11 ms·

The chase for fusion energy

108 points by bpierre 5y ago

Russelfuture 5y ago
I debated for a while if I should post this - but decided I had to. I actually built a working IEC fusion reactor in my basement, back in 2005-2006. I got to "first fusion" on Sept. 25th, 2006, and posted a video of the reactor working, on Youtube. I just checked, and the video is still there. https://www.youtube.com/watch?v=g18xpYXamAs https://www.youtube.com/watch?v=g18xpYXamAs IEC (Inertia Electrostatic Confinement) fusion can be done, with a high-vacuum system, a high-voltage DC supply, and a vacuum-chamber with a high-voltage feed-thru. It is dangerous, but doable, and I believe I had the first working, amateur-built fusion reactor in Canada. One can confirm that fusion is occuring, by using sensitive chemical neutron detectors that workers in nuclear fission plants typically carry. I used BTI (Bubble Technology Inc.) detectors, which look like little test-tubes, and show small bubbles in a gel-like liquid, if exposed to a neutron flux. My reactor was never able to produce more than 10^6 to 10^7 neutrons per second, which is a very weak neutron field. I used a small "lecture bottle" of non-radioactive deuterium (heavy hydrogen gas), and it worked well. I had to construct a deuterium injection system, using some high-vacuum valves, and a gas-feed-thru on one of the vacuum-chamber ports. The vacuum-chamber itself, and the high-vacuum diffusion pump (which used a mechanical vacuum pump, connected to a device which uses hot-oil vapour) and the high-voltage DC power supply, were all sourced from surplus equipment found on eBay, and imported from USA into Canada. The importation of each item was an adventure in itself. One needs to put about 15,000 to 25,000 DC volts negative, on the confinement grid, and the vacuum chamber needs to be evacuated to about 10^-4 torr or better. I estimated the device needed mean-free path length of almost a 1 cm, for the D2 ion circulation, which is a very rarified environment. What is really interesting about fusion, is how difficult it is to make happen. A palladium-wire grid would be better for the spherical confinement grid, but I used stainless steel. (Palladium is expensive, I had no source for it, and I am not Tony Stark...) But the reactor did produce nuclear fusion events, using the D2 gas, and the high-voltage charge on the confinement grid. This technology was first invented and patented by Philo Farnsworth, an American researcher and inventor, who in the 1930's, invented electronic television. He invented the first electronic TV camera - the iconoscope - and fought with Sarnoff at RCA for years over the patent rights for electronic TV. Farnsworth's IEC fusion reactors also worked, but attempts to scale up the technology were not successful. The various attempts at creating commercially viable fusion reactors are interesting. We keep getting close - but nothing that produces a useful level of net energy output, has yet to demonstrated, as far as I know. I sincerely hope some sort of breakthru is possible, at some point. My device - and most of the IEC devices - are able to produce a significant amount of neutrons, and research efforts at the University of Wisconsin, Madison, were able to demonstrate a powerful IEC reactor, which produced an intense neutron flux, sufficient to ablate the walls of the vacuum chamber (the chamber wall looked like swiss-cheese, under electron-microscope examination), so we know this technology is able to produce a serious amount of fusion events. But taking this approach and using it to generate a net-energy output, has not been possible. My device was roughly 1500 watts in, and 1500 watts of heat out, plus maybe one or two extra milliwatts (or maybe a few hundred nanowatts). Not even enough to really measure. I have followed all the various attempts to get some net useful energy out of fusion reactor technology, and I truly hope something becomes possible. We seriously will need this technology, and we are so close to having it. I wish all these researchers - public and private - the very best of luck.
- AtlasBarfed 5y ago
  Are you familiar with LFTR and if so can you indicate why fusion is practically superior to it? Cost, fuel availability, safety, vessel lifetime, etc. LFTR scales down, has working examples (fit in a closet in ORNL) fuel availability: lots of thorium, ignition fuel is a problem though vessel lifetime: lots of caustic stuff in LFTR, but fusion is high temperature and will suffer vessel degradation from neutrons, won't it? Safety: LFTR is meltdown proof due to liquid fuel and plugs, and seems to consume all its nuclear fuel (compared to solid rod). Fusion is "clean" but makes the reactor eventually radioactive? Cost: Fusion is a ???, LFTR is undeveloped, and both will be a decade+ down the road during which solar/wind/battery will get substantially cheaper, moving the goalposts for cost/investment.
- ohiovr 5y ago
  Congrats on your experiement!
rjzzleep 5y ago
Let that sink in for a moment, there are 17 companies doing research on a hugely important topic with only 2.4billion in funding(disclosed). Magic leap alone has burned more money than that. Theranos has burned almost a billion. Elsewhere in the world, people have to scramble to get money to do groundbreaking work and in the US you get thrown after you for knowing the right people. I'm not saying the other places in the world are good places to be. Caring about every penny you spend is definitely not how you want to run a company doing groundbreaking work, but there's definitely a middle ground.
- colechristensen 5y ago
  I mean, depends on how you slice it and what you count, but ITER had an initial budget of 6 billion and updated total cost estimates between 20 and 40 billion dollars or euros. That one fusion project is probably the most expensive human effort since the ISS and its successor is already being planned. Yes there’s a lot of dumb venture capital going around, but there’s also a lot of money going towards trying things beyond searching for the next unicorn tech fad.
