Boeing Patents an Engine Run By Laser-Generated Fusion Explosions 242
MarkWhittington writes: Boeing has had a patent approved for an aircraft engine that uses laser-generated nuclear fusion as a power source, according to a story in Business Insider. The idea is already generating a great deal of controversy, according to the website Counter Punch. The patent has generated fears of what might happen if an aircraft containing radioactive material as fuel were to crash, spreading such fuel across the crash site.
WHAT radioactive materials? (Score:4, Insightful)
Fusion doesn't use any.
Re:WHAT radioactive materials? (Score:5, Insightful)
Go and read the article - the fusion is only a source of neutrons that then impact U-238 and cause fission to generate heat.
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Go and read the article.
You made me cry. "The concept is just in the patent stage and is a long way from even being a design, not to speak of a prototype". Once upon a time patents were meant to protect inventors who had come up with actual inventions.
Magical Pixie-dust Patents (Score:2)
Unless there's some sort of game they play with "continuations" of patents to keep them going forever (like at least one of the remaining patents around .mp3 encoding [google.com]) it seems like most of these sorts of patents should expire before there's even a working prototype. Is this just parasitism by company IP lawyers and associated corporate baggage tryi
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Yes, U238. That lovely "stable" substance that if you fire neutrons into it results in Pu239.
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Not if the neutrons are energetic enough. The reason H-bombs run away to such high yields is that the U-238 tamper jacketing the device becomes a massive source of fissile bomb-fuel once the fusion "spark" ignites and blasts high-energy neutrons in all directions. Just sayin'. Have a nice day.
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While deuterium is stable, tritium has a half life of 12.32 years. However there wouldn't need to be a lot of tritium and it could be contained in such a way that it wouldn't be spread over a crash site.
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Elemental tritium would certainly not be spread over any crash site, not unless it was carefully packaged. Otherwise it would head directly for space.
Secondary radiation, however, is a different matter. And someone said that the fusion was only a source of neutorns to enhance fission. (That seems like a pretty wierd idea, since we don't currently have fusion working.)
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Elemental tritium would certainly not be spread over any crash site, not unless it was carefully packaged. Otherwise it would head directly for space.
Half right. Tritium is chemically hydrogen. As a gas, it would not spread over the crash site except for a small bit that might bond to solid materials if there is a fire. Most would go into the atmosphere where it would eventually bond with oxygen forming radioactive water. Fun.
Secondary radiation, however, is a different matter. And someone said that the fusion was only a source of neutorns to enhance fission. (That seems like a pretty wierd idea, since we don't currently have fusion working.)
Secondary radiation from the tritium is a non-issue. It is a beta emitter (free electrons) so it can't cause other materials to become radioactive. The neutrons from fusion and the induced fission, on the other hand are quite u
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Some people freak out about tritium because it's radioactive. But really, while tritiated water is poisonous, we deal with lots of stuff in our everyday lives that are far more dangerous, with far lower LD50s. And outside the body it does nothing, the beta is just too weak to penetrate. And given that tritium costs about $50k per gram, you're never going to encounter a large quantity of it at once.
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A gram of D+T also represents nearly a hundred bloody megawatt hours of power generation.
But anyway, back to cost. The LD50 for tritiated water is, what, 0.1mg/kg? So a lethal dose costs $50. That's orders of magnitude more expensive than a lethal dose of almost any common poison on Earth. Cadmium, lead, mercury, cyanide, any rat poison, insect poison... pretty much anything toxic that comes to mind in your every day life costs orders
Re:WHAT radioactive materials? (Score:5, Informative)
we don't currently have fusion working
We don't currently have economically viable, contained fusion reactors working.
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Hate to break the news, but bog-standard fission bombs have been getting a boost from fusion-generated neutrons since the 50s (maybe 40s -- I don't feel like looking it up ATM.
The Fictional Radioactive Materials (Score:5, Insightful)
From a fictional engine that doesn't exist and won't exist until we actually have practical fusion.
Really this is what is wrong with the patent system. Now anyone developing engines using any kind of fusion is going to have a visit from Boeings lawyers over something they have done nothing to make work.
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No, this engine proposal is quite doable. Because most of the power doesn't come from fusion, it comes from fission. It's a subcritical fast reactor which uses fusion neutrons only to achieve criticality. It's like an ADR. ADR designs usually only call for about 10% or so of the neutrons from an accelerator; the same would apply for a fission neutron source.
