Always happy to see people doing new and interesting stuff with fusion. I got into nuclear technology because of ITER back in the early 2000s. Worked on it continuously (mostly in advanced fission) ever since.
> "The timeline question is a tricky one," he says. "I don't want to be a laughing stock by promising we can deliver something in 10 years, and then not getting there. First step is setting up camp as a company and getting started. First milestone is demonstrating the reactions, which should be easy. Second milestone is getting enough reactions to demonstrate an energy gain by counting the amount of helium that comes out of a fuel pellet when we have those two lasers working together. That'll give us all the science we need to engineer a reactor. So the third milestone is bringing that all together and demonstrating a reactor concept that works."
The fourth step is to deliver the reactor concept as promising machine. The fifth step is to attach it to power generating equipment and demonstrate the power plant. The sixth step is to scale up a supply chain capable of delivering multiple units that compete with other sources of commodity electricity (or other energy products). The seventh step is to scale to large scale without being unduly burdened by either supply chain (raw material, skilled labor) or regulatory impact/public concern that inevitably scales with any large fleet of any new tech.
Fission made it to step 7 and then faltered and is now teetering depending on where you look. It never scaled past 5% of total world primary energy.
The promise of fusion is to deliver nuclear energy with less public concern than fission because it makes less radiologically hazardous material. The challenge is to go through the physical, engineering, and commercial viability phases as a power plant.
A number of these steps become easier if the reactor is physically small. A plant that fits in a shipping container has a way easier path to commercial viability.
Small plants require less capital. They're easier to manufacture. They can iterate faster. They have less environmental impact, and therefore fewer regulatory hurdles. They require less labor to build and a smaller supply chain.
I expect that the engineering is harder, because scale can bring efficiencies. But still, I think the winner is going to be a small device, not a behemoth, if only because a small device can come online years earlier.
I expect that you lose efficiencies with respect to security. I.e., it's not easy to secure one large nuclear reactor (fission or fusion), but it's a lot easier than securing dozens of small reactors.
Off-topic question: is there some software part in nuclear energy systems that is restricting plants or research? I'd like to contribute to the industry as a non-physicist, but it's hard for me to imagine what kind of software might be missing or is being sold by too expensive specialist companies.
I imagine most software is tied to the specific devices they run on, but perhaps there's coupling or analytical software that could be better geared towards the problem domain. Is there any fundamental issue that is waiting for a good software solution?
It just so happens that a nuclear fission reactor analysis framework recently emerged on github partially with hopes that people like you would be interested in contributing. It hasn't been widely publicized and is pretty esoteric but is there.
I'm not an expert at all, but I follow news about fusion energy with keen interest. Getting to conditions where fusion reactions can take place requires modeling the physics with supercomputers. I think the physicists have a handle on the software required to do that modeling; they also have access to the computers.
I think if you have a software background and want to contribute, you should consider applying for a job with one of the projects themselves. General Atomics lists 135 software jobs (https://www.ga-careers.com/search-jobs/software/499/1) for instance.
I've been trying to find affordable software for modeling my proposed fusion reactor, but some of the software packages I've looked at cost upward of $50k, with no guarantee that they will be able to give the answers I need. It seems to be a problem of low demand for highly specialized software, and scale issues in the different regimes within the device.
In my device, sometimes, some ions will be traveling in a vacuum with a high mean free path, and at other times, the plasma will be as dense as lead. It's VERY difficult to simulate, to the point that it's almost better to just estimate and start building to see if I can start to get close to a solution through careful experimentation.
> The fifth step is to attach it to power generating equipment
The part that jumped out at me as strange is that they claim their process generates electricity "directly" without having to drive a turbine. Supposedly they produce helium cations, and that can drive a circuit.
The main Proton-Boron reaction produces charged particles instead of neutrons. You can capture the charged particles directly as a source of voltage with no intermediate step. Just stick a piece of metal in the way and hook up wires.
Conventionally, neutrons are used to generate heat which is then used to drive steam turbines.
Most fission plants throw away about two-thirds of their energy output as waste heat (according to: https://www.answers.com/Q/How_much_of_the_heat_generated_in_...), and their cooling towers are so much bigger than the reactor itself that they've become a symbol of the plants as a whole.
In principle this could be more efficient than a heat engine, although the Wikipedia page seems to say that an "economically feasible" version would have around 60% efficiency, which is the same as a combined-cycle power plant.
I don't know whether this is a legit breakthrouhg. But technological progress is often a sigmoid (S-shaped) growth curve, it may take a while to get past certain steps but once you are through, money flows and more people devote time to that technology which accelerates the process. It is not hard to imagine, say, 20 years from now, we have power plants running on fusion given the interest we have in solving the climate crisis.
