In nuclear fusion, the triple product – also known as the Lawson criterion – defines the point at which a nuclear fusion reaction produces more power than is needed to sustain the fusion reaction. Recently the German Wendelstein 7-X stellarator managed to hit new records here during its most recent OP 2.3 experimental campaign, courtesy of a frozen hydrogen pellet injector developed by the US Department of Energy’s Oak Ridge National Laboratory. With this injector the stellarator was able to sustain plasma for over 43 seconds as microwaves heated the freshly injected pellets.
Although the W7-X team was informed later that the recently decommissioned UK-based JET tokamak had achieved a similar triple product during its last – so far unpublished – runs, it’s of note that the JET tokamak had triple the plasma volume. Having a larger plasma volume makes such an achievement significantly easier due to inherently less heat loss, which arguably makes the W7-X achievement more noteworthy.
The triple product is also just one of the many ways to measure progress in commercial nuclear fusion, with fusion reactors dealing with considerations like low- and high-confinement mode, plasma instabilities like ELMs and the Greenwald Density Limit, as we previously covered. Here stellarators also seem to have a leg up on tokamaks, with the proposed SQuID stellarator design conceivably leap-frogging the latter based on all the lessons learned from W7-X.
Top image: Inside the vacuum vessel of Wendelstein 7-X. (Credit: Jan Hosan, MPI for Plasma Physics)
Net break-even fusion is still 20 years away, but it’s really exciting that there’s actual progress now compared to 20 years ago.
it is the gift that keeps on giving. Not giving energy, but news stories.
You’ll be able to copy/paste this comment in 20 years.
People fail to appreciate how little funding fusion research gets – except when it comes to ITER which is a huge money sink that goes nowhere, because that’s the point of it: draw the available funding to itself and then do nothing with it.
The W7 received just over 1 billion Euros in funding over 18 years to build it. 56 million per year is basically nothing. That’s a small-to-medium size business enterprise in terms of yearly revenue. Just paying the rents of the facilities and salaries of the personnel who cannot do much in the lack of resources is eating up all the money. It’s like driving a car by letting it creep on idle without touching the gas pedal – all you’re doing its burning fuel and not going anywhere.
So… if we can convince Musk that this is the cheap way to run his data centres, we could see some actual progress?
The guy who owns a solar panel company? I doubt that would happen.
“except when it comes to ITER which is a huge money sink that goes nowhere, because that’s the point of it”
A lot of the other projects end up reusing research that was for ITER. Most of the other projects are just plasma research (‘just’ is not intended as a diminutive here, only to specify what they’re studying) whereas a lot of ITER’s stuff is materials research that the other projects need anyway but you don’t want to duplicate it because of the hazard issues.
For instance, search for breeder blanket design (which every fusion reactor design will need) and they’re all ITER (or DEMO) projects, and that’s just one example. ITER could literally never turn on and it would’ve still been of critical importance to the field.
“The W7 received just over”
It’s fusion research. You can’t partition it up like that. They use simulation code and research that was developed under all the research, in total. These aren’t separate companies or anything. Throw more money at W7 and it wouldn’t magically become a fusion reactor.
It’s a totally fair opinion to say that ITER should’ve been a different design and it would’ve cost less, but it’s not a “swap the ITER cost for W7 cost” type of thing – it would’ve been a much smaller decrease.
You can’t say “re-using” when the technology was never used in the first place by ITER, because it’s so much behind schedule that it never got around to do it.
Other projects are skipping the contributions of ITER and doing their own research instead because it is moving so slowly that waiting for its results would actually be retarding the whole scene.
Yes they are. The W7 project is literally the competing fork for the ITER. They both started in the 1980s, both competed for funding with a different approach to solve the problem, and ITER got the main interest while the stellarator approach got basically nothing, and yet they still pulled ahead.
No it’s not! Seriously! Go look at the guys getting funding for W7X and marvel at all the ITER publications they *also” have.
It’s research. It’s not a competition.
Dumb question: could we do fusion with something more like a particle accelerator with it getting up to speed and go through a choke to initiate fusion?
I was thinking that if it worked it’d make it easier to have a more continuous runtime, the heat at the end could be captured with some sort of heat sink vent, and the neutrons might be easier to handle since they’d be more directional.
You’re describing Inertial Confinement Fusion
https://en.wikipedia.org/wiki/Inertial_confinement_fusion
I suppose by the literal definition perhaps but that typically refers to the systems that use lasers to crush a pellet and magnets would likely still be used for confinement and the choke I was describing.