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That's my problem with this. I've read more fleshed out 'inventions' in sci-fi novels. Why don't we just go ahead and issue a patent for the Romulan micro black hole warp core? It might be slightly easier to get going than a laser powerful enough to induce fusion but small and light enough to use in an airplane.
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Really this is what is wrong with the patent system. Now anyone developing engines using any kind of fusion is going to have a visit from Boeings lawyers over something they have done nothing to make work.
What's the point of filing now? Won't the patent expire long before we have a working engine?
... or maybe Boeing knows something about fusion engines that we don't.
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I assume they are going to use some variant of the submarine patent.
It was a technique perfected ? by Jerome Lemelson in the 1950s. He filed patents for technologies related to barcodes. At the time the technology to make them work wasn't available, when someone would actually develop one of the concepts he would pop up with patents the poor boobs didn't even know existed.
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Don't worry about it; the patent will expire by the time a working model is built.
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Dude that's the problem they won't own it.
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using a fissile material as fuel
it would seem that the writer doesn't understand the difference between fission and fusion...
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No, deuterium is not radioactive. Tritium is trivially radioactive. No, the fissile material is bombarded by the fusion neutrons; it's hybrid fission/fusion.
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Yes, and creating a fission-powered aircraft would obviously be insane:
https://en.wikipedia.org/wiki/... [wikipedia.org]
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That might be more practical today. Drone technology is good enough to make the aircraft unpiloted, which means a fraction of the shielding requirements.
It's still a ridiculous idea because of the crash risk, but the engineering issues could be solved. Not sure what you'd do with it. It's not really good as a nuclear bomber any more, as you couldn't effectively stealth something so big and slow - as soon as the war breaks out AA missiles would be launched.
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Tritium is radioactive, and the neutrons that are produced will react with various elements to create radioactive isotopes.
Uranium is also radioactive
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WHAT radioactive materials?
Fusion doesn't use any.
I'm almost certain any such device will contain at least one atom with an atomic weight above lead, which by definition is a radioactive particle :P
Re:WHAT radioactive materials? (Score:5, Informative)
All current fusion reactor designs rely on deuterium and tritium. Tritium is _quite_ radioactive, with a half-life of 12 years. There is also very little of it. The world supply is on the order of 20 kilograms, and it's all accumulated from fission reactors. quoting Wikipedia, "Commercial demand for tritium is 400 grams per year and the cost is approximately US $30,000 per gram." Tritium cannot be reasonably refined: all tritium on earth in quantities large enough to refine is from fission reactors. Growing commercial production could improve the price tremendously, but it's source remains dangerous and expensive and inefficient to produce tritium.
Deuterium is stable, and available, but also quite expensive at $1000/kg. for deuterium oxide. With an atomic weight of 2, with two oxygen atoms of atomic weight of 16, the deuterium is only 2 / 34 of the mass. So the cost for pure deuterium itself is roughly $17000/kg, or about $17/gram. It's refinable from water, but the dollar cost reflects the energy costs of refining it.
The only large scale source of either isotope that would not be prohibitively expensive or rely on quite large scale fission generators is the solar wind. But much like large scale fission generators to create tritium it's senseless in terms of energy production. If you're bothering to build the plant for tritum, why not simply harvest the energy of the plant itself? A solar sail in orbit gathers roughly 2 kilowatts/square meter, and a roughly square kilometer mirror is quite feasible. That would be roughly 2 Terawatts of power. One could theoretically harvest deuterium and tritium from it, but with such a large power source, there seems to be no need to harvest it for fuel production for a much less efficient and quite radioactive system.
Re:WHAT radioactive materials? (Score:5, Informative)
It's worse - as is noted below, it's not actually a fusion engine proposal, but rather a hybrid fission/fusion proposal. It's not a new concept, but the key is, a lot of (read: "most of") the power is to come from fission.
I really can't think that Boeing would be so daft as to think that anyone would ever use this on Earth. Surely the point of the patent is to use it for exploration of other planets. Right? I hope so...
