Amazing new algorithm makes fusion power slightly less incredibly inefficient Google and Tri Alpha Energy, a Californian energy company, say they have come up with an algorithm that appears to help scientists generate hotter plasma more efficiently for nuclear fusion experiments. Keyword: experiments. Billions of dollars have been poured into achieving clean, carbon-free energy harnessed from smashing …
I've never figured out whether I want to tell him "better" is more accurately formed letters or higher contrast letters. Sometimes the choice is between a perfectly formed 'E' that's got medium level contrast, and an 'E' that has a slight aberration that's got very high contrast. Which is better for actual vision?
I've never figured out whether I want to tell him "better" is more accurately formed letters or higher contrast letters.
Tell them what you're seeing. So they can choose the next lens to try with more information.
Admittedly things are rather different for me. When you've got about 5% of normal vision the 5%-odd inaccuracy of the test is more-or-less equal to what you're trying to measure.
So the correct way to test vision this rubbish is apparently to work out the prescription for the lenses, and work backwards from that. The difference is between not being able to read the top letter on the chart, or maybe being able to read it with glasses on. So admittedly my answer above is given based on the fact that I'm dealing with people who're probably better trained and certainly have more experience (as they work in an eye hospital).
The other difference to having your eye test done in a hospital is they have these weird, massive, metal chairs. Bolted to the ground and with foot-rests. Which look like they've probably got mountings, so they can strap you in. And the room is filled with all sorts of gear that looks like torture equipment. Especially the thing with the chin-rest and massive lights they shine in your eyes and the probe that has to touch your eyeball in order to do the pressure test.
Is it safe. Is it safe...
My optometrist has all that stuff you describe and he's just in a normal office, not in a hospital. Except that several years ago he replaced the probe that touches your eyeball with something that does the pressure test by blowing a puff of air into your eye. Still a bit annoying, but at least it means you no longer need the numbing drops!
Is this better, or worse?
I asked several friends about this, and apparently, I've been going to the wrong sort of optometrist.
Mine sticks sharp wooden needles in my eye and asks if if hurts more or less than the previous.one.
I think I'd best go to a different one.
You are describing the epitome of research. Shame on you. Sticking pins in stuff to see what happens is how scientists all over the globe function. Sadly, most of this is a complete failure, and the pins are never recycled. But, they do use acres of paper made from trees to publicise their efforts. My own research area is how to recycle old scientists. Despite their undoubted scientific skills, most couldn't turn a sausage on barbecue if they tried. I have this theory ( yet to be published) that scientists would serve us better by helping chefs to cook stuff normally, and to avoid using foreign words on menus. :-)
I thought your sentence was going to end "scientists would serve us better as casserole".
But it turns out you decided they should teach us to cook. I'm happy to have a replacement for kitchen-french, but only if they don't replace it with kitchen-maths.
I don't want to have boeuf bourguignon replaced with:
beef³+seared@523.15K+boiled@373.15K+wine
> I remember there being anti-nuclear protests outside the JET project at Culham, despite the physical impossibility of the machine doing anything dangerous (in the nuclear sense)
Mind you, any research which increases our knowledge of nuclear fusion processes is going to be gladly accepted by the people who make bombs.
This sounds like a species of genetic algorithm with operator input.
The company's name is Triple Alpha, but they're developing proton-boron fusion instead?
Could this be a viable source of helium? Proton-boron fusion creates 3 atoms of helium and 8.7 MeV of assorted energy. Assuming a 1 GW total energetic output from fusion, a plant would create 3592 mol/s, which is a hair under 900 grams of helium per second. A few plants could conceivably meet the total helium needs of the entire world. This seems like a lot of helium output, but the reaction is about 1/20 as energetic as fission, so maybe I didn't screw up the math. Anyone care to check?
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According to Wikiwhatnot this company are pursuing the proton-boron fusion reaction precisely because this releases all its energy into the three alpha particles produced. No tricky neutron energy to absorb/convert. Trouble is it needs approx 10x the plasma pressure of D-T fusion.
Nice to see this example of machine learning even if it is human-in-the-loop.
When I was a lad at a school in Oxfordshire (*) in the eighties we went on a field trip to the local fusion reactor experiment. I seem to recall that they talked about orders of magnitude out from sustainable fusion rather than a factor of two. I remember seeing a graph of progress with a logarithmic Y axis and a fair way to go on the X axis.
