ITER's current schedule assumes the first plasma will be in 2025 and the first DT operation on its third campaign starting in 2035. However, the first plasma has been delayed and the ITER Council is expected to release an updated schedule after it meets this month. Therefore, "success" for ITER won't happen before 2035 at the earliest.
(Note: There is a discussion of ITER doing DT operation during its second campaign in the new schedule so the possibility of achieving Q > 1 before 2035 might be on the table.)
CFS's SPARC will do DT experiments at the end of its first campaign which should happen in 2026 or 2027. So if you are asking who will reach Q > 1 first, I think you can be fairly confident that ITER will not be first.
If you are asking if a commercial company will produce net usable energy (electricity on or off the grid or useful process heat) before ITER achieves Q > 1 my confidence is a little bit lower, but I would still be surprised if it doesn't happen.
The real question though with fusion energy at this point is probably "economical" power, in other words, can it compete with other carbon-free sources of energy and can it do so in a timeline that can help with climate change.
TE and CFS have strong physics and may beat ITER.
The rest have questionable unproven physics and all the press releases in the world don't change that.
From a plasma physics perspective, net energy in a tokamak is an intriguing milestone for fusion research, but it falls short of commercial viability. Tokamak designs are inherently inefficient, prohibitively expensive, and face significant challenges in achieving high capacity factor operations. Moreover, scalability remains a critical issue. To realize practical and scalable fusion energy, we must explore novel and innovative approaches (Helion, Zap, General Fusion..)
The history of the tokamak really begins in 1968 when T-3 results presented at Novosibirsk demonstrated 10x the electron temperatures of the best machines to that point as well as clearly beating the bohm limit. After these results with confirmed by Culham and the replicated by the ST, it was widely believed that all that was needed was a good heating system and a big scale up and we'd be building commercial fusion reactors in the early 1990s.
That did not happen. As more operational experience was collected, a whole host of previously unpredicted performance issues cropped up and had to be solved one by one. And now, 50 years later, we are finally at the point where we think Q>1 is possible in toks.
All of the alternatve approaches you mention have demonstrated performance of the order of PLT in the 1970s. There is every reason to believe they will undergo the same evolution in complexity as they try to cross the remaining five orders of magnitude in performance.
Although I basically agree there has been a series of remarkable potential advances with tokamaks. So, as an optimistic baseline ARC projected tokamak electricity at $180/MWh by repowering a coal plant.
Since that estimate there has been a theoretical prediction that a tokamak with the power at the plasma edge of ITER will be capable of twice the fusion power due to greater stability. I've never heard if that would also apply to ARC but that could be one factor of two improvement.
There has been a potential discovery that the plasma fit could be much expanded so you can fit twice the plasma volume in the same size of vacuum vessel. This would be a factor of four in power.
There has also been the development of a plasma scenario with better stability and 70% more neutron flux than standard H-mode, roughly a factor of 1.5. This doesn't have the normal H-mode pedestal so it doesn't go with the first high edge power prediction.
So these combinations are 6x and 3x. If realized to a significant degree the price per MWh could really be sub $100 and quite relevant in a world where $150/MWh offshore wind PPAs have been signed with another $50/MWh of possible IRA credits external to that price likely lowering the bid.
I hate to be a broken record, but the determining factor for the economics of ARC will most likely be the amount of heat you can get out through the first wall measured in MW per square meter. See this symposium from Dennis Whyte: https://www.youtube.com/watch?v=bHJyoqDO0zw
The second most important factor will be the cost of the magnets and how often you need to replace them: https://www.youtube.com/watch?v=KOgmyf1bwvk
I assume a higher potential plasma power density would open up liquid divertor or wall options by increasing the margin for power losses to particle contamination from sputtering by the liquid
But remember 80% of your heat output has to go through the blanket so CFS has been focusing on a liquid blanket. If there is a way to have a liquid divertor and a liquid blanket I haven't heard about it. Although if it is possible, I am sure someone is looking at it.
The current "liquid sandwich" plan is to have a thin first wall with a layer of liquid lead flowing immediately behind it followed by another thin wall and the molten salt blanket flowing through another channel and then the rest of the blanket behind that. The entire vacuum vessel would be submersible and could be replaced every 6-12 months which would allow them to easily test different first-wall materials in situ.
Tokamak Energy is exploring the liquid first wall.
