Helion hasn't published the triple product results for their latest Trenta reactor, but for the previous Venti they achieved a triple product of ~10^19 keV.s/m^3 at an ion temperature of 2 keV. The Trenta reactor has achieved an ion temperature of 9 keV. For D-T fusion, you need a triple product of about 3x10^21 kev.s/m^3 at 10 keV. For the D-He reaction that helion intends to use, they need to achieve a similar triple product at 50 keV. So it looks like they're still 2-3 orders of magnitude off from where they need to be to achieve ignition. Their neutron production rate is comparable to industrial fusors at ~10^11 n/s, which while useful as neutron sources are nowhere near producing net power. Compare this with tokamaks that have achieved a triple product around 1.5x10^21 keV.s/m^3, or about half of what they need to achieve ignition.
While it's possible that helion has made improvements to ion density and confinement allowing them to achieve a significantly higher triple product and close the gap to power production, I see no reason why a company looking for investment would hide such a result, especially while putting out press releases celebrating other milestones. I doubt they're anywhere near the point where an economical plant could even be considered, though I'd love to be proven wrong.
Something I consider to be a "red flag" in the press releases of any new kind of energy source, power plant, or engine is when they start talking about the potential applications of something fungible like electricity.
E.g.: In the Tech Crunch article linked elsewhere in this discussion there is this quote:
"Helion’s CEO speculates that its first customers may turn out to be data centers"
Do you know what else a 50MW generator could be used for? Anything. Anything that electricity is used for now. Why talk about things we all already know? Why talk about specific applications?
It's like a car company advertising that their new engine could be used to drive to Starbucks to get a coffee.
Once you notice this pattern, you'll see it everywhere in Free Energy / LENR circles...
Eventually a power source can power anything, but choosing good first customers is important. Usually, v1 of the product is expensive and flaky. So you need first customers who are willing to pay extra for the privilege of being early adopters, or for PR value. Data centers seem like a good bet here.
As you get better at mass producing the machines, the cost will come down and you can make money selling power to the grid at much lower prices.
You would buy a few solar panels for your house at a few thousand dollars a pop, but would you buy a 50MW fusion reactor for your house, at the prices they'd be selling at? If not, there's clearly a continuum between you and the person they'll end up selling to first.
They are rightly taking every opportunity to clarify to investors who their potential market would be.
It has to be someone without vested interests in coal supply contracts and therefore the delayed success of your product, with a huge amount of money to throw at energy security, at a large enough scale for it to be worth a big start up cost. You also need someone to go first, because fusion is scary. This is non obvious. It is an essential part of their pitch, and no amount of cringe from people who know what electricity is is worth omitting it.
It isn't as strange as you might think. Electricity isn't perfectly fungible, so new technologies do get deployed to specific use cases.
For example, solar panels got enthusiastic use in very remote areas even when they theoretically were more expensive than a grid connection. Because there was no grid in remote areas, and no population to support one.
Helion is a non-ignition fusion reactor. They aim to avoid the need for ignition by having efficient energy recapture. The website goes into more detail, and the prototypes have demoed this capability.
The lawson criterion is the point at which the plasma is heated by fusion faster than it is cooled by losses. It is a lower threshold than ignition. Even without ignition, you still need to achieve it to produce net power.
Ironically, their efficient method of energy capture actually makes their job harder than for a thermal system where heat losses due to bremsstrahlung and neutron heating are partially recovered; indeed this is the output for a conventional fusion reactor. For helion, only the energy of the plasma is harvested and thus they must exceed breakeven by enough to not just maintain but to heat the plasma by some economically useful amount.
They're not exactly looking for investment, are they? With close connections to investors with deep pockets, in a race to commercialize fusion, it's not exactly surprising that they would keep their cards close to their chest.
IIRC, ITER wont be fully operational until 2035, and will only ever be a research reactor. Even if it can produce net energy (I'm skeptical), it's cost and size are way up there.
Even if Helion is behind the tokamaks, perhaps this play is more about reaching an economically viable reactor design? Not first to fusion, but first to scalable fusion?
Achieving fusion is a necessary step along the road to achieving economically viable fusion. They have a long ways to go before they achieve the easier of the two steps.
