The company is also hiring: https://blog.samaltman.com/helion-needs-you
I do not personally have the ability or knowledge to independently evaluate claims, but the history of "it will never work" for something that does not outright violate the laws of physics as we understand them is notable too.
Interestingly, I am told Helion looked at using their scheme for DT fusion and concluded it would be more expensive than going to advanced fuels, since it would require heat -> electricity conversion in turbines and rotating generators.
Will this still be too expensive to compete with renewables? Quite possibly, but I think it's more than attractive enough to spend the money to find out.
I'm glad Helion seems to have broken into that exponentially increasing mindshare hype phase. It's going to be interesting waiting for Polaris to come online in 2024. It's also going to be interesting see the effect on other fusion efforts. I suspect this is good news for the other FRC competitors (TAE, Princeton Fusion Systems). Possibly it will not be good news for the more staid traditional approaches, like those using tokamaks.
At a more practical level, any device actually producing non trivial amounts of fusion using helium 3 would quickly make the device extremely radioactive from all the high energy protons being produced.
PS: DD fusion produces H3 half the time, it also produces tritium the other half which isn’t generally going to be a waste product it’s going to fuse in the reaction chamber filled with D producing very high enegry neutrons.
It's so strange to see someone use a PR logic process ("optics") to evaluate a technical claim, rather than using physics and engineering.
The advanced fuel cycle and the direct conversion of plasma pressure to energy are connected. The former enables the latter, and the latter is quite clever.
I think it’s fair to apply the “smell test” in this case.
We’ve recently see several high profile collapses of fraudulent companies like Nikola and Theranos that claimed to have miraculous technology breakthroughs.
Nikola claimed to have solve problems in hydrogen synthesis, transportation, fueling, electricity generation, engine miniaturization, and more. They didn’t have a piece of that technological chain and yet made some incredibly bold claims so they could continue inflating the hype around the company and skyrocket its valuation.
I’m not saying Helion is in the same boat as Nikola but it’s fair to be skeptical.
Nikola was always an obvious fraud if you looked at the technology. Tech claims demand tech analysis.
For me the biggest reason to take them seriously is their biggest investor, Sam Altman, believes in them and he's smart and presumably can see the data. Maybe they've conned him - who knows? Still I think they'll do ok.
Commercial success is one of the possible outcomes.™ That's more than I can say for ITER et al.
Why exactly do you think they need to provide public data? They're a company, not academics. They've provided data to their funders, who have also had external experts review the results, including the famous JASON physicists. The result of this got them $500M for Polaris and another $1.7B conditioned on the success of that machine.
My impression of Helion is from when I thought their ideas didn't work. This invariably ended up being because I had some misunderstanding of what they were doing. When I thought of a concern, I would find they had already addressed it. This makes all of the things they're doing ring very true. Maybe it will end up not working, but it's not because of anything obvious.
Your comment about high energy protons is wrong. The fraction of MeV-scale protons that will undergo a nuclear reaction in a target is very small and drops to essentially zero if the material has high atomic number (because the Coulomb barrier is too high). The induced radioactivity from the protons will be negligible in a properly designed system.
About the tritium: the pulse in Helion's design is so short that the tritium nuclei do not have time to thermalize. At the energy they are initially produced the DT fusion cross section is about an order of magnitude smaller. So, most of the T (I'm estimating all but a few percent) will not fuse before the pulse ends. If they have a gas with a low D:3He ratio, DT fusion is suppressed even more. They appear to planning a scheme where there are DD reactors that make 3He, and then D3He reactors that consume it. The latter could be designed with a much more favorable neutron environment.
High energy Neutrons are nasty, the issue with high atomic number shielding is it doesn’t slow them down very well. Sort of like tossing a ping pong ball at a bowling ball it just doesn’t transfer much energy. Even 1% Tritium would be a problem.
Of course neutrons will cause issues, but the point is the very energetic ones could be much less of a problem than in a DT reactor. It might make the difference between replacing the first wall once a year and replacing it once a decade (say). I will add that the cylindrical geometry should make such replacement much easier.
I advise you to study what they've said with an open mind. I believe you'll change your opinion, or at least convince you to reserve judgment.
It’s really the technical details they are providing actually makes them seem more like a scam, if they shared less it might seem more reasonable. But sharing a lot except any relevant numbers while suggesting it’s ready soon screams scam.
For example they need 2 DD reactions to on average produce 1 H3 which means their producing more high energy neutrons than a pure DT design for the same energy. If T is a waste product then they need to do separation etc. At the same time they are also going to have some DT reactions which means they will need basically identical radiation shielding either way.
The idea of extracting energy from magnetic field interactions sounds plausible until you consider all the waste heat that’s being produced. Even if everything worked as described they would still want massive amounts of cooling which is either a problem or another power source. If they had said they are using a mix of both that would be far more believable.
Really, what is your problem here? I get a strong Dunning-Kruger impression from your objections. You think you know more than you do.
Example: your objection to recovery of energy from the magnetic field. This is not hard to understand! They increase the magnetic field to compress the FRC. This heats the particles adiabatically, just like a piston compresses a gas. And JUST LIKE A PISTON, this is a completely reversible process: allowing the FRC to expand again does work on the coil, sustaining its current and allowing energy to be extracted.
Sure, some energy might be recoverable that way but what percentage of energy is extracted and what percentage ends up as waste heat. At a minimum those neurons from DD fusion, and photons from hot plasma etc are’t being recovered. A mere 100 MW device operating at an awe inspiring 90% efficiency would still be producing a 10MW aka a fuck ton of waste heat and I doubt anything close to 90% would be theoretically possible.
Not to mention mechanical stresses etc from such detonations.
The heating part I'd worry about most is photons hitting the inner surface of the fusion chamber. These will be absorbed in a thin surface layer, and since the system is pulsed the instantaneous heating could be quite high. They might have to resort to a liquid layer that's ablated by the thermal pulse. This would eject gas into the chamber, but they're using a pulsed approach anyway so this could be ok, if the pulse is shorter than the time the evaporated gas needs to reach the plasma.
PS: Anyway, to correct a mistake breeding Tritium from D doesn’t produce a neutron the reactions should roughly equal amounts of:
D-D → He3 + n + 3.268 MeV
D-D → T + p + 4.032 MeV
D-He3 → He4 + p + 18.354 MeV (Slightly less due to escaping He3)
Plus some contamination with Tritium resulting
D-T → He4 + n + 17.571 MeVNot waste, but they do want to store it for ~20 years to wait for it to decay into He3.
If someone says they came up with a perpetual motion device you can say they didn’t without actually investigating the device in question.
If you call someone a pedo because you don’t have any evidence their not a pedo and you don’t like them then that’s malicious disregard for the truth.
The bar is very low, you can for example call someone a murder even if they got acquitted at trial.
https://www.reddit.com/r/fusion/comments/zo9831/the_real_eng...
It would take more energy to extract lunar ³He than could be got by fusing it. In principle, input energy could be intermittent solar, but it is still a losing proposition.