Do they even have the design of an actually working fusion reactor? This seems like a crucial detail that is suspiciously ommitted.
"but said it remains on track to deliver power by 2028" - so casually written! I HIGHLY doubt this.
They've been through a few generations of test machines. They have something called "Polaris". It was supposed to be finished around the end of 2024.[1]
Their own site still talks of it as being under construction.
Discussion on Reddit.[2]
They previously built something called "Trenta".[3] That generates two balls of plasma and fires them at each other. There's no fusion or fusion fuel. It's a test rig for plasma generation and manipulation. That was running two years ago.
"Polaris" is a scale-up of Trenta, with something to fuse, and with energy recovery. It's very unclear how far that project has progressed. If they were getting energy out, that would be big news.
Helion is vague about how that's progressing.
> If they were getting energy out, that would be big news.
That's rather underselling it. If they have a proven, working, commercially viable design for a fusion power plant, they could probably just write a paper about how it works and collect their Nobel prize for physics next year.
I'm ambivalent about whether their design can work but if they were confident in their design and have the necessary funding, a paper and a nobel prize are going to be very far down their priority list.
A Nobel prize is about the best marketing you could ask for. You can raise money in an environment where everyone (quite reasonably) doubts you have goods, or you can raise money in an environment where you’ve earned a Nobel prize for actually inventing the thing you claim you have. If you actually have the thing (at the point where you’re ready to deliver power at scale by 2028) this should not be a huge lift.
Commercially viable means more than getting energy out of it though - it also requires that the build, operation and maintenance costs over the lifetime of the machine don't outweigh the value of the net energy generated. Of course it needs to work on paper before you build it, but this is experimental science and until you have built it you haven't proved it.
No, of course they don't. This is Sam Altman's fusion company, backed by Microsoft in 2023 with a signed power purchase agreement: either Altman has some serious dirt on Satya Nadella, or (more likely!) Satya Nadella is a gullible idiot who thought "Sam Altman is the Boy Genius Who Invented AI, so he can solve fusion too!"
(Remember this is same same Satya Nadella who offered Altman an unspecified CEO-level position after he got fired... while publicly admitting he didn't know why Altman was fired! If I was a MSFT investor I would be pretty upset about this.)
Presumably 2025 MSFT is more sober-minded about Altman. I wonder if they're gonna try to wiggle their way out of the PPA. Otherwise I am truly baffled.
The problem is that the agreement does not seem to specify that the electricity has to come from fusion![1] This is actually common in renewable PPAs - if the specific project doesn't come online then the provider has to find an alternative. But those are usually done with established providers which have > 0MW overall capacity. Helion does not. If the PPA is fixed amount vs fixed price, Microsoft might end up on the hook for inflated wholesale prices instead of cheap fusion.
FWIW I agree with the author of that Data Center Dynamics post, it's quite likely that MSFT and Helion are essentially in cahoots by stoking investors with vaporware. But it also seems like Altman might have sold Nadella 50MW of magic beans.
Investors gets ruined on PPAs all the time. With renewables, there's usually some sort of wind turbine or solar park attached, so after declaring bankrupcy the new owners can settle out of court and continue production.
Here there's realistically no way to continue electricity production so the assets will likely be chopped up and sold, if possible. Nobody owns anyone anything and Microsoft doesn't have to pay a dime. They won't get their power of course, but there's no downside for them.
These types articles where a PPA contract is confused with an investment is really common, mostly for nuclear and renewables, but that doesn't make them any more true. Microsoft hasn't invested anything, likely because they know this is (pardon the pun) hot air.
It is not exactly Altman’s company. It was founded in 2013 by David Kirtley, John Slough, Chris Pihl, and George Votroubek. These three won the ARPA-E competition around then. Altman funded the company more recently and is on the board. But he isn’t a founder or executive there.
>Presumably 2025 MSFT is more sober-minded about Altman.
If nothing else, that, after all the good they had done to him, should do it:
"OpenAi v. Microsoft: Altman ready to sue for unfair competition
...
OpenAI has put a potentially devastating weapon on the table: accusing Microsoft of anti-competitive practices and raising the attention of the Federal Trade Commission. It would be a low blow...