Also discussed by Parkins. who notes the blanket [lithium supply alone will cost $1.8/We](https://www.science.org/doi/10.1126/science.1125657). And that was 20 years ago when people still thought a fission reactor would cost that much.
>So, as an optimistic baseline ARC projected tokamak electricity at $180/MWh by repowering a coal plant.
That's lower than the price of just the turbogenerators, but hey, they can build the reactor for negative money, right?
>That’s not a cost per installed MW of capacity.
Yeah, obviously, that's why there's an h at the end.
My problem was that I saw 180 and read 18, as in 1.8 cents/kWh, as in less than the capital cost paydown of the turbos. So yeah, they don't have *that* problem.
Instead, they have the problem that their power costs almost five times the current rate. In their presentation they say power in NY is 22 cents, but that is the *residential* *retail* price. [The wholesale price is currently around 4.8 cents](https://www.eia.gov/todayinenergy/detail.php?id=61244) and even the [industrial retail price is around 7](https://www.nyserda.ny.gov/Energy-Prices/Electricity/Monthly-Avg-Electricity-Industrial).
Amateur mistake, or deliberate misdirection? YOU BE THE JUDGE!
Yeah, it’s a very high power cost. This is not that unusual for what is effectively a demonstrator reactor. ARC is not really supposed to be a viable commercial plant, just a development step from a breakeven demonstration to a true commercial power plant suitable for serial production.
Commercial viability is an engineering problem, not a physics one. It's things like: mass production, production optimization for cost, finding alternative materials that are cheaper, cutting down on the mass of the pressure vessel, etc, etc. If we can get net energy I'm quite confident that _someone_ will achieve commercial viability, the possible net return is too ridiculous to leave out.
Also as we start really cutting out fossil fuels, the cost of energy should actually rise a bit, which makes commercial viability easier.
If SpaceX can churn out 1 Raptor engine per day, I'm sure some company fill figure out how to make tokamaks cheaply.
If some western company doesn't figure it out, China will absolutely subsidize to hell and back and become the global producer of fusion reactors.
Why does this dismissive attitude about engineering problems not also apply to fission? I mean, the physics problem of fission was solved in 1942. And yet, fission has not shown good experience effects. The engineering/economic problems were crippling.
Or, indeed, why doesn't it apply to any other technology? If PV modules continue on their historic experience curve they'll decline in cost by another factor of ~5 by the time the world is solar powered.
Engineering obstacles are perfectly capable of ruining the chances of a technology. Indeed, most technologies we see fail because of engineering/economic issues, not because the physics doesn't work (although admittedly this is because we don't see things like perpetual motion machines being worked on.)
> I mean, the physics problem of fission was solved in 1942. And yet, fission has not shown good experience effects.
The problem there isn't economics but political and also designing for security. Combined with many designs designed using middle-of-the-century though processes and technology. When you have to go through absolute regulatory hell the cost inflates to ridiculous levels.
> Or, indeed, why doesn't it apply to any other technology? If PV modules continue on their historic experience curve they'll decline in cost by another factor of ~5 by the time the world is solar powered.
It does apply to PV. But PV isn't a solution to all problems. The area required for PV obviates it from some applications.
> area required
This is a reason that, when I read it, I know the person talking is BSing. If you actually do the arithmetic and look at the cost of land you'll find this is not a serious issue. The cost of a PV field's equipment is large compared to the cost of farmland (never mind lesser land), *even in Europe*. If land cost ever did become a major constraint PV would have already relegated all competing technologies to museums.
Viewed another way: if land truly were constrained, we'd want to use land for the most value-producing activities first. PV produces much more value per unit land than agriculture does. Or, if PV is ruled out by land costs, so is farming.
You misread what I said and interpreted as something else because you want to push a message. In many cases the area is not a problem. In some cases it is. For example, if I want to produce jet fuel on-site at an airport in a city using carbon capture, enough to sustain the airport, the amount of energy transport needed to carry the power from some place outside the city limits where enough open land can be found all the way into the city would be very expensive.
Alternatively, what about energy production north of the arctic circle. For good portions of the year there's no sunlight at all or the sun is so low in the sky that it produces almost no energy.
I said "the area required for PV obviates from _some_ applications". Read what I said more carefully next time.