High temperature superconductors are absolutely an interesting pathway to make magnetic confinement fusion significantly easier than the big tokamaks like ITER. I have friends working at Commonwealth Fusion who are good people and I wish them much success. That said there are still a lot of phases to go through, from physical viability at stage 1 to scaled commercial fleet at stage 7, and that pathway is impossible to predict without getting on the ground and going through the stages. I certainly think it's worth running through the stages.
There is no actual expectation of ever getting useful power generation from magnetic confinement fusion (ITER, Tokamak): it has always been, instead, a jobs program for high-neutron flux physicists, to maintain a population to draw on for weapons work.
p-boron fusion is interesting as a possibly practical energy source. The hurdles are a matter of engineering and finance, not fundamental design flaws. But it's useless as a jobs program for weapon experts, so must rely on commercial investment.
> The alpha particles generated by the reaction would create an electrical flow that can be channeled almost directly into an existing power grid with no need for a heat exchanger or steam turbine generator."
It isn't that simple. This thing will be DC, and at some random voltage. They will need huge bits of kit to convert the output into some sort of usable power. It is electricity yes, but not clean useful power.
Spot on analysis. There is one loophole which is Total Cost of Ownership (TCO).
If you energy production solution can achieve a lower TCO in an existing market segment, steps six and seven (production and supply chain) take care of themselves. The poster child for this was 'on premise PV generation.'
Once a nuclear technology demonstrates a lower TCO for baseline power generation, its game on.
Tangent, but assuming fusion energy generation will be a reality in the next 30 years, what do you believe the price/KWH will be? I am not knowledgeable enough to parse the estimates I've seen and want to believe in the post-energy-scarcity future.
Price per kwh is not solely about generation efficiency, it's also about distribution and infrastructure. There will always be a cost associated with that which will rise with inflation. Even if we went totally renewable and all your electricity was "free" then you'd still have to account for on demand storage and infrastructure costs.
The main benefit of nuclear is its relatively low carbon footprint and in theory less risk of spiking fuel costs because we run out of raw materials. That's the dream of fusion anyway.
Nuclear power infra is not cheap and even fusion will have security and decommissioning costs.
Forget cost as the main factor, grid power will never be free. That's a fantasy - even publicly owned utilities will/are funded by taxation. You're paying for price and power stability. Domestic fusion means you don't need to rely on foreign resources (eg Russia cutting off the gas).
Putting renewable generators in your home has a high capital cost, but people forget that you're also cushioning yourself against grid outages. It's insurance more than anything else.
I doubt we are even anywhere near close to being able to calculate that because there’s still too many unknowns with regards to materials required to build, their rate of depreciation, and other things we discover in the scaling/commercialisation phases, and also exactly how much net energy will be produced!
You don't get to precisely choose which isotopes are produced by the reaction. Even among the light elements, there are radioactive isotopes, such as tritium. And it doesn't take much of it, to render the entire mixture hazardous unless refined in some fashion. One hope is that the refinement process can return the radioactive stuff to the cooking pot, so that the ultimate waste products are safe.
Neutrons produced in this reaction, being chargeless, cannot be contained within the electromagnetic field, thus leaving plasma and reacting with the surrounding material (e.g. tokamak chamber walls) and producing radioactive elements. This leads to activation and radioactive degradation of the reactor itself.
27 comments and not one hit of the word “inertial”! The line about not being thermonuclear and the description of the device in question (a sphere with lasers) points towards an inertial confinement fusion (ICF) device. Most of the fusion research eggs are in the thermonuclear basket, specifically magnetic confinement fusion. It is good to research a diverse set of approaches, but there are more engineering challenges to ICF reactors than there are to MCF reactors. Pulses on the order of 1-2 Hz requires a mechanical system that can cycle out the exhaust and replace the pellet in that time. Going to reactor scales also requires high load thermal cycles. MCF ain’t easy, and brings it’s own engineering challenges. The ones I always hear are things like wall materials and fuel recycling, but these are largely solved or in the process of being solved. The engineering challenge I see as the most difficult for MCF are related to steady state operation. Tokamaks have no way of being steady state. Stellarators do, but now the next problem is wall conditioning. Wall materials outgas in hot plasma. A lot. Like more than the fuel puffed in. The way this is handled in science machines is with glow discharges of various species: plasma just below the temperature to cause wall sputtering, coating the wall with carbon and boron for their absorptive properties, etc. No one’s run a steady state hot plasma before, so no one knows if these will be a non issue in reactors. Keeping the plasma clean may be a challenge to keep the plasma from terminating. Aside from that MCF is ready for prime time. It needs a big reactor for scaling laws to make it energy profitable (and potentially money profitable). We just need some very expensive test reactors to smooth out these issues.
It seems easy to conflate any or all approaches as fringe when no one's done it yet, and especially if there are political and program-$ecurity concerns overriding doing what's best, but some approaches scream magical thinking with unexplained reasoning more than others (like one or more cold fusion proposals in the early 1980's). OTOH, it seems like ICF and tokamak are the officially-sanctioned dogma and all other approaches are discounted automatically.