They talked about "50 years away" (or was it 25 - that X axis was hard to interpret!) and I note that reasonably current articles in New Scientist still mention similar timescales. It will happen one day but it is rather expensive and rather hard to get politicians to sign off the vast sums needed for a very, very long slog.
(*) WTF Google - that's how its spelt - what's with the squiggly underscore?
The article talked about an improvement in the temperature and efficiency over current methods by a factor of 2.
You can go online and find YouTube vids on MIT research in to Fusion and their take on R&D outside of the large scale Tokamacs ?sp? where they want to use the plasma shape to help with its efficiency.
The issue is to raise the temps and the longevity of the 'burn'.
And yes... its still just 50 years away.
I blame Bush, Obama and Congress over the past 12+ years for killing high energy funding.
The interesting thing is the super conducting materials used to help create the magnetic fields has advanced. Kinda cool. So you should check out the vids.
"this doesn't seem to even begin to make a dent in the problem"
I quite agree - all this really consists of is a virtual board of knobs - the operator can then twiddle them one by one, (then all over again) until they get the best possible results from the current method - it doesn't directly alter the method at all, and unless they take some time to analyse the _reason_ why these settings are optimum, then they will have learned nothing.
But at least they are trying.
To the research scientists trying to understand fusion (instead of building reactors that make electricity).
Here's some free ideas. You're welcome.
1. start acting like this is a problem that needs to be SOLVED, instead of UNDERSTOOD
2. 1 word: RESONANCE [if you're a nuke scientist you know what this means]
3. Study how a 'travelling wave tube' works when it's creating or amplifying microwave frequencies, particularly with respect to "electron bunching" (and RESONANCE). Applications obvious.
4. Consider magnetic lenses and magnetic compression, not a toroid
5. There's an existing design that seeks to eliminate the effects of a torus causing the inside track to be slower than the outside track, something that was once pursued by the U.S. Navy, but somewhat recently abandoned [probably for something a whole lot better that's classified]
6. You're going to have to get energy out of the reaction at some point. Have you figured out how to do this? I suggest making the reaction happen inside a cavity within a large tank of water [aka 'boiler']. Steam systems would then attach to it. the rest is kind of obvious.
7. superconducting magnets lose their magnetism and/or superconducting properties under high doses of gamma radiation. don't use them. Pulsing electromagnets would have other benefits as well. Try those.
8. electrostatic focusing has been used for DECADES with various kinds of vacuum tubes/valves. Resurrect that tech, except using it for protons/deuterons/tritions etc.
9. deuterium and tritium are NOT the only fusion fuels. How about firing high energy protons at a solid lithium target? Or maybe lithium at lithium? Whatever, just try things. Inertial confinement seems to work kinda well with a solid fuel pellet, though it takes too much energy to burn the fuel. How about if that pellet crashes into "other fuel" ?
anyway, just thought I'd mention things like this in a different venue. who knows, it might work.
You need to check out some of the research by MIT.
There are designs that make using newer super conducting magnets viable. And newer materials.
Tokamack ?Sp? is based on toroid design but some of the incremental research is using linear systems.
More funding is needed and leaps in R&D and material science.
just need to remove as much latency as you can from magnets to sensors to make fusion reactors alot more efficient, it needs to be in nano seconds, 2ms is a year to the life of plasma, so fibre and a quantum computer will save the day soon
uk's tokamack would have the upper hand by being new, with modern PCB design's etc
6. You're going to have to get energy out of the reaction at some point. Have you figured out how to do this? I suggest making the reaction happen inside a cavity within a large tank of water [aka 'boiler']. Steam systems would then attach to it. the rest is kind of obvious.
It still surprises me that nuclear power generation still relies on steam technology. Has there been any research on improved methods for converting energy into electricity? We got ride of steam trains for a reason.
There are ideas for helium cooled fission reactors that use the hot helium directly in power turbines. This misses out the heat exchanger commonly found in fission reactor plants. The designs are quite clever - self regulating graphite pebble bed reactors could be entirely passively controlled. About the he only perceived difficulty is how to make the graphite pebbles not fall to pieces as a result of the neutron flux running through them. The design relies on cycling pebbles through the reactor and out the he other end when done with, but if one breaks then it's a big mess.