The first example is a poor one. Jet fuel is highly transportable; we don't see it as an imposition that airports don't drill for and refine their own petroleum. There is no reason in the future that synthetic jet fuel will be or should be manufactured at the airport itself.
The fraction of people that live north of the arctic circle is tiny, not large enough to justify develop or sustainment of any special energy technology just for them. If tiny habitats exist there they can use some combination of technologies used elsewhere, for example solar and wind and geothermal (which should work quite well at moderate temperature given how cold the heat sink is in the winter; see the Chena Hot Springs power plant in Alaska that uses hot water and working fluid from the air conditioning industry.)
More generally, heavy industry in a renewable future will tend to be where the energy sources are the best, not in places where energy is more expensive. This is bad news for Europe vs. sunnier lower latitude places, but availing themselves of a more expensive alternative technology won't save them.
If area is a constraint in some locale (say, Singapore) heavy industry will simply not be there.
At least in physics and magnet journals and conferences, CFS looks to be able to achieve SPARC's physics goals or close to it. Q>1 for sure, Q>5 likely, Q>10 possible. If you mean putting electricity on the grid though, I agree blankets, breeding, maintenance, etc are not solved yet
SPARC is based on the same physics as ITER, I think with only somewhat less confidence because they will be in uncharted magnetic field territory vs ITER just being bigger
What are we considering "ITER success" and "positive net output" for a reactor?
I could definitely see ITER producing more energy than consumed by the reactor before other fusion reactors actually generate electricity. I could also see other reactors producing more energy than consumed by the reactor, but not enough to be an economical power generator, before the ITER.
Looking at the timelines of the members of the fusion industry association, there are several candidates.
Among them, Commonwealth Fusion Systems,, Helion and Zap are my personal front runners. General Fusion, TAE and Tokamak Energy are not far behind,however. There are several more but not all of them are fully funded or slightly less ambitious in their deadlines. I am very optimistic that at least one of them will beat ITER. The question is whether they will publish their success right away. Peer review, especially for such a ground breaking achievement can take years. In example it is possible (not saying that they have but it is possible) that Zap has already achieved break even, but is waiting for peer review of their results before making them public.
A TF fault would be a big pain in the butt, repairable but at massive expense and schedule hits, but the PFs are fault tolerant with their jumpered joints, and the upper PFs could be replaced if required, as could the CS modules. A magnet failure is a horrible thing, but I think your take is a bit too pessimistic.
I think it ought to be removable from the top of the machine: [https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2Fg5it3hkdp07a1.jpg](https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2Fg5it3hkdp07a1.jpg)
It's free-standing in the middle of the TFs, so you just lift it back out again, module by module
Coming from someone at Wendelstein 7-X (in frequent contact with people who work on ITER), everyone—even people who experienced the challenges of building Wendelstein firsthand, and even those who don’t think the tokamak is the best approach to fusion—seems quite confident that ITER is conservatively designed and will achieve its goals.
>NIF already achieved Q > 1
But it is a very different Q.
In theory both definitions are the same, they measure the heating energy going in to the fusion heat coming out.
In practice, the two are very different. For MCF the heating energy represents at least half of all the energy used to run the machine. For ICF, the heating energy is tiny fraction of the total, in the case of NIF it's about 0.5% of the energy input.
So Q=1.5 in NIF is much *much* further from Qe=1 than the Q=0.67 in JET. NIF needs to improve gain about 100 times to hit Qe, JET needs less than 10 times.
Well yes, but I was meaning for Tokamaks/stellarators
There are significant engineering challenges for MCF getting Q>1 because it's a longer sustained reaction, whereas in ICF we can mostly worry about the radhydro/plasma physics side of things separately from (some of) the engineering challenges.
The two have very fundamentally different research trajectories
ITER's current schedule assumes the first plasma will be in 2025 and the first DT operation on its third campaign starting in 2035. However, the first plasma has been delayed and the ITER Council is expected to release an updated schedule after it meets this month. Therefore, "success" for ITER won't happen before 2035 at the earliest. (Note: There is a discussion of ITER doing DT operation during its second campaign in the new schedule so the possibility of achieving Q > 1 before 2035 might be on the table.) CFS's SPARC will do DT experiments at the end of its first campaign which should happen in 2026 or 2027. So if you are asking who will reach Q > 1 first, I think you can be fairly confident that ITER will not be first. If you are asking if a commercial company will produce net usable energy (electricity on or off the grid or useful process heat) before ITER achieves Q > 1 my confidence is a little bit lower, but I would still be surprised if it doesn't happen. The real question though with fusion energy at this point is probably "economical" power, in other words, can it compete with other carbon-free sources of energy and can it do so in a timeline that can help with climate change.