  - bpodgursky 5y ago
    I would bet $10,000 that the technology behind the first commercial fusion reactor does not come from ITER.
    - dd444fgdfg 5y ago
      i don't disagree. but there are valuable side effects. like engineering technology learned. a place and economy for physicists to "work". The web came from CERN, think of all the things we got from the moonshot. we get a lot from big science projects if not the end goal.
    - spaetzleesser 5y ago
      I think it will definitely contribute. For example SpaceX also could learn from expensive mistakes like the Space Shuttle . I think it will be the same with ITER.
Turing_Machine 5y ago
PDF version if (like me) you find the animated slide images distracting without actually providing any additional useful information. I only wish this link had been at the top of the article rather than the bottom. https://media.nature.com/original/magazine-assets/d41586-021-03401-w/d41586-021-03401-w.pdf https://media.nature.com/original/magazine-assets/d41586-021...
- neonate 5y ago
  https://archive.md/RLkQ3 https://archive.md/RLkQ3 also works
m0zg 5y ago
We'd have electricity beaming out of our asses by now if we didn't attack Iraq, Afghanistan, and Syria, and instead spent $2T on fusion R&D. And hundreds of thousands civilians would be alive, on top of that.
- leephillips 5y ago
  I don’t see why spending more money would have led to anything other than a more expensive failure. There are fundamental physical reasons why controlled fusion is unlikely to be a practical commercial power source. Nature is not impressed by how big your budget is.
  - m0zg 5y ago
    See Moon landings and the Manhattan project for an example of what unlimited budget and the best brains were able to accomplish in this country between the 40s and 70s. Then it all went way downhill precisely because of this kind of reasoning, utter lack of vision and ambition, and mismanagement. And even if this were an utter and complete failure in the end, it'd have generated priceless knowledge, and hundreds of thousands of Middle Eastern civilians would be alive. No matter how you slice it, this would have been a _way_ better way to spend taxpayer money. That's if it were a failure. If it were a success, we'd end global warming, attach a ginormous rocket booster to the world's economy without dooming the planet, kick the stool from underneath several authoritarian/theocratic regimes, and who knows what else.
    - leephillips 5y ago
      There might have been a choice even better than war or a doomed fusion program: we could have spent the money on improving infrastructure, healthcare, education....
    - wolverine876 5y ago
      Those were intelligently chosen projects; many more were no doubt rejected. Just throwing money at things doesn't work; beyond the obvious cost, there also is opportunity cost: it takes money from other valuable investments. What makes you say that management and vision declined? NASA does incredible things, as does NIH, NSF, etc. > this would have been a _way_ better way to spend taxpayer money. In order to do research, you need freedom, and political and economic stability, and those require militaries - not solely or most importantly, but necessarily. Sometimes militaries will be misused or used inefficiently, but there is no option to just spend all the money elsewhere.
wolverine876 5y ago
> In this respect, advocates of fusion technology say it has many parallels with the space industry. That, too, was once confined to government agencies but is now benefiting from the drive and imagination of nimble (albeit often state-assisted) private enterprise. This is “the SpaceX moment for fusion”, says Mowry ... I don't think that's a good comparison. SpaceX didn't develop ground-breaking firsts like Sputnik and the moon landings; they took something we've done for 50 years and do it more efficiently. Government agencies are the ones with helicopters flying on Mars, who visited Pluto, developed and operate the space telescopes, etc. Fusion energy generation is like the Manhatten Project.
- virgilp 5y ago
  > didn't develop ground-breaking firsts - First full flow staged combustion engine that actually flies - horizontal flight, vertical landing (belly flop) - booster reuse on an orbital class rocket
  - TaylorAlexander 5y ago
    Yeah that was so funny to read that about the company that was the first to demonstrate reusuable boosters!
  - AtlasBarfed 5y ago
    I know this is included in booster reuse, but it demands being emphasized: SpaceX is landing rockets at sea on comically small platforms.
  - edouard-harris 5y ago
    > First full flow staged combustion engine that actually flies Indeed, and I'll observe that the significance of this one is often lost on more casual observers.
    - virgilp 5y ago
      Yeah, and besides, beyond the fact that the claim of "no groundbreaking firsts" was easily falsifiable, I found this one funny: > took something we've done for 50 years and do it more efficiently. One can argue that this is "all" that happened in AI in recent years. We took something that was arguably done before, in some similar way or shape, and made it practical. But this is HUGE. It's not a minor accomplishment! It may very well be harder than doing some prototype for the first time.
hoseja 5y ago
>(albeit often state-assisted) The journo always has to point this out, despite SpaceX simply being the cheapest, best option even for government launches.
ohiovr 5y ago