>For the D-He reaction that helion intends to use, they need to achieve a similar triple product at 50 keV
The triple product is 16x higher for D-He3.[0] They also need to get D-D reactions going to produce the He3. The triple product for that is 30x the D-T value. (Yeah, you could run the D-D reaction at a loss or at barely-breaking-even I guess).
They're talking about letting the T from the D-D reaction decay to produce more He3. Tritium has a half-life of 12 years, so in steady-state, there is about 20x the annual tritium production sitting in storage. That's a massive amount -- a 1GW D-T reactor would use something like 50kg of T in a year, so that's about 1 tonne of T. (Just getting some rough approximation.) Even if you scale it down to 50 MW, that's still 50kg. It's a major radioactive hazard.
>I see no reason why a company looking for investment would hide such a result
Exactly. Fusion companies tend to trumpet their successes from the rooftop.
So basically it's a low probability win with an extremely big payoff and the added difficulty of a general lack of transparency to the public (but perhaps not to angel or series A/B/C investors), same as any startup investment.
This is the type of investing one (at least me) dreams of doing if you're fortunate enough to get to $B+ in net worth. Sam knows enough people who knows how this tech works to get a read on quality / achievability, and if he gets it right (however challenging/unlikely), it means incredible things. If it doesn't work, whatever -- at least he's shooting at something interesting. And talk about something intellectually interesting to be involved with -- it must be a collection of great minds at this company.
Completely agree with this. This is throwing money at an interesting problem with an incredibly low outcome of success.
Given the amount of public dollars already put into this without success and the amount of money they are going to have too continually pour into this to make it successful it seems like a serious hail mary. Even if they do have the brightest minds working on it. I wish them the greatest success - we need this.
To your point it's an incredibly privileged investing position to be in and to be honest - he can take a lot of the gains he has already had in relatively uninteresting companies that have been successful and hope to something truly remarkable for humanity.
> This is throwing money at an interesting problem with an incredibly low outcome of success.
But an incredibly high return if successful. Nuclear fission (edit... accidentally wrote fusion here), if we can figure it out, is potentially the golden ticket to reducing our carbon footprint. Unlike geothermal energy, it can be done anywhere. Unlike wind or solar, it can be done at any time. It doesn't have the safety issues associated with fusion, nor does it generate waste products nearly as hard to deal with.
Right now, carbon emissions breakdown in the US are broken down by:
Transportation - 29%
Electricity production - 25%
Industry - 23%
Commercial and Residential - 13%
Agriculture - 10%
Land use and forestry - 12%
By moving to fusion, you can all but eliminate fossil fuel usage in the first two (and largest) categories. You can knock a large chunk out of the next two categories, where much of the emissions is due to burning fossil fuels for energy (heating, etc.). You'll still have emissions from agriculture and land use, but you can clamp down on most emissions in a big way.
If you can figure out fusion and get it working on an industrial scale level on par with other forms of electricity production (which is a big if), then you'll have achieved a monumental technological leap and you'll make a lot of money while at it.
Why d'you think? Helion has been super successful with their demos so far. The timelines are optimistic but I don't see why you'd expect the technology itself to fail with, say, >80% probability.
I have been thinking a lot about this. I wish I could invest my paltry funds into climate-focused ventures as part of a crowd of like-minded small-scale investors. So I am investing in things like renewable energy ETFs. But my impression (correct me if I’m wrong) is that I am investing in companies deploying proven technologies, rather than moonshots. I want to invest in moonshots, given the fact that I think we need moonshots in order for human civilization to survive. But a) I would need significant funds to do so, and b) realistically, I wouldn’t be able to evaluate those moonshots for technical and economic feasibility. It is a discouraging realization.
I spend a lot of time thinking about this as well as someone who has worked in climate tech for > decade and am currently looking to deploy capital. It's quite tough.
1. Impossible to get anywhere close to good investing rounds. And deal flow requires serious capital on any meaningful technology (sorry carbon accounting software doesn't move the needle, needed but it isn't a game changer).
2. Investing in companies in the market as an equity holder. It feels like it doens't actually help the company - there's an argument that it helps the industry as there is more money/attention/talent attraction. Seems like a poor investment for myself given the P/E ratios on most of the companies.