There are “fusors” that achieve fusion this way, but at such low efficiencies that they’re not really worth mentioning. For what they’re worth, they can be used as neutron radiation sources for research.
fusors are useful as neutron generators. but because the plasma is in direct contact with the grid you end up with metal in your plasma and that just saps energy and destroys the grid.
there is the polywell which is like a fusor, but with a virtual annode (electrons contained by magnets) so you can have a plasma that is mostly clean. some have complained to debunk them, however i think there is still life in the concept. its not as well developed as tokamaks/stellarators are. they have the problem that plagues all fusion start ups. they are constantly looking for funding while others are building reactors and testing them.
The reason why these “polywell” type machines are infeasible is because the proposed designs need to have their superconducting magnets right in the core of the reactor. You’ve got to keep them extremely cold right next to the fusion plasma that is glowing at millions of degrees, and somehow prevent the high neutron flux from destroying the superconductive material.
They make great headlines for technology demos and fundraisers, but if you actually turned it on with live fusion plasma, it would proceed to eat itself in a matter of seconds.
Is there anything more like what I am describing where it’s a more linear acceleration and not heading towards a central core?
People run deuterated (or tritiated) targets on normal accelerators all the time. Accelerate deuterons on to them and use the neutrons produced for stuff. We do it on our cyclotron and are developing a target at the moment to do it on our other machine.
It’s just a very an inefficient way of doing it because the energy you put into the deuterons which don;t interact on the way through the target leaves the system and is wasted.
Doesn’t that usually refer to the setups that use electrostatics to accelerate towards the center where they collide randomly? I’m thinking of something more linear, though I don’t know how efficient it’d be since I’ve never seen what I’m describing be built.
ive heard of something like that along those lines. heavy ion fusion. but i never really looked into it thoroughly. i think it falls under inertial confinement replacing lasers with particle beams due to the relatively inefficiency of lasers.
Seems similar but not what I was going with. I’m taking about trying to push the high speed plasma through a constriction like a choked flow that spikes the pressure.
That seems to describe a plasma version of inertial confinement which normally uses a laser.
There will be no nuclear fusion commercial devices until we figure out reliable muon production.
A contained fusion generator would undeniably be useful, but I should point out that we already have 2 of the necessary scifi tropes/technologies:-
1) A working nuclear fusion generator points at sun
2) Wireless power transmission with ~20-25% efficiency points at solar panels
The only thing left to do is figuring out how to turn it on and off at will.
The Simpsons did it.
Mr Burns planned to block his greatest nemesis, who was providing his customers with free light, heat and energy – the sun, but that was only over Springfield. You would need to go much bigger. Search for “I call this enemy: the sun” on you tube for the clip.
better solar panels and batteries could always be a thing. but those, especially the latter, tend to have the fusion problem of always being 5 years out. but compared to fusion thats a lot faster. the only thing slower than fusion may be the reactos dev team.
Making solar panels requires high volume industrial capacity and cheap access to resources. This is not feasible on a small scale, such as having domestic industries in each country make their own solar panels. This was attempted in the early 2000’s but the subsidies granted to such manufacturers all just slipped to the far east and the factories emerged there.
The economics of solar panels pushes the manufacturing to places where it can be massively concentrated and centralized, such as China. That creates issues such as the opportunity to weaponize the supply chains for geopolitical control, which they already do with e.g. restricting rare earth metals exports to extort more favorable politics from other countries.
A nuclear reactor is expensive to make but fundamentally requires no great manufacturing industries because it’s a very concentrated source of energy. You build it once and it runs for 60-100 years, and it’s mostly just steel and concrete, so it can be made just about anywhere, as long as you have people who know how.
you need about two orders of magnitude more performance than what is presently available. the good news is its constantly moving towards that. the bad news is the rate we are going will produced fusion in 200 years. if the iter timeline is accurate, 100 years. granted a major breakthrough could slash that. it tends to be very incremental.
The good news is that stellarators can achieve indefinite run times because they don’t rely on pulsed operation like traditional tokamaks, so it’s relatively easy to scale the triple product performance up by several orders of magnitude.
The ITER timeline is not a meaningful reference, since the whole project is a boondoggle that was never seriously meant to be completed. It’s supposed to be a proving ground for technologies, but other research projects are running rings around ITER in that respect as well.