Lets get to the point, really. The only way magnetic confinement will ever achieve confinement times conducive to technologically useful power output will come from electromagnetic field strengths beyond what we are capable of doing at the present time with bitter superconductor magnets. And should we discover the secret to making this superlative magnetic field, we will need structures capable holding it together without smashing itself to bits. Stronger magnets mean tighter and tighter gyroradii. Every atomic collision pushes the plasma to the edges and there is no magic to stopping it. There is really no such thing as magnetic confinement. The magnetic fields only slow the progression to the walls. It can work if the progression is slow enough. 17 telsa magnets is only a fraction of the strength needed for anything practical. Go for 100 teslas or come back and say it will be another 30 years. Whoever figures out the hypermagnet will be just one step away from producing net fusion that is useful. I'd say divert all attention to that instead of new tokamaks. We know tokamak will work (economically too), if it only had the secret ingredient of unbelievably powerful magnets.
- DennisP 5y ago
  So I assume you're familiar with the scaling laws of tokamak fusion and can show your work? Because here's a presentation by the head of MIT's fusion program, who introduces those scaling laws and concludes that the latest commercially-available superconductors are indeed sufficient for net power, from a reactor of reasonable size and structural strength: https://www.youtube.com/watch?v=KkpqA8yG9T4&t=1370s https://www.youtube.com/watch?v=KkpqA8yG9T4&t=1370s
  - ohiovr 5y ago
    I never saw Lockheeds "show your work" on their proposal for a fictitious reactor that could supply 100 megawatts from a tractor trailer bed. Yet they got billions of dollars of funding for it. If I had a 100 tesla magnet wouldn't that be useful for tokamaks? Because iter's 17 tesla magnet isn't going to lead to a revolution. It is only another iteration over the JET tokamak which barely had success, but enough success to be a viable lead. If the government listened to crackpots like me they could have saved billions of dollars. Its pretty simple really. A charged particle when it slams into another will gyrate in a magnetic field. If that magnetic field is twice as strong, the gyro-radius is half as wide. And the containment vessel would require half the volume. It takes many many strikes to fuse two nuclei. That is why it is necessary to have ultra powerful magnets. Because it might take dozens or hundreds of strikes, each one potentially enlarging the radius of the circulating plasma. Maybe stellerators have an edge but I don't see it with my limited knowledge. But simple brute force ought to get 'the job done'.
ArtWomb 5y ago
Anyone desiring a more rigorous intro to the subject, I recommend the lectures of PPPL Director Steven Cowley. Like listening to James Bond 007 wax poetic about stellerators ;) Getting to a Fusion Pilot Plant https://www.youtube.com/watch?v=35C0BewtfvA https://www.youtube.com/watch?v=35C0BewtfvA
tuatoru 5y ago
How to tell whether fusion-powered electricity is 10 years away:- 1. Lazard has published a (favourable) preliminary levelised cost of energy assessment for it. (2. Which implies that there have been convincing demonstrations.) 3. Fusion companies are spending their time on working with regulators and explaining their systems to investors (manufacturing, construction, operation, decommissioning and disposal), and their money on bringing up core systems and assuring the public that it is safe.
bradleyjg 5y ago
> promises to have commercial reactors ready in the next decade I’ve heard that before. Are we also going to have room temperature superconductors and usable quantum computers?
- ohiovr 5y ago
  Maybe we'll have room temperature superconductors but no promises on how strong the magnets will be developed from it.
  - willis936 5y ago
    If operated at liquid helium temperature: pretty damn strong. You'd be running into issues with materials ripping themselves apart before hitting critical current or critical field.
ohiovr 5y ago
I'll just say this: there is a lot of obvious fraud in fusion energy. Cold or hot, a lot of nonsense gets billions in funding. I doubt steam pistons blasting liquid vortexes will yield anything other than an expensive mess. And I doubt anything that does not depend on magnetic fields far stronger than what we have now will ever lead to fusion energy being more economical than burning whale oil for steam powered electric plants.
- Retric 5y ago
  It’s a mixed bag, but plenty of options are theoretically viable. However, it’s much easier to pull off a scam than build a practical fusion device. Still looking around you can find many seemingly reasonable designs. Using fusion bombs to heat up rock and then extracting energy is completely buildable today, but not currently economically viable. The history of inertial confinement fusion had more to do with validating models of fusion bombs than a realistic energy source, but things have ramped up enough that it’s starting to seem more possible though still unlikely to work any time soon. Outside of that things get odd. Simply firing a fusion bullet scales really well, but runs into serious issues designing the gun. A coil gun in high vacuum might in theory work, but trying to actually build one is another story Piston fusion is quite similar to inertial confinement in theory. Of course it’s a long shot that’s closer to snake oil than a practical design, but high risk reward long shots aren’t scams as long as the team is upfront about what’s going on. Sometimes physics just doesn’t work the way you think it would. Sonoluminescence is one of my go to examples that seems stranger than fiction. PS: A liquid vortex is actually one method for building a blanket for steady state magnetic fusion setup. It solves several real problems, but is mostly about economic viability not achieving break even.
black_13 5y ago
Clean cheap fusion energy would be worst thing for this planet it would allow humans to cover it unfettered.
AtomicOrbital 5y ago
Possibility is energy will be free so challenge is to lean towards ideas and bias solutions who strive for progress independent of energy constraints