There's also ideas for direct working gas cooling of Americium reactors. You need far less material, and the Americium can be in direct physical contact with the working gas (it doesn't need to be a powdered oxide fuel like is needed for Uranium/Plutonium fuels).
"This misses out the heat exchanger commonly found in fission reactor plants"
actually, the differential temperature across the tubes in a typical nuke plant boiler isn't all that much, maybe 40 deg F or so. The main limitation is the steam pressure. The Molier diagram for water more or less outlines the physical properties, and if you operate around 1000psi or so, you get maximum benefit. Most nuke plants will use oil-fired steam superheaters also, from what I understand, most likely to prevent condensation on the way to the turbines. Condensation is bad for turbines. It tends to damage the blades.
Anyway, all of this has been taken into account, more or less, which is why pressurized light water reactors are more common. Other designs exist, but these are generally the safest [unless something stupid happens, like no emergency cooling for several days (Fukushima), or the relief valve sticks open on the pressurizer and nobody notices because the indicator light is off and they're paying attention to pressurizer level, which is going up because of the pressure drop, so they DUMP COOLANT to lower it [this happened at 3 mile island].
Additionally the physics of water as a moderator is actually very good, much better than helium or heavy water would be. Still you can moderate with liquid sodium, and other materials, as long as the reactor design allows for it. Yet most reactors still use pressurized water. Must be something 'right' about it.
anyway... I used to operate a nuke plant for the U.S. Navy on a submarine a couple of decades ago. So I have some experience with it, though it's been "that long".
Ah yes, subs. I remember an RN sub steam kettler explaining the antiquity of the turbine machinery design, effectively harking back to the days before superheated steam in the early 20th century. Big slow turbines, to deal with the damp steam. Nothing like the small fast turbines found in surface ships circa 1940s.
Re: heat exchangers - sure, they're pretty good, and of course they bring further benefits too in a nuclear plant; the turbine machinery shouldn't (all being well) get contaminated. That was the main attraction of helium as a coolant; it wouldn't be transmuted into anything else and become radiologically nasty. So provided the pebbles remain intact, the turbine machinery would remain clean despite being driven directly by the primary coolant.
I didn't know that civil power reactors often had oil fired superheaters. Seems like cheating somehow!
I think there is probably a place for a Raspberry Pi somewhere in a Fusion reactor.
Perhaps a little python script to control the magnets that do the suspension of the plasma and then trigger the bombardment of energy, all dependent on sensors feeding back through the IO pins.
Might have a go tonight when I get home. How hard can it be?
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The reaction Tri-Alpha and some other groups (Focus Fusion etc) are aiming for an Aneutronic design, these use pBoron-Hydrogen for the reaction rather than D-T.
The advantage of this is there are no neutrons released from the reaction and minimal neutrons released from subsequent interactions.
The advantage is the reaction produces helium ions, depending on the reactor type these can be focussed.
Therefore you can generate electricity directly from the reaction and the electricity generating equipment effectively becomes solid state.
The problem with this design is it requires much higher temperatures and pressures to 'ignite' the reaction.
steam tech is pretty good for large amounts of power. all heat engines reject heat, and solar panels are no exception. I think their efficiency is in the 20-25% range nowadays, which is about like a 1000psi steam plant, i.e. your basic power plant. It's all 2nd law of thermodynamics and so on.
Some people like the idea of using air turbines instead, but it's harder to get the air flow to work that way. Steam naturally goes from liquid to gas and run down the pipes, then you condense it [in a vacuum of course] and pump back into the boiler. If you can find a liquid that works BETTER than water for that, well maybe you can improve the process a bit, but it's a tried+true tech and works exceedingly well.
The only other things I know of that convert heat or radiation directly into electricity are Peltier devices, and they'd probably reject even MORE heat than a steam plant [and be less efficient].
But yeah a linear reactor design - that's what I'd suggest, and I'm glad MIT is looking into it. It's something that's more likely to get you a sustained reaction and enough power to power itself.
and of course, some kind of "impulse drive". to which you'd have to add water. because momentum is mv, and you double mass flow rate to double thrust (which is twice the energy), or you quadruple energy to double velocity to double thrust. So you'd have to add mass for an impulse engine to work. So you'd still need fuel, but it could be something really heavy instead. [I figure best fusion rocket design would squirt water on the inside surface of the engine and into the center of it, to boil off and prevent engine melting, and provide the extra thrust from the mass - the fusion would provide the energy for velocity and therefore delta momentum = thrust]
but yeah, screwing around with Tokomak isn't getting anybody anyplace, but consumes a LOT of research money.