"
I'm not aware of Helion publishing any peer reviewed data claiming a physics breakeven (the point where the total energy generated by the reactor exceeds the external energy fed in to maintain the reaction going); let alone an engineering breakeven (the point where the fission generates about an order of magnitude more energy, to allow for the energy conversion losses, cooling and fuel breeding etc. so as to actually output any useful amount of electricity); let alone an economic breakeven, where the reactor generates sufficient useful energy that its market price can allow the capital and operating costs of the reactor and associated infrastructure to be recovered in a certain number of decades.
If fusion had all three today, it would still e a though sell; fission has them and is still failing economically.
I don't disagree with any of what you say but if Helion's approach works (and that's a huge if) it would generate electricity directly, without need for a steam turbine or any of the associated plumbing. My understanding is that a big part of the cost for fission is the turbine etc.
See "Induction systems"[1] The concept was proposed in 1963, but nobody ever made it work.
That's the plan. Magnetohydrodynamic generators [2] do work, but they have electrodes in the gas. That works for jet engine type MHD generators, but fusion plasma is too hot for any solid material.
What they're trying to do is known physics but very hard engineering.
They're also trying for aneutronic fusion, using helium-3. If the plant generates large volumes of neutrons, it chews up the first wall between the reaction and the outside. It also
makes what it hits radioactive, so there's a waste problem. Aneutronic fusion uses reactions that (mostly) generate alphas and betas. This is, again, known physics but very hard engineering.
If they can get a demo machine going which solves either problem, that would be a huge advance.
So far, that does not seem to have happened.
There are other startups in this space. It's probably the way commercial fusion power will eventually be done. Not via the tokamaks, like ITER.
> There are other startups in this space. It's probably the way commercial fusion power will eventually be done. Not via the tokamaks, like ITER.
There is literally no evidence to suggest this: Helion are making big claims but as noted have shown little incremental progress on their machines.
The balance of history says if it happens it'll come out of a large government funded project: that's how fission happened, and there's plain old fission startups too who also are yet to deliver anything and we know fission works.
I feel very comfortable saying in 5 years Helion won't have anything.
Because HackerNews was soooo confident that a startup style skunkworks initiative would lead to over-unity fusion in 5 years[1]...in 2014.
Then they were soooo confident that MIT was going to blow past ITER to over unity fusion[2] ... in 2020.
It's 2025, and the latter project is still running but now predicting it'll finish it's big reactor post-2030.
Helion are currently now reporting no new results, but claiming they'll hit net-energy in 2028 somehow despite little technical detail. After claiming they'll show net-energy fusion in 2024.[3]
So there's my evidence. Where's your evidence?
It should be noted that I'm not actually against private fusion research - more research is great. But the unfounded confidence with which HackerNews users make predictions of the obvious superiority and success of private industry in achieving fusion has a track record of "we still don't have fusion" despite company's dating back as early to early last decade when we're mid-2020s now.
I like how your mode of argument would have led you to confidently assert SpaceX was going to fail. Please conduct some QA on your logic, mkay?
Who here is "soooo" confident Helion will succeed? One can be excited about a company without thinking they're a sure thing. The world is going to spend maybe a quadrillion dollars on energy in this century, so even low odds bets can be very worthwhile.
Those two HN links there were to stories about companies other than Helion. I agree the DT efforts are dubious.
Helion has been reporting results, btw. Have you been reading? Maybe you're complaining they haven't finished all of the next machine yet? "They didn't snap their fingers to make their machine, therefore they're frauds!" isn't a good look.
> Fusion generates electricity by ramming atoms into each other, releasing energy without emitting significant greenhouse gases or creating large amounts of long-lasting radioactive waste. But despite billions of dollars of investment, scientists and engineers still have not figured out a way to reliably generate more energy with fusion than it takes to create and sustain the reaction.
Helion is still working on how to do that with its current prototype, called Polaris, which is housed in Everett, Washington, where it plans to build components for the machine to be built at Malaga, called Orion.
And Helion has built upon "a ton" of work from predecessors as well.
The quoted argument is basically "it hasn't happened yet, therefore it can't happen". Why does this argument not also apply to SpaceX, for all the things they've been the first to do?
