Boeing Patents an Engine Run By Laser-Generated Fusion Explosions

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.

Comments

WHAT radioactive materials?

[Anonymous Coward]

Fusion doesn't use any.

Re:WHAT radioactive materials?

[Anonymous Coward]

It creates them.

The large flux of high-energy neutrons in a reactor will make the structural materials radioactive. The radioactive inventory at shut-down may be comparable to that of a fission reactor

Re:WHAT radioactive materials?

[beelsebob]

Go and read the article - the fusion is only a source of neutrons that then impact U-238 and cause fission to generate heat.

Re:WHAT radioactive materials?

[Paleolibertarian]

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.

Re:WHAT radioactive materials?

[HiThere]

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.)

Re:WHAT radioactive materials?

[Anonymous Coward]

you mean depleted uranium?

Re:WHAT radioactive materials?

[beelsebob]

Yes, U238. That lovely "stable" substance that if you fire neutrons into it results in Pu239.

Re:WHAT radioactive materials?

[erice]

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 up to task.

Using fusion as a source of neutrons for fission isn't all that weird. We *do* have fusion working. What we don't have is fusion that produces more energy than it consumes. That is not a problem for a neutron source. It has the advantage over direct fission that bomb making material is never available. If you have a strong enough neutron source, you can fission Uranium 238 directly. No need to breed plutonium, like you would in a breeder reactor.

Re:WHAT radioactive materials?

[Anonymous Coward]

Most would go into the atmosphere where it would eventually bond with oxygen forming radioactive water. Fun.

Ever heard the phrase, "pissing in a river?" That applies here. The amount of heavy water produced compared to the amount that naturally occurs in the oceans..is tiny. Even then, the heavy water is going to eventually decay to regular water anyways. Meh. RADIATION RADIATION RADIATION! Are you having a panic attack yet? RADIATION RADIATION RADIATION! I swear RADIATION is pretty much equivalent to FNORD in the minds of most.

Re:WHAT radioactive materials?

[Type44Q]

I'm pretty sure that hydrogen isotopes (deuterium, tritium, etc) are, in fact, radioactive... but the from the following quote (from the article),

using a fissile material as fuel

it would seem that the writer doesn't understand the difference between fission and fusion...

Re:WHAT radioactive materials?

[Prune]

I love nuclear, but let's be fair here: tritium is radioactive, with a half-life of just over 12 years.

Re:WHAT radioactive materials?

[Type44Q]

we don't currently have fusion working

We don't currently have economically viable, contained fusion reactors working.

Re:WHAT radioactive materials?

[Anonymous Coward]

But only for 24,0000 years. Don't be so shortsighted.

Re:WHAT radioactive materials?

[overshoot]

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.)

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.

Re:WHAT radioactive materials?

[Rei]

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.

Re:WHAT radioactive materials?

[Rei]

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.

Re:WHAT radioactive materials?

[Rei]

No, deuterium is not radioactive. Tritium is trivially radioactive. No, the fissile material is bombarded by the fusion neutrons; it's hybrid fission/fusion.

Re:WHAT radioactive materials?

[rilister]

Yes, and creating a fission-powered aircraft would obviously be insane:
https://en.wikipedia.org/wiki/...

Re: WHAT radioactive materials?

[Anonymous Coward]

wat?

Re:WHAT radioactive materials?

[Anonymous Coward]

And given that tritium costs about $50k per gram, you're never going to encounter a large quantity of it at once.

And that a gram is more than a couple thousand times times the LD50 level. And one of the big problems with various fusion designs is that the amount of tritium needed in the system is much larger than the amount consumed by the reaction, in part because it tends to attach to various surfaces. Some projects talk about having inventories in the kilograms. Having worked on such projects, the issues with managing tritium is a big mess, even if there are much worse things out there.

Re:WHAT radioactive materials?

[Anonymous Coward]

truth

Re:WHAT radioactive materials?

[WheezyJoe]

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.

Re: WHAT radioactive materials?

[Rei]

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.

Re:WHAT radioactive materials?

[Rei]

And that a gram is more than a couple thousand times times the LD50 level.

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 of magnitude less for a lethal dose than tritium. Inventories in the kilograms? Some industries keep inventories of toxic materials in kiloton quantities.

No, it's toxicity can't be ignored. But on the scale of "poisonous things", tritium is pretty far down there.

Re:WHAT radioactive materials?

[Anonymous Coward]

Be completely fair: It's also a very light gas, so it isn't exactly going to hang around at the crash site for 12 years.

Re:WHAT radioactive materials?