3. Investing in actual projects - small returns but meaningful results. You don't get the outsized returns on companies growing quickly.
4. I do believe the success of humanity in the climate tech space is actually not through moon shots but a constant deployment of ready tech (read solar, ESS, wind, etc) and getting our politicians to probably signal the value proposition that climate tech brings. I do think moon shots have a place and we should bet on them.
I am open to ideas on how to help and new models if anyone has any!
For us, I think the sweet spot is a little riskier than renewable energy ETF's but a lot less risky than a fusion moonshot.
If electricity gets just a little cheaper (and it's fairly obvious that it will), then Power-to-Gas technology becomes viable, and could displace fossil fuels quite rapidly.
I'm looking into it. Email in profile if you're interested.
No comment on this technology but only commenting on the thought process that Sam or any of these “intellectual billionaires” are right about complex scientific problems because they know enough people who know how this tech works is not valid. The people who circle billionaires have a huge conflict of interest to convince them to fork over billions, and they know people like Sam are smart enough that you can’t lie to them. So they do (subconsciously often) what George Costanza said which is believe in the lie themselves. So yeah don’t trust experts If they’re looking at you for a cheque (even if they themselves won’t directly get the check).
It seems like this would be a great place for a prediction market. Anonymously aggregate the information of people who know enough that they are prepared to lay money on the line. Replace the conflicts of interest with a direct interest in profiting from being right.
Completely agree. More abundant clean power, combined with the eventual takeover of Graphene in the battery sector (dramatically increases power density, recharge time and reduces weight) and I believe we will have a path to significantly decrease global emissions.
When we get to the point of putting Graphene batteries in planes than can fully recharge in the time it takes to unload and reload passengers/luggage it’s going to be pretty incredible.
Aircraft will probably adopt LH2, instead, carried in tanks slung under the wings, like the engines. Or maybe with very thick wings. The LH2 will be made on the spot at the airport from power drawn from high-tension power lines to wind & solar farms.
Once the hydrogen-powered aircraft start flying, kerosene-powered craft will find it impossible to compete.
This! I'm not positive on nuclear fission reactors because I don't think they are robust against the climate challenges we face. Too much bad waste that requires functioning societies to maintain. However, fusion doesn't seem to have these problems. I'm hopeful something comes out of it and the world moves fast.
Main thing I wanted to say is that we all love to shit on how Silicon Valley has basically gotten rich off investing in websites and SaaS products over the past ~15 years, areas which the Internet has provided a natural monopoly to the winner but haven't really been the type of "societal innovation" we've been craving. This, however, is obviously different, and if it works (a huge if), would be on par with the transistor in terms of societal effects. Kudos to Sam for swinging big.
I mostly didn't follow the talk about confinement, but I am slightly concerned about neutron activation. He3 fusion is more "neutron-light" than it is completely aneutronic. Operating at reasonable power levels, the reactor is going to be fairly radioactive after a few years. Widespread adoption of fusion is going to require the general public to be more relaxed about low level radioactive waste than they historically have been.
The quotes about total system efficiency is also odd. "95% efficient"? They're not planning on capturing heat energy, so neutron heating is totally wasted, and they're talking about using entirely resistive 12 tesla magnets, which will also throw off a lot of heat.
> Main thing I wanted to say is that we all love to shit on how Silicon Valley has basically gotten rich off investing in websites and SaaS products over the past ~15 years
500 years ago, these people would've chased Jewish financiers out of strongly catholic areas, or shit on Dutch merchants getting rich in the spice trade.
When it comes to human nature, things don't really change.
Positive View - "In 2021, the firm announced that its 7th prototype, Trenta had reached 100 million degrees C after a 16-month test cycle with more than 10,000 pulses. Magnetic compression fields exceeded 10 Tesla, ion temperatures surpassed 8 keV, and electron temperatures exceeded 1 keV.[16][17] Helion's seventh-generation prototype, "Polaris" is under development and is expected to be completed in 2023.[18] It will increase the pulse rate from one pulse every 10 minutes to one pulse per second for short periods.[19] The Polaris facility will economically produce helium-3 on a commercial scale."
