. Isn't that also a problem now, that the hohlraum closes to 1-omega light too early?
I also agree that direct drive ignition should also be easy in principle, but I would urge the same kind of caution as must now be felt for the 2012 Ignition Campaign.
@@ImprobableMatter Oh yeah, I'm pretty sure the seed pulse from the pulse generation room is definitely YLF generated on OMEGA, I think they're using ytterbium doped fibers or something in NIF's master oscillator room...
Ah I see about the frequency thing now, and keeping in mind we're really approaching the edges of my limited knowledge as a mere non-scientist engineer, my understanding was that the longer wavelengths caused unacceptable electron preheat (because of the high e-field? ....I guess?) before the bang time, but I see the energy absorption also scales favorably with frequency...
So you were right about the absorption efficiency relationship to irradiation frequency: Taken from Gordinier et al. 2003: "While carbon dioxide gas lasers can be pulsed and have efficiencies approaching 10%, their wavelength of 10.6 μm is too long for efficient coupling to pellets. The interaction of an electromagnetic wave (laser light) and the ablating plasma at the edge of the pellet can result in total reflection of the incident light at a critical density layer defined as the radial location where the laser light frequency matches the plasma frequency. The plasma frequency is proportional to the square root of the plasma density. Thus, for deep pellet penetration, a high frequency (low wavelength) light source is required. Long-wavelength lasers therefore have a difficult time efficiently coupling to pellets and achieving the compression factors required to initiate a thermonuclear burn."
Yes, caution in this field is obviously in a perpetual deficit, and we should always strive for more of it. Though the recent 1.3 MJ yield shot on NIF last August really did surprise everyone I think. There seemed to be a general resignation among many that the R-T hydro instabilities were underestimated (yet again) for NIF scales, and the cross-beam energy transfer, and the laser plasma interactions.... etc. were going to conspire to prohibit ignition from ever being reached. But now, well...it really seems right around the corner at least for indirect ICF. It'll never result in a power reactor of course, but even being able to achieve ignition in the laboratory at all I believe is going to open up a whole new world of ultrahigh flux neutron experiments, among other things, that make the machine itself a valuable new tool in high energy density science. Thanks much again for your videos, they're really excellent.
@@Muonium1 Do you know what the exact reason behind choosing the hohlraum method over direct drive? Was it purely because it was functional in nuclear tests and they didn't want to dedicate NIF to an as-of-yet-unproven method? There must have been some reason for it, seeing as the physics suggests it is a big bite out of the efficiency.
"I will release a follow-up video about stars that mostly fuse heavier elements such as silicon about a trillion years from now when it becomes relevant." 🤣🤣🤣
The dry humor is great.
I came to the comments to see how many others picked up on that one. God I am so happy to find this channel FINALLY some non dumbed down stuff in an understandable format.
@@TheClumsyFairy I feel the same way. It gets so tiresome clicking on videos about fusion that spend the whole time going "The reactor burns hotter than the sun! Wow how cool is that!" when experimental fusion temperatures hotter than the sun haven't been new since the 60s.
I recommend subscribing to the channel. One might forget to check till then.
surely a sneak peak for special people like us is doable?
This is almost equal to a college lecture about fusion introduction. Love the fact that a little about the aneutronic approach is mentioned too.
Subscribed to make sure I don't miss that video in a trillion years
Okay I admit I was already subscribed
The seriousness with which you said the line at 7:46 really cracked me up
Hey mate, I've recently found your channel, and have just got to say, I'm loving it. You've earnt a subscriber for a long, long time to come. Your subject matter understanding and excellent communication combined with simple informative graphics make your videos a powerhouse of knowledge. Keep up the amazing work :D
Thanks!
Been such a treat finding this channel. I won't say I "understand" it now per se, yet undoubtedly I now know how much I didn't understand. Can't thank you enough for the useful explanations & demos, minus pie in the sky rhetoric. Now if only a similar honest & straightforward take was made toward our current best source for energy. Substituting the hype of one with the removal of fear from the other.