[Khashishi]

Tritium is radioactive, and the neutrons that are produced will react with various elements to create radioactive isotopes.
Uranium is also radioactive

Re:WHAT radioactive materials?

[quenda]

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 challenges can be overcome, its hard to imagine this being economically viable over a conventional jet engine, even if you have to synthesise the fuel on the ground with nuclear power.
I miss the days when to get a patent you needed a working model, instead of just a vague idea that might never work.

Re:WHAT radioactive materials?

[redwraith94]

It can. It depends on the isotopes used.

I like the wiffle ball reactor design the best. The controlled laser implosion method seems like it could literally be thrown off by a grain of dust.

Re:WHAT radioactive materials?

[redwraith94]

Heavy water is already present in normal water. Deuterium is around to the tune of 1 part per 6700 parts Protium, anywhere you can find Hydrogen (including organic material) Deuterium / heavy water isn't radioactive at all. Though it is somewhat chemically toxic to us. Tritium water is highly radioactive, and frankly based on your attitude, and ignorance, my pitchfork, and I have determined that you don't get a vote on the subject.

Heavy water doesn't decay at all (unless Protons do decay). Tritium actually decays by electron (beta) emission, converting a single neutron into a proton, so it converts into Helium 3, and Oxygen. It doesn't decay to normal water. Most isotopes can decay into a variety of different elements, with a probability for each. It isn't as simple as you say.

Re:WHAT radioactive materials?

[redwraith94]

Tritium (1 Proton, 2 Neutrons) decays be emitting an electron (and an anti-neutrino, and a gamma ray), converting itself to Helium 3 (2 Protons, 1 Neutron); it doesn't produce neutron radiation at all.

Re:WHAT radioactive materials?

[Anonymous Coward]

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.

Re: WHAT radioactive materials?

[cb88]

huh? wats are meansured in standard unit's of giant rubber duck.

https://timenewsfeed.files.wordpress.com/2013/05/167870961_1500x1001.jpg

Re:WHAT radioactive materials?

[Anonymous Coward]

Ever heard the phrase, "pissing in a river?"

Ever hear of the Ganges? Drink from it and you've got a mouthful of piss, shit, rotting carcasses, and all sorts of other filth. Might even be some FNORD in there to boot.

Re:WHAT radioactive materials?

[dissy]

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?

[Anonymous Coward]

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.

Great, so now we patent ideas on hypothetical machines. But hey I bet there is the word "on a computer" or "on the internet/cloud" somewhere on the patent application.

Can't we just burn down the Patent Office (and Congress along with it) ?

Re:WHAT radioactive materials?

[Anonymous Coward]

https://en.wikipedia.org/wiki/Voyager%27s_Return

previous art?

Re:WHAT radioactive materials?

[SuricouRaven]

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.

Re:WHAT radioactive materials?

[peragrin]

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 fast engines in space just to make travel time practical.

Re:WHAT radioactive materials?

[Pallas Athena]

Maybe that's the point - when the enemy shoots them out of the air, THEY get the radioactive waste!

Re:WHAT radioactive materials?

[serviscope_minor]

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.

Re:WHAT radioactive materials?

[angel'o'sphere]

We have fusion working since decades, it is just not net positive energy wise!

Re:WHAT radioactive materials?

[Antique Geekmeister]

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?

[Anonymous Coward]

A gram of D+T also represents nearly a hundred bloody megawatt hours of power generation.

And you've completely missed the part about the problem with tritium inventory in fusion experiments, that many designs require way more tritium circulating within the reactor than is actually consumed by power production, because only a small fraction of it is available to the reaction within the core of the experiment and a lot of it ends up trapped in other places. Also, with next generation fusion devices expecting to be producing hundreds to thousands of MW of fusion power, and needing orders of magnitude more fuel than is used up, that is how you start getting estimates of kilograms circulating through a single machine.

The LD50 for tritiated water is, what, 0.1mg/kg? So a lethal dose costs $50.

You're mixing up the cost of tritium and tritiated water, which differs by an order of magnitude. Regardless, this doesn't change that such projects will have a dangerous amount of material on hand, and some of the properties of tritium can cause it to be difficult to deal with (tendency to stick around in annoying places). It doesn't matter how much more poisonous other things are, just that it is poisonous enough to be a serious problem.

Re:WHAT radioactive materials?

[quenda]

Yeah. I think you'll find jet turbines don't work so well in space.
GP was saying these might be useful in the atmosphere of another planet.

Re:WHAT radioactive materials?