108 points by bpierre 5y ago

I debated for a while if I should post this - but decided I had to. I actually built a working IEC fusion reactor in my basement, back in 2005-2006. I got to "first fusion" on Sept. 25th, 2006, and posted a video of the reactor working, on Youtube. I just checked, and the video is still there. https://www.youtube.com/watch?v=g18xpYXamAs https://www.youtube.com/watch?v=g18xpYXamAs IEC (Inertia Electrostatic Confinement) fusion can be done, with a high-vacuum system, a high-voltage DC supply, and a vacuum-chamber with a high-voltage feed-thru. It is dangerous, but doable, and I believe I had the first working, amateur-built fusion reactor in Canada. One can confirm that fusion is occuring, by using sensitive chemical neutron detectors that workers in nuclear fission plants typically carry. I used BTI (Bubble Technology Inc.) detectors, which look like little test-tubes, and show small bubbles in a gel-like liquid, if exposed to a neutron flux. My reactor was never able to produce more than 10^6 to 10^7 neutrons per second, which is a very weak neutron field. I used a small "lecture bottle" of non-radioactive deuterium (heavy hydrogen gas), and it worked well. I had to construct a deuterium injection system, using some high-vacuum valves, and a gas-feed-thru on one of the vacuum-chamber ports. The vacuum-chamber itself, and the high-vacuum diffusion pump (which used a mechanical vacuum pump, connected to a device which uses hot-oil vapour) and the high-voltage DC power supply, were all sourced from surplus equipment found on eBay, and imported from USA into Canada. The importation of each item was an adventure in itself. One needs to put about 15,000 to 25,000 DC volts negative, on the confinement grid, and the vacuum chamber needs to be evacuated to about 10^-4 torr or better. I estimated the device needed mean-free path length of almost a 1 cm, for the D2 ion circulation, which is a very rarified environment. What is really interesting about fusion, is how difficult it is to make happen. A palladium-wire grid would be better for the spherical confinement grid, but I used stainless steel. (Palladium is expensive, I had no source for it, and I am not Tony Stark...) But the reactor did produce nuclear fusion events, using the D2 gas, and the high-voltage charge on the confinement grid. This technology was first invented and patented by Philo Farnsworth, an American researcher and inventor, who in the 1930's, invented electronic television. He invented the first electronic TV camera - the iconoscope - and fought with Sarnoff at RCA for years over the patent rights for electronic TV. Farnsworth's IEC fusion reactors also worked, but attempts to scale up the technology were not successful. The various attempts at creating commercially viable fusion reactors are interesting. We keep getting close - but nothing that produces a useful level of net energy output, has yet to demonstrated, as far as I know. I sincerely hope some sort of breakthru is possible, at some point. My device - and most of the IEC devices - are able to produce a significant amount of neutrons, and research efforts at the University of Wisconsin, Madison, were able to demonstrate a powerful IEC reactor, which produced an intense neutron flux, sufficient to ablate the walls of the vacuum chamber (the chamber wall looked like swiss-cheese, under electron-microscope examination), so we know this technology is able to produce a serious amount of fusion events. But taking this approach and using it to generate a net-energy output, has not been possible. My device was roughly 1500 watts in, and 1500 watts of heat out, plus maybe one or two extra milliwatts (or maybe a few hundred nanowatts). Not even enough to really measure. I have followed all the various attempts to get some net useful energy out of fusion reactor technology, and I truly hope something becomes possible. We seriously will need this technology, and we are so close to having it. I wish all these researchers - public and private - the very best of luck.