The note about tracking pellets and rapid firing reminds me of the type of work that went into semiconductor manufacturing, the EUV machines needs to fire a drop of tin and lasers to vaporise it incredibly rapidly and in such accuracy to ensure a “constant beam of light” for the production of the chips… it’s insane and I wonder if the knowledge can be shared with the nuclear fusion industry too!
Yes, I've been to workshops where inertial fusion people are talking to, or swap around academic posts with EUV chip fab people.
I think I've read that the Cymer laser used in ASML's EUV machine fires at something like 30 KHz, with a tin droplet being blasted to plasma by a CO2 laser for each pulse. But the power levels are only a few hundred watts, compared with the much higher levels needed for ICF.
@@tristan7216 Yeah, it's quite small vs what is needed here. Tho, I would say it is an ideal technology demonstrator for something bigger!
I do feel like with a lot of modern tech, people forget that there are usually many iterations done before you get to where a "completed" or "presentable" product will be!
It's funny how inertial confinement sounds really fancy and high tech but in practice it's just "put something heavy in the way of the plasma".
Trans lives matter or not 😢😢
Love the dry humour, love the information density!! I just hope I'm opaque enough to not let it all go over my head...
Mate I appreciate the effort you put into the diagraming everything!
All these wacky inertial fusion approaches remind me of the 50kHz laser produced plasma we use for EUV Litho. Thanks for the great video
Great entry to the series. This really is a useful resource for showing the shape of the problems faced by fusion power research to people who are not fusion power researchers (there are a surprising number of those around).
Funny timing with JET's recent nuclear campaign press release a few days ago.
I did read the news about the JET D-T campaign (not in touch with my former colleagues there anymore). I considered doing a text post on here, or a short video about it, but I will probably cover it in the next full video.
@@ImprobableMatter hyped
This channel is great for debunking VC hype and finding out what's really going on - steady progress but no flying fusion cars next year 😸. Thanks.
Presentation was excellent, clear, and detailed with explanation. Thank you for the effort.
I feel like your whole channel is just an argument for appreciating and diverting funds to fission from fusion.
Great video! Waiting for the next on magnetic confinement! Also interested in your take on some of the more unorthodox approaches, like Helion Energies' pulsed FRC tech
Enjoying this series so far. Thank you! Very much looking forward to the next installment. Any news on that?
Glad you enjoyed it. Audio for the next section is recorded and I am animating it, but have been super busy with my day job and other things.
@@ImprobableMatter splendid!
Love your informative and structured videos!
Are you maybe also planning videos about fission or similar topics?
I'm really interested in fusion/fission :D
Can't wait for the next in the series!
It's a shame that the caprice of the all-powerful algorithm throws such high quality videos like this to the dogs, with a mere 2 thousand views, simply due to some fickle lack of a face or red arrow in the thumbnail or somesuch, while some "which phone will survive being run over by my car!!??!?!?" garbage gets a thousandfold more hits in an hour. Oh well, maybe they'll randomly suggest this video to everyone 7 years from now...
From my experience, a video needs to have a "click through rate" of above 10% when it reaches 1600 views to start getting recommended widely (not sure if that 1600 is a magic number in the algorithm or not). Technical videos like this one don't get up to the required rate.
To be fair, I can see why people don't want to watch anything educational on here. People watch RUclips to relax, so drama and negative videos are easier to digest.
Another great video. Question - Why has tritium-tritium fusion got a lower cross-section compared to D-T fusion? I would have thought that the extra neutron would increase the weak nuclear attraction and help them fuse. Any info to help me understand this would be greatly appreciated!
It is true that D-T appears to be the outlier: adding neutrons seems to help all other hydrogen isotopes to fuse. The simple reason is that there is a resonance in forming Helium-5 which boosts up D-T specifically. For a detailed explanation, you can look up Gamow factors and so on.
@@ImprobableMatter Thanks! Looking forward to your next video!
Very interesting video. Does the tritium breeding ground need to be part of the reactor or is there another high efficiency way of producing tritium?