Q0: Without bias from my opinion, how fringe or potentially legitimate does IEC seem?
Q1: Props to the article's team that they invented some awesome lasers. Is there enough experimental data yet on their novel approach to backup their claims to justify funding a prototype? Would such a team be able to test this on a shoestring budget without spending millions?
"Millions" is pretty much a shoestring budget for fusion projects. There is some experimental data, but without actual fusion since the lasers weren't powerful enough yet.
This team didn't invent the lasers. They've been waiting for the lasers to get sufficiently powerful to attempt fusion with them. Those lasers are finally becoming available for researchers to use, so it should be quite inexpensive to test this idea. Worst case, they have to build one for tens of millions, which is comparable to other private fusion projects, but hopefully they can run the experiment on other people's lasers.
Personally, without drawing from rigorous empirical proof that doesn’t exit, I don’t think things like unique IEC approaches are based in fairy tales. Fusion science used to be very tribal and dogma was important. That era has largely passed. Tokamak, stellarator, ps laser, steam machine, whatever. If you can find the money to make it and do the science to show its performance, great. Everyone wants you to do that. This idea of pulling resources away is tricky to navigate, because there is finite resources spent on research and getting any one design to work takes significant effort. That’s why so much is being poured into ITER instead of other promising leads. Humans are ready to see a machine work. It’s painful to get there. It’s not my first pick on a machine. But in order to keep progress moving a real reactor needs to be made of some kind.
As an absolute dummie I had to think of ASML where they repeatedly hit molten tin droplets in flight with CO2-lasers, to produce some plasma, to get extreme ultraviolet light out of it. 50.000 times per second. So the part to hit something very small in flight, in a vacuum, precisely and repeatedly exists on an industrial scale already. Though not simple, small and cheap. Should ask Cymer or Trumpf who do this. And forget about all that unnecessary light generating stuff, just ripping out the necessary parts and adapt for their application. And of course harden it against the FUSION happening. Simple, isn't it?
Complete layman to this, but are these approaches fundamentally incompatible with one-another, or is it just that each one on its own seems to be “enough” to get a reactor to work? Could you have a reactor that just combines all these confinement approaches at once?
They're not incompatible in the sense that they assume different physics, but they are very different strategies.
The fusion triple product is the go to figure of merit for napkin calculations, it's temperature X confinement time X ion density
MCF strategies go in on maximizing confinement time, while ICF jack up temperature and ion density. This particular ICF approach, (if I'm understanding their paper correctly) is going so high on both that they're leaving the thermal regime behind and doing an honest to glob nuclear chain reaction with having the alpha products prompt other boron nuclei to accelerate up to fusion speed causing more reactions, which is pretty exciting.
I don't have the Physics chops to untangle the likelihood of this tech and the credibility of the process and its authors, so I'm hoping the HN crowd will be able to pad out the story behind this.
Certainly, from my layperson's perspective, their website isn't exactly encouraging... https://www.hb11.energy/
- ed re: last line - "books and covers, and all that"
Check the publications page for the encouraging part. They might be wrong but they're doing real science. I've personally spoken to a fusion scientist who thought they might be on to something.
Exponential progress does sometimes have results that seem too good to be true. In this case the progress has been in picosecond lasers, which for a while have been getting ten times more powerful every three years or so.
What's great about this is it should be pretty cheap to test. The petawatt lasers only cost tens of millions in the first place, and China is finishing up a 30PW laser which they plan to let other researchers use. If Hora is right then that should be powerful enough. Even more powerful lasers are being planned elsewhere.
HB11 isn't the only company working on aneutronic fusion. The largest is TAE (formerly Tri Alpha), with about $700 million invested. There's also Helion and LPP.
>Check the publications page for the encouraging part. They might be wrong but they're doing real science. I've personally spoken to a fusion scientist who thought they might be on to something.
I checked the publications page and so far I'm not seeing any real theory here. That doesn't mean it's wrong, but it certainly feels weird. The most in-depth equation I saw in any of their linked papers is the definition of the electromagnetic field tensor.
I'm not saying you couldn't develop a fusion reactor by doing purely experimental work with bleeding-edge laser technology. But I'd feel a lot more confident if they were to produce, for example, some kind of prediction of their net power, or a relation between e.g. laser power and fusion yield, or some other quantitative prediction about something.
For example, I'm not sure what prediction they exceeded by a factor of a billion in TFA. Shouldn't you mention that somewhere?
Another poster mention's Todd Rider's thesis, a famous barrier to creative fusion. In this particular case I think the way they evade Rider is by using higher laser powers and shorter reaction times than Rider considered to be possible. One of the important exceptions Rider acknowledges (and that I remember) is ultradense fusion; ultrafast fusion seems to be at least similar in principle.
