It's forward progress, but nowhere near being useful.
By "more energy out than they put in", they mean passing "theoretical breakeven", generating more energy as heat than they put in as electricity. Not converting that energy back to electricity and making the thing self-powered. Brief periods of theoretical breakeven have been achieved before.
Ahead lies "sustained theoretical breakeven" - the thing can be kept running for a while. So far, other tokomak experiments have achieved 70 seconds of plasma containment (Korea) and 120 seconds (China). That's below ignition temperature, though. Then "self-sustaining breakeven" - the thing can power itself. Then, someday, "economic break-even" - it can pay for itself. Then, maybe, useful power generation.
There's the problem of getting the energy out in some useful form. This begins with the "first wall" problem of finding something that can survive the conditions just outside the magnetic field. Those conditions include huge numbers of neutrons, which tend to split atoms in the first wall material and cause unwanted transmutation. This causes radiation embrittlement, which is not good for materials.
There are many milestones and at each one there are going to be people saying “but it’s not …” without really adding any information.
What we have now that we didn’t have before is the ability to draw a line around an area inside a test reactor and say we can, for very brief periods, get more energy exiting that area than enters it. This is major progress.
It isn’t a self-powered plant, it isn’t a plant that can sell power at any price, it isn’t a plant that is economically viable, and none of that is important to point out.
We have a baby taking its first steps being criticized for not running a marathon.
Babies grow into humans which are clearly capable of running marathons. This science has no such birthright and may eventually prove to be truly unfeasible.
I doubt the science is infeasible. We do have working fusion reactors. Some time in the next few hundred years we will surely figure it out, if we don't go extinct first.
The economics are much more likely to make it infeasible. If fusion power is forever more expensive than solar+storage is there any point to it? Even fission has been priced out of the market and I never heard anybody claim that fusion will be cheaper than fission.
Electricity prices have recently skyrocketed and generally have bounced around a lot. Right now fission is quite economically viable, blue that will continue in the future depends on how fossil fuels will be priced and how solar power grows.
Fusion will definitely have big up front costs but the fuel costs could be as low as essentially zero or quite high depending on the tech that makes it, and who can say what the maintenance costs might be.
How much energy might be produced for how much operating cost is a really open ended question and there is a wide range of possible answers.
Then you haven’t been keeping up with the news. European electricity prices hit record highs just a few days ago and have been growing enormously all year.
Worldwide oil prices have been going way up, we’re in a much different energy market than at have been for quite a while.
The long-term secular cost of electricity from renewables has been falling, with a trend that can be projected back at least 50 years. The incremental improvements are slow, but very steady. I suspect this is what ncmncm is referring to. In time, that cost curve will make all but the most essential of fuel-based generation, including nuclear fission, economically infeasible.
Yes, storage needs further development. That's also been coming along, and I believe we have sufficient options to address most needs.
I suspect you're referring to recent fluctuations in grid costs within Europe, and yes, that's also a reality, but a short-term one.
Both of you would do well to actively listen to the other, and clarify points of disagreement and/or misunderstanding.
Eh. Assuming energy costs will continue to drop indefinitely (at the kwh delivered, overall) despite significant recent evidence from one of the top renewable energy markets is it’s own type of fallacy no?
Renewables have a much more complicated cost structure due to production timing issues and capacity issues, that show up especially during winter in a cold climate - which is exactly the issue Europe is having.
They keep getting papered over by advocates, but having had to deal with this directly by building my own off grid energy system - at some point you have to deal with it or you freeze.
Indirectly, I think they’re both touching on different elements of the problem and using incomplete data from both perspectives.
Costs are falling and consistently along an experience curve. They're approching a lower bound. But that lower bound is well below the costs of both fossil and nuclear power, both of which are further exhibiting increasing costs over time.
I'm not dismissing or minimising issues involved in a sustainable carbon-neutral energy scheme. But it's within reason.
The challenge with that assessment for renewables, is as California and Germany both are discovering, there are missing elements of the cost equation being used that aren’t being accounted for, but someone has to pay for it or bad things happen. Notably bad even for politicians, like people freezing to death or dying from heat in the summer.
Both are currently pretending (near as I can tell) to understand what it means, and report numbers that seem pretty rosy.
Cost of energy total, however, in both these places continues to skyrocket.
They may be able to continue to avoid it, if folks take the price signal to heart and find workarounds (like finally improve insulation in the stock of older housing and public spaces, or switching energy consumption pattern to flatten peaks). I can tell you that California so far seems to not get the hint.
In Germany it’s the winter heating load, and figuring out how to actually keep themselves from freezing during outlier (but not that infrequent) events.
In California, it’s the aging transmission infrastructure and shifting peak production vs peak demand without adequate storage leading to brownouts, blackouts, and high surge pricing during summer air conditioner loads.
In California they changed new construction energy codes, but it’s mostly BS. With the rate of new construction being tiny compared to existing (old) stock, it’s not going to make a significant difference for 50+ years. A decent portion of existing homes have either no insulation, or 50 year old insulation with poor or zero maintenance, and are grandfathered in.
Energy prices in both places continue to increase, that may do it. Both places are near world records highs already, and have been for some time.
aka Transmission. That's what HVDC will fix. The challenge in the USA is policy, not technical. I know nothing about EU, but assume they have a similar rat's nest of red tape.
FWIW, David Roberts' Volts newsletter covers the USA-centric stuff.
For sure, though all that adds costs and makes it clear we just don’t know yet what the actual cost is of the right solution (or what the actual right solution is).
Transmission alone can’t fix this due to national security concerns, which is also a huge factor in the current energy cost problem in Europe - a large portion of European natural gas comes from Russia, and Russia has made it clear they’re willing to use gas for larger policy goals in the past. Including turning it off and causing huge safety issues if Germany and others won’t play ball.
Even solar in the Sahara has this problem, as these lines are easy to cut during a war or ‘accident’, and hard to protect over these distances.
Energy supplies and access to them played a huge role in WW2, and that hasn’t stopped.
Well, yes, the entire concept of geopolitics has grown out of the global distribution of petroleum sources and consumers. And that itself is only the another round in competition over global resources that traces back at least as far as the 1750s and the Seven Years War (arguably the first true World War).
The history of the significance of sources, transports, and consumers of oil and gas loom large in recent histories. I recommend Daniel Yergin's The Prize (1991) with its treatments of WWI, WWII, and the Cold War, and Vaclav Smils' Energy and Civilization (2017) which addresses more technically the role of energy in human progress. (There are a few other histories through the lens of energy I could recommend as well if you're interested.) The role of the Suez Canal, of Beruit as a transshippment point for Saudi oil piped across the desert to the Medeterranian, of submarine warfare aimed in large part at oil shipments to Japan and within and from the United States, as well as the central role of the Middle East in post-WWII geopolitics, all come to mind.