AtlasBarfed 5y ago
Are you familiar with LFTR and if so can you indicate why fusion is practically superior to it? Cost, fuel availability, safety, vessel lifetime, etc. LFTR scales down, has working examples (fit in a closet in ORNL) fuel availability: lots of thorium, ignition fuel is a problem though vessel lifetime: lots of caustic stuff in LFTR, but fusion is high temperature and will suffer vessel degradation from neutrons, won't it? Safety: LFTR is meltdown proof due to liquid fuel and plugs, and seems to consume all its nuclear fuel (compared to solid rod). Fusion is "clean" but makes the reactor eventually radioactive? Cost: Fusion is a ???, LFTR is undeveloped, and both will be a decade+ down the road during which solar/wind/battery will get substantially cheaper, moving the goalposts for cost/investment.
ohiovr 5y ago
Congrats on your experiement!

rjzzleep 5y ago

Let that sink in for a moment, there are 17 companies doing research on a hugely important topic with only 2.4billion in funding(disclosed). Magic leap alone has burned more money than that. Theranos has burned almost a billion. Elsewhere in the world, people have to scramble to get money to do groundbreaking work and in the US you get thrown after you for knowing the right people. I'm not saying the other places in the world are good places to be. Caring about every penny you spend is definitely not how you want to run a company doing groundbreaking work, but there's definitely a middle ground.

colechristensen 5y ago
I mean, depends on how you slice it and what you count, but ITER had an initial budget of 6 billion and updated total cost estimates between 20 and 40 billion dollars or euros. That one fusion project is probably the most expensive human effort since the ISS and its successor is already being planned. Yes there’s a lot of dumb venture capital going around, but there’s also a lot of money going towards trying things beyond searching for the next unicorn tech fad.
- bpodgursky 5y ago
  I would bet $10,000 that the technology behind the first commercial fusion reactor does not come from ITER.
  - dd444fgdfg 5y ago
    i don't disagree. but there are valuable side effects. like engineering technology learned. a place and economy for physicists to "work". The web came from CERN, think of all the things we got from the moonshot. we get a lot from big science projects if not the end goal.
  - spaetzleesser 5y ago
    I think it will definitely contribute. For example SpaceX also could learn from expensive mistakes like the Space Shuttle . I think it will be the same with ITER.

Turing_Machine 5y ago

PDF version if (like me) you find the animated slide images distracting without actually providing any additional useful information. I only wish this link had been at the top of the article rather than the bottom. https://media.nature.com/original/magazine-assets/d41586-021-03401-w/d41586-021-03401-w.pdf https://media.nature.com/original/magazine-assets/d41586-021...

neonate 5y ago
https://archive.md/RLkQ3 https://archive.md/RLkQ3 also works

m0zg 5y ago

We'd have electricity beaming out of our asses by now if we didn't attack Iraq, Afghanistan, and Syria, and instead spent $2T on fusion R&D. And hundreds of thousands civilians would be alive, on top of that.