I get that skepticism is warranted, but please don't cross the line into blatant technical nihilism.
https://en.wikipedia.org/wiki/Magnetohydrodynamic_generator is the gist of it. If you have enough conductive plasma then just moving it through a magnetic field generates a current. Applied to fusion power, you heat the plasma through the fusion reaction then divert part of the plasma through the MHD generator.
Tbh, I very much doubt that this is a realistic path in the coming decade (but would love to be proven wrong). AFAIK no experimental reactor has yet generated any net electrical power at all, let alone with any big (ie dozens to hundreds of) MW MHD generators. Getting even one of these aspects working would be a major advance, let alone doing both at once.
> Energy is captured by direct energy conversion that uses the expansion of the plasma to induce a current in the magnetic compression- and acceleration – coils. Separately it translates high-energy fusion products, such as alpha particles directly into a voltage. 3He produced by D–D fusion carries 0.82 MeV of energy. Tritium byproducts carry 1.01 MeV, while the proton produces 3.02 MeV.
> This approach eliminates the need for steam turbines, cooling towers, and their associated energy losses. According to the company, this process also allows the recovery of a significant part of the input energy at a round-trip efficiency of over 95%.
Their system can reversibly compress the plasma by energizing a coil. If the plasma acquires more energy in that time (by fusion producing energetic charged particles), the expansion stroke can return more energy to the capacitors than the compression consumed.
It's the electromagnetic plasma equivalent of a reciprocating internal combustion engine.
... except for the fact that they're claiming 95%+ efficiency in an engine type nobody has ever seen running when actual existing reactors of that type can't seem to make it to 1%, and the two types of engine you can compare this (ICE, steam turbine) have SOTA efficiencies of 35% and 48%. This seems less than realistic.
Then again, this is being done with private funds. So let them, and frankly, I really hope it works. Hell, if they wanted reasonable subsidy for this, I say give it to them.
They have been doing compression and reexpansion on plasmas for a long time. They are claiming high efficiency on energy recovery in these (non-fusion) plasmas. They can also do energy injection and recovery just by pulsing the coils around an empty vacuum chamber (or one filled with nonconductive gas).
There's nothing that should be unbelievable about this claim, and to dispute it would be to assert that they are outright lying. For short timescales where do you expect the energy to be going, if not back to the capacitors? Inductive energy storage on short time scales should be very efficient. Both the coils used and the plasma itself have sufficiently low resistivity. I think the gating technology for this was the switches.
The 1% figure you give there isn't for anything resembling this process, so I don't know why you brought it up except for reasons of obfuscation or your own confusion.
> And how would you "generate electricity directly", specifically?
Using a particle accelerator (decelerator?) in reverse. I'm an investor in Tri-Alpha Energy, and they have tested a direct converter with the claimed 90+% efficiency.
Sure, they aim to extract energy directly from the field, but the three breakeven points are still important. A significant part of the energy will be lost as x rays and neutrons, since their D-H3 fuel cycle is not aneutronic; they will also have significant D-D reactions that are required to breed Tritium which they capture and then let ti decay to Helium-3.
Overall, when you look at the total complexity and energy balance of the full reactor + fueling cycle, maintaining vacuum, keeping superconducting magnets at cryogenic temperatures, tritium extraction etc. then generating an order of magnitude more energy than inserted still seems necessary to achieve engineering breakeven.
In the cycle under question (two DD reactions per D3He reaction), 91% of the fusion energy goes into charged nuclei, not into neutrons. In steady state where T is being allowed to decay into 3He and there's just one DD reaction, the fraction of energy in charged nuclei is even higher.
X-ray emission is strongly dependent on electron temperature. One of the important aspects of Helion's scheme is the electron temperature is much lower than the ion temperature. Not only does this greatly reduce x-ray emission, it reduces plasma pressure at a given ion temperature vs. a plasma where the ions and electrons are in thermal equilibrium, thereby increasing the ion density and fusion rate. The pulses in Helion's scheme end (and the plasma energy is recovered) before the electrons can heat up.
And danger. Turbines are more powerful at high temps, and now you have hot liquids near your reactor. Or you use molten salt as a middleman so the potential steam explosions are a little farther from the reactor.