Thanks to yourself and randallsquared below for your responses - I'd since posting read the following Abstract by the authors, which hinted that the underlying science was viable: https://www.cambridge.org/core/journals/laser-and-particle-b... , however my only awareness of existing 'laser fusion facilities' was the American National Ignition Facility (https://en.wikipedia.org/wiki/National_Ignition_Facility) , which I think I'd always written off as a covert testing facility for weapons that skirted Nuclear Testing limitation treaties.
The Hydrogen Boron reaction is real and well-known to be a way to do fusion without lots of stray neutrons. The sticking point has always been that it's more difficult to cause that reaction than deuterium/tritium or deuterium/deuterium.
The big problem with H-B11 and other heavier fusion processes is that the energy radiated away as brehmsstrahlung is greater that the energy gain from the fusion. This was worked out by Todd Rider in his 1995 PhD thesis.
Yeah, in theory it might be possible to capture the brehmsstrahlung and pump it back into the reactor with sufficiently high efficiency, but we're pretty far away from that.
That being said, all these fancy fusion reactor schemes are interesting. Just make them work on boring old D-T fuel first, then lets see if these other fuels are usable, no?
Yes, but Rider based that on various assumptions, and included an appendix on various ways those assumptions might be violated to achieve net power with aneutronic fuels. I think this reactor would qualify, since it doesn't rely on thermal heating.
I can’t tell for sure from the article but I think they are accelerating protons with TNSA (target normal sheath acceleration). I worked in a lab in undergrad that was doing something similar, except with lithium instead of boron. The main challenges that I recall from a decade ago with TNSA are (WARNING: there almost certainly has been progress since a decade ago):
-Conversion efficiency of laser energy into ion (proton) kinetic energy
-TNSA accelerates mainly the contaminated layer on the back of targets, which may not be a big deal if you are interested in accelerating protons
-TNSA protons are not beam like. They do not have a uniform kinetic energy, and they have a wide angular divergence.
-Various laser related issues (prepulse, focal spot size/shape).
I also anticipate that it will have the same engineering problem as ICF/NIF, in that it will need to continuously replenish targets.
After reading the article and skimming some of the innumberable references (the article is all references) it seems like the unobtanium part of using laser pondermotive force to accelerate blocks high density plasma from solid state is that the laser "contrast ratio" has to be very high. In the paper it cites many failed replication efforts to use this particular laser pondermotive force due to lack of "contrast ratio".
I have no idea what "contrast ratio" means, it isn't defined, and isn't in the references. Does anyone know what "contrast ratio" means in terms of high power pulsed lasers?
> the laser pulse contrast ratio (LPCR) is a crucial parameter to take into consideration. Considering the laser pulse intensity temporal profile, the LPCR is the ratio between its maximum (peak intensity) and any fixed delay before it. A low contrast ratio can greatly modify the dynamics of energy coupling between the laser pulse and the initial target by producing a pre-plasma that can change the interaction mechanism.
It seems to be how fast the laser turns on, the rate of change of intensity.
Do a google search for "laser induced fission". Generating plasmas with CPA lasers is becoming more common, but isn't widespread yet because the technology is very new.
These plasmas can be the source for all kinds of particles and energy in particular forms, so they may have lots and lots of uses.
One person in particular is proposing to use a CPA laser to accelerate nuclear decay, to allow radioactive waste to decay faster and become less toxic more quickly.
Of course, my own concern would be that being able to induce fission with a table top laser means that the tech may eventually exist to create a fission or fusion bomb without a nuclear trigger....
If they succeed in creating a viable p-B11 fusion power plant and that gets developed into a bomb, wouldn't it be a good thing in the sense that it could replace many thousands of fission-based bombs that have huge fallout risk?
I don't know. I think a really flashy website would be more concerning. This is a serviceable website that gets it's point across without consuming a gig of bandwidth on a video in the header background.
Yeah I've become wary of "scientific breakthrough" articles that never seem to materialize into anything.
But ITER uses huge tower cranes and trucks in the thousands of tons of material required to sustain a temperature hotter than the surface of Sol because of their fuel selection.
It seems the small player with a new approach that perhaps demands less complexity in their scaled up commercial reactor could win a commissioning contract with a lower bid during late 2020s early 2030s international bidding.
"First milestone is demonstrating the reactions, which should be easy."
And "chirped pulse laser amplification" is the recent discovery Hora says will make it possible.
As a researcher I really like 'scientific breakthrough" articles where the impact never seems to materialize. It reminds me that technology development works very differently on earth than it does in my imagination.
Breakthroughs happen everyday but the road to real impact is longer and more failure prone after you make the breakthrough than before it.
Not a physicist, but I thought it seemed fishy as well. I’m curious how they plan to sustain a reaction, since their setup didn’t seem to be useful for more than a single shot…
This reads like a type of ICF which normally has a stream of pellets being fed in after the initial pellet has reached a hot enough temperature to sustain the fusion reaction.