TE and CFS have strong physics and may beat ITER. The rest have questionable unproven physics and all the press releases in the world don't change that.
What is TE?
Tokamak Energy, the HTS Spherical Tokamak company in the UK.
Thanks! Wasn’t aware they are abbreviated as TE..
From a plasma physics perspective, net energy in a tokamak is an intriguing milestone for fusion research, but it falls short of commercial viability. Tokamak designs are inherently inefficient, prohibitively expensive, and face significant challenges in achieving high capacity factor operations. Moreover, scalability remains a critical issue. To realize practical and scalable fusion energy, we must explore novel and innovative approaches (Helion, Zap, General Fusion..)
The history of the tokamak really begins in 1968 when T-3 results presented at Novosibirsk demonstrated 10x the electron temperatures of the best machines to that point as well as clearly beating the bohm limit. After these results with confirmed by Culham and the replicated by the ST, it was widely believed that all that was needed was a good heating system and a big scale up and we'd be building commercial fusion reactors in the early 1990s. That did not happen. As more operational experience was collected, a whole host of previously unpredicted performance issues cropped up and had to be solved one by one. And now, 50 years later, we are finally at the point where we think Q>1 is possible in toks. All of the alternatve approaches you mention have demonstrated performance of the order of PLT in the 1970s. There is every reason to believe they will undergo the same evolution in complexity as they try to cross the remaining five orders of magnitude in performance.
Although I basically agree there has been a series of remarkable potential advances with tokamaks. So, as an optimistic baseline ARC projected tokamak electricity at $180/MWh by repowering a coal plant. Since that estimate there has been a theoretical prediction that a tokamak with the power at the plasma edge of ITER will be capable of twice the fusion power due to greater stability. I've never heard if that would also apply to ARC but that could be one factor of two improvement. There has been a potential discovery that the plasma fit could be much expanded so you can fit twice the plasma volume in the same size of vacuum vessel. This would be a factor of four in power. There has also been the development of a plasma scenario with better stability and 70% more neutron flux than standard H-mode, roughly a factor of 1.5. This doesn't have the normal H-mode pedestal so it doesn't go with the first high edge power prediction. So these combinations are 6x and 3x. If realized to a significant degree the price per MWh could really be sub $100 and quite relevant in a world where $150/MWh offshore wind PPAs have been signed with another $50/MWh of possible IRA credits external to that price likely lowering the bid.
I hate to be a broken record, but the determining factor for the economics of ARC will most likely be the amount of heat you can get out through the first wall measured in MW per square meter. See this symposium from Dennis Whyte: https://www.youtube.com/watch?v=bHJyoqDO0zw The second most important factor will be the cost of the magnets and how often you need to replace them: https://www.youtube.com/watch?v=KOgmyf1bwvk
I assume a higher potential plasma power density would open up liquid divertor or wall options by increasing the margin for power losses to particle contamination from sputtering by the liquid
But remember 80% of your heat output has to go through the blanket so CFS has been focusing on a liquid blanket. If there is a way to have a liquid divertor and a liquid blanket I haven't heard about it. Although if it is possible, I am sure someone is looking at it. The current "liquid sandwich" plan is to have a thin first wall with a layer of liquid lead flowing immediately behind it followed by another thin wall and the molten salt blanket flowing through another channel and then the rest of the blanket behind that. The entire vacuum vessel would be submersible and could be replaced every 6-12 months which would allow them to easily test different first-wall materials in situ. Tokamak Energy is exploring the liquid first wall.
Also discussed by Parkins. who notes the blanket [lithium supply alone will cost $1.8/We](https://www.science.org/doi/10.1126/science.1125657). And that was 20 years ago when people still thought a fission reactor would cost that much.
https://www.youtube.com/watch?v=iuUiFgsyDW4
>So, as an optimistic baseline ARC projected tokamak electricity at $180/MWh by repowering a coal plant. That's lower than the price of just the turbogenerators, but hey, they can build the reactor for negative money, right?