"Rather than heat, could we not look to harness electromagnetic directly ?"
Yes well see that's a bit of a problem when your main form of energy coming out of the reaction is neutrons moving really fast. Having no electric charge by definition, they're a bit hard to harness any other way than having them slam into stuff aka heating it up (and also making it radioactive, unfortunately). That said, depending on the specific fuel and fusion reaction you use there are options which aren't producing neutrons (surprisingly and inventively named "aneutronic fusion") which are actually being looked into by some researchers, but we're nowhere near reaching appropriate densities / temperatures to make it actually generate more that it takes to keep going. Fusion does happen mind you, they do make it "work", it just isn't outputting as much as it eats. Yet. However, if they can figure this one out, the resulting fast, charged particles could be used to extract electricity directly - although we'd need to also capture some other forms of energy the reaction generates (such as x-rays).
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Rather than heat, could we not look to harness electromagnetic directly ?
Magnetohydrodynamic power conversion was a popular concept for fusion in the 1960s to 1980s, but MHD power plants (as demonstrated in some experimental coal and gas plants) can be very finicky and not competitive with conventional alternatives. They also complicate the whole process of containing the fusion plasma. You're already juggling thousands of variables to keep the plasma from touching anything but the diverter plates, so to toss in the electromagnetic variables in a MHD power system just complicates the whole mess.
It's not elegant, but it is easier for fusion plants to boil water or heat helium.
Steam loco's went because of fuel, oil products in combustion engines don't need the medium of steam to produce rotational energy. Reactors produce heat that needs to be converted into rotational energy in order to drive the generators, water has all of the properties required to achieve that and is easily managed, is cheap and even it's downsides like corrosion are well understood and can be dealt with relatively easily and economically
And that reason was coal.
Also ease of use and ease of maintenance. Diesel trains could be started and shut down in minutes. Steam engines could take hours to make a cold start and were, comparatively speaking, hangar queens. Dieselisation had enormous economic attraction to railways, except for all the steam engine workers that got fired by diesel engines.
You haven't heard of coal fired steam engines? You can burn coal all day long and not go anywhere, except release a bunch of ash and nasty things into the atmosphere, you have to convert the heat into rotational energy, a Stirling Engine, which are not know for their energy output.
One reason we got rid of steam trains is that it's hard to build an efficient condenser that uses air as the coolant; the heat transfer is too slow. Water, on the other hand, is quite good at heat transfer, so steam plants that use condensers cooled by water (as in lakes or oceans) are much more efficient. And as I'm sure you know, the efficiency of any heat engine is determined by the difference in temperature between the hot working fluid (steam, ICO a steam plant) and the cold working fluid (condensate).
Fossil-fueled steam-driven ships lasted a lot longer than steam trains, in part because the ocean makes a great coolant for the condenser. I was Main Propulsion Assistant on one of the last ones in the US Navy, decommissioned in 1993. Steam plants were replaced on non-nuclear naval vessels because the darned steam plants were getting too complicated and too dangerous: 1200psi steam at 975 degrees (F) of superheat, and we had around 5000 valves in our plant (four boilers, two main engines). I'm told that the gas turbines that replaced them are much simpler. (Possibly more efficient, I don't know.)
Must count.. Yes. When I was 14 I was working on fusion with my father at the Berkeley Rad Lab . We were using a neon filled axial fusion simulator with end mirrors. At the same time I was attending physics lectures and helping with the Standard Model by visually scanning the bubble chamber photos. It quickly became obvious that one cannot balance a repelling permanent magnet on top of another (not spinning).
Most of my work was taking pictures of the very high quality oscilloscopes and keeping accurate notes . Other than that it was very cool to see a 50 foot violet bar of ionized air from a beam dump on the Bevatron as well as watching the walking bubble chamber. Cooking a doughnut in the waveguide in 2 milliseconds was fun. Plenty of LN2 to play with.
I really wonder if this will ever work here on Earth? Gravity is the best container.
Patent pending:
"Method of generating fusion energy by utilizing closed timelike curves to control plasma instability"
Essentially a souped up version of active feedback.