To shed a different light on this: think of temperature as walking through mud. Your legs lose energy trying to slowly pull a lot of mud behind you. Now think about skiing. A lot less snow is dragged with you but it flies fast.
Here, what is interesting is if one fusion reaction does happen, then the alpha (helium) particles leave at 2.9 MeV. After two collisions with protons, if the second proton they have hit hits in turn a boron nucleus, then it will have exactly the right energy (612 keV) to have maximum chances at initiating a second fusion reaction.
612 keV is like almost 7 billion degrees °C if considered as thermal energy, and no experiment anywhere will get that hot for long. But compared to the energy of the exiting helium nuclei, it's still much lower (0.612 MeV vs 2.9 MeV).
In other words, instead of cascading all the energy down and hoping the sea of particles rises to a few billion degrees so enough particles do fusion to keep the sea of other particles hot, here, the energy is preempted by proton atoms after just 2 collisions and used immediately to start a second reaction, which yields more helium nuclei at 2.9 MeV, essentially producing an "avalanche" effect.
Finally, yes, they seem to have devised a way to obtain at least a small part of the energy electrically, without relying on thermal energy, via direct electric field deceleration of very fast charged particles.
This is like "the ultra rich (very fast particles) manage to create value among themselves without having to cascade their wealth down to the crowd (cold particles), and then upload that value to hyperspace (the electric field from the electrodes), without ever interacting with the mass of the crowd (the mass of the target), until a sufficient amount of fusion reactions have been realized"
And yes, a petawatt (the energy of present day ultra-fast lasers) is a lot of power. It was just chance that there was very little practical use to this kind of power - until now.
That being said, I am not a true expert myself of this topic, so the true barriers laying in front of this concept might be better explained by the other comments here.
> This is like "the ultra rich (very fast particles) manage to create value among themselves without having to cascade their wealth down to the crowd (cold particles), and then upload that value to hyperspace (the electric field from the electrodes), without ever interacting with the mass of the crowd (the mass of the target), until a sufficient amount of fusion reactions have been realized"
This was actually a helpful analogy for me. I'll have to take your word on the accuracy of it, though.
https://www.nature.com/articles/srep01170 ehich is the first linked paper in that section explains it well. The laser fires through the hole and ablates material from the back disc. The electrons from the created plasma reach the other side of the disc first before the ions because they are lighter, causing a buildup of negative charge on the other side. This charge differential drives a current between the two plates, which creates a magnetic field inside the coil.
"the ultra rich (very fast particles) manage to create value among themselves without having to cascade their wealth down to the crowd (cold particles), and then upload that value to hyperspace (the electric field from the electrodes), without ever interacting with the mass of the crowd (the mass of the target)"
Are you saying this kind of fusion is anti social justice? We should ban this immediately!
Sigh: Second milestone is getting enough reactions to demonstrate an energy gain by counting the amount of helium that comes out of a fuel pellet when we have those two lasers working together. That'll give us all the science we need to engineer a reactor.
I love the work, I love that they have exploited the fact that we can build things (lasers) now that we could not economically build before. But the fact is that so many many things die on the aforementioned step from the article.
That is the step wherein the science doesn't give you a way to engineer a reactor, instead it illuminates something you didn't know before and so that you now realize you can't ever build a reactor that way.
So when I read these papers and the science isn't all figured out, I temper my enthusiasm. High hopes, low expectations, that's a good motto here. Unlike the stellerator where all the science is "known" and they are engineering an implementation step by step by step.
I've added it to my fusion project collection under "interesting long shots", check back in 5 years to see what the science taught them.
Upvoted — the first minute or so of the video is very helpful; it shows (what looks like) PowerPoint slides with drawings of a proton (1H nucleus) hitting a boron nucleus (5B11); the proton fuses into the boron nucleus to create what presumably is a single carbon nucleus (6C12), which then splits into three helium nuclei (each 2He4) without emitting free neutrons.
(The very-crude video technique was fascinating to this non-artistic person: Create PowerPoint slides, add subtitles for "narration" that float in and out, and finally add stock music for background. That might be useful for flipped-classroom courses.)
> and most rely on a deuterium-tritium thermonuclear fusion approach that requires the creation of ludicrously hot temperatures, much hotter than the surface of the Sun, at up to 15 million degrees Celsius (27 million degrees Fahrenheit).
I think they might be thinking of the corona of the sun
> The temperature in the corona is more than a million degrees, surprisingly much hotter than the temperature at the Sun's surface which is around 5,500° C
Fusion happens in the core of stars but is powered by gravity. “Temperature” in this case is individual particle speed (in eV) because the particle speed distribution is not necessarily Boltzman. Higher particle speeds are needed because our confinement fields are weaker than the force of gravity inside a star.
Assuming you're talking about the temperature, it's always been a source of human pride to me that the hottest place in the entire universe, as far as we are aware, has been created at the LHC on Earth.