Well, a dolar is still a dollar and they need to sell on the same energy market. It's well understood that fission projects have become economically infeasible because they are dominated by capital costs, and the risks these projects come with are not compatible with the decades required for economic breakeven.
Everything we know about current approaches to fusion seem to indicate they will have the same economic problems. The scaling factors of confinement, power and reaction rates push towards immense reactors with vacuum chambers the size of apartment buildings, massive superconducting magnets etc. hence the ITER project spiraling out of control trying to build one just big enough that at least have a fair chance of achieving engineering breakeven. The basic plasma physics works the same for Helion, and the best triple product they achieved places them two orders of magnitude behind tokamaks, albeit with much less capital.
So when and if the best approaches to fusion succeed, it looks like they will yield these massive plants that share the costs problems of fission. While they won't be able to meltdown, the regulatory constraints will be very similar, the intense neutron flux will activate the structure of the reactor and poses similar proliferation and decommissioning concerns, there is radiological risk to the civil population in the form of Tritium leaks etc.
And unlike fission, which is very well understood and mature, fusion plants will be much riskier economically, on par with the attempt to introduce fast fission breeders into commercial service, which notoriously failed.
So while the physics is indeed very different, we know enough to compare fusion and fission economically, and the outlook is very bleak.
Why do you think fission plants are expensive? Do you think it's the pumps and turbines and concrete?
Pro tip: it's not. It's because there is millions of man-hours of regulatory burden attached to every decision, to every bolt, to every instrument or valve installed.
There is a reason for all that regulatory burden, of course. It's the release of long lived and deadly radiation from a meltdown. If it wasn't for that regulation building a nuke plant would actually be quite inexpensive, relative to current costs- On the scale of a hydro dam.
Fusion has none of those costs because it has none of the same dangers. It's a wildly different problem with wildly different cost basis. The expensive part is research. Once that's done that cost is gone.
Fission plants are expensive because malfunctions cannot be tolerated. Malfunctions cannot be tolerated because the government would not give them a liability cap if there was a significant chance of serious accident.
Guess what? Fusion reactors also can't tolerate malfunctions. Not because of public safety, but because large (DT reactors being 40x the size of a fission reactor for a given power output) complex devices that are too radioactive for hands on maintenance are unrepairable.
Helion is claiming they can go with materials with very low beyond short term activation, and that the cylindrical geometry would make swapping out hot components easier. Whether that is enough remains to be seen, but IMO DT approaches are complete dead ends.
Solar energy has achieved such a cost reduction that nuclear can't compete even if the actual nuclear reactor part is free. Just the classical, steam turbine parts are becoming more expensive than solar, and this is evident for new natural gas plants, who don't even have any radiation concerns. Sure, fusion energy would be dispatchable, unlike solar, but momentum is building towards large scale interconnections, perhaps even at intercontinental levels, spanning many time-zones and climates and achieving highly reliable solar.
While it's unclear when all this will be achieved, nobody is ready to bet 10 billions that it won't happen in the next two decades they need to recover costs.
I agree solar is very tough to beat, and even more so as storage improves. As I've said before, I consider Helion is the least dubious fusion approach, but that doesn't imply I think their absolute chance of commercial success is high.
One very significant issue with Helion's scheme is the enormous quantity of tritium produced. To put this in context: to power the world with such reactors might require ~10 TW. If using 2DD + D3He, this would produce 12 grams of tritium per second. If this stream were all released into the environment (which it would not be, but this is for purposes of illustration) it would lift all the water in the entire biosphere close to the US legal limit for tritium in drinking water, including all 1.3 billion cubic kilometers in the oceans. Tritium capture and containment will have to be extremely good for this technology to be globally acceptable.
I know some friends who are total believers in llms solving all problems. I keep pointing out the issues you are raising. They just want to believe in magic. They also believe in this WA fusion company, even though it has problems as raised here, never demonstrated a working system really.
I see similar behaviors in people that believe tesla has almost cracked self-driving, just trust them because it will start working "real soon now", and also optimus robots from tesla will take over (but there's no brain for the robot, not even a demo, all the demos were remote controlled but they don't care!).
My experience using them to make OpenSCAD code is marginally better than you may expect from @simonw's pellican-on-a-bike challenge, but only marginally.