leephillips 5y ago
I don’t see why spending more money would have led to anything other than a more expensive failure. There are fundamental physical reasons why controlled fusion is unlikely to be a practical commercial power source. Nature is not impressed by how big your budget is.
- m0zg 5y ago
  See Moon landings and the Manhattan project for an example of what unlimited budget and the best brains were able to accomplish in this country between the 40s and 70s. Then it all went way downhill precisely because of this kind of reasoning, utter lack of vision and ambition, and mismanagement. And even if this were an utter and complete failure in the end, it'd have generated priceless knowledge, and hundreds of thousands of Middle Eastern civilians would be alive. No matter how you slice it, this would have been a _way_ better way to spend taxpayer money. That's if it were a failure. If it were a success, we'd end global warming, attach a ginormous rocket booster to the world's economy without dooming the planet, kick the stool from underneath several authoritarian/theocratic regimes, and who knows what else.
  - leephillips 5y ago
    There might have been a choice even better than war or a doomed fusion program: we could have spent the money on improving infrastructure, healthcare, education....
  - wolverine876 5y ago
    Those were intelligently chosen projects; many more were no doubt rejected. Just throwing money at things doesn't work; beyond the obvious cost, there also is opportunity cost: it takes money from other valuable investments. What makes you say that management and vision declined? NASA does incredible things, as does NIH, NSF, etc. > this would have been a _way_ better way to spend taxpayer money. In order to do research, you need freedom, and political and economic stability, and those require militaries - not solely or most importantly, but necessarily. Sometimes militaries will be misused or used inefficiently, but there is no option to just spend all the money elsewhere.

wolverine876 5y ago

> In this respect, advocates of fusion technology say it has many parallels with the space industry. That, too, was once confined to government agencies but is now benefiting from the drive and imagination of nimble (albeit often state-assisted) private enterprise. This is “the SpaceX moment for fusion”, says Mowry ... I don't think that's a good comparison. SpaceX didn't develop ground-breaking firsts like Sputnik and the moon landings; they took something we've done for 50 years and do it more efficiently. Government agencies are the ones with helicopters flying on Mars, who visited Pluto, developed and operate the space telescopes, etc. Fusion energy generation is like the Manhatten Project.

virgilp 5y ago
> didn't develop ground-breaking firsts - First full flow staged combustion engine that actually flies - horizontal flight, vertical landing (belly flop) - booster reuse on an orbital class rocket
- TaylorAlexander 5y ago
  Yeah that was so funny to read that about the company that was the first to demonstrate reusuable boosters!
- AtlasBarfed 5y ago
  I know this is included in booster reuse, but it demands being emphasized: SpaceX is landing rockets at sea on comically small platforms.
- edouard-harris 5y ago
  > First full flow staged combustion engine that actually flies Indeed, and I'll observe that the significance of this one is often lost on more casual observers.
  - virgilp 5y ago
    Yeah, and besides, beyond the fact that the claim of "no groundbreaking firsts" was easily falsifiable, I found this one funny: > took something we've done for 50 years and do it more efficiently. One can argue that this is "all" that happened in AI in recent years. We took something that was arguably done before, in some similar way or shape, and made it practical. But this is HUGE. It's not a minor accomplishment! It may very well be harder than doing some prototype for the first time.

hoseja 5y ago

>(albeit often state-assisted) The journo always has to point this out, despite SpaceX simply being the cheapest, best option even for government launches.

ohiovr 5y ago

Lets get to the point, really. The only way magnetic confinement will ever achieve confinement times conducive to technologically useful power output will come from electromagnetic field strengths beyond what we are capable of doing at the present time with bitter superconductor magnets. And should we discover the secret to making this superlative magnetic field, we will need structures capable holding it together without smashing itself to bits. Stronger magnets mean tighter and tighter gyroradii. Every atomic collision pushes the plasma to the edges and there is no magic to stopping it. There is really no such thing as magnetic confinement. The magnetic fields only slow the progression to the walls. It can work if the progression is slow enough. 17 telsa magnets is only a fraction of the strength needed for anything practical. Go for 100 teslas or come back and say it will be another 30 years. Whoever figures out the hypermagnet will be just one step away from producing net fusion that is useful. I'd say divert all attention to that instead of new tokamaks. We know tokamak will work (economically too), if it only had the secret ingredient of unbelievably powerful magnets.