A renewables-centric world seems to afford far greater multipoliarity and far less concentration of strategic interests. It's fairly trivially possible to capture or bomb oil wells. It's less feasible to entirely destroy solar collectors --- yes, they're fragile, but the very fact that they do cover large tracts of land makes direct attack expensive. Interconnects, particularly those envisioned across the Mediterranean, would be attractive targets, though also likely armoured and defended. At the same time, distribution of other forms of generation, including wind, hydroelectrc, and geothermal, would make the impact of such attacks, and the likely retaliation on any aggressor (themselves all but certainly a major state power) large.
If I were to draw up risk scenarios, I'd likely put more emphasis on materials sourcing, especially of rare and strategic minerals: lithium for batteries, copper for wiring generally, coltan, rare earths, and the like. These aren't consumables to the same extent fuels are, but access could disrupt an adversary for a considerable time, though all but certainly at a cost of global trade disruptions.
Any large, arid, low-population, sun-rich region becomes a potential energy producer and exporter, in a solar-dominated world. This includes many of the Middle-Eastern petro-states, but also their less-endowed neighbours, much of North Africa, the Southwestern United States, Northern Mexico, potentially regions of western South America, and much of Australia. Where direct electical shipments aren't possible, either production or synfuels created using surplus electrical power (much of it direct analogues of petroleum hydrocarbons) is another option. Carbon-neutral production of such fuels is not especially effient in a round-trip energy sense, and retains some local pollution concerns in combustion (particulates, partially-combusted hydrocarbons, nitrous oxides, carbon monoxide), but would not suffer from either CO2 emissions or sulfur emissions from current low-grade fuels. There is the potential for alternate fuels --- hydrogen, ammonia, methane (arguably a petroleum analogue), and alcohols being among them. I'm leaning in favour of synfuel hydrocarbons myself for numerous reasons, but all would offer the ability to capture sunlight and ship it elsewhere in a far more decentralised fashion than the present fossil-fuel-depedent global economic system exhibits.
It expect there will be large and frequent shipments of electrically synthesized anhydrous ammonia carried in supertankers from multiple competing tropical countries to northern Europe, and large reserve stocks of it kept at terminals there, and inland regionally. That ammonia will be burned in existing gas turbines or converted to H2 for industrial uses.
Then, the trans-national HVDC transmission lines also being built out will enable access to reduced spot prices, while remaining strategically unnecessary.
As I said, I'm a fan of hydrocarbon alkane analogues, not so much hydrogen or, as you suggest, ammonia.
Ammonia is useful as fertiliser. It's the 2nd most hazardous material noted in the US (I'd participated in an earlier thread pointeing this out), after the far more prevalent carbon monoxide. As a fuel, ammonia would prove an extraordinary hazard.
Ammonia is dangerously toxic if released indoors. Outside, NH3 is buoyant, rising away from leaks as fast as it evaporates. Besides its fertilizer and feedstock uses in the millions of tons annually, NH3 is already in heavy use as an industrial-scale refrigerant.
For those millions of tons of NH3 handled industrially, 1153 incidents is very small.
I'd like to learn about realpolitik. Henry Kissinger, Jean Kirkpatrick, etc.
Much as I despise that world view, I'm not sure they're wrong.
At the very least, I'd like to understand them better. Like how the Know Your Enemy podcast surveys modern conservativism. https://www.patreon.com/knowyourenemy
I've got some books about Kissinger in my queue. I figure I'd start there.
I likewise find the PoV unsavory, though ... pragmatic. Yergin's general philosophy (and enthusiastic boosterism of the oil industry) is not my own viewpoint, but his storytelling and knowledge are excellent. Discover enough about the field, however, and the bits he skips over become apparent. The bits he covers, however, are valuable.
Manfred Weissenbacher's Sources of Power (note that this is in two volumes, catalogue listings vary in including both) is similar to Smil's works on energy/history, but focuses far more on the political dimensions and their relationship to the power (physical and political) afforded through energy regimes. It becomes increasingly polemical as it approaches the present, possibly with strong justification.
What really emerges from all three authors --- Yergin, Smil, and Weissenbacher, is how absolutely transformational the oil age proved to be. It is liquid power in every sense of that word.
I'm familiar with Realpolitik as a term. There's the related "geopolitics" which arises out of German doctrine, and borrows heavily from principles of the use of naval power. That, if I'm recalling correctly, traces to Alfred Thayer Mahan's treatise on sea power:
https://en.wikipedia.org/wiki/Alfred_Thayer_Mahan#Sea_power
Otherwise, this is an area I'm mostly fumbling around in. Appreciate the podcast recommendation.
In exchange, Neal Conan's swan song might also be of interest, "Truth, Politics, and Power". I'm not sure it covers quite the same topic though it's own I've been meaning to listen to.
Oil prices are rising as production falls. That is falling because exploration is not expected to pay off. It is a fundamental mistake to confuse short-term fluctuations with trends.
Yes and: I concluded "peak oil" happened once Big Oil stopped investing in infrastructure, like refineries, choosing to extract as much wealth as possible on the way down. In all these food fights, I wish more of us arm chair pundits paid attention to what the major players were actually doing (finance, investment), vs taking cues from other pundits.
Energy prices are not plummeting globally, the drop that did happen can primarily be put squarely on america developing enormous new oil resources which broke the opec cartel which couldn’t get its act together in the new environment (and was trying to bankrupt the more expensive NA oil by dumping below production cost for tar sands). Geopolitics and world events have ended this period of cheap oil which is still fluctuating but the contribution of wind and solar is just not big enough yet to dominate the energy market.
> If fusion power is forever more expensive than solar+storage is there any point to it?
Yes, because fusion has the potential of harnessing much more power in a relatively small power plant. Even if it's more expensive, it's TWs you wouldn't otherwise get.
I think we have most of the actual science problems figured out. We essentially know that a sufficiently big tokamak will produce net energy. We do not yet know in detail how to build one that lasts long enough to make financial sense. ITER will probably answer the remaining engineering questions.
Of course there are more open questions around the other potential ways of achieving fusion, because we haven't thrown as much money at them as we did for tokamaks. So there is a possibility that there are much cheaper designs that also work.
Indeed, this is no baby, but a random blob of cells. Two things we can be certain of:
1. No economically viable hot-neutron Tokamak fusion plant will ever be built;
2. Every cent wasted on this, instead of being spent on building out solar, wind, and storage, brings climate catastrophe incrementally closer.