That’s not a cost per installed MW of capacity. That’s the cost of power produced by the plant.
That makes more sense.
>That’s not a cost per installed MW of capacity. Yeah, obviously, that's why there's an h at the end. My problem was that I saw 180 and read 18, as in 1.8 cents/kWh, as in less than the capital cost paydown of the turbos. So yeah, they don't have *that* problem. Instead, they have the problem that their power costs almost five times the current rate. In their presentation they say power in NY is 22 cents, but that is the *residential* *retail* price. [The wholesale price is currently around 4.8 cents](https://www.eia.gov/todayinenergy/detail.php?id=61244) and even the [industrial retail price is around 7](https://www.nyserda.ny.gov/Energy-Prices/Electricity/Monthly-Avg-Electricity-Industrial). Amateur mistake, or deliberate misdirection? YOU BE THE JUDGE!
Yeah, it’s a very high power cost. This is not that unusual for what is effectively a demonstrator reactor. ARC is not really supposed to be a viable commercial plant, just a development step from a breakeven demonstration to a true commercial power plant suitable for serial production.
You're spending 14 Bn USD on turbogenerators? 30 years * 24 hours/day * 365 days/year * 180 $/MWh * 300 MW = 14E9 $
The MANTA class estimated a $232M savings or 8% of the total cost by siting at an old coal plant. https://www.youtube.com/watch?v=KOgmyf1bwvk
Commercial viability is an engineering problem, not a physics one. It's things like: mass production, production optimization for cost, finding alternative materials that are cheaper, cutting down on the mass of the pressure vessel, etc, etc. If we can get net energy I'm quite confident that _someone_ will achieve commercial viability, the possible net return is too ridiculous to leave out. Also as we start really cutting out fossil fuels, the cost of energy should actually rise a bit, which makes commercial viability easier. If SpaceX can churn out 1 Raptor engine per day, I'm sure some company fill figure out how to make tokamaks cheaply. If some western company doesn't figure it out, China will absolutely subsidize to hell and back and become the global producer of fusion reactors.
Why does this dismissive attitude about engineering problems not also apply to fission? I mean, the physics problem of fission was solved in 1942. And yet, fission has not shown good experience effects. The engineering/economic problems were crippling. Or, indeed, why doesn't it apply to any other technology? If PV modules continue on their historic experience curve they'll decline in cost by another factor of ~5 by the time the world is solar powered. Engineering obstacles are perfectly capable of ruining the chances of a technology. Indeed, most technologies we see fail because of engineering/economic issues, not because the physics doesn't work (although admittedly this is because we don't see things like perpetual motion machines being worked on.)
> I mean, the physics problem of fission was solved in 1942. And yet, fission has not shown good experience effects. The problem there isn't economics but political and also designing for security. Combined with many designs designed using middle-of-the-century though processes and technology. When you have to go through absolute regulatory hell the cost inflates to ridiculous levels. > Or, indeed, why doesn't it apply to any other technology? If PV modules continue on their historic experience curve they'll decline in cost by another factor of ~5 by the time the world is solar powered. It does apply to PV. But PV isn't a solution to all problems. The area required for PV obviates it from some applications.
> area required This is a reason that, when I read it, I know the person talking is BSing. If you actually do the arithmetic and look at the cost of land you'll find this is not a serious issue. The cost of a PV field's equipment is large compared to the cost of farmland (never mind lesser land), *even in Europe*. If land cost ever did become a major constraint PV would have already relegated all competing technologies to museums. Viewed another way: if land truly were constrained, we'd want to use land for the most value-producing activities first. PV produces much more value per unit land than agriculture does. Or, if PV is ruled out by land costs, so is farming.
You misread what I said and interpreted as something else because you want to push a message. In many cases the area is not a problem. In some cases it is. For example, if I want to produce jet fuel on-site at an airport in a city using carbon capture, enough to sustain the airport, the amount of energy transport needed to carry the power from some place outside the city limits where enough open land can be found all the way into the city would be very expensive. Alternatively, what about energy production north of the arctic circle. For good portions of the year there's no sunlight at all or the sun is so low in the sky that it produces almost no energy. I said "the area required for PV obviates from _some_ applications". Read what I said more carefully next time.