Criticism - "Retired Princeton Plasma Physics Laboratory researcher Dr. Daniel Jassby mentioned Helion Energy in a letter included in the American Physical Society newsletter Physics & Society (April, 2019) as being among fusion start-ups allegedly practicing "voodoo fusion" rather than legitimate science. He noted that the company is one of several that has continually claimed "power in 5 to 10 years, but almost all have apparently never produced a single D-D fusion reaction".[24] However, the Helion team published peer-reviewed research into its colliding FRC system demonstrating D-D neutron production as early as 2011,[11] and further detailed D-D fusion experiments producing neutrons in an October 2018 report at the United States Department of Energy's ARPA-E's annual ALPHA program meeting.[25] According to the independent JASON review team,[26] VENTI, a sub-scale prototype Helion had developed partially for the ALPHA program, achieved initial results of 8·1022 ions/m3, 4·10-5 seconds confinement time and a temperature of 2 keV for a triple product of 6.4·1018keV·s/m3 in 2018."
I went looking for more information about their technology, and found the top thread on this reddit post from a few days ago interesting. It's a debate between two people involved in the field about whether or not Helion's approach appears to be viable:
fizzix_is_fun does a really good job laying out flaws in the reasoning that Elmar puts forward. The remarkable thing is that it's not just Elmar -- the Helion website seems to be the source of some them.
I wish there was a good summary article of all the mainstream and alternative fusion approaches out there, like ITER, (SP-)ARC, General Fusion, Wendelstein 7X, etc.
It's interesting that they do direct electricity capture instead of the usual heat -> steam -> turbine approach. They also seem to be loaded with patents around this. I totally see why this investment might make sense and hope it works out.
Direct conversion geometry was worked out a long time ago. The patents aren't very useful because the plasma temperatures that make aneutronic fusion attainable are far out of reach. If you can't demonstrate D+T then you have no hope for D+D or p+B11.
Everything is still either magnetic- or inertial confinement-based, right?
And within those there are the variety of designs.
I hate to say it, but a tiny part of me doesn't discount the possibility of energy majors subtley killing small-scale fusion approaches and pushing internation-scale huge projects (i.e. ones unlikely to be delivered quickly).
> Everything is still either magnetic- or inertial confinement-based, right?
Pretty much, but there are some that are kinda-sorta both (General Fusion's approach is "magneto-inertial"), and also a lot of variety within each bucket. Like, Zap Energy's approach is magnetic, but involves no external magnets, whereas developing the fancy magnets is a key operational challenge for CFS.
I read Arthur Turrell's "The Star Builders": https://www.simonandschuster.com/books/The-Star-Builders/Art... a few months ago, and it gives a decent overview of many of the players and approaches, with the caveat that I don't think it talks about FRC reactors at all (what this and TAE are) at all from what I remember, probably because I think many people in the "mainstream" academic/government fusion community seem to not think it's a particularly serious contender.
The general sense that I get (as a purely amateur observer but one who reads a fair bit about the various efforts) is that pretty much everyone thinks ITER will reach a decently high Q, but that it will take forever and be incredibly expensive, and that beyond that, of the people that think any of the startups have a chance (which seems to be a minority among fusion people but a decently big one), there's the most consensus around the potential of the high-field tokamak startups (so that's CFS/(SP)ARC and Tokamak Energy), because the physics is basically the same as with ITER, except facilitated by the much higher-strength fields allowed for by high-temperature-superconductor magnets; there are engineering challenges there still, but it seems like if the physics underlying ITER are sound and the magnets work (which has at this point been demonstrated as a stand-alone thing), the math all adds up. Stellarators (Wendelstein etc.) seem like the next-highest consensus: people seem to think the physics is sound, but it's less far along. Beyond that, other things seem to fall into one of: "the physics basis seems fine but the economics seem questionable" (probably most inertial approaches), "this has been considered at length and many believe this is physically impossible, but it'd be amazing if they're wrong" (TAE, arguably General Fusion, possibly also Helion), or "it'd be incredible if it works and physics doesn't forbid it but it's wildly novel and nobody really knows yet if it has legs" (things like Zap Energy's shear-stabilized Z-pinch plan).