It is just barely possible that something learned while fooling with this stuff will turn out to be helpful for making a practical non-Tokamak fusion system for spacecraft propulsion. The plasma fluid-dynamics physicists employed on these massive boondoggles are who would make that. But the longer they bumble about with this, the longer it will be until they can get started on that.
Every cent wasted on this, instead of being spent on building out solar, wind, and storage, brings climate catastrophe incrementally closer.
But in the real world the money going into this is on top of that going into solar / wind / … and not instead of. The nature of the climate crisis is such that we need to stop debating which things to do and just do all the things unless we genuinely run into limits of what we can spend, which we are nowhere near reaching.
We need to spend the money on things that will help, and take away the money from things which are not helping. Those latter things include weapons, internal-combustion vehicles, Portland cement, and Tokamak fusion projects.
For the past decade, total US spending has been at or below $600 million/year, or 0.003% of total US GDP. Even with my low expectations of success or viability, the research itself is worth pursuing. US spending is a large fraction of global fusion spending, and though I don't have an aggregate total, it is also in all likelihood too small to matter.
There are vastly larger areas of expenditure that are far more harmful to achieving a sustainable, renewable, carbon-neutral energypath. Pressent fossil-fuel based infrastructure and exploration is among the leading candidates. You should be focusing your ire there, or other similarly significant areas.
IDK. I guess I'm fine with it. Keeping the lights on. I more or less agree with Saul Griffins: Fission and maybe fusion will be important in a few decades. As a successor to renewables. Useful if we survive this key hole event.
Of all the things we waste money on, I don't much resent Dream Big efforts like fusion, space exploration, and stuff.
I feel that people want to point out just how much more work remains because it can potentially be one of those wishful thinking-blockers for climate action.
Fusion power will continue to be high on our agenda and it should but it should never be seen as a solution for climate change because that is wishful thinking. Fixing climate change has a much tighter timescale than we can expect for fusion power.
Both can be true at the same time. None of us should _count_ on nuclear fusion being available as an energy source until at least the very first critical demo reactor _that actually generates useful electrical energy_, and we as a society need to move on as if it wasn't happening.
That being said, my mind was stuck in Animat's state as well for a long time, mainly because of neutron flux. Neutrons were the ultimate end boss at the end of the goal by laughing at your fusion progress and just destroying every containment that comes their way. What excites me these days are modern contenders like HB11 Energy and Helion Fusion jumping directly to aneutronic fusion.
This is the stuff most physicists didn't dare to dream of as of late, mostly because they weren't even close to sustaining the simplest D-T reactions for long, and aneutronic fusion takes even considerately hotter and denser plasmas — as well as being plagued by fuel availability concerns (HE3). But it's something that's within reach due to massive advances in ultra-short laser technology, coil breakthroughs and some other clever hacks like breeding HE3 on site.
That, combined with the other advance of direct electrical harvest instead of thermic conversion puts fusion into territories of believable reach for the first time in my mind. After decades of disappointedly following the status quo, I'm getting seriously excited.
Is anyone actually saying “let’s not do anything and keep pumping carbon into the atmosphere because fusion is almost here!” ?
I mean I’m sure you can find someone saying it (like anything) but there’s no reason to argue against an imaginary opposing viewpoint which isn’t being expressed.
What’s actually happening is people like to argue against things because naysaying is fun and people genuinely don’t really have a solid concept of what progress is being made and what progress is still needed, but go on with their vague impressions and defend their ideas anyway (and often against imaginary opponents).
No, it is because money is fungible, and every cent wasted on dead-end crap is a cent not spend fending off imminent climate catastrophe.
Long before the natural world experiences a phase change, civilization will collapse. While that will radically reduce carbon output, it seems like a thing to prevent.
You're assuming if we stop spending it on A it will mean more funding for B, and that is not at all clear or even likely - if all the funding isn't going to B already, there's little reason assume you can convince those who believe funding for A today is justified will suddenly all accept it should go to B if A is shut down.
not if the parents of the baby keeps saying that the baby could be walking any minute now, for the past 50 years. it's likely that this will take another 50 years to reach the success level.
Pushing too optimistically a story to the public might make them feel that it's closer than it really is, and possibly modify public policies that would otherwise not have been modified.
> it's likely that this will take another 50 years to reach the success level.
There's another technology that's been hyped relentlessly for 50 years, and is always "just around the corner": general AI.
Call me when you think you can build a reactor that can contribute power to the grid AND make a profit for the operators. I won't be holding my breath.
We have something that might be a baby taking its first steps. It might also be a weird freak that won't live past its first few years, dying of some painful deformity. Time will tell - I'm hoping for baby, but won't be surprised by circus freak.
The "baby" is making its first steps for literal decades now. It is old enough for its own children, grandchildren, and perhaps even great-grandchildren. It always "success just around the corner." Skepticism is warranted.
I’m not quite sure what the analogy you’re considering is, but if we’re equating fusion power plants to transistor-based circuits, I think we’re currently proving different types of solid state diodes are possible to create in a lab.
I suppose you could make a timeline of technology development, fusion is still in the lab stage but past the conceptual and experimental stages and into the early making it practical stage with several approaches competing for first to actually achieve something useful.
What’s left isn’t just straightforward work, but a lot of finding and fixing inefficiencies and that sort of work.
No, because transistors were clearly going to be useful.
Fusion (especially DT fusion) has a good chance of never being useful (except for H-bombs).
These comparisons with old embryonic technologies also miss the point that lots of embryonic technologies never go on to success. Focusing on the rare ones that did is survivor bias.
Sabine Hossenfelder essentially called the nuclear fusion PR a fraud, because they do not report true (full-system) efficiencies. https://www.youtube.com/watch?v=LJ4W1g-6JiY
She also overstated things and made things out to be worse than they actually are. Getting to fusion plasma power breakeven IS the hardest part. And it's always been so far away, setting and talking about realistic goals is better than trying to immediately jump to the far end goal.
This is the difference between ITER and projects like SPARC though, they both plan to get fusion plasma power breakeven, but ITER's design has zero hope of ever being economical.
As I recall her point about the deceptive reporting of gain figures was spot-on. It’s something I’d observed throughout the 20 years that I followed the field fairly closely, being intermittently involved in several fusion-related projects. Especially in inertial confinement, claims of “break-even” are almost entirely devoid of meaning. So how, exactly, do you think she overstated anything?
Extracting useful energy from the plasma, and protecting the reactor (magnets, control etc) from neutron bombardment are also hugely difficult problems.
Not to mention, trying to fool public opinion about how far away we are from any chance of a fusion power plant is still ethically wrong. Let's not forget that even if ITER achieves all of its goals and milestones, we will be able to start on the power extraction problem in 2030.