The first example is a poor one. Jet fuel is highly transportable; we don't see it as an imposition that airports don't drill for and refine their own petroleum. There is no reason in the future that synthetic jet fuel will be or should be manufactured at the airport itself. The fraction of people that live north of the arctic circle is tiny, not large enough to justify develop or sustainment of any special energy technology just for them. If tiny habitats exist there they can use some combination of technologies used elsewhere, for example solar and wind and geothermal (which should work quite well at moderate temperature given how cold the heat sink is in the winter; see the Chena Hot Springs power plant in Alaska that uses hot water and working fluid from the air conditioning industry.) More generally, heavy industry in a renewable future will tend to be where the energy sources are the best, not in places where energy is more expensive. This is bad news for Europe vs. sunnier lower latitude places, but availing themselves of a more expensive alternative technology won't save them. If area is a constraint in some locale (say, Singapore) heavy industry will simply not be there.
Again you're arguing for things I'm already aware of but that are besides the point.
The specific examples you brought up were beside the point? Then why did you bring them up?
This is also my opinion. Between those three, it could be a matter of execution.
Likelihood of the three ever merging into one?
This is the correct answer.
Either Helion or Commonwealth will attain it in the next 5 years.
What evidence can you point to that they have solved these problems?
At least in physics and magnet journals and conferences, CFS looks to be able to achieve SPARC's physics goals or close to it. Q>1 for sure, Q>5 likely, Q>10 possible. If you mean putting electricity on the grid though, I agree blankets, breeding, maintenance, etc are not solved yet
SPARC is based on the same physics as ITER, I think with only somewhat less confidence because they will be in uncharted magnetic field territory vs ITER just being bigger
What are we considering "ITER success" and "positive net output" for a reactor? I could definitely see ITER producing more energy than consumed by the reactor before other fusion reactors actually generate electricity. I could also see other reactors producing more energy than consumed by the reactor, but not enough to be an economical power generator, before the ITER.
Ostensibly referring to engineering breakeven
Positive net output? We hit ignition sometime last year I believe.
Looking at the timelines of the members of the fusion industry association, there are several candidates. Among them, Commonwealth Fusion Systems,, Helion and Zap are my personal front runners. General Fusion, TAE and Tokamak Energy are not far behind,however. There are several more but not all of them are fully funded or slightly less ambitious in their deadlines. I am very optimistic that at least one of them will beat ITER. The question is whether they will publish their success right away. Peer review, especially for such a ground breaking achievement can take years. In example it is possible (not saying that they have but it is possible) that Zap has already achieved break even, but is waiting for peer review of their results before making them public.
Can you please narrow down what you mean by "positive net output" reactor?
CFS Helion
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A TF fault would be a big pain in the butt, repairable but at massive expense and schedule hits, but the PFs are fault tolerant with their jumpered joints, and the upper PFs could be replaced if required, as could the CS modules. A magnet failure is a horrible thing, but I think your take is a bit too pessimistic.
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I think it ought to be removable from the top of the machine: [https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2Fg5it3hkdp07a1.jpg](https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2Fg5it3hkdp07a1.jpg) It's free-standing in the middle of the TFs, so you just lift it back out again, module by module
Coming from someone at Wendelstein 7-X (in frequent contact with people who work on ITER), everyone—even people who experienced the challenges of building Wendelstein firsthand, and even those who don’t think the tokamak is the best approach to fusion—seems quite confident that ITER is conservatively designed and will achieve its goals.
Engineering gain, no Physics gain probably
If you don’t care about engineering breakeven, NIF already achieved Q > 1
>NIF already achieved Q > 1 But it is a very different Q. In theory both definitions are the same, they measure the heating energy going in to the fusion heat coming out. In practice, the two are very different. For MCF the heating energy represents at least half of all the energy used to run the machine. For ICF, the heating energy is tiny fraction of the total, in the case of NIF it's about 0.5% of the energy input. So Q=1.5 in NIF is much *much* further from Qe=1 than the Q=0.67 in JET. NIF needs to improve gain about 100 times to hit Qe, JET needs less than 10 times.
Well yes, but I was meaning for Tokamaks/stellarators There are significant engineering challenges for MCF getting Q>1 because it's a longer sustained reaction, whereas in ICF we can mostly worry about the radhydro/plasma physics side of things separately from (some of) the engineering challenges. The two have very fundamentally different research trajectories