DennisP 5y ago
So I assume you're familiar with the scaling laws of tokamak fusion and can show your work? Because here's a presentation by the head of MIT's fusion program, who introduces those scaling laws and concludes that the latest commercially-available superconductors are indeed sufficient for net power, from a reactor of reasonable size and structural strength: https://www.youtube.com/watch?v=KkpqA8yG9T4&t=1370s https://www.youtube.com/watch?v=KkpqA8yG9T4&t=1370s
- ohiovr 5y ago
  I never saw Lockheeds "show your work" on their proposal for a fictitious reactor that could supply 100 megawatts from a tractor trailer bed. Yet they got billions of dollars of funding for it. If I had a 100 tesla magnet wouldn't that be useful for tokamaks? Because iter's 17 tesla magnet isn't going to lead to a revolution. It is only another iteration over the JET tokamak which barely had success, but enough success to be a viable lead. If the government listened to crackpots like me they could have saved billions of dollars. Its pretty simple really. A charged particle when it slams into another will gyrate in a magnetic field. If that magnetic field is twice as strong, the gyro-radius is half as wide. And the containment vessel would require half the volume. It takes many many strikes to fuse two nuclei. That is why it is necessary to have ultra powerful magnets. Because it might take dozens or hundreds of strikes, each one potentially enlarging the radius of the circulating plasma. Maybe stellerators have an edge but I don't see it with my limited knowledge. But simple brute force ought to get 'the job done'.

ArtWomb 5y ago

Anyone desiring a more rigorous intro to the subject, I recommend the lectures of PPPL Director Steven Cowley. Like listening to James Bond 007 wax poetic about stellerators ;) Getting to a Fusion Pilot Plant https://www.youtube.com/watch?v=35C0BewtfvA https://www.youtube.com/watch?v=35C0BewtfvA

tuatoru 5y ago

How to tell whether fusion-powered electricity is 10 years away:- 1. Lazard has published a (favourable) preliminary levelised cost of energy assessment for it. (2. Which implies that there have been convincing demonstrations.) 3. Fusion companies are spending their time on working with regulators and explaining their systems to investors (manufacturing, construction, operation, decommissioning and disposal), and their money on bringing up core systems and assuring the public that it is safe.

bradleyjg 5y ago

> promises to have commercial reactors ready in the next decade I’ve heard that before. Are we also going to have room temperature superconductors and usable quantum computers?

ohiovr 5y ago
Maybe we'll have room temperature superconductors but no promises on how strong the magnets will be developed from it.
- willis936 5y ago
  If operated at liquid helium temperature: pretty damn strong. You'd be running into issues with materials ripping themselves apart before hitting critical current or critical field.

ohiovr 5y ago

I'll just say this: there is a lot of obvious fraud in fusion energy. Cold or hot, a lot of nonsense gets billions in funding. I doubt steam pistons blasting liquid vortexes will yield anything other than an expensive mess. And I doubt anything that does not depend on magnetic fields far stronger than what we have now will ever lead to fusion energy being more economical than burning whale oil for steam powered electric plants.

Retric 5y ago
It’s a mixed bag, but plenty of options are theoretically viable. However, it’s much easier to pull off a scam than build a practical fusion device. Still looking around you can find many seemingly reasonable designs. Using fusion bombs to heat up rock and then extracting energy is completely buildable today, but not currently economically viable. The history of inertial confinement fusion had more to do with validating models of fusion bombs than a realistic energy source, but things have ramped up enough that it’s starting to seem more possible though still unlikely to work any time soon. Outside of that things get odd. Simply firing a fusion bullet scales really well, but runs into serious issues designing the gun. A coil gun in high vacuum might in theory work, but trying to actually build one is another story Piston fusion is quite similar to inertial confinement in theory. Of course it’s a long shot that’s closer to snake oil than a practical design, but high risk reward long shots aren’t scams as long as the team is upfront about what’s going on. Sometimes physics just doesn’t work the way you think it would. Sonoluminescence is one of my go to examples that seems stranger than fiction. PS: A liquid vortex is actually one method for building a blanket for steady state magnetic fusion setup. It solves several real problems, but is mostly about economic viability not achieving break even.

black_13 5y ago

Clean cheap fusion energy would be worst thing for this planet it would allow humans to cover it unfettered.

AtomicOrbital 5y ago

Possibility is energy will be free so challenge is to lean towards ideas and bias solutions who strive for progress independent of energy constraints