It really does need to. The only other way is with fission reactors like the CANDU, but you would need many fission reactors just to supply a single fusion power plant.
@Improbable Matter Would it be possible to use a particle accelerator, or even a power consuming inertial electrostatic confinement fusion device, to breed Tritium?
I love the series of fusion based videos so far, but I have a question. In the nTte equation, would it be possible to substitute frequency and amplitude with Temperature to make up for the temperatures needed? Something like this: n(ω + A)te. It just feels like getting a plasma that hot is very innefficient to me.
I'm not sure I understand in this case: frequency of what?
@@ImprobableMatter I'm thinking you could replace the temperature with the atomic frequency of the fuel your trying to fuse to 'excite' it and then increase the Amplitude of that frequency to forcefully induce fusion through that excited phase.
P.S. Sorry for my Butchered English structuring. I am a native speaker of the language but when I get excited about something, I tend to use the wrong words to try and explain what I'm thinking.
Edit: In other words, Couldn't we use frequency and amplitude to mimic the properties of temperature by using the atomic frequency of the fuel and increasing the amplitude to make fusion possible?
I would gladly subscribe to a Patreon if it meant more quality content like this. 10/10
I'd pay to have a version of the video without the background sounds. The tinny organ music was driving me crazy.
A version without background music should be available here: www.dailymotion.com/video/x892d47
Weird request but in case you’ve ever watched the podcast “Well There’s your Problem”, you’d make a great guest and you should get in touch with them! If you haven’t seen it, I recommend it highly
Thanks for the suggestion, I have seen them. No idea how to arrange to go on there, though.
I'd watch a nuclear engineering podcast with slides.
You are quite amazing.
Thks for taking the time to explain this geeky subject so-well. However now I'm pessimistic about practical fusion.
I wonder if you were king of all fusion research, ?what practical approaches would you try to make fusion practical?
I think the magnetic approach is more practical in the near-term. Going from 1 shot per day to 1 shot per second is tough; making a tokamak like the ones currently, but slightly larger and with a higher magnetic field seems easier.
Great vid!
Kinda funny but with many star, the Q plasma will be around 100-1000 by the time the star dies, but will be less than 2, and in many cases, much less than 1, after that. gravitational collapse releases a bunch more energy that can't be used for fusion and if it produces a white dwarf, the overall energy spent in the process is on the same order of magnitude as the fusion energy. If it produces a neutron star or black hole, there will be far more energy released by the actual crushing of the star into such a small object than ever gets released by fusion.
Huh, I guess maybe instead of fusion power, we should find a way to generate energy by dropping things into really extreme gravity wells.
A version of this video (and all my other educational ones) without background music is available on my DailyMotion: www.dailymotion.com/video/x892d47
21:11 - the budgeting office wishes for a status report on the KV-2 power plant. How far along are you with training them to shoot ten times a second and would an autoloader help?
8:55 OMG!!! Since when was this known? In the science fiction book "The curents of space" from Isaac Asimov, he talks about how how there are two tipes of fusion, for one of which carbon serves as a catalyst (in the book this results in super novas). On the end of the book he added an addendum later in his life, saying for people not too take his writing about this too seriously, because at the time of writing far less was known about fusion and solar processes. Since I am am pretty sure novas are not caused by this carbon stuff I assumed that this carbon reaction was also wrong. But here it is! In its full beauty! This is hella epic.
The CNO cycle has been known about since the 30s or 40s.
@@ImprobableMatter Wow so it was accurate and not just a lucki guess on his part. Very cool. Thanks for the answer
This is great content. I really wish you wouldn't add background sounds.
Could you please do a video on Runaway Electrons? :)
In magnetic fusion? I mention disruptions in part 3 of this series.
Excellent concise presentation! THANK you for reviewing the math! Question: WHY don't we invest in LFTR technology? It has already been proven to work since the middle of last century, it has far less hazardous waste and some of the by-products are useful for medicine and space flight. Further, LFTR reactors are fail-safe and produce no fissile materials that could be misused. WHY IS NO ONE TALKING about that?