I was surprised to see any nuclear power funded in Washington, what with the state’s infinite hydro power and all, but on reflection, it may be a sort of more is more situation - along with existing hydro is tons of electrical and service infrastructure. Interesting to imagine Wenatchee becoming even more of a data center and power hub over the next 10 years.
I have to warn all the reflexive skeptics here: there is a lot going on with this concept that is very clever. Do try to rein in your ignorance-based opinions before you educate yourselves.
As I have learned more about the intricacies of what they're doing I found myself getting SpaceX vibes.
with power hungry AI datacenters popping up like mushrooms after a rain the timing couldn't be better for fusion. I guess VCs see that too. Well, some VCs also paid for that back then https://en.wikipedia.org/wiki/Rotary_Rocket - single stage half-helicopter half-rocket to orbit (and $30M in VC funding 30 years ago were really huge money) - despite 6th grade math.
Discussion on Reddit.[2]
They previously built something called "Trenta".[3] That generates two balls of plasma and fires them at each other. There's no fusion or fusion fuel. It's a test rig for plasma generation and manipulation. That was running two years ago.
"Polaris" is a scale-up of Trenta, with something to fuse, and with energy recovery. It's very unclear how far that project has progressed. If they were getting energy out, that would be big news. Helion is vague about how that's progressing.
[1] https://www.helionenergy.com/polaris/
[2] https://www.reddit.com/r/fusion/comments/1hlojqu/any_news_on...
[3] https://www.youtube.com/watch?v=_bDXXWQxK38
That's rather underselling it. If they have a proven, working, commercially viable design for a fusion power plant, they could probably just write a paper about how it works and collect their Nobel prize for physics next year.
(Remember this is same same Satya Nadella who offered Altman an unspecified CEO-level position after he got fired... while publicly admitting he didn't know why Altman was fired! If I was a MSFT investor I would be pretty upset about this.)
Presumably 2025 MSFT is more sober-minded about Altman. I wonder if they're gonna try to wiggle their way out of the PPA. Otherwise I am truly baffled.
FWIW I agree with the author of that Data Center Dynamics post, it's quite likely that MSFT and Helion are essentially in cahoots by stoking investors with vaporware. But it also seems like Altman might have sold Nadella 50MW of magic beans.
[1] https://www.datacenterdynamics.com/en/opinions/microsoft-and... This is second-hand, the agreement is not public.
Here there's realistically no way to continue electricity production so the assets will likely be chopped up and sold, if possible. Nobody owns anyone anything and Microsoft doesn't have to pay a dime. They won't get their power of course, but there's no downside for them.
These types articles where a PPA contract is confused with an investment is really common, mostly for nuclear and renewables, but that doesn't make them any more true. Microsoft hasn't invested anything, likely because they know this is (pardon the pun) hot air.
Seemed like there was a certain amount of magic thinking about neutron damage but a bit less than fission typically does. Guess we’ll see.
Another option is this was to sweeten the pot during OpenAI negotiations.
If nothing else, that, after all the good they had done to him, should do it:
"OpenAi v. Microsoft: Altman ready to sue for unfair competition
...
OpenAI has put a potentially devastating weapon on the table: accusing Microsoft of anti-competitive practices and raising the attention of the Federal Trade Commission. It would be a low blow... "
https://en.ilsole24ore.com/art/openai-v-microsoft-altman-rea...
If fusion had all three today, it would still e a though sell; fission has them and is still failing economically.
How would that energy generated from nuclear fusion be transformed into electricity "directly"? By which process / series of processes?
What they're trying to do is known physics but very hard engineering.
They're also trying for aneutronic fusion, using helium-3. If the plant generates large volumes of neutrons, it chews up the first wall between the reaction and the outside. It also makes what it hits radioactive, so there's a waste problem. Aneutronic fusion uses reactions that (mostly) generate alphas and betas. This is, again, known physics but very hard engineering.
If they can get a demo machine going which solves either problem, that would be a huge advance. So far, that does not seem to have happened.
There are other startups in this space. It's probably the way commercial fusion power will eventually be done. Not via the tokamaks, like ITER.