Note that it's not 100% necessary for neutron bombardment to create radioactive material. One of the nice things about incident induced radioactivity is that it's avoidable and/or manageable... albeit with tradeoffs that usually mean that accepting some radioactivity is the best option. You could for example have enough of a neutron absorbing material to fully consume the neutrons - for example, boron, which breaks down via the huge cross section B10(n,alpha)7Li reaction. 7Li neutron capture produces 8Li, which quickly decades into 8Be (releasing a ton of energy), which virtually instantly breaks down into two alphas. B10 neutron capture (much rarer than (n, alpha) yields B11, which is stable. B11 neutron capture produces B12, which very rapidly breaks down into C12 (stable). C12 neutron capture is rare and turns into stable C13. The only way you get to anything that's radioactive that doesn't instantly break down is to get a rare neutron capture of C13 after going through all of those previous steps, some of which are rare. And that "radioactive isotope" is only C14, which is a naturally occurring radioisotope we're evolved to live with, with a not very powerful decay. And if you isolate it (which isn't anywhere on the difficulty scale of, say, removing actinides from nuclear waste), it's highly valuable.
Another good example would be to make your structure out of beryllium. Beryllium is a superb metal in almost every respect and would be widely used in the world if not only for two niggling details: its dust is highly toxic and it's very expensive. But things do get built out of it (and it's not hazardous when there's no dust). 9Be capture produces 10Be, which is radioactive, but with a half life of 1.5 million years, the radiation level is extremely small, you'd need a lot of it to present a hazard. Which would never happen; 10Be has a reasonably high neutron capture cross section, becoming 11Be, which breaks down into 11B, which we've already covered above.
You can also get additional reactions to the above cases with fast neutrons, but they generally only improve the situation.
Pretty much anything out of light elements poses little to no hazard from induced radioactivity. You start to get a bit once you get to aluminum, but not much - aluminum has to go through an awful lot of captures to turn into a silicon or phosphorus isotope with a relevant half life, the amount transmuted is pretty irrelevant in most situations. It's only if you need higher strength or heat tolerance than aluminum (or better, lithium-aluminum) can give you that you start getting into problems - titanium, iron, iron alloying agents, other common structural metals, they all have significant issues with induced radioactivity. But even with them, it's still nothing on the scale of, say, waste fuel rods.
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but the key is, a lot of (read: "most of") the power is to come from fission.
I really can't think that Boeing would be so daft as to think that anyone would ever use this on Earth.
I think you may have missed that only the fusion products come out the back. The fission products are contained, and its relatively easy to contain the fission chamber in the event of a crash, unlike nuclear-powered spacecraft, which re-enter with 1000 x the energy of a subsonic aircraft.
Surely the point of the patent is to use it for exploration of other planets. Right? I hope so...
It has the advantage of operating without fuel or oxygen, but why would a planetary explorer need a jet engine? Whats the hurry?
They can just float around with a small solar or RTG-powered propeller.
Even if the technical ch
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what's the hurry? Space is big, it is so big your ego will get lost.
Right now our longest closed deployment is submarines. they go 4-6 months between restocking. Even at that point all the fresh food was gone months before hand.Just to get to mars with typical engines is a 4-6 month process, plus time to evaluate and study and the return flight.
The moon is only 3-4 days away that need to be reduced to a 12 hour flight. Then we can begin sending supplies for a colony to push farther afield.
We need really
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I really can't think that Boeing would be so daft as to think that anyone would ever use this on Earth.
You might want to read about project pluto. A mach 3 ram jet with a nuclear fuel supply. Sadly it was only stopped by the advent of ICBMs. They got it working in a wind tunnel though, so it would have flown.
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Well, usually one uses electron volts to measure the energies in the above reactions, but if you want watts just divide eV/s by 6.24e18.
Great (Score:2)
absolute BS (Score:5, Insightful)
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I agree. This type of patent should immediately be declared invalid, at huge cost to the applicant, and the idea should be made public domain. This is fraud, plain and simple.
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This.
The time has come for the patent offices of the world to mandate that you must have at least a prototype implementation of a system in order to be able to patent it.
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Yeah, it essentially sounds like they've patented magic here.
I didn't realize you could patent tech you can't create and which has huge gaping holes of "and a series of scientific breakthroughs happen here in the middle but we don't know how".
This patent seems to rely on step 2 of the underpants gnomes business plan -- which means it's not so much a patent as a concept with some wishful thinking and creative writing.