These videos are fantastic, please keep making them.
Wow, this is a very informavie and intersting video. Looking forward to part 3.
What are your thoughts on Helion Energy and their approach. They have recently gotten a lot of attention and billions in investment from VCs.
Watch the first part of this series. Deuterium-Helium3 is a very hard reaction to do. One thing I can say for certain: the reaction releases enough neutrons that a power plant based on their idea would have to be a certified nuclear facility. Logistically difficult.
@@ImprobableMatter I might misunderstand, but I thought their Trena reactor has already been doing D-He3 fusion for over a year during its test run. The next test reactor (Polaris, due date sometime in 2023) is intended to generate larger amounts of He3 and show a proof of concept positive net electricity sometime in 2024. Going to be interesting to see if they actually achieve that.
@@jRoy7 I highly doubt it.
@@jRoy7 doing anything at all for over a year isn't exactly realistic if the net energy required over that time is to lie exclusively in the future...they must've done fusion over a year ago and hopefully do fusion regularly enough, but remember that at any given time, charging capacitor banks is most likely going to preclude them from doing anything even related to fusion instead
Thank you so much
Can you maybe make a video about hb11 energy startup from Australia? It's working on proton boron reaction. They are claiming it becomes possible because of major improvements in laser technology. I just watched some of your videos and in particular about startups being cheeky. Is this hb11 energy startup one of those or do they have some sort of science that backs them up?
Did you watch part 1 of this series? In short, it won't work.
@@ImprobableMatter haha OK. No I have not seen it but I will now. Thanks for the reply.
@@ImprobableMatter I've seen the one that states we won't have fusion by 2040. The central idea being net energy gain is basically worth nothing outside research communities. But the examples in the video were based on other type of fusion. But I guess the same is true for the proton bor reaction because of the low efficiency of lasers.
@@ruffyistderhammer5860 This one: ruclips.net/video/2DzKXN1pcwY/видео.html
Oh yes, sunday gift! Thanks friend!
Maybe there is a little "grit" that could be added to smooth out the larger instabilities in the plasma
Love the channel! Keep at it!
Can you defeat instabilities by measuring the plasma and having a feedback loop?
For inertial fusion, where the times are less than a nanosecond - no. For magnetic fusion, yes for certain ones.
thank you for the video
Amazingly educational
"Keepeing the plasma confined long enough....."
Xrays are rarely ever mentioned when confinement is mentioned. Fusion gives off tremendous amounts of Xrays. Xrays can accelerate electrons and protons to tremendous velocities according to Compton scattering. But electrons are two and three thousand times lighter than D and T so one might expect electrons to be accelerated much easier. They refer to electron volts when talking about Xrays as if they are a voltage source. If a fusion plasma can be somewhat confined by voltages as low as 10,000 volts in a Farnsworth Fusor then the zillions of Xrays and Gamma rays coming from a fusion plasma would be a real problem.
One Xray or Gamma Ray can deliver hundreds or thousands of volts to an electron or proton.
Xrays might also be used for confinement. A book I found in a public library said that Xrays are used to confine the plasma because otherwise a hydrogen bomb would have to be much larger like the first bomb that was many times bigger than the little warheads that they can fit into a cruise missile warhead. One might suspect that if it is in a book at the public library then it is no longer classified. But the author said that when he wrote the book decades ago it was still classified. He went around to hydrogen bomb manufacturing facilities on the public tours that they give and asked a lot of questions. He found out that they made Uranium foils at one factory. He asked a leading question about the foils to the tour guide and the use of uranium foils to reflect Xrays to help confine the bomb plasma. The tour guide suddenly asked him how he found that out because it is classified information. He was just guessing but the tour guide confirmed his suspicion.
If a big sphere of DT was heated at the center by lasers to the point that the plasma began to emit Xrays near the center then the Xrays might be used to confine a small plasma at the center. The concentric convergence of the lasers would tend to generate Xrays with the same convergence. If Xrays accelerate electrons much more easily than ions because of the weight difference, one might suspect that a buildup of negative voltage at the center might be very useful for confining a plasma as in a Farnsworth Fusor.