The overarching tldr is that it seems like the approaches that the most people think will work also have some of the most significant operational challenges if they do (breeding tritium, dealing with high neutron flux, etc.), which is why anybody is bothering with the quirkier approaches: if they work, they will probably ultimately work better than the tokamaks do, but they might not work.
Using the plasma's pressure on the containing magnetic field to induce a current (rather than heating water in order to use steam to run a turbine, as is currently what we do with fission) is pretty damn clever, and might lead to smaller reactors and lower costs - I really hope this works out.
I'm curious though, what happens to the plasma before the next pulse - in the animations it neatly dissipates, but I doubt it's that simple.
The big issue with other fusion reactor designs is how to make sure this incredibly hot plasma doesn't touch and melt any part of the reactor. Current designs try to "levitate" and contain the plasma with a magnetic field, but it's really, really difficult to successfully contain something as energetic and chaotic as plasma. I'm guessing part of the point of the pulses here is to answer the problem of "we can't contain it for long" with "we don't have to".
The field-reversed-configuration (FRC) creates a somewhat-stable moving donut of plasma that doesn't need to be "contained" per-se. The configuration of the plasma induces a magnetic field, tightening the donut as it moves.
TAE is exploring static FRC which has instabilities over longer timescales. Helion uses a pulsed approach which means they don't need to worry about these long-term stabilities and can simply optimize for peak power in non-equilibrium systems.
Over the years, many fusion designs have been shut down due to losses at equilibrium. It seems that Helion avoids these factors altogether by having a non-equilibrium system.
Readit News
While it's possible that helion has made improvements to ion density and confinement allowing them to achieve a significantly higher triple product and close the gap to power production, I see no reason why a company looking for investment would hide such a result, especially while putting out press releases celebrating other milestones. I doubt they're anywhere near the point where an economical plant could even be considered, though I'd love to be proven wrong.
E.g.: In the Tech Crunch article linked elsewhere in this discussion there is this quote:
"Helion’s CEO speculates that its first customers may turn out to be data centers"
Do you know what else a 50MW generator could be used for? Anything. Anything that electricity is used for now. Why talk about things we all already know? Why talk about specific applications?
It's like a car company advertising that their new engine could be used to drive to Starbucks to get a coffee.
Once you notice this pattern, you'll see it everywhere in Free Energy / LENR circles...
As you get better at mass producing the machines, the cost will come down and you can make money selling power to the grid at much lower prices.
They are rightly taking every opportunity to clarify to investors who their potential market would be.
It has to be someone without vested interests in coal supply contracts and therefore the delayed success of your product, with a huge amount of money to throw at energy security, at a large enough scale for it to be worth a big start up cost. You also need someone to go first, because fusion is scary. This is non obvious. It is an essential part of their pitch, and no amount of cringe from people who know what electricity is is worth omitting it.
For example, solar panels got enthusiastic use in very remote areas even when they theoretically were more expensive than a grid connection. Because there was no grid in remote areas, and no population to support one.
Deleted Comment
Ironically, their efficient method of energy capture actually makes their job harder than for a thermal system where heat losses due to bremsstrahlung and neutron heating are partially recovered; indeed this is the output for a conventional fusion reactor. For helion, only the energy of the plasma is harvested and thus they must exceed breakeven by enough to not just maintain but to heat the plasma by some economically useful amount.
What exactly would they gain from keeping this particular card close to their chest?
Even if Helion is behind the tokamaks, perhaps this play is more about reaching an economically viable reactor design? Not first to fusion, but first to scalable fusion?
The triple product is 16x higher for D-He3.[0] They also need to get D-D reactions going to produce the He3. The triple product for that is 30x the D-T value. (Yeah, you could run the D-D reaction at a loss or at barely-breaking-even I guess).
They're talking about letting the T from the D-D reaction decay to produce more He3. Tritium has a half-life of 12 years, so in steady-state, there is about 20x the annual tritium production sitting in storage. That's a massive amount -- a 1GW D-T reactor would use something like 50kg of T in a year, so that's about 1 tonne of T. (Just getting some rough approximation.) Even if you scale it down to 50 MW, that's still 50kg. It's a major radioactive hazard.