[1] https://en.wikipedia.org/wiki/Direct_energy_conversion
[2] https://en.wikipedia.org/wiki/Magnetohydrodynamic_generator
[3] https://spectrum.ieee.org/aneutronic-fusion
There is literally no evidence to suggest this: Helion are making big claims but as noted have shown little incremental progress on their machines.
The balance of history says if it happens it'll come out of a large government funded project: that's how fission happened, and there's plain old fission startups too who also are yet to deliver anything and we know fission works.
Because HackerNews was soooo confident that a startup style skunkworks initiative would lead to over-unity fusion in 5 years[1]...in 2014.
Then they were soooo confident that MIT was going to blow past ITER to over unity fusion[2] ... in 2020.
It's 2025, and the latter project is still running but now predicting it'll finish it's big reactor post-2030.
Helion are currently now reporting no new results, but claiming they'll hit net-energy in 2028 somehow despite little technical detail. After claiming they'll show net-energy fusion in 2024.[3]
So there's my evidence. Where's your evidence?
It should be noted that I'm not actually against private fusion research - more research is great. But the unfounded confidence with which HackerNews users make predictions of the obvious superiority and success of private industry in achieving fusion has a track record of "we still don't have fusion" despite company's dating back as early to early last decade when we're mid-2020s now.
[1] https://news.ycombinator.com/item?id=8458339
[2] https://news.ycombinator.com/item?id=24629828
[3] https://en.wikipedia.org/wiki/Helion_Energy
Who here is "soooo" confident Helion will succeed? One can be excited about a company without thinking they're a sure thing. The world is going to spend maybe a quadrillion dollars on energy in this century, so even low odds bets can be very worthwhile.
Those two HN links there were to stories about companies other than Helion. I agree the DT efforts are dubious.
Helion has been reporting results, btw. Have you been reading? Maybe you're complaining they haven't finished all of the next machine yet? "They didn't snap their fingers to make their machine, therefore they're frauds!" isn't a good look.
https://x.com/helion_energy?lang=en
Also:
> Fusion generates electricity by ramming atoms into each other, releasing energy without emitting significant greenhouse gases or creating large amounts of long-lasting radioactive waste. But despite billions of dollars of investment, scientists and engineers still have not figured out a way to reliably generate more energy with fusion than it takes to create and sustain the reaction. Helion is still working on how to do that with its current prototype, called Polaris, which is housed in Everett, Washington, where it plans to build components for the machine to be built at Malaga, called Orion.
1. https://www.reuters.com/business/energy/helion-energy-starts...
The quoted argument is basically "it hasn't happened yet, therefore it can't happen". Why does this argument not also apply to SpaceX, for all the things they've been the first to do?
I get that skepticism is warranted, but please don't cross the line into blatant technical nihilism.
Tbh, I very much doubt that this is a realistic path in the coming decade (but would love to be proven wrong). AFAIK no experimental reactor has yet generated any net electrical power at all, let alone with any big (ie dozens to hundreds of) MW MHD generators. Getting even one of these aspects working would be a major advance, let alone doing both at once.
> Energy is captured by direct energy conversion that uses the expansion of the plasma to induce a current in the magnetic compression- and acceleration – coils. Separately it translates high-energy fusion products, such as alpha particles directly into a voltage. 3He produced by D–D fusion carries 0.82 MeV of energy. Tritium byproducts carry 1.01 MeV, while the proton produces 3.02 MeV.
> This approach eliminates the need for steam turbines, cooling towers, and their associated energy losses. According to the company, this process also allows the recovery of a significant part of the input energy at a round-trip efficiency of over 95%.
https://en.m.wikipedia.org/wiki/Helion_Energy
I assume their building permit includes plans. Someone should look them up.
It's the electromagnetic plasma equivalent of a reciprocating internal combustion engine.
Then again, this is being done with private funds. So let them, and frankly, I really hope it works. Hell, if they wanted reasonable subsidy for this, I say give it to them.
There's nothing that should be unbelievable about this claim, and to dispute it would be to assert that they are outright lying. For short timescales where do you expect the energy to be going, if not back to the capacitors? Inductive energy storage on short time scales should be very efficient. Both the coils used and the plasma itself have sufficiently low resistivity. I think the gating technology for this was the switches.