@ImprobableMatter You said for the laser approach "the input energy is usually DEFINED as beam energy" however, that definition is irrelevant and misleading. The input energy is the total energy into the system which is the 20 MJ of electricity required to produce the laser + the beam energy. Total input energy = 22 MJ and if we consider the 40% loss from the fusion = 20 MJ then we can represent the total energy of the system. The total output = 30 MJ however the total loss = input energy + conversion loss = 20 MJ + 22 MJ = 44 MJ. 44 MJ (input + losses) > 30 MJ (output) so there is no net energy gain. Therefore, it is impossible to have net energy gain from this process without either (1) improving the conversion efficiency of the laser (which is theoretically possible) or (2) improving the thermal conversion efficiency which is impossible. Thus, the only way to get net energy gain from this method is to improve the beam conversion efficiency. Thus the claim by the US Department of net energy gain is false and misleading. The numbers don't lie. Thanks for this series it was very informative
This is not correct. You can get an arbitrarily large amount of fusion energy out so that it exceeds the losses.
Music in the background 8 bit. How much power can a wood pellet make? What is the goal a cup of coffee and a warm meal?
How do we actually get energy out of fusion? Are there more efficient approaches than "make things hot and drive a turbine"?
"Hot things drive a turbine" is the only way. Most of the energy is carried by neutrons, and the only way to extract that is by allowing them to collide with a solid blanket and deposit their energy as heat. Then a turbine is as good as it gets.
@@ImprobableMatter Thanks!
I had seen a video a while ago where the creators claimed that their fusion generator was powered by the expansion of the plasma directly inducing a current in the electromagnets containing it. Which seemed very interesting.
But even if that works, if most of the energy is in the neutrons that seems ridiculously inefficient.
I have seen these kinds of claims for aneutronic fusion, but you can watch the first part of this series to see why that would be very hard to make work.
Can you do a vidio abut what to bild your tokamk out of? How do scientist know that the things they bild the reactor out of wont be canged by the Nutron radiation the plasma gives of?
Will do. Tokamaks video next, then one about materials, neutrons, how to build a reactor and so on.
Could you find a way to use the explosion of a pellet to focus on a secondary pellet?
15:30 So... does that violate the Nuclear Test Ban Treaty? The treaty does not specify a size and it is technically structured like a nuke and could be interpreted as the world's smallest nuke. I'm being sarcastic of course but the thought popped up the first time I heard about what the NIF was doing and how the fuel capsules were structured.
The facility was mostly built for the exact reason of continuing testing without falling foul of that treaty.
"Energy leaks out of the sun as observed on earth during the hours of daylight." - I laughed
People overlook the fact that the sun has a near-infinite amount of energy to generate fusion with: its own gravity
There is no way to achieve such a reaction without emulating this system, and current efforts don't produce as much as they spend trying to artificially create and maintain the pressures and heat. Gravity is the answer.
Interesting that the idea behind repeating ignition in laser fusion is somehow similar to what aslm is doing to creating euv light in chip lithography
Listened to a couple of your videos and now feel thoroughly parasocially bonded now. Looking forward to more of your stuff but gonna have to ration the back catalogue.
I am curious about how fusion works, if a thermonuclear bomb (say 500 megatons) is detonated deep under ocean, since water doesn't compress the resulting hot water plasma would be under immense pressure, would that cause fusion of water plasma? could it cause chain reaction of water up to the water surface?
In short: no.
As you will see from part (1) of this video, Hydrogen itself is less reactive than the Deuterium-Tritium mix in modern bombs by a factor of 10^25 = 1 followed by 25 zeros; it takes an average of 9 billion years for a given Hydrogen atom in the sun to fuse. Deuterium on its own, which is not common, is much more reactive, but still less than a 50:50 D-T mix.
Water does compress when you're dealing with the sorts of pressures described here. It would be squeezed until the electrons are stripped from atoms and it becomes a plasma. However, it would not be compressed or heated nearly enough to achieve the necessary triple product even if you had D-T surrounding the bomb instead of seawater.