And let's also not forget that inertial confinement fusion, while also being presented as a potential fusion power plant concept, with great fanfare occasionally, is simply a weapons research program with no imaginable way of progressing to economical power generation.
CFS's ARC reactor design will use a FLiBe molten salt blanket to shield everything except the vacuum chamber itself, which is a steel doughnut with 2cm thick walls. They plan to build a proof of concept reactor by 2025 that will have net energy gain (Q > 10), and then a full demo power plant by 2030. CFS believes they can move faster than ITER because the newer stronger magnets that they're using make smaller reactors viable. Smaller scale means cheaper to build, which means a nimbler private company can build it rather than a bureaucratic international project.
Let's see if it actually materializes. It's not hard to make such claims, it's much harder to deliver on them. I very much doubt the 5 year timeline from "net energy gain" (net plasma energy gain) to an actual power plant (actual net energy gain). Again, extracting energy from the plasma is mostly a theoretical idea at this time, and all the proposed mechanisms would likely require significant engineering challenges (the biggest temperature differential in the solar system; neutron bombardment).
If you have the gigawatts of electricity required to run the inertial fusion lasers, there are probably better ways to use that power to get around. Massive ion engines, or powering the pumps for a nuclear salt water engine, maybe, depending on how exciting you want your ride to be.
Inertial containment fusion relies on firing a laser at an extremely precisely machined piece of heavy metal (called a hohlraum), heating it until it emits X-Rays, and using the X-Rays to create 2 implosion shockwaves in a tiny pellet of tritium + deuterium that have to meet in the dead center, so that where they meet they can start a fusion reaction, and ideally have the fusion reaction consume the whole pellet before the shockwaves dissipate enough to stop confining the plasma. A few microseconds after the laser blast, you get a puff of helium (+hydrogen if the reaction wasn't complete) and a mangled piece of metal, and some heat that in principle you could capture somehow, though no one has yet tried. Then, you throw away the now useless hohlraum, get a new one and a new pellet and you fire again for another little burst of energy, over and over.
The hohlraum is the biggest problem here: the level of precision needed to achieve the exact geometry inside the pellet to actually ignite a plasma means that every hohlraum is (a) extraordinarily expensive (currently in the millions of dollars range), and (b) entirely useless after a single shot - while continuous operation for a 1500 MW plant is estimated to require ~20 hohlraums/second).
For a spaceship design, this would mean that your engine would have to include a smelter and high-precision machining bay to constantly create new micrometer-smooth hohlraums from spent ones. Not even close to a promising technology.
NIF also has an expendable blast shield in from of each mirror of the final optics. These mirrors have to be in line of sight of the explosion. If you tried using something like this in space, without that shield the expanding plasma/hohlraum fragments would go right out though the vacuum to hit the mirrors. Even slight imperfections there will explode under high energy pulsed laser irradiation.
I'm a software engineer who saw a few videos on YouTube, and read a few articles on this topic, I don't think I am the right person to ask about this, sorry.
Commonwealth Fusion Systems plans to hit Q>10 net energy gain in their SPARC reactor in 2025, and then turn on a continuously operating ARC power plant around 2030. They plan to use a steel vacuum chamber which will need annual replacement. The rest of the ARC reactor will be shielded by a FLiBe molten salt blanket which will absorb neutrons and convert their energy into heat.
The ARC reactor described in the 2014 arxiv paper uses a lot of beryllium. To provide the 18 TW of primary energy used by the current world economy with these reactors would require 10 million tonnes of Be. The annual mine production of Be is just ~200 tonnes, and the global estimated (by USGS) Be resource (not reserve) is 100,000 tonnes.
The gross fusion power density of ARC from that paper is 0.5 MW/m^3, vs. 20 MW/m^3 for the fission power density of a PWR reactor vessel. ARC is going to be a much more complex and expensive way to boil water than a fission reactor.
My only counterargument would be that a lot of technology starts out requiring some rare or expensive element to function, but through improvement is later able to transition to some less exotic replacement.
In this case, lead would be more difficult but would still do the basic job of multiplying fusion neutrons. Last I saw, General Fusion was planning to use lead.
Lead (or lithium lead) would not work for ARC, because it is electrically conductive. It would not be possible to pump it in the strong magnetic field because of the back EMF generated. This is also why PbLi with vanadium structures was abandoned for DEMO: it proved impossible to make an insulating coating for the metal structures that would prevent the induced currents from flowing. Even slight cracks in the coating were found to be ruinous.
General Fusion is trying a crazy approach of using liquid metal as both the containment vessel and the means to capture the heat. Magnetic containment isn't the only path to fusion being tried.
There's maybe "Helion has a clear path to net electricity by 2024, and has a long-term goal of delivering electricity for 1 cent per kilowatt-hour. (!)" - Sam Altman.
"The Helion Fusion Engine will enable profitable fusion energy in 2019,” from NBF 7/18/2014.
“If our physics holds, we hope to reach that goal (net energy gain) in the next three years,” D. Kirtley, CEO of Helion, told The Wall Street Journal in 2014.
“Helion will demonstrate net energy gain within 24 months, and 50-MWe pilot plant by 2019,” from NBF 8/18/2015.
“Helion will attain net energy output within a couple of years and commercial power in 6 years,” Science News 1/27/2016.
“Helion plans to reach breakeven energy generation in less than three years, nearly ten times faster than ITER,” from NBF 10/1/2018.
----
Having quoted that, I consider Helion a less unlikely bet than the DT fusion approaches.
> Brief periods of theoretical breakeven have been achieved before.
Source? I'm not aware of any reactor that has done that.
> Ahead lies "sustained theoretical breakeven" - the thing can be kept running for a while. So far, other tokomak experiments have achieved 70 seconds of plasma containment (Korea) and 120 seconds (China). That's below ignition temperature, though.
Ignition temperature is not set just by the time you run it. The larger you go the longer you need to run before you can get to ignition. ITER will need something like 1000 seconds, but SPARC will only need 10.
> Then, someday, "economic break-even" - it can pay for itself.
For ITER-like designs that's impossible because the massive manufacturing cost.
> This begins with the "first wall" problem of finding something that can survive the conditions just outside the magnetic field. Those conditions include huge numbers of neutrons, which tend to split atoms in the first wall material and cause unwanted transmutation. This causes radiation embrittlement, which is not good for materials.
Radiation embrittlement is only a problem for certain types of materials. Some material types do not absorb neutrons at fusion energies and simply pass them through. This is a complex materials problems and you can't just use steel but there's already many designs that people are experienced with for this and it's well known because of the history of fision energy research with neutrons.
Brief periods of theoretical breakeven have been achieved before...Source? I'm not aware of any reactor that has done that.