The real problem is where are they going to get the tritium from to run the thing? It has a half life of 12 years and it is phenomenally difficult and expensive to produce. The current world stockpile is probably of the order of ~50kg, and they will need tons per year per machine.
ITER was supposed to demonstrate tritium breeding via a berilliium and Li-6 blanket lining the tokomak. This was the only real thing of value it was going to prove. It was quietly dropped in an admission of reality, as the process is incredibly toxic and unlikely to succeed due to its complexity. Oh and Li-6 is nearly as hard to come by as tritium.
The whole show of D-T fusion funding is a bureaucratic fraud to part taxpayers from their money.
What LPP fusion are doing with their Boron proton direct fusion electrodes looks genuinely interesting. Will it work? Who knows, but at least someone is trying a new approach after 70 years of continuous tokomak failure.
“It was quietly dropped in an admission of reality,”
Really? See, that’s weird, because it’s still actively in development, so I have zero idea what the heck you’re talking about.
If you’re talking about the fact that ITER won’t actually have full breeder blanket coverage, that’s because it’s designed to test breeder blankets, not actually use them, and we don’t know which ones will be best yet, or even how to use them at all. There are multiple completely separate designs which will be tested simultaneously.
“Oh and Li-6 is nearly as hard to come by as tritium.”
The issue isn’t the availability, it’s the enrichment of it – Li6 is almost 8% of all lithium, so you’ve probably got as much Li6 in a Tesla plant as there is tritium on the entire planet. And there it’s because there’s no demand, so no one enriches it (except people who wouldn’t sell it to you). There’s plenty of Li-6 available overall. It’s one of the reasons why there are multiple breeder designs out there, including ones that use natural lithium and neutron multipliers rather than heavily enriched.
“The ITER timeline is not a meaningful reference”
It’s not a meaningful timeline because it’s a portion of a larger overall research umbrella. It’s entirely possible that a large portion of what it’s doing will be rendered obsolete (tokamak design, for instance) but you can’t split up the funding and say “$X for ITER was a waste” because the money that you “designate” for ITER is really just for fusion research.
It’s not like these are separate companies hiding in their own little bubbles never talking to each other. Just go read the research papers. Look at the authors and their citations. There isn’t a “W7X crowd” or “ITER cabal.” It’s the same people. You can’t split up the funding like that. Funding cryogen pump studies nominally under ITER doesn’t mean that they don’t use it for anything else.
From the looks of it, there kinda is. You know the whole tokamak vs. stellarator thing?
It looks like the stellarator vs. tokamak debate was originally about East vs. West German politics. The W7 was supposed to be built 10 years earlier, but with the little funding they received they couldn’t manage to make that happen. Then right around the time the W7 was supposed to be completed, rather than supporting the project the politicians agreed on funding the ITER instead and diverted almost all of the money away, leaving the W7 in the dust. That left the project standing for a decade until they finally managed to complete it, test it, and show that it actually works way better than the proposed ITER designs.
Yes, but you could fund the cryogen pump under the W7 project instead and advance both instead of holding things back.
“fund the cryogen pump under the W7 project instead and advance both”
Dude! It did! It’s the same guys! What, do you think they put on a “W7 hat” and “ITER hat” and suddenly were like “man, I forget all this stuff I did when I put on the ITER hat”?
It ain’t a company! The money comes from research funding organizations that fund both and specifically ask if there are synergies with other experiments! That’s how it works!
Have they discovered the magical tritium mines yet?
Because otherwise Boron – proton fusion is the only feasible option, and all of these publicly funded entities pretending to offer ‘commercial’ power plants in ~20 years times are just fraudulent enterprises.
Was going to mention that, too, but my last comment (elsewhere) about such was wiped out by the editors.
One of the well-known (and stable) solutions using boron-proton fusion is relatively cheap – last I checked they (team of engineers, NOT bureaucrats) want between $300K and $500 per, that’s it, and the reactor size is about the size of SUV, but R&D is still needed – not for the thing, it is already quite well researched, but for the technology itself, ie, perfecting already working solution.
The problem is well-known, bureaucrats don’t like small efficient budgets, they want huge spending budgets overviewed by many bureaucrats with the trickle-down economy paying meager engineers’ salaries. It may work for well-established economies (renting money for money, aka “banking”, where no R&D is needed, “technology” is thousands years old, nothing new has been “discovered” ever since King Solomon), but not with the economies driven by the R&D results, where administrators/bureaucrats most of the times is not the ballast needed, but a deadweight slowing things down.