@@ImprobableMatterI was very curious about water plasma properties and how much of that water plasma would be fused in such extreme situation when a 500 MT bomb was detonated at ocean floor.
Since deuterium is 0.05% of sea water, would the deuterium and whatever else is in water plasma be easier to fuse than protons? Would deuterium + helium 3 fusion occur?
This part is confusing for me -"However, it would not be compressed or heated nearly enough to achieve the necessary triple product even if you had D-T surrounding the bomb instead of seawater."
If fission reaction can set of fusion in surrounding D-T, why can't first stage fusion be used to start second stage D-T fusion surrounding the first stage? Or D-T fusion is not fist stage, but second or later stage?
I read that in theory it would be possible to endlessly add fusion stages, and only reason it is not practical is because of the size and mass of such a device/bomb.
As you can see from this video, the primary fission explosion must be set off so that the x-rays precisely compress the secondary fusion bomb. If you just let x-rays expand in all directions, the compression would not be enough. In order to add another fusion stage, the device would have to be engineered to cause the x-rays to work in a similar way (not just randomly expanding in all directions).
Now, let's say you replaced the secondary with seawater so that it does indeed reach the density and even temperature necessary. Whenever two Deuterium atoms collide (there is very little Helium 3 in seawater), they might fuse, less frequently than D-T. However, because, Deuterium is uncommon in seawater, only a tiny tiny fraction of the collisions would lead to exactly two Deuterium atoms colliding and then fusing. So a secondary made of seawater would add almost no additional energy.
@@ImprobableMatter I wasn't thinking seawater as secondary, more like quaternary after primary fission that sets of secondary fusion that sets of tertiary fusion, I was just thinking how would one make biggest bomb possible.
When Soviet scientists were making Tsar Bomba in 50s they were worried about setting of a fusion chain reaction, later it was proven to be impossible in the air, I was think what would be the situation deep under water with much higher density and pressure, also no need for chain reactor, adding let's say 50% energy to initial bomb would be a huge improvement
Why can Helium-3 fuse in the Sun at 10-15 million degrees, but ITER needs 600 million degrees, is it the difference in pressure?
Helium-3 will fuse in ITER. It is just that even there the reaction will go too slowly to achieve a net gain in energy.
Has asml helped with confinement fusion? They have figured out how to shoot tin droplets with big lasers for EUV lithography. Based off the insane engineering, holding the semiconductor industry hostage and they are billions making I'm assuming they figured out a lot of the problem.
They have some tangential overlap. I've worked with colleagues who are now in both fields.
"The power of the *sun* is the palm of my hand..."- Doc Ock
Sun's core is assumed to be very dense and hot.
The current solar model suggests the density at the core's outer edge be 20 g/cc, heavier than the uranium, while the hydrogen is in plasma state.
We don't even have an agreed upon phase diagram for hydrogen for such density and temperature, but let's assume it's plasma there.
Then, what prevents the entire core of the sun from imploding and become helium or heavier element instantly?
When hydrogen bomb explodes, it will keep fusion reaction until the pressure/temperature get removed or lowered.
In the solar core, gravity holds the pressure, and more fusion means hotter temperature, so more fusion should lead more and more fusion.
What's acting as a so-called "control rod" in the sun's core, which prevents further fusion reaction?
If you watch the video, you will see that the peak density in the sun is 200 g/cc while inertial fusion reaches up to 900 g/cc (sometimes even greater) as shown at 18:21 in the referenced figure. The temperature is also higher than the center of the sun. The phase diagram, equation of state and so on for hydrogen at even greater extremes than the center of the sun is achieved every day at the National Ignition facility, among other experiments. The state of matter is very well understood.
The temperature and density in the sun is a balanced and stable equilibrium. If the temperature increased, so would the pressure; the plasma would expand until its density dropped; lower density would lower the fusion rate until the temperature dropped back down. The system is therefore self-regulating. This is in contrast to fission reactions which would grow exponentially if the control rods as you put it are not there.