Not in a plasma reactor, yet. The laser Nuclear Ignition Facility at Lawrence Livermore Labs claimed "scientific breakeven" back in 2014.[1] That's the setup where they have a huge building full of pulse lasers focused on one tiny target.
This is breakeven for a very weak definition of breakeven: “thermonuclear energy out” > “energy absorbed by the fuel capsule”. Not "> energy required to run the lasers." That's for a very brief period, nanoseconds. It's taken Lawrence Livermore 45 years of zapping tiny targets with big lasers to get to this point.
This was being touted as a potential approach to fusion energy back in the 1970s. It's not, really. It's mostly a way to study bomb-type fusion without setting off H-bombs. It's now part of "stockpile stewardship", keeping some people working on fusion to prevent forgetting how to make H-bombs.
And it’s important to note that “energy absorbed by the fuel capsule” is not measured; it means the absorbed energy calculated by a model using a classified code that no one outside the program is allowed to see.
All materials have problems with fusion neutrons. The neutrons from DT fusion are sufficiently energetic to cause (n,alpha) and (n,p) reactions, causing hydrogen and helium gas to accumulate. Helium in particular is a problem, because it collects into tiny very high pressure bubbles that rip the material apart from the inside. Simple elastic scattering of neutrons off the atoms cause them to scatter many atomic diameters in the material, scrambling its crystalline structure.
There are also just a few elements that do not produce unacceptably long lived radioisotopes under fusion neutron bombardment. This greatly limits the choice of elements from which to make the reactor structure. Right now, the best choice is RAFM steel, but it has a number of serious drawbacks.
Late response, hopefully you see the comment, but you seem to be assuming a solid material. If the material is a liquid, why are hydrogen and helium gas a problem?
The lifetime (in displacements per atom) of RAFM steel still isn't that great. Moreover, after some irradiation, the material becomes brittle unless hot. The temperature window (300 to 550 C) between where the material becomes sufficiently ductile, and the upper temperature where the material undergoes creep, is rather small. The upper temperature isn't that high, either, which makes high temperature blanket concepts harder to design.
RAFM steel is also ferromagnetic, which interferes with the design of the reactor.
>> known as ITER, which the United States and other countries are building in southern France to generate 10 times more power than it took to generate the fusion reaction.
ITER is a physics experiment, not dissimilar to the LHC. It is not going to generate "power" but energy. The goal is to provide a steady fusion reaction from which to then develop potential technologies to turn that energy into usable electricity. ITER is not a powerplant. It is a scientific reactor.
>> ITER will be the first fusion device to produce net energy. ITER will be the first fusion device to maintain fusion for long periods of time. And ITER will be the first fusion device to test the integrated technologies, materials, and physics regimes necessary for the commercial production of fusion-based electricity.
This article is not about ITER, it is discussing a new reactor being built by an MIT spin-off company called Commonwealth Fusion Systems. They plan to build a demo reactor by 2025, and a full scale power plant by 2030.
The article doesn't really go into detail about this (it's mentioned in the video) but the key breakthrough they're referring to is increasing the magnetic field strength from HTS (high-temperature superconducting) magnets to 20 Tesla [1].
It's hard not to come away from reading any of this without thinking what a huge boondoggle ITER was and is and there was plenty of reason to think that before now.
A lot of talk here is given to net energy production. That is a key milestone but it's not by itself sufficient for commercial fusion power production.
Example: imagine a plant costs $10B and products 100MW of net power. It has a lifespan of 30 years and requires $500m/year in maintenance and staffing. That capital cost and operating costs need to be amortized over the lifespan of the plant so even though it's 100MW of net power production, those numbers simply aren't commercially viable.
I applaud these efforts but I remain skeptical on when (if ever) we'll have commercial fusion power production, for several reasons:
1. The issues of turbulence with a super-heated plasma;
2. Power loss through neutrons; and
3. Damage caused by neutron embrittlement of the reactor itself.
Personally I think solar is still the frontrunner for the first renewable mass-scale power production method that will be cheaper than fossil fuels and thus replace fossil fuel plants for economic reasons.
I'm glad there are a bunch of commercial enterprises focused on this. I hope at least some of them explore some of the alternative forms of fusion (ie other than hydrogen). For example: proton-Born fusion [2]. Aneutronic fusion would have huge advantages.
Commonwealth Fusion Systems has addressed all of those issues:
1. The higher field strength from the new HTS magnets eliminates turbulence.
2. The ARC reactor will use a FLiBe molten salt blanket to capture energy from neutrons and breed tritium to be used in the fusion reaction.
3. The ARC reactor is designed to have a swappable 2cm thick vacuum chamber, which is the component subjected to the most neutron radiation (everything else is shielded by the molten salt blanket). These chambers are expected to last a year, and while they are moderately radioactive waste, the amount of material is relatively small and they should become safe in the order of a decade.
I highly recommend watching Dr. Whyte's talks on YouTube, he discusses the challenges, design, and performance in an approachable way. There's a timestamp index in the comments on this video:
>> In order to deliver the cooling fluids to the machine, a large cooling plant has been built at ITER that ranks as the most powerful single-platform cryoplant in the world.
That's ITER. The article is mostly about CFS, which uses REBCO high-temperature superconductors that can be cooled with liquid nitrogen. And due to the stronger magnetic field they can support, the reactor can be made much smaller for the same output.
Isn't that to be expected during proof-of-concept builds? Once you can show that it's actually possible, you can start optimizing the process.
Fusion could be a super breakthrough, even if it never gets super cheap and "we power the world by doing this one weird trick and all we need is one building". Provides reliable energy 24/7, is safe to use (as in no melt-down potential that people would be scared about) and does neither produce co2 nor blast coal dust particles all over the world.
I'm sure we could do the same with nuclear power, but it's politically impossible in many countries, because the name short-circuits people's minds.
> Provides reliable energy 24/7, is safe to use (as in no melt-down potential that people would be scared about) and does neither produce co2 nor blast coal dust particles all over the world.
None of this is really plausible for any fusion plant, especially in the early phase. The first plants will likely be plagued by expensive time consuming periodic maintenance. They will be prone to catastrophic failures if plasma containment fails, easily killing everyone in or near the plant. They will be constantly spewing radioactive tritium. They will require fission plants to produce new tritium. They will require rare materials to create the superconducting magnets and others.
>> if plasma containment fails, easily killing everyone in or near the plant.
That couldn't be further from the truth. "Magnetic containment" doesn't mean the magnets are holding in the reaction. The magnets are compressing/heating everything to start and sustain the reaction. Any containment failure will cause the reaction to stop instantly. Letting the plasma touch anything solid, any metal/wood/ceramic, would be like throwing a bucket of ice water on a burning candle.