>I see no reason why a company looking for investment would hide such a result
Exactly. Fusion companies tend to trumpet their successes from the rooftop.
[0] https://en.wikipedia.org/wiki/Nuclear_fusion#Neutronicity,_c...
Given the amount of public dollars already put into this without success and the amount of money they are going to have too continually pour into this to make it successful it seems like a serious hail mary. Even if they do have the brightest minds working on it. I wish them the greatest success - we need this.
To your point it's an incredibly privileged investing position to be in and to be honest - he can take a lot of the gains he has already had in relatively uninteresting companies that have been successful and hope to something truly remarkable for humanity.
But an incredibly high return if successful. Nuclear fission (edit... accidentally wrote fusion here), if we can figure it out, is potentially the golden ticket to reducing our carbon footprint. Unlike geothermal energy, it can be done anywhere. Unlike wind or solar, it can be done at any time. It doesn't have the safety issues associated with fusion, nor does it generate waste products nearly as hard to deal with.
Right now, carbon emissions breakdown in the US are broken down by:
Transportation - 29% Electricity production - 25% Industry - 23% Commercial and Residential - 13% Agriculture - 10% Land use and forestry - 12%
By moving to fusion, you can all but eliminate fossil fuel usage in the first two (and largest) categories. You can knock a large chunk out of the next two categories, where much of the emissions is due to burning fossil fuels for energy (heating, etc.). You'll still have emissions from agriculture and land use, but you can clamp down on most emissions in a big way.
If you can figure out fusion and get it working on an industrial scale level on par with other forms of electricity production (which is a big if), then you'll have achieved a monumental technological leap and you'll make a lot of money while at it.
Why d'you think? Helion has been super successful with their demos so far. The timelines are optimistic but I don't see why you'd expect the technology itself to fail with, say, >80% probability.
1. Impossible to get anywhere close to good investing rounds. And deal flow requires serious capital on any meaningful technology (sorry carbon accounting software doesn't move the needle, needed but it isn't a game changer).
2. Investing in companies in the market as an equity holder. It feels like it doens't actually help the company - there's an argument that it helps the industry as there is more money/attention/talent attraction. Seems like a poor investment for myself given the P/E ratios on most of the companies.
3. Investing in actual projects - small returns but meaningful results. You don't get the outsized returns on companies growing quickly.
4. I do believe the success of humanity in the climate tech space is actually not through moon shots but a constant deployment of ready tech (read solar, ESS, wind, etc) and getting our politicians to probably signal the value proposition that climate tech brings. I do think moon shots have a place and we should bet on them.
I am open to ideas on how to help and new models if anyone has any!
edit for formatting
If electricity gets just a little cheaper (and it's fairly obvious that it will), then Power-to-Gas technology becomes viable, and could displace fossil fuels quite rapidly.
I'm looking into it. Email in profile if you're interested.
When we get to the point of putting Graphene batteries in planes than can fully recharge in the time it takes to unload and reload passengers/luggage it’s going to be pretty incredible.
Once the hydrogen-powered aircraft start flying, kerosene-powered craft will find it impossible to compete.
Dead Comment
Main thing I wanted to say is that we all love to shit on how Silicon Valley has basically gotten rich off investing in websites and SaaS products over the past ~15 years, areas which the Internet has provided a natural monopoly to the winner but haven't really been the type of "societal innovation" we've been craving. This, however, is obviously different, and if it works (a huge if), would be on par with the transistor in terms of societal effects. Kudos to Sam for swinging big.
The quotes about total system efficiency is also odd. "95% efficient"? They're not planning on capturing heat energy, so neutron heating is totally wasted, and they're talking about using entirely resistive 12 tesla magnets, which will also throw off a lot of heat.
- Fusion reactors are an order of magnitude physically larger than fission reactors,
- The particle energies are an order of magnitude higher than fission, resulting in much nastier activation
and that results in orders of magnitude more highly radioactive waste.
500 years ago, these people would've chased Jewish financiers out of strongly catholic areas, or shit on Dutch merchants getting rich in the spice trade.
When it comes to human nature, things don't really change.
Also I think you mean "Catholic", not "catholic".