[Khashishi]

I was referring to the neutrons from the DT reaction.

Re:WHAT radioactive materials?

[Ihlosi]

Tritium.

Re:WHAT radioactive materials?

[KGIII]

So you have four cookies... One is a neutron emitter, one is a alpha...... (snip)

Ah... Radiation will alway be cookies to me. Me? Imma eat everyone of those bitches. Free cookies!

Re:WHAT radioactive materials?

[CustomSolvers2]

What basically means that we don't have too much as far as the two missing bits are the most important and difficult to be solved issues. It has to be contained, because nobody wants something as hot as the sun to run free (to not mention that being contained is a basic requirement to generate usable energy, what precisely represents its only goal); and in case of not making it economically viable, why even considering fusion? Bear in mind that huge amounts of resources are already required to perform this kind of researches and for what? For creating a more expensive, unknown & difficult-to-be-controlled source of energy? On the other hand, how can you contain what (with our current technology) cannot be contained? Or how to replicate at a relevant scale what we can eventually just do at a really tiny one? Does building a scale model of a skyscraper mean having almost built a real one?

I don’t think that your corrections added too much to the original statement, because nothing means more or less the same than having something except these two issues.

Re:WHAT radioactive materials?

[Anonymous Coward]

Well just to be completely pedantic, we do have contained fusion reactions working now, its just that they are contained 93 million miles east of here. We get a lot of radiation from it, and people (tree huggers) claim this kind of nuclear radiation is "clean". A molten salt nuclear jet engine would also generate a lot of heat and could run for a hundred thousand hours on its initial fuel load without emitting any carbon, (and in the instance of a crash, be inherently safe), but at first blush (and until someone who is also a tree hugger explains it to them, then re-explains it to them, then tells one of the very smartest of the tree huggers who actually gets it), will cry out and gnash their teeth. One of the issues is that tree huggery is its own social order and they have a group of followers who claim to always 'be right' but aren't always bright.

Re:WHAT radioactive materials?

[CustomSolvers2]

I think that I got a bit lost in what you were trying to say; but are you insinuating that nuclear fusion is possible today? Could you please provide some reference proving that there is any way (regardless of the required resources) to get a macroscopic relevant fusion reaction? To make any simple task, for example: heating a cup of coffee during 5 minutes?

If creating (, containing and terminating at will) a fusion reaction (requiring whatever amount of heat and as crazily big resources as needed; but being actually possible by just putting money on the table) capable to perform an as simple action as the aforementioned one is possible (= has already been done, at least once), I would certainly change my mind on this front, because my knowledge regarding what is/is not possible would have been proven wrong. Please, provide a reference to a reliable source proving that a result on these lines has already been achieved, such that I can move my opinion about fusion from "fantastic nonsense" to "lots of work ahead, but might be worth trying".

Re:WHAT radioactive materials?

[Anonymous Coward]

Heavy water doesn't decay at all (unless Protons do decay).

The tritium will decay regardless of whatever chemical bond it is in. Nuclear decay doesn't give a shit what the electrons are doing.

Re:WHAT radioactive materials?

[HiThere]

Sorry, I was speaking loosely several posts up the thread. We actually *DO* have fusion reactors. They're too heavy to carry on a ship, and they require more power than they produce. And they've got many othe problems. So I summarized it as "We don't have fusion reactors", but I should have remembered where I was posting.

Re:WHAT radioactive materials?

[HiThere]

You've got a point, but that's only done to produce bigger explosions, which is not what you want on a vehicle engine. Particularly since the working fusion reaction has to be set off by a fission explosion. (Boeing is talking about Lasers, but, at least effectively, we don't have that working.)

Re:WHAT radioactive materials?

[CustomSolvers2]

We have fusion reactors? Where? How? As per my knowledge, the first fusion reactor (of the history) is currently being built and is called ITER (https://www.iter.org/), and this project is systematically behind schedule. A couple of weeks ago, I read that they are so late in so many fronts at the moment that the deliverables will completely redefined in a meeting at the end of this year (September/October I think)

As per my knowledge, the only fusion reactions (other than the natural ones, in the sun for example) have occurred in laboratories and at microscopic level; and honestly I have even my doubts about the exact reliability of such a statement (perhaps just rumours).

Please, provide relevant references to prove your point and dismiss mines.

Re:WHAT radioactive materials?