The far more dangerous aspects of this project are the same any any large industrial process: compressed gasses in big tanks. High power electrical lines. Fire. Confined spaces. Gas leaks resulting oxygen displacement. Normal industrial only dangerous to those persons inside the building. But I wouldn't want to have any metal fillings too close to those magnets when they power up. At 20 teslas they might start moving though your head like a bullet.
I exaggerated with "anyone near the plant", but accidentally allowing 800 cubic meters of radioactive plasma/gas starting at 150 million degrees to suddenly expand would certainly hurt any human being it comes into contact with.
Hopefully it wouldn't actually be that hard to construct a reinforced concrete shield around the actual reactor to prevent an explosion of the high temp, high pressure, radioactive material from reaching too far into the facility.
The reactor and all its complex components would almost certainly be utterly destroyed, so even if no human victims are made, the money will just have to be written off.
The dangerous thing in the ARC reactor is not the plasma; it's the magnets (most of the mass of the reactor is the steel supports needed to constrain the stored energy) and the titanium hydride neutron shield for the magnets. This shielding is close to the molten salt; at the temperature of that salt TiH2 fully decomposes, releasing its hydrogen gas. There's a lot of hydrogen there.
Sure, I'm not claiming that they'll be there next year (or possibly ever). If the predictions/promises/whatever you might want to call it, hold true, they'd be great, and it's not totally crazy like the perpetual motion people.
If not, then we've spent a few billions and probably just learned a lot of interesting stuff and improved a bunch of scientific areas.
It stops being plasma, but it keeps being hundreds of cubic meters of hot gas at about ten times the temperature of the (core of) the sun. It's low by mass, but it would still be extremely dangerous, and radioactive.
Catastrophic failures won't kill anyone near the plant, but when the expensive radioactive fusion reactors breaks themselves and can't be easily (or at all) repaired, it could well kill interest in fusion reactors.
I am reminded of what they did at Hanford when installing the facilities where spent fuel would be processed to extract plutonium: to show that the machinery in the hot cells could be repaired with remote control manipulators, they had the workers install that machinery with the manipulators. I'll believe a tokamak can be repaired remotely when the build one the same way.
My father, who was born in the early 30s, used to regularly bring up his memory of the introduction of nuclear (fission) power and how it was oft-quoted as going to be "too cheap to meter".
“These advancements aren’t incremental; they are quantum leap improvements.” I hope that physicist Dennis Whyte was being misquoted here.
We need to rapidly ramp down the use of fossil fuels and replace them with technology that works today, such as photovoltaics and nuclear fission (in the interim). Aspirational projects that might possibly have a working proof-of-concept in a decade or five are not part of the solution to the climate crisis.
>I hope that physicist Dennis Whyte was being misquoted here.
Why? Because quantum leaps are small? The metaphor is not comparing it to the size of the quantum leap; the metaphor is that quantum leaps are discontinuous.
I thought he also believed that the advances were of significant size, but maybe I’m wrong and he did, in fact, mean to admit that this recent, discontinuous progress was minute.
He is correct however. There's no possibility of replacing all power with renewables energy within 10 years, so having a 5 year time scale for a working prototype is completely reasonable. We're not even going to have all cars converted to electric vehicles within 20 years even in countries with the most strict rules, let alone all power generation and fossil fuel use for other applications. (Even if fossil fuel sales were forbidden tomorrow, it would still take 20 years for the existing vehicles to be taken out of the used market.)
Climate predictions end in 2070, but the world does not. "We're fucked" isn't a reason to throw our hands up and not try.
Fusion is "too late" the same way every other decarbonization tool is too late. It doesn't matter. Do it anyway. In 200 years the people who threw up their hands will be seen as short-sighted.
People who wasted fortunes on dead ends will be seen in a rather worse light.
We already know what we need to stave off climate catastrophe: solar and wind, with storage and hydrogen synthesis, might be enough. Each cent pissed away on useless frivolity incrementally reduces our chance of success.
Nothing about fusion energy research indicates that it is a pointless frivolity. Things that fall in that category are adtech or fintech or middle management.
Fundamental plasma physics research is a boon. It might be worth all the spurious fusion work to get the plasma research, and continuous employment for the population of plasma physicists.
If we are serious about ramping down the use of fossil fuels, we should start with the eliminations of vehicles that we don't need, such as cars.
In order to eliminate cars, however, it will require a drastic readjustment of our urban planning policies. Land use policies are what made cars viable and public transport unviable.
I would also like to see a more walkable future, but I've given up hope that such a big transition will happen within a timeframe small enough to make a difference for things like GHG emissions. I guess I've made my reluctant peace with a rapid electrification of the world's vehicle fleet (which, yes, isn't exactly clean either).
This will NEVER happen. People rarely listen to urban planners, no one is going to tear up their cities and reorganize them around some untested ideological idea, and finally no one is going to give up their cars -- like it or not-- they are annoying.
It's much easier to just make them all electric and decarbonize grid production.
Haha, that is a bit out of touch with reality unfortunately.
Cars were immediately, obviously valuable to individuals - they gave people the freedom to go where they want to, with whom they wanted to, when they wanted to, and often allowed them to carry things that would otherwise be difficult to carry while doing so. Something which was otherwise very difficult to do previously.
If you use public transit, it’s very difficult to go somewhere others do not want to go, or at a time when others do not want to go. You’re tied to what everyone else wants, pretty explicitly, since unpopular routes or schedules get less frequent (or no) coverage, and are expensive to run. You also can’t carry arbitrary heavy stuff since that tends to require infrastructure that is difficult to carry by hand or is not compatible with typical people on foot.
Public transit is a system efficiency win, but a general loss for any outliers for individuals.
And since everything is public, it adds a lot of friction if you want to go with someone who you otherwise would have issues being seen with in public, or are going somewhere/doing something you’d rather not publicize, or who struggles with crowds or similar problems (such as those with disabilities, children who are too young to self ambulate well, etc).
Not unsolvable, but adds friction.
Cars are (when roads aren’t completely mangled anyway), individual luxury items - because they enable a large degree of useful freedom for individuals.
It’s no wonder that every economy that is able to pay for them goes crazy until it turns into a tragedy of the commons situation.
Right, but those were the motor companies behind that. IE: Concrete, spendable money. Urban planners get very little cred unfortunately.
If they were smart -- the urban planners -- they would get all computational and build highly accurate models of the cities they work for that people could just go online and check out. Then planners could create new versions of the real city, testing different ideas and sharing them interactively with the public.
Most planners these days seem to just say "mass transit GOOD!" and "cars BAD!", without really any substance behind it. This often doesn't really convince the public of much.