Criticism - "Retired Princeton Plasma Physics Laboratory researcher Dr. Daniel Jassby mentioned Helion Energy in a letter included in the American Physical Society newsletter Physics & Society (April, 2019) as being among fusion start-ups allegedly practicing "voodoo fusion" rather than legitimate science. He noted that the company is one of several that has continually claimed "power in 5 to 10 years, but almost all have apparently never produced a single D-D fusion reaction".[24] However, the Helion team published peer-reviewed research into its colliding FRC system demonstrating D-D neutron production as early as 2011,[11] and further detailed D-D fusion experiments producing neutrons in an October 2018 report at the United States Department of Energy's ARPA-E's annual ALPHA program meeting.[25] According to the independent JASON review team,[26] VENTI, a sub-scale prototype Helion had developed partially for the ALPHA program, achieved initial results of 8·1022 ions/m3, 4·10-5 seconds confinement time and a temperature of 2 keV for a triple product of 6.4·1018keV·s/m3 in 2018."
https://en.wikipedia.org/wiki/Helion_Energy
https://old.reddit.com/r/fusion/comments/qkvzjs/fusion_energ...
I wish there was a good summary article of all the mainstream and alternative fusion approaches out there, like ITER, (SP-)ARC, General Fusion, Wendelstein 7X, etc.
In a sense, them patenting it so early is sort of a public good =)
And within those there are the variety of designs.
I hate to say it, but a tiny part of me doesn't discount the possibility of energy majors subtley killing small-scale fusion approaches and pushing internation-scale huge projects (i.e. ones unlikely to be delivered quickly).
Pretty much, but there are some that are kinda-sorta both (General Fusion's approach is "magneto-inertial"), and also a lot of variety within each bucket. Like, Zap Energy's approach is magnetic, but involves no external magnets, whereas developing the fancy magnets is a key operational challenge for CFS.
The general sense that I get (as a purely amateur observer but one who reads a fair bit about the various efforts) is that pretty much everyone thinks ITER will reach a decently high Q, but that it will take forever and be incredibly expensive, and that beyond that, of the people that think any of the startups have a chance (which seems to be a minority among fusion people but a decently big one), there's the most consensus around the potential of the high-field tokamak startups (so that's CFS/(SP)ARC and Tokamak Energy), because the physics is basically the same as with ITER, except facilitated by the much higher-strength fields allowed for by high-temperature-superconductor magnets; there are engineering challenges there still, but it seems like if the physics underlying ITER are sound and the magnets work (which has at this point been demonstrated as a stand-alone thing), the math all adds up. Stellarators (Wendelstein etc.) seem like the next-highest consensus: people seem to think the physics is sound, but it's less far along. Beyond that, other things seem to fall into one of: "the physics basis seems fine but the economics seem questionable" (probably most inertial approaches), "this has been considered at length and many believe this is physically impossible, but it'd be amazing if they're wrong" (TAE, arguably General Fusion, possibly also Helion), or "it'd be incredible if it works and physics doesn't forbid it but it's wildly novel and nobody really knows yet if it has legs" (things like Zap Energy's shear-stabilized Z-pinch plan).
The overarching tldr is that it seems like the approaches that the most people think will work also have some of the most significant operational challenges if they do (breeding tritium, dealing with high neutron flux, etc.), which is why anybody is bothering with the quirkier approaches: if they work, they will probably ultimately work better than the tokamaks do, but they might not work.
I'm curious though, what happens to the plasma before the next pulse - in the animations it neatly dissipates, but I doubt it's that simple.
The big issue with other fusion reactor designs is how to make sure this incredibly hot plasma doesn't touch and melt any part of the reactor. Current designs try to "levitate" and contain the plasma with a magnetic field, but it's really, really difficult to successfully contain something as energetic and chaotic as plasma. I'm guessing part of the point of the pulses here is to answer the problem of "we can't contain it for long" with "we don't have to".
TAE is exploring static FRC which has instabilities over longer timescales. Helion uses a pulsed approach which means they don't need to worry about these long-term stabilities and can simply optimize for peak power in non-equilibrium systems.
Over the years, many fusion designs have been shut down due to losses at equilibrium. It seems that Helion avoids these factors altogether by having a non-equilibrium system.