@@ImprobableMatter "The state of matter is very well understood."
-> I don't think they actually "measured" any properties of the "plasma" state when the fusion is taking place. Viscosity, conductivity, impossible to measure.
"If the temperature increased, so would the pressure; the plasma would expand until its density dropped; lower density would lower the fusion rate until the temperature dropped back down."
1. In the Sun, because the gravity is holding the entire core together, if density gets lowered for any reason, the core will expand, temperature lowered, fusion rate lowered, and the density and temperature lowered further, and then the fusion would stop entirely.
2. Instead, if fusion did "ever" take place inside the sun, one helium atom is much smaller than four hydrogen atoms, so the density gets denser, and due to fusion, it's hotter, so more fusion should take place, and denser helium will further make the core more compact, core gets smaller, denser, and hotter, encouraging more and more fusion.
The current solar model is an unstable system, not self regulating stable fusion reactor.
The Sun's core should have become helium or heavier atom almost instantly 4 billion years ago, as soon as fusion started.
Solar fusion is an unstable model. The entire Sun's core is a fusion pallet firmly held by the gravity pressure, no escaping from it.
You are mistaken. Numerous experiments, including the NIF, have directly measured plasma properties at high temperatures and densities.
Your point 1 is logically incorrect: when the temperature is lowered, the pressure will lower and the core will contract again. It is therefore a stable system. Your point 2 is also misinformed, since most of the hydrogen has not yet fused and therefore the effect of having fewer particles is not significant. Will it be in the future? You bet, and models of the late stages of the sun's life take this into account. They agree with astronomical observations of red giants in our galaxy.
Anyway, I am leaving this comment mostly for the benefit of anyone else reading this, not because I hope to change the mind of anyone who believes the Earth is hollow or some other nonsense.
@@ImprobableMatter "They agree with astronomical observations of red giants in our galaxy."
Give me a break. We don't even have an agreement what the calm Jupiter is made of, what state it is in, after sending probes after probes with High Definition Photos.
We don't have real working models for any star, let alone the Sun.
Just check out wikipedia, or any astronomy books, like "Universe" from Smithsonian, p 178, or any astronomy college level text books, and take a look at the cut-away diagram of Jupiter. The "GAS GIANT", has gas layer only at the very top, like the earth or venus. The rest is supposed to be liquid metallic hydrogen, liquid hydrogen, helium rain, and at the core, very small rocky ball. Add them up in density, and try to come up with 1.3 g/cc for the overall density of Jupiter.
Let me help you. The density of liquid metallic hydrogen is 0.7 g/cc. Liquid or solid hydrogens are 0.06 - 0.07 g/cc. The rocky core is less than 1% of the whole volume. How can you average up 0.06 - 0.7 g/cc thing, which is 99% of the volume, and come up with 1.3 g/cc density?
Thus, according to wikipedia, Smithsonian, Gas Giant has definite surface -> "not gas giant".
According to their cutaway views, Jupiter is a hydrogen ball, but the basic math, density, doesn't add up. Self contradicting. aka Wrong.
If you can solve this puzzle, I will pay you $300 USD, Zelle or whatever. So go on.
Oh, and logically, think about this. We don't know what Jupiter is made of... let alone its internal structures.... with all the pictures and videos in details.... But you believe the claim that we know the Sun, its interior, how it makes energy? Furthermore, we know anything about Red giant, Blue giant, white dwarf, the birth of galaxy and the universe?
You must be kidding....
@@ImprobableMatter "Your point 1 is logically incorrect: when the temperature is lowered, the pressure will lower and the core will contract again. It is therefore a stable system. "
Why temperature is lowered? Because fusion rate is lowered? Ok, let's start from there then. You are wrong anyway.
1. Temperature is lowered "SOMEHOW".
2. Fusion slows down.
3. Pressure lowered
4. Core contracts
5. Density increase
6. Temperature increase
7. Fusion occurs more
# 8. 4 hydrogens become 1 helium -> lot mode dense.
9. Core contracts, temperature increase,
10. Pressure decrease by factor of 4 (H -> He) & Pressure increase by factor of temperature (not much change) => net less pressure.