Barring other species as intelligent as ours elsewhere (which is of course possible, but unknown), the very hottest thing in the entire unimaginably-large universe full of exotic stars and black holes and supernovae, was created by a tiny group of apes on a minuscule planet orbiting a smallish, boring star on the unfashionable side of a galaxy.
Readit News
> "The timeline question is a tricky one," he says. "I don't want to be a laughing stock by promising we can deliver something in 10 years, and then not getting there. First step is setting up camp as a company and getting started. First milestone is demonstrating the reactions, which should be easy. Second milestone is getting enough reactions to demonstrate an energy gain by counting the amount of helium that comes out of a fuel pellet when we have those two lasers working together. That'll give us all the science we need to engineer a reactor. So the third milestone is bringing that all together and demonstrating a reactor concept that works."
The fourth step is to deliver the reactor concept as promising machine. The fifth step is to attach it to power generating equipment and demonstrate the power plant. The sixth step is to scale up a supply chain capable of delivering multiple units that compete with other sources of commodity electricity (or other energy products). The seventh step is to scale to large scale without being unduly burdened by either supply chain (raw material, skilled labor) or regulatory impact/public concern that inevitably scales with any large fleet of any new tech.
Fission made it to step 7 and then faltered and is now teetering depending on where you look. It never scaled past 5% of total world primary energy.
The promise of fusion is to deliver nuclear energy with less public concern than fission because it makes less radiologically hazardous material. The challenge is to go through the physical, engineering, and commercial viability phases as a power plant.
Small plants require less capital. They're easier to manufacture. They can iterate faster. They have less environmental impact, and therefore fewer regulatory hurdles. They require less labor to build and a smaller supply chain.
I expect that the engineering is harder, because scale can bring efficiencies. But still, I think the winner is going to be a small device, not a behemoth, if only because a small device can come online years earlier.
I imagine most software is tied to the specific devices they run on, but perhaps there's coupling or analytical software that could be better geared towards the problem domain. Is there any fundamental issue that is waiting for a good software solution?
https://github.com/terrapower/armi
Some more open source things in the domain can be found here: https://github.com/paulromano/awesome-nuclear/blob/master/RE...
I think if you have a software background and want to contribute, you should consider applying for a job with one of the projects themselves. General Atomics lists 135 software jobs (https://www.ga-careers.com/search-jobs/software/499/1) for instance.
In my device, sometimes, some ions will be traveling in a vacuum with a high mean free path, and at other times, the plasma will be as dense as lead. It's VERY difficult to simulate, to the point that it's almost better to just estimate and start building to see if I can start to get close to a solution through careful experimentation.
The part that jumped out at me as strange is that they claim their process generates electricity "directly" without having to drive a turbine. Supposedly they produce helium cations, and that can drive a circuit.
Can anybody comment on whether that makes sense?
Conventionally, neutrons are used to generate heat which is then used to drive steam turbines.
Most fission plants throw away about two-thirds of their energy output as waste heat (according to: https://www.answers.com/Q/How_much_of_the_heat_generated_in_...), and their cooling towers are so much bigger than the reactor itself that they've become a symbol of the plants as a whole.
In principle this could be more efficient than a heat engine, although the Wikipedia page seems to say that an "economically feasible" version would have around 60% efficiency, which is the same as a combined-cycle power plant.
What is your opinion on SPARC and tokamak energy?
p-boron fusion is interesting as a possibly practical energy source. The hurdles are a matter of engineering and finance, not fundamental design flaws. But it's useless as a jobs program for weapon experts, so must rely on commercial investment.
> The alpha particles generated by the reaction would create an electrical flow that can be channeled almost directly into an existing power grid with no need for a heat exchanger or steam turbine generator."
Deleted Comment
If you energy production solution can achieve a lower TCO in an existing market segment, steps six and seven (production and supply chain) take care of themselves. The poster child for this was 'on premise PV generation.'
Once a nuclear technology demonstrates a lower TCO for baseline power generation, its game on.
The main benefit of nuclear is its relatively low carbon footprint and in theory less risk of spiking fuel costs because we run out of raw materials. That's the dream of fusion anyway.
Nuclear power infra is not cheap and even fusion will have security and decommissioning costs.
Forget cost as the main factor, grid power will never be free. That's a fantasy - even publicly owned utilities will/are funded by taxation. You're paying for price and power stability. Domestic fusion means you don't need to rely on foreign resources (eg Russia cutting off the gas).
Putting renewable generators in your home has a high capital cost, but people forget that you're also cushioning yourself against grid outages. It's insurance more than anything else.
Why is there any radioactive material produced by a fusion reactor ?
Neutrons produced in this reaction, being chargeless, cannot be contained within the electromagnetic field, thus leaving plasma and reacting with the surrounding material (e.g. tokamak chamber walls) and producing radioactive elements. This leads to activation and radioactive degradation of the reactor itself.