If you know where and when the plasma is going to buckle then applying the counterforce before the event will prevent it occuring in the first place.
The interesting thing is that time travel in the sense of a closed system is actually consistent with thermodynamics, if the information never leaves that system.
So a time machine in an impermeable box is feasible, and quantum computers can be viewed as a time machine that sends back its "answer" to a short time after switch-on.
I'm guessing that means a) There's a lot of parameters to twiddle (Not < 10, 100s or 1000s). b) "Success" criteria are complex (it's one of those n-dimensional optimization problems).
c)Prioritizing them is a massive PITA d) This algo (and its UI) implement a "Method of Experiments" process to identify what parameters would give the biggest data take from a shot and e) Then use human judgement to evaluate the result so the operator decides which is "better."
It would seem that building hardware that can run on an 8 min turnaround cycle is at least as important to this as the SW.
A few notes on other fusion systems and fission reactors.
PWR don't run at 1000F they run at around 593F. They run at about 200Atm to stop the water boiling until then. Their efficiency is around 25-30%. Modern high pressure coal/gas/oil boilers can hit 932F, about 35%+. PWR's are only dominant because the USN paid essentially all the development costs for Westinghouse. As power plants they make great submarine drives.
The USN did fund a fusion project directed by the late Dr Bussard (he of interstellar ramjet fame). It was progressing well. His lectures on youtube are interesting for why people don't think tokamaks are very good. I think they are still in business and still making slow progress, more due to lack of funding and the need to improve their modelling SW (their design is not exactly off the shelf).
Both MIT with ARC and a British company text of link plan to use High Temperature Superconductor tapes of Rare Earth Barium Copper at around 20K (which is high temperature to people who are used to liquid He at 4K) with innovative engineering of the tokamak to deliver a net power generating fusion system costing less than $300m to develop. Both plan much higher magnetic fields than ITER, and hence can be much much smaller.
Yes physicists have thought about getting the heat out. Current plans call for a blanket of molten Lithium to absorb the neutrons from the Deuterium Tritium fusion reaction to breed more Tritium without a fission reactor and the run it through an HX to drive a steam turbine at the same conditions as a conventional fired power plant. The wall materials are difficult as they have to take space ship reentry temperature and high radiation fluxes and be repairable/replaceable by remote control. Something like the nose of the space Shuttle (RCC) seems to be a candidate.
And as for a free idea....
Laser fusion systems turn the laser energy into "Extreme Ultra Violet," or (as everyone who isn't trying to sell a wafer fab exposure tool calls it) soft X-rays.in the 250eV range. The EUV tools use 20Kw lasers to hit a liquid metal target to get < 100W of actual exposure energy (IIRC more like 10W), which is not much when you're trying to expose a 300mm dia wafer.
A more direct route would be to use a "Smith Purcell" generator. This uses electrons launched across a diffraction grating of alternating conducting and insulating ridges. There appear to be conflicting theories of how the process works at the quantum level (so plenty of opportunity to optimize it), the grating frequency would be in the nanometre range and the electron beam (ideally a wide wave front) needs to be as close to the grating (roughly) as the grating frequency, IE about 6-7nm period for emissions at right angles to the grating, which needs a near atomically smooth plane. Coupling improves exponentially with distance, so closer is better, without hitting the grating.
The upside is that electron emission is a very efficient process and can be quite fine tuned to a specific emission energy, making acceleration to the level needed to drive the grating quite efficient also, if you can form a layer
I'm guessing there's 2-3 PhD's and a shed load of degrees to be earned building a machine that could make this work.
"The amount of energy required to fire up and operate today's fusion systems would vastly outweigh whatever useful energy you can get out of them."
Not actually correct. As far back as 1997, 16MW was extracted from JET for 23MW input. Obviously, still a net loss, but not "vastly".
We've already got a huge fully functional, self-sustaining fission reactor 150m km away - how about putting all of that money and effort into increasing the efficiency of converting into electricity all of that free energy that's already raining down on us?
Not that I don't enjoy the whole research-for-research's-sake thing as much as the next person, but if that's the end-game...
You might like to look up the difference between fission and fusion.
In fact concentrator solar arrays can hit 43%.
The problem is not the array.
It's getting a big enough array to orbit, and getting the power back.
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