Cars replaced horse-drawn carriages which already filled cities. Poo covered the streets of New York City. Modern US cities were designed around the horse-drawn carriage, not the car.
I totally agree. But another big contributor to the over-use of cars is the shared illusion that everyone has to “go to work”. I think the extended pandemic is contributing to shattering that illusion.
In 2017, only about 15% of vehicle trips in the US were taken for commuting [1], the rest are for shopping/errands (45%) and for socializing/recreation (the balance). So even if we eliminate half the commute trips, we still have a long way to go to reduce the miles traveled.
[1] https://www.bts.gov/statistical-products/surveys/national-ho...
I thought it was more; thanks for the information. Although 15%, or say half that after subtracting the people who actually need to be physically at work, is still significant. Also, note that 15% of miles will be more, probably much more, than 15% of the pollution, because those miles are the slowest ones that people travel.
But < 5 mile local errands are much more polluting per mile than longer trips though as the engine doesn’t heat up to an efficient temperature so it uses something like 4 times as much fuel per mile.
I think your numbers are off somewhere. Maybe you are thinking of some particular form of pollution rather than fuel efficiency? Short trips before the engine warms up are less fuel efficient, but nowhere near only 1/4 as efficient. Here's the US government suggesting a worst case combination of cold weather and a cold engine can cause a 24% drop in miles per gallon (ie, still more than 3/4 as efficient):
Fuel economy tests show that, in city driving, a conventional gasoline car's gas mileage is roughly 15% lower at 20°F than it would be at 77°F. It can drop as much as 24% for short (3- to 4-mile) trips.
I also thought it was more (I remember reading about 30% in the early 2000's), so I was kinda surprised. I think you are right that miles traveled will be higher, so from an emissions perspective the decrease in commuting is good news. From the perspective of cars being everywhere and making environments unpleasant, as long as people don't think twice about hoping in the car to go Starbucks twice a day, we've got a huge problem.
I grew up in NYC and don’t regard cities, like Atlanta, covered in highways, to be cities. I never understood why places like this were built or how people enjoy living there, but clearly some do.
Suburbs don't have to be structured around cars! You can have lots of trees, lots of grass, be removed from bustle, and still be able to get around by car. The problem is that zoning rules have essentially regulated these sorts of suburbs out of existence. See: https://www.youtube.com/watch?v=MWsGBRdK2N0
As I said, different strokes. I'd soon go batshit crazy (to the extent I'm not already) living in that kind of cramped space surrounded by that kind of population density.
I grew up in Brooklyn, and I'm currently on team rural. I couldn't think straight with all those noises and distractions, and I was going broke trying to keep up with rent hikes.
>In 2017, only about 15% of vehicle trips in the US were taken for commuting
This describes commuting as a percentage of total trips, but it would be more useful to find the percentage of total vehicle miles traveled. I imagine that would be higher than 15%.
If you live somewhere that requires a long commute to work (ie. an exurb) you are likely completely dependent on a private vehicle for all other aspects of your lifestyle.
Good transportation policy is actually good land use policy, and good land use policy is great climate policy.
We don't need fusion reactors in space to stop climate change. We need walkable neighborhoods, an international carbon price and more trains.
The harmful fantasy being sold to the public is that we can solve climate change while still having the vast majority of people living in far flung suburbs and driving a seven person truck 10km to go pick up a carton of eggs.
>I think the extended pandemic is contributing to shattering that illusion.
Or, the opposite? How could you be so out of touch as to think society did not depend on all the masses of people who continued going to work continuing to go to work?
Realize these are the low wage workers who will be tasked to pay for your carbon tax, and they won’t blink an eye at re-electing Trump, who in such a case would be the left wing candidate regardless of his party affiliation.
It's not difficult to imagine a situation in which someone does not /strictly/ need a car (it also seems urban life is quite common these days). It should also be extremely easy to imagine having a car as extremely beneficial.
(By the way: epidemics still being far from forgotten, it's really odd to paint collective, "public" transport as aproblematic.)
Now, to attack the problem, one could also (and in some contexts primarily) hit house heating. There are voices recommending heating limited to 16°C/61°F. The issue is just about quality of life. Including enabling operations. Hacker should be attentive on their instruments, since they are instrument crafters.
Since the control of resources has always been linked to their price (which is also equivalent to, or actually including, an externality tax) - so given a clear alternative -, I am not sure how the whole idea of "we will do without", restricting "freedom" (in abstract terms, as a primary value for constitutional decisors) and operation, came to be.
(Up to not seeing "the car" as a life changing revolution... Reading just recently the first pages of a history text, the car was immediately mentioned as "expanding the possibilities for movement to unimaginable heights even for the richest of fifty years before". It has always been very clearly a most prominent gift of engineering, as if a third dotation of natural limbs: it's odd to now read about it as "negligible".)
Most cars are parked by the roadside most of the time (constricting the cariageway).
If most people who needed a car could just pick one up at their chosen departure point and abandon it at their destination, and if that were massively cheaper than private ownership (which it should be, because shared cars would see much greater utilization), that would slash the number of cars on the road.
If these were self-driving, then presumably if the model you want doesn't happen to be at your departure point, you could just ask it to come to you.
It's not difficult to imagine a situation in which someone does not /strictly/ need a car (it also seems urban life is quite common these days). It should also be extremely easy to imagine having a car as extremely beneficial.
Interurban rails and other form of mass transit gained prominence especially in the early 20th century. They were eventually outcompeted by cars on a wide variety of factors, including public support for funding of roads.
It's not too difficult to imagine freight traveling on streetcar rails.
(Up to not seeing "the car" as a life changing revolution... Reading just recently the first pages of a history text, the car was immediately mentioned as "expanding the possibilities for movement to unimaginable heights even for the richest of fifty years before". It has always been very clearly a most prominent gift of engineering, as if a third dotation of natural limbs: it's odd to now read about it as "negligible".)
The car is simply not as viable without proper infrastructure and implicit subsidies.
> It's not too difficult to imagine freight traveling on streetcar rails
So? What do you mean, what is your conclusion from that?
You wrote that «we don't need ... cars». I wrote that you don't "need" (much) heating either, relevantly to impact, but the impact on quality of life can be massive. Try performing intellectual (reduced motion, in general) activities in the cold. Try buying groceries without a car when living in a very low density, non urbanized area. Maybe you don't care about the advantages of a car: to others they are vital.
> The car is simply not as viable without proper infrastructure and implicit subsidies
So? What do you mean?
You dismissed the car as expendable, I noted that it has been called an historical revolution with a massive impact in the quality of one's life, for good.