11. More contraction
12. More fusion. -> Go back to #8.
Unstable? You Bet.
Did I get anything wrong here?
If so, tell me where.
Keith Bruckner thought inertial fusion would be easy 50 years ago. Essentially every researcher has underestimated the nonliearity of MHD.
60% thermal to electricity is very very optimistic more like 45 to 50%
True. This was the most optimistic scenario.
I heard it was only 10 year away... 30 years ago.
It seems like a lot of effort for something that might not even work at the end.
Wouldn't doing new nuclear fission reactors be a better way to go.
ahh yes the kv-2 example puts it into perspective
Do you have any thoughts on LFTR?
Dude you are funny 🙏🏻👏😂
Or you could initiate an extremely confined column of lithium dueteride creating a jet of neutrons up through a building turning thousands of tons of steel into dust and making the rest as brittle as glass.... for a short period of time.
You'd just have to build a six cylinder intertial fusion engine for cycle times and then accept a certain amount of duds. Easy peasy!
I have designed an entirely successful fusion power plant. The solution lied in the creation of a z-pinched stellerating spherical tokamak. I am unable to release the full design to the public at this time because a portion of my design may infringe upon currently valid patents, and also because I must complete my prototype power reactor for safety testing. The test bed reactor will have to wait another month though because the primary coil of the reactor is needed by my lawn mower until such time as the grass stops growing - and I also need to get my electricity reconnected. It is frustrating when your local utility blocks the advance of civilization.
Why don't we blow up TNT the same way? And collect the energy. We don't really need fusion.
Everyone got a lithium cross section wake up at Castle Bravo.
Much more pure science work needs to be done by CERN like That done by Peter Higgs.
Coal does not sound so bad now
Okay.
Perhaps with neutrons , which have 150 T and Protons.
Photons have only 0,03 T as UV light.
Light lasers tend not to be inertial fusion lasers at 0.03 Tesla (for momentum-balancing particles with UV)
Neutrons have 150 T . Nucleons become per charge and field strengths
brought to mutual resonance paths up to the right fusion.
in the core they continue to circle the nucleons in between. (not the laser electrons)
from the projector or LCD screen 😁. They're probably somewhere else.
The halogen lamp would probably be 100 times stronger when shined in from the Mono - Laser side?
(More like a joke) Cheap LED advertising from China keeps popping up!
Of course, the sun doesn't shine like limone when it comes to nuclear fusion on earth.
Also, limone light does not increase nuclear fusion on Earth!
Cleavage of borisotopes alone and Laser moon light - as nuclear f i s s i o n became the first time in the world ?
No No. some disco - jokes either more ! Not light makes ignition , but f u s i o n ignition makes some little light too but
more gamma. how media works i will not say . What is imaginative nuclear bomb power and what is good joule ?
ilmango ?
I don't remember subscribing to this...
The only fusion power plant that will ever be built is already in operation, and it is generating power "today". We named it long ago, using various appellations, but to us, it is called the Sun.
Which intermediate technology is developed to justify such investment when the math shows that is not practical?
A collateral technology needs to get out during the endeavor to justify the continuous pursuit of the great goal
Solar energy nuclear fusion renewable energy production and energy efficiency 168000 miles per second earth to sun travelling
how to keep that crazy dancing plasma contained, sounds like a problem for AI
stars are powered by birkland currents, you can see them all over the universe
Lol fusion
Please translate in Bengali language.
God gave us a sun, use it.
Why create a second one?
Sounds like an impractical pain in the ass. 😑
I think so.
21:11 you know your internet memes I see.
Hat's off to you sir.
What if we use a standard nuclear reactor as a source for fusion ?
Something like a CANDU fission reactor produces far less Tritium than a fusion reactor would use. There would need to be a network of multiple fission reactors for a single fusion power plant, which makes the latter rather pointless.