For ICF, a long-pulse laser is used like a hammer to heat and compress the material to fusion conditions.
This scheme, as far as I can tell, uses the large EM fields of a short-pulse laser to accelerate a ‘beam’ of ions into cold material to induce fusion.
Q0: Without bias from my opinion, how fringe or potentially legitimate does IEC seem?
Q1: Props to the article's team that they invented some awesome lasers. Is there enough experimental data yet on their novel approach to backup their claims to justify funding a prototype? Would such a team be able to test this on a shoestring budget without spending millions?
"Millions" is pretty much a shoestring budget for fusion projects. There is some experimental data, but without actual fusion since the lasers weren't powerful enough yet.
This team didn't invent the lasers. They've been waiting for the lasers to get sufficiently powerful to attempt fusion with them. Those lasers are finally becoming available for researchers to use, so it should be quite inexpensive to test this idea. Worst case, they have to build one for tens of millions, which is comparable to other private fusion projects, but hopefully they can run the experiment on other people's lasers.
* https://en.m.wikipedia.org/wiki/Polywell
(stupid grin)
The fusion triple product is the go to figure of merit for napkin calculations, it's temperature X confinement time X ion density
MCF strategies go in on maximizing confinement time, while ICF jack up temperature and ion density. This particular ICF approach, (if I'm understanding their paper correctly) is going so high on both that they're leaving the thermal regime behind and doing an honest to glob nuclear chain reaction with having the alpha products prompt other boron nuclei to accelerate up to fusion speed causing more reactions, which is pretty exciting.
I don't have the Physics chops to untangle the likelihood of this tech and the credibility of the process and its authors, so I'm hoping the HN crowd will be able to pad out the story behind this.
Certainly, from my layperson's perspective, their website isn't exactly encouraging... https://www.hb11.energy/
- ed re: last line - "books and covers, and all that"
Exponential progress does sometimes have results that seem too good to be true. In this case the progress has been in picosecond lasers, which for a while have been getting ten times more powerful every three years or so.
What's great about this is it should be pretty cheap to test. The petawatt lasers only cost tens of millions in the first place, and China is finishing up a 30PW laser which they plan to let other researchers use. If Hora is right then that should be powerful enough. Even more powerful lasers are being planned elsewhere.
HB11 isn't the only company working on aneutronic fusion. The largest is TAE (formerly Tri Alpha), with about $700 million invested. There's also Helion and LPP.
I checked the publications page and so far I'm not seeing any real theory here. That doesn't mean it's wrong, but it certainly feels weird. The most in-depth equation I saw in any of their linked papers is the definition of the electromagnetic field tensor.
I'm not saying you couldn't develop a fusion reactor by doing purely experimental work with bleeding-edge laser technology. But I'd feel a lot more confident if they were to produce, for example, some kind of prediction of their net power, or a relation between e.g. laser power and fusion yield, or some other quantitative prediction about something.
For example, I'm not sure what prediction they exceeded by a factor of a billion in TFA. Shouldn't you mention that somewhere?
Another poster mention's Todd Rider's thesis, a famous barrier to creative fusion. In this particular case I think the way they evade Rider is by using higher laser powers and shorter reaction times than Rider considered to be possible. One of the important exceptions Rider acknowledges (and that I remember) is ultradense fusion; ultrafast fusion seems to be at least similar in principle.
1 proton + (5 protons, 6 neutrons) -> 3 * (2 protons, 2 neutrons)
https://www.hb11.energy/our-technology
Yeah, in theory it might be possible to capture the brehmsstrahlung and pump it back into the reactor with sufficiently high efficiency, but we're pretty far away from that.
That being said, all these fancy fusion reactor schemes are interesting. Just make them work on boring old D-T fuel first, then lets see if these other fuels are usable, no?
Bremsstrahlung
FTFY
-Conversion efficiency of laser energy into ion (proton) kinetic energy
-TNSA accelerates mainly the contaminated layer on the back of targets, which may not be a big deal if you are interested in accelerating protons
-TNSA protons are not beam like. They do not have a uniform kinetic energy, and they have a wide angular divergence.
-Various laser related issues (prepulse, focal spot size/shape).
I also anticipate that it will have the same engineering problem as ICF/NIF, in that it will need to continuously replenish targets.
https://www.hb11.energy/news-and-publications
I have no idea what "contrast ratio" means, it isn't defined, and isn't in the references. Does anyone know what "contrast ratio" means in terms of high power pulsed lasers?
edit: To answer my own question, ref: https://cdn.intechweb.org/pdfs/24813.pdf
> the laser pulse contrast ratio (LPCR) is a crucial parameter to take into consideration. Considering the laser pulse intensity temporal profile, the LPCR is the ratio between its maximum (peak intensity) and any fixed delay before it. A low contrast ratio can greatly modify the dynamics of energy coupling between the laser pulse and the initial target by producing a pre-plasma that can change the interaction mechanism.