The 1% figure you give there isn't for anything resembling this process, so I don't know why you brought it up except for reasons of obfuscation or your own confusion.
Using a particle accelerator (decelerator?) in reverse. I'm an investor in Tri-Alpha Energy, and they have tested a direct converter with the claimed 90+% efficiency.
Overall, when you look at the total complexity and energy balance of the full reactor + fueling cycle, maintaining vacuum, keeping superconducting magnets at cryogenic temperatures, tritium extraction etc. then generating an order of magnitude more energy than inserted still seems necessary to achieve engineering breakeven.
X-ray emission is strongly dependent on electron temperature. One of the important aspects of Helion's scheme is the electron temperature is much lower than the ion temperature. Not only does this greatly reduce x-ray emission, it reduces plasma pressure at a given ion temperature vs. a plasma where the ions and electrons are in thermal equilibrium, thereby increasing the ion density and fusion rate. The pulses in Helion's scheme end (and the plasma energy is recovered) before the electrons can heat up.
Everything we know about current approaches to fusion seem to indicate they will have the same economic problems. The scaling factors of confinement, power and reaction rates push towards immense reactors with vacuum chambers the size of apartment buildings, massive superconducting magnets etc. hence the ITER project spiraling out of control trying to build one just big enough that at least have a fair chance of achieving engineering breakeven. The basic plasma physics works the same for Helion, and the best triple product they achieved places them two orders of magnitude behind tokamaks, albeit with much less capital.
So when and if the best approaches to fusion succeed, it looks like they will yield these massive plants that share the costs problems of fission. While they won't be able to meltdown, the regulatory constraints will be very similar, the intense neutron flux will activate the structure of the reactor and poses similar proliferation and decommissioning concerns, there is radiological risk to the civil population in the form of Tritium leaks etc.
And unlike fission, which is very well understood and mature, fusion plants will be much riskier economically, on par with the attempt to introduce fast fission breeders into commercial service, which notoriously failed.
So while the physics is indeed very different, we know enough to compare fusion and fission economically, and the outlook is very bleak.
Pro tip: it's not. It's because there is millions of man-hours of regulatory burden attached to every decision, to every bolt, to every instrument or valve installed.
There is a reason for all that regulatory burden, of course. It's the release of long lived and deadly radiation from a meltdown. If it wasn't for that regulation building a nuke plant would actually be quite inexpensive, relative to current costs- On the scale of a hydro dam.
Fusion has none of those costs because it has none of the same dangers. It's a wildly different problem with wildly different cost basis. The expensive part is research. Once that's done that cost is gone.
Guess what? Fusion reactors also can't tolerate malfunctions. Not because of public safety, but because large (DT reactors being 40x the size of a fission reactor for a given power output) complex devices that are too radioactive for hands on maintenance are unrepairable.
Helion is claiming they can go with materials with very low beyond short term activation, and that the cylindrical geometry would make swapping out hot components easier. Whether that is enough remains to be seen, but IMO DT approaches are complete dead ends.
While it's unclear when all this will be achieved, nobody is ready to bet 10 billions that it won't happen in the next two decades they need to recover costs.
One very significant issue with Helion's scheme is the enormous quantity of tritium produced. To put this in context: to power the world with such reactors might require ~10 TW. If using 2DD + D3He, this would produce 12 grams of tritium per second. If this stream were all released into the environment (which it would not be, but this is for purposes of illustration) it would lift all the water in the entire biosphere close to the US legal limit for tritium in drinking water, including all 1.3 billion cubic kilometers in the oceans. Tritium capture and containment will have to be extremely good for this technology to be globally acceptable.
Has an LLM ever generated any complex CAD design like this that has been built & worked?
I see similar behaviors in people that believe tesla has almost cracked self-driving, just trust them because it will start working "real soon now", and also optimus robots from tesla will take over (but there's no brain for the robot, not even a demo, all the demos were remote controlled but they don't care!).
> The highest gain as of 2025 of Q = 4.13 yielded 8.6 MJ from 2.08 MJ of laser energy
https://www.pbs.org/video/the-final-barrier-to-nearly-infini...
https://www.youtube.com/watch?v=nAJN1CrJsVE
As I have learned more about the intricacies of what they're doing I found myself getting SpaceX vibes.