[Anonymous Coward]

TFTR had 50 MW of fusion power in the 90s although it was a net loss as more power was put into the reactor than it produced. Several other fusion research reactors are in similar situations, where fusion happens, but not at a net positive energy release (heck, high school students can build Farnsworth fusors that produce macroscopic amounts of fusion, although very, very inefficiently). Even some of the experiments that run with DD instead of DT reactions will get enough fusion to use the neutrons emitted as a diagnostic, even if it isn't a useful amount of power involved.

Re:WHAT radioactive materials?

[CustomSolvers2]

But why people keep saying things completely against what I am defending without providing any kind of reference? Now high school students can create macroscopic (or even microscopic) fusion reactions!? But where are you getting all these weird ideas from?

Humankind hasn't been able to create fusion reactions with relevant macroscopic effects in their whole history! Currently, many countries are investing lots of money in the ITER project to create the first actually-working fusion reactor ever! They are so lost (because nothing on these lines has ever been done before) that this project is being systematically delayed!

When I firstly read some of the comments to this article, I said to me "wow! Pure knowledge in action!". Why have I to participate in so extremely pointless discussions? How can such worthy comments be written so close to nonsense on the lines of there-are-tons-of-fusion-reactors-because-I-say-so?!

Re: WHAT radioactive materials?

[ceoyoyo]

Laser initiated fusion works just fine. It's just not net energy positive. But you don't need it to be when you're just using it as a neutron source. The fission reaction it kicks off is enthusiastically energy positive.

Re:WHAT radioactive materials?

[Anonymous Coward]

You were given plenty of information to find things on your own at whatever level is appropriate (even if the other AC got the 50 MW wrong, when it was 10 MW), but apparently you need to be spoon fed:

TFTR via Wikipedia

TFTR via PPPL's own website although it is very barren

A review paper on TFTR, which includes the example 10 MW fusion power shot 80539.

A more detailed paper on a 5 MW fusion power result

This all took 30 seconds to find with a google search for "TFTR fusion", would have all been covered if you looked at all at any summary of fusion history, whether on Wikipedia, or some place like PPPL. It takes far longer to create links to all of these than it does to find them.

It sounds like you are the type of person trying to use "Please provide a reference" as a roadblock, to shoot down others because they don't want to spend twice the effort it would have taken you to find things on your own to present them to you. You also provide no references to any of your claims. If you continue such tactics, you will only end up with a false sense of victory as people won't take the effort to spoon feed you when you were given more than enough information to find every reference you could possibly need (unless you have some sort of learning disability...).

Heck, you could have even just copy pasted the "Farnsworth fusor" name also already given to you and find anything from wikipedia level articles including discussion of high school level examples, to commercial products that involve almost a watt of fusion reactions as a neutron source.

So are you actually interested in learning and have any excuse why you could find this info (in less time than it would have taken to write your reply)? Or do you just want to bully people around and look like you are right with minimal effort...

Re:WHAT radioactive materials?

[Anonymous Coward]

You can't use current economics to discuss future tritium amounts. Projects like ITER are expected to use nearly all if not exceed all current tritium reserves. Pretty much any future involving DT fusion is going to involve tritium breeding from lithium, which will completely change the economics of tritium.

Re:WHAT radioactive materials?

[CustomSolvers2]

After a really quick look at the first link, I saw "world-record of 10.7 megawatts" (around 50 times less than a small fission plant?! Impressive! -> just joking; this is a good enough proof to dismiss my point). Anyway... I have to go through all this information to make sure that the name "fusion" is used as I understand it. In any case, this is precisely what I was asking for: thanks.

All what you write after "you are the type of person..." has nothing to do with my personality and what happened here. I seriously thought that “no viable fusion” meant never happened at all (other than in laboratories and under very restricted conditions). This is the reason for my inactivity: not believing that it was possible (-> nothing to do with your interpretation. Curious, isn’t it? Might it be possible that just by asking directly you might understand anything better than by building whole theories based on misinterpretations?). I will take a look and this information and come back to you ASAP.

Re:WHAT radioactive materials?

[CustomSolvers2]

First of all: thanks for your patience and for making the (small) effort of putting together these ideas. I do recognise that have learned some things which I didn’t know (e.g., the magnetic container proposed by the ITER has already been tested in many different situations, although just during some seconds).