Can I patent my anti-gravity device if I don't know how to do anti-gravity?
Re:absolute BS (Score:5, Interesting)
Perhaps this patent is part of a psychological operations in which someone wants to make someone else believe we have capabilities we don't.
This is where the rabbit wearing glasses thing comes from. We hid our radar capabilities in the early days of the cold war by saying carrots improved your vision and our pilots ate tons of them. This had the added benefit of spys recording locations of orange people and we got good ideas on locations of Soviet air bases as well as identities of suspected pilots that could be worked for info.
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LOL ... is that a real fact, or one of those stupid internet facts?
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Almost. It was the Brits during WWII, hiding the fact that they were able to spot German planes with their radar technology. Instead they started the rumor that British pilots ate lots of carrots, which improved their eyesight so they could spot the German planes more easily.
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That might be a reasonable (for values of reasonable) idea, IF we hadn't started using radar in WW2 (along with the Germans, Brits, Japanese, USSR)....
In other words, radar wasn't much of a secret in the Cold War, since by the time it started, pretty much everyone had been using it for years.
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Even some sort of peer review to say that you have at least solved the key problems.
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About the only thing that can ever happen with this patent is to be used by a troll in case anyone does really manage to build a fusion power plant that uses some of the same terms used in this science fiction document, such as lasers.
The most wonderful thing about a patent troll attempting to sue me for successfully building a fusion power device, is that by definition I have just built a working fusion device!
There is pretty much nothing that can prevent such a device from simply making the patent troll disappear, almost literally (OK technically the atoms the patent troll used to consist of would not be destroyed, they would simply be rearranged into a non-trollish and non-living form, diluted over a much larger volume of space than p
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Yeah, damn those shark activists
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Sorry, but this doesn't sound as workable a the Orion project to me. And it seems to be a different concept.
P.S.: Our fusion weapons use fission as an ignition system, not the other way around. You can, of course, then use the fusion to create a larger fission explosion, but that's not the way to build a working engine.
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Our thermonuclear weapons use fission to produce neutrons to produce more fission. Deuterium-Tritium fusion just happens to be a good source of neutrons, besides producing a little energy.
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There is no technical reason it couldn't be built now, only political ones.
Yeh, um.... no. If there were no technical reasons this couldn't be built right now, Boeing would have a working prototype at minimum.
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Fusion or Fission? (Score:2)
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Re:Fusion or Fission? Neither. (Score:2)
It is pure fiction. As in: has been talked about for years but nobody can actually get it to work.
Patents like this are a travesty and a long lineup of attorneys and examiners should be ashamed of themselves.
Bullshit worries... (Score:2)
People worrying about some very short half-life Helium really, really have no clue what they are talking about. Just have a look at what gets _shipped_ in radioactive materials all the time, and there you may find something to worry. Or not, if packed properly.
Quote of the day (Score:2)
Businessisider.com down? (Score:2)
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I don't even believe the intent is real. This looks like a truly stupid idea, even if you could get the technology to work. (If you've got a nice fusion reaction for your engine, why mess everything up by irradiating U238 with neutrons. It's make enough plutonium to be refined into something dangerous, but not enough to use directly.)
With their track record. (Score:2)
First lithium-ion battery fires [wikipedia.org], now this. What could go wrong?
Tired of anti-nuclear editors on Slashdot! (Score:2)
CounterPunch is a monthly magazine published in the United States that covers politics in a manner its editors describe as "muckraking with a radical attitude".[1] It has been described as left-wing by both supporters and detractors.[2][3][4]
This magazine is about as merely "left-wing" as the Death Valley in Mojave is merely "warm" in the summer.
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I suspect this isn't about anti-nuke so much, as their Dice bosses pushing it because the posts using Counterpunch and The Bulletin of Atomic Scientists get lots of replies.
Just wait till the Dice PHBs figure out that posting articles from Worldnet Daily get even more outraged replies.
Project Orion is Prior Art (Score:2)
The basic concept is similar to Freeman Dyson's Project Orion https://en.wikipedia.org/wiki/... [wikipedia.org] which makes any patent subject to prior art claims. If they're patenting a specific technique, then good for them!
So *many* mistakes in the article (Score:2)
So many terrible mistakes...