> In order to eliminate cars, however, it will require a drastic readjustment of our urban planning policies.
(Emphasis added)
The idea that we can eliminate the use of cars with urban planning policies is a clear indication of someone who has never spent any significant amount of time outside a city, or at least has never seriously thought about what it means.
Most of the land in the world is not urban. Many millions of people live outside urban areas. That's not going to change. Probably ever. Though I'm a strong proponent of massively increased public transit systems, including both high-speed rail corridors and normal-speed rail branching off into smaller areas, cars will remain by far the most efficient means of point-to-point transport outside of well-planned urban centers (even in good rail corridors, outside of the very common cases they solve) for the foreseeable future.
How about instead we get rid of the people we don't need, so everyone driving cars involves a much smaller multiplier and we can preserve a high quality of life without trashing the place.
There's not much new info here since the last time the project was discussed. The first two comments here link to informative videos about how the reactor works: https://news.ycombinator.com/item?id=24629828#24634733
News since then:
CFS has now raised $1.8B
They have demonstrated a full-size magnet with a field strength of 20 Tesla
They have started construction on the new SPARC reactor facility.
If you're wondering what PR buys you, it's a constant stream of articles like this one. There's no new information to report, but Commonwealth Fusion Systems is in the news again!
I've got my own novel fusion reactor design that really needs to be tested.
What do you do when you have an idea that could change the world? I wish I could drop it, but I can't. It haunts me with it's elegance and simplicity, and has defied all of my attempts to find flaws in the theory.
I'm trying to move forward on my own. I'm not comfortable selling a promise. I have no guarantee that my device will work, but I have no reason to believe that it won't.
It's great that all this money is being thrown at fusion recently, but that's almost the easy part.
My gut feeling is that if you don't already know anyone you could talk to about this—which is the likely result of being an expert in the field, studying at a high level and interacting with other such experts—your design probably isn't going to work better than what's already out there, and even if it did, you wouldn't have the credibility with the field to get them to listen to you without years of work building relationships and trust.
I'm not going to try to claim that it's impossible to self-train in nuclear physics to the degree necessary to come up with a novel fusion reactor design that's a) viable, and b) genuinely novel, but it's going to be so vastly less likely than the various alternatives that, as the sibling commenter notes, even if you've already got 100% of the knowledge and understanding required to do this and you're 100% right, your best bet is almost certainly to get into a PhD program in this field, and publish this as your dissertation.
It's not that I'm trying to come up with a novel design, I already have.
I've spoken with many plasma physicists about the idea. Some actually look at it without dismissing it. The ones that understand it all say that it's either beyond their expertise, or that it needs more study, but so far nobody else seems to want to study it.
Where does that leave me? Building it myself without much outside help. I've simulated it to my satisfaction, I've been issued a patent on it, and I'm currently buying parts to build a prototype.
It's honestly a bit of a curse. I wish someone would really help me put a nail in its coffin, but as long as it has a possibility of working I have to be the advocate for it. The cost to humanity of losing a viable fusion reactor are too high for me to give up on it.
My gut feeling is that NOBODY has a reactor that really works yet. Many of these efforts might be in the same boat I am, but keep up a better exterior.
As they used to say, "Nobody ever got fired for buying IBM", well my current feeling is that tokamaks are the IBM of fusion. They're a crutch for people who are after easy money working on something safe.
Honestly, I don't think that changes the answer much. If your design were the subject of a peer-reviewed paper in respected journals, that would be much more likely to get it attention in the scientific community than what you've done thus far.
That's the kind of step that starts to make it possible for other people—beyond those you can easily personally contact—to go over your design, understand the theory behind it, and either believe it will work (and thus possibly help move it toward prototype stage), or believe it will not (and likely tell you why, with sources).
I don't claim to know much about nuclear fusion, or the people who work on it, but my impression is that they tend more toward the academic side of things than the industrial. If that's the case, peer-reviewed scientific papers laying out what you've got and why you think it'll work are, IMO, much more likely to get their interest than a random person reaching out to them with a design (even if that design does seem sound) or a patent.
Either way, best of luck. I certainly agree that if you do have a viable alternative design, getting it out there is one of the more important endeavors of the day.
Thank you. I do agree that peer review must be done, but it's almost too simple.
None of the parts of my proposed prototype are very interesting or controversial. I'm not using extreme magnetic fields, or exotic materials or new physics. Nothing about the device requires more than highschool physics and geometry to understand.
With a new arrangement, this novel solution to contain and collide ions falls out.
It's a gedanken that just needs to be built because the basic idea is less involved than some homework I've had.
Here's the main idea in the style of a highschool homework assignment:
Draw a point on a piece of paper. How many unique circles you can draw that pass through that point?
Each of those circles represents the cyclotron trajectory of a single deuterium ion in my device.
There's basically nothing to write about until an experiment is built.
Nuclear fusion isn't near until they actually start generating electric power. If they can generate power, even if it costs $1,000+ per watt, then I'll be like "Sure, maybe in a couple decades we'll see it in military or specialist applications where cost isn't a factor." But if you can't even generate a single watt of power with a couple hundred billion dollars, it is nowhere close.
It's worth noting that nuclear fission was a theoretical, barely experimental thing for decades since 1911 and 1917, until 1942 when the first successful reaction was produced.. From there you know he rest. Fusion is more difficult, so it's to be expected that more of ramp-up time is warranted. We at least know that the basic concept works. It's visible every day, worldwide.
"We at least know that the basic concept works. It's visible every day, worldwide."
The basic concept is a very hot, very big star. We cannot really rebuild that. We can make bombs with the principle since a while - but we are still far from controlling that energy.
Building a reactor that is economical is not so easy.
Fast neutrons, tritium management, corrosive molten salts, beryllium supply constraints…whole lotta material science problems you gotta work out at scale and on budget.
By "more energy out than they put in", they mean passing "theoretical breakeven", generating more energy as heat than they put in as electricity. Not converting that energy back to electricity and making the thing self-powered. Brief periods of theoretical breakeven have been achieved before.
Ahead lies "sustained theoretical breakeven" - the thing can be kept running for a while. So far, other tokomak experiments have achieved 70 seconds of plasma containment (Korea) and 120 seconds (China). That's below ignition temperature, though. Then "self-sustaining breakeven" - the thing can power itself. Then, someday, "economic break-even" - it can pay for itself. Then, maybe, useful power generation.
There's the problem of getting the energy out in some useful form. This begins with the "first wall" problem of finding something that can survive the conditions just outside the magnetic field. Those conditions include huge numbers of neutrons, which tend to split atoms in the first wall material and cause unwanted transmutation. This causes radiation embrittlement, which is not good for materials.
It's going to be a long haul.