It seems to be how fast the laser turns on, the rate of change of intensity.
These plasmas can be the source for all kinds of particles and energy in particular forms, so they may have lots and lots of uses.
One person in particular is proposing to use a CPA laser to accelerate nuclear decay, to allow radioactive waste to decay faster and become less toxic more quickly.
Of course, my own concern would be that being able to induce fission with a table top laser means that the tech may eventually exist to create a fission or fusion bomb without a nuclear trigger....
But ITER uses huge tower cranes and trucks in the thousands of tons of material required to sustain a temperature hotter than the surface of Sol because of their fuel selection.
It seems the small player with a new approach that perhaps demands less complexity in their scaled up commercial reactor could win a commissioning contract with a lower bid during late 2020s early 2030s international bidding.
"First milestone is demonstrating the reactions, which should be easy."
And "chirped pulse laser amplification" is the recent discovery Hora says will make it possible.
Breakthroughs happen everyday but the road to real impact is longer and more failure prone after you make the breakthrough than before it.
- with some exceptionsOn ignoring the H B-11 reaction with high intensity lasers: https://www.nature.com/articles/ncomms3506
On the reaction avalanche: https://www.cambridge.org/core/journals/laser-and-particle-b...
On the conversion of alpha particles to electricity: https://www.cambridge.org/core/journals/laser-and-particle-b...
Deleted Comment
Deleted Comment
Here, what is interesting is if one fusion reaction does happen, then the alpha (helium) particles leave at 2.9 MeV. After two collisions with protons, if the second proton they have hit hits in turn a boron nucleus, then it will have exactly the right energy (612 keV) to have maximum chances at initiating a second fusion reaction.
612 keV is like almost 7 billion degrees °C if considered as thermal energy, and no experiment anywhere will get that hot for long. But compared to the energy of the exiting helium nuclei, it's still much lower (0.612 MeV vs 2.9 MeV).
In other words, instead of cascading all the energy down and hoping the sea of particles rises to a few billion degrees so enough particles do fusion to keep the sea of other particles hot, here, the energy is preempted by proton atoms after just 2 collisions and used immediately to start a second reaction, which yields more helium nuclei at 2.9 MeV, essentially producing an "avalanche" effect.
Finally, yes, they seem to have devised a way to obtain at least a small part of the energy electrically, without relying on thermal energy, via direct electric field deceleration of very fast charged particles.
This is like "the ultra rich (very fast particles) manage to create value among themselves without having to cascade their wealth down to the crowd (cold particles), and then upload that value to hyperspace (the electric field from the electrodes), without ever interacting with the mass of the crowd (the mass of the target), until a sufficient amount of fusion reactions have been realized"
The avalanche process is explained in Hora's 2016 publication, with a schematic page 9: https://aip.scitation.org/doi/10.1016/j.mre.2017.05.001
And yes, a petawatt (the energy of present day ultra-fast lasers) is a lot of power. It was just chance that there was very little practical use to this kind of power - until now.
That being said, I am not a true expert myself of this topic, so the true barriers laying in front of this concept might be better explained by the other comments here.
This was actually a helpful analogy for me. I'll have to take your word on the accuracy of it, though.
https://www.cambridge.org/core/services/aop-cambridge-core/c... I found this overview a bit confusing and sort of low quality, but at least it references a lot of papers. (But haven't started hunting down any of them.)
Are you saying this kind of fusion is anti social justice? We should ban this immediately!
I love the work, I love that they have exploited the fact that we can build things (lasers) now that we could not economically build before. But the fact is that so many many things die on the aforementioned step from the article.
That is the step wherein the science doesn't give you a way to engineer a reactor, instead it illuminates something you didn't know before and so that you now realize you can't ever build a reactor that way.
So when I read these papers and the science isn't all figured out, I temper my enthusiasm. High hopes, low expectations, that's a good motto here. Unlike the stellerator where all the science is "known" and they are engineering an implementation step by step by step.
I've added it to my fusion project collection under "interesting long shots", check back in 5 years to see what the science taught them.
They haven’t even demonstrated the reaction? What’s all the talk about results being “billions” of times better than expected?
Deleted Comment
(The very-crude video technique was fascinating to this non-artistic person: Create PowerPoint slides, add subtitles for "narration" that float in and out, and finally add stock music for background. That might be useful for flipped-classroom courses.)
Surface of the Sun - 6000 C
Center of the Sun - 15000000 C
> The temperature in the corona is more than a million degrees, surprisingly much hotter than the temperature at the Sun's surface which is around 5,500° C
https://scied.ucar.edu/solar-corona
Barring other species as intelligent as ours elsewhere (which is of course possible, but unknown), the very hottest thing in the entire unimaginably-large universe full of exotic stars and black holes and supernovae, was created by a tiny group of apes on a minuscule planet orbiting a smallish, boring star on the unfashionable side of a galaxy.