Other than that, I am afraid that my ideas haven't changed appreciably (at least, not in the I-was-wrong direction). I think that there are quite a few not-completely-clear-to-everyone points which provoke systematic misunderstandings. Thus, to reward your effort (, to prove that your interpretation of my behaviour was completely wrong) and to avoid future misunderstandings, here you have a set of more detailed (perhaps too evident at some point; but will surely avoid misterpretations) ideas:

- What we want fusion for? For somehow emulating what the current fission reactors (logically by bearing in mind the multiple differences between both phenomena) are doing; more specifically, to emulate the stable (and not-too-high-temperature) heat generation outputted by the fission reactions. Why the fission reactors have to generate stable (and not-too-high-temperature) heat? Because all the fission-based power plants (equivalently to what is expected to happen with the future(?) fusion ones) are based on a very simple but perfectly working idea: the electricity is generated from the rotation of a turbine; this turbine has to be regularly rotating for as long periods as possible (because we need all the possible electricity and more); this rotation is achieved by boiling water, phenomenon which happens only its temperature is within certain pretty small range (a bit below/above 100C). The current nuclear (fission) plants get this stable source of heat (with not-too-high-temperature) by taking advantage from what the fission reactions generate. This generated temperature is quite low and that’s why it represents a good source of energy on this context (i.e., a good waiter-boiler). You also don’t need too much energy to start the fission reactions; in fact: you don’t need to start them too often (almost never), this is the beauty of the chain fission reactions and that’s why this form of energy (independently upon the associated dangers) is very efficient and that’s why the nuclear fission plants are the most powerful ones.

- The fusion reactors are expected to apply exactly the same ideas than the fission ones; because the fusion reactions are also expected to generate a regular source of heat (which is basically what we want). The problem is that this time, starting the process (and maintaining it) is not so easy. Additionally the temperature of the generated heat is so high that provokes lots of problems. Creating a chain reaction in fission is very easy; you can see it as a pool (billiard) game: you through a ball which hits another one, which hits the wall, which hits another one After the process is started, it will continue for really long. In fact, without chain reactions nuclear energy would make any sense (= couldn’t considered a form of energy) as far as the heat generated in just one event (fission/fusion) is not too relevant. When you say that fusion hasn’t reached the break-even or that you have put in x and it can only generate x-1, you are not defining a form of energy, but a form of consumption (equivalently to the water which is expected to be boiled).

- Thus, when I talk about fusion I understand a form of energy capable to deliver what is expected, that is: generating heat (at an adequate temperature) for a long enough period of time (to boil water which will then generate electricity). If you are able to fuse two nuclei, excellent; if these first two nuclei generate enough heat to automatically provoke the fusion of the neighbour ones (and so on and so forth), excellent too; if you need lots of energy to perform these fusions but you create a properly working framework, excellent. But don’t call it form of energy i

Re:WHAT radioactive materials?

[Anonymous Coward]

With an atomic weight of 2, with two oxygen atoms of atomic weight of 16, the deuterium is only 2 / 34 of the mass.

Deuterium oxide = H2O, 2+2+16 = 20, so 4/20 mass wise, therefore $1000 X 5 = $5000 + [price of electrolysis]/kg.

Re:WHAT radioactive materials?

[tehcyder]

we don't currently have fusion working

We don't currently have economically viable, contained fusion reactors working.

Indeed, H-bombs have been proved to work.

Re:WHAT radioactive materials?

[Plumpaquatsch]

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.

We're not looking for a cost-efficient way to kill somebody, we're looking at the potential risk of an engine design. And that will use as much tritium as it needs, cost for a part of it will not matter much as long as the total cost will be acceptable for its use.

Re: WHAT radioactive materials?

[crunchygranola]

Laser initiated fusion works just fine. It's just not net energy positive. But you don't need it to be when you're just using it as a neutron source. The fission reaction it kicks off is enthusiastically energy positive.

For some extremely unusual definitions of "fine" perhaps. At least it exists, which may be the very low bar you are setting for "fine".

This paper reports on the current state of the art of laser initiated fusion. The accomplishment was to get slightly more energy (about 14 kJ) out the D-T fuel (~30% more) that was deposited in the fuel itself. This was less than 1/10 the laser beam energy delivered to the capsule though (150 kJ).

Although fission, produced by a fusion neutron, produces more energy than the fusion reaction itself, the ratio is about 17-fold, which just barely compensates for the current low yield relative to the laser pulse. Meanwhile the best available lasers for this type (ultra-short tailored pulses) are 0.5% efficient, and the ability to convert fission heat into electricity to drive the laser in the aircraft would be on the order of 10%, and then we need this system to perform at much larger than system break-even levels to drive an actual aircraft. Fusion energy schemes typically assume a yield advantage larger than 10-1 (usually 100-1) to make the system a viable energy producer. So we are short by a factor of 100,000 or so in terms of system capability (fusion explosion round trip back to laser pulse generation) to support the concept. There are plans to upgrade the laser using diode pumps