Deuterium and tritium are not in fact "fissile material", but are inert, non-radioactive materials. The "pellets" are cryogenic hydrogen gas isotopes fond in natural hydrogen.
Fusion is the opposite of fission, and while it's a nuclear process.
The U-238 that they would line the engines with is *also* not "fissile", and is not radioactive (the radioactive isotope is U-235), and is used for neutron absorption from the fusion process to turn the neutrons into heat so that no one is
So *many* mistakes in your post: (Score:2)
So many more mistakes:
Tritium is indeed radioactive with a half life of about 12.5 years (That's why it's great for making glow in the dark dials that require no light recharging or electricity. Only a tiny amount is needed, but a 12.5 year half life is pretty darn "hot" in the vernacular, and if you have a lot of it, you get a lot of energy release. It emits beta rays (high energy electrons) which aren't as much of a problem as gamma, but do cause surface burning, etc.).
U238 is indeed radioactive. It's an
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So many more mistakes:
[ ... ]
As previously noted: the Tritium will remain cryogenically suspended, or it will "boil off". It's not an issue.
As for U-238: cadmium and Neodymium have the same level of "danger" as U-238, and are probably in your cell phone and the bluetooth headset you stick in your ear. They are closely followed by the following, to which you are generally exposed environmentally every day: xenon, molybdenum, barium, gadolinium, osmium, calcium, selenium, platinum, germanium, zirconium (quick, remove your rings!), tungsten, potassium, and bismuth.
http://www.nndc.bnl.gov/chart/ [bnl.gov]
But you know, feel free to get all pedantic, and we can throw in charcoal briquettes, if you want. Imagine the environmental horror, if a train carrying a bunch of Brita water filters derailed, instead of, you know, getting to the store, and having all your drinking water go through them.
P.S.: Pedantry helps no one but alarmists, who want a technical detail hook on which to hang their argument.
And how large will this be? (Score:2)
Here is the actual patent:
http://pdfpiw.uspto.gov/.piw?P... [uspto.gov]
It's almost gibberish. It's full of sentences like (and I'm quoting)
"Alternatively, when propellant 18c of FIG 4 is utilized in the embodiment of FIG 1, the laser system 22 of Fig. 1 may comprise one or more free-electron lasers for providing pulsed laser beams to vaporize, using pulsed laser beams, pellets each comprising the propellant 18c of Fig 4."
Fig 1 is basically the drawing from the Business Insider article with the parts numbered. Fig 4 is
The materials science isn't there (Score:2)
No way this is going to work with current materials. ICF is low density and there are no lightweight low-volume radiation shields available.
The original fission powered proposals from the 1950s-1960s have more of a chance to actually work. This proposal is a Rube-Goldberg contraption.
Maybe the military will use it (Score:2)
I don't see anyone outside of the US military using it... and even them using it is a stretch.
Short of that... Nope.
sort of already exists (Score:2)
I don't get it (Score:4, Funny)
Deuterium or tritium (Score:2)
The article says the patent specifies deuterium or tritium. Only if the engine uses tritium will there be any radioactive fuel to be spread.
Patent reduces risk it will be built (Score:2)
This kind of patent on a general concept acts as a string disincentive to others to invest the resources needed to turn such concepts into practical implementations. Usually, that is undesirable. In this case, some seem to believe strongly that the concept should not be pursued. These people should be celebrating.
Re:Even U238 isn't radioactive. (Score:5, Insightful)
But the plutonium produced by firing neutrons into it is.
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If you want to absorb neutrons you use parafin, not u238. U238 is quite picky about the neutron energies it will absorb, and the rest pass right through. Hydrogen (as in parafin) is a lot more willing to accept different energies. So if you wanted to use neutrons from a fusion reaction to energize U238 you'd probably need to run it through a moderator...probably either graphite (think Chernobyl) or heavy water.
That doesn't sound like a good airplane engine to me.
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Well, if you want to absorb neutrons, you want a neutron poison like boron. If you want to moderate them, you want something rich in some combination of hydrogen (most effective, but too capture prone for some needs), deuterium (pretty good at moderating, extremely low capture, very expensive), helium (zero capture, fairly expensive, not a very efficient moderator, esp from a volume perspective), carbon (pretty low capture, fair at moderation, cheap, but need to avoid buildup of wigner energy), or oxygen (q
Re:Even U238 isn't radioactive. (Score:5, Informative)
U238 will happily absorb neutrons (which are produced by the fusion) and become U239. U239 will happily absorb beta radiation (also production by the fusion) and become Np239. Np239 will also happily absorb beta radiation and become Pu239. Pu239 is nasty stuff that you don't want to get anywhere near you.
This is in fact exactly the reaction used in the production of Pu239 for nuclear weapons.
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This is in fact exactly the reaction used in the production of Pu239 for nuclear weapons.
Cool. Portable nuclear proliferation. Now that's progress.
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Re:Even U238 isn't radioactive. (Score:4, Interesting)
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P+e^- = N+\nu_e
There used to be a cool webpage where you could traverse all the isotopes and see how they were produced but I can't seem to find it now.
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Alpha emitters are harmless outside the body, but inside the body they're far worse per unit decay energy than beta or gamma emitters. Read about how ridiculously dangerous polonium 209 is, for example - there's a reason it was chosen by the Russians as an assassination tool. Even with orders of magnitude higher half life than 209Po, 239Pu is still very dangerous if ingested or inhaled. If you had some "scattered as shot across the floor", you're making an inhalation hazard.
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Probably a naive question, but isn't u238 the non-fissionable isotope of uranium? It sounds like it's chosen because it's one of the few superdense materials we have access to, to limit the thickness of the shielding needed to absorb the energy from the neutrons.
It depends on the energy of the neutron. Slow neutrons are reflected by U-238, which is why it is used as a tamper in nuclear weapons. Higher energy neutrons are absorbed by U-238 to lead to a transmutation to the toxic and explosive Pu-239, ala breeder reactors. With really really high energy neutrons, like you might get from a fusion reaction, U-238 will undergo fission just like its less stable 235 cousin.
If I understand correctly, any element heavier than Fe can be made to undergo fission with a powe
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https://en.wikipedia.org/wiki/... [wikipedia.org]
One of those
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Not exactly. 62Ni has a higher binding energy per nucleon than 56Fe. The misconception exists because not much 62Ni is produced in supernovae while large amounts of 56Fe is; for the most part, 56Fe represents the highest binding energy reached in a supernova..
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Probably a naive question, but isn't u238 the non-fissionable isotope of uranium? It sounds like it's chosen because it's one of the few superdense materials we have access to, to limit the thickness of the shielding needed to absorb the energy from the neutrons.
U-238 is fissionable with fast neutrons. Fusion reaction produce fast neutrons.
In this patent, they say they hope that the laser-induced fusion of the pellet would create fast neutrons that would in turn cause fission in the U-238, thus boosting the energy output.
This is how modern so-called hydrogen bombs work. A fission bomb surrounds a core of fusionable material (deuterium and tritium etc). The fission bomb compresses and causes fusion of the light-element core. The bomb is encased in a jacket of U-238.
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"Not radioactive"
Not true.
It's an alpha emitter with a half life of 4.5 billion years.
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Yes it is, it has a half life of 4.468 billion years and undergoes alpha decay.
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Not THAT kind of turbine (although you could rig it that way - very Rube Goldberg). It uses hot exhaust gas (non radioactive so it isn't at all like Orion like TFA intimates) to directly push the aircraft (or rocket or what have you) in an equal and opposite direction.
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Not to mention that there's tons of ways to make 3He here on Earth. Including the natural decay of tritium.
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That aside, i think the counter argument is a bit premature, as the engine itself is a pipe dream at this point.
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It's a fusion-fission hybrid system: the lasers initiates a small fusion blast; part of the blast is directed to provide thrust, but the neutrons radiate in all directions; a shell of U238 surrounds the blast chamber and captures the neutrons, resulting in fission; the heat from the fission is used to power the lasers.
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Or, if some smart guy has the ability to overcome the fusion break even problem, he looks around, realizes that a bunch of corporations are sitting on bullshit patents, (We have no idea how to build it. But we have a patent on some imaginary crap that makes some overlapping claims.) and says, "Screw fusion. I'm going to build the Son of Twitter."
This is why, in order to patent something, you should have to bring a working model in and show it to the patent examiner.
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But what about Alienware computers?
I'm not saying it's aliens, but...
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Actually this is more like Project Daedalus in that it uses ICF to a degree.
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But do you need to pay royalties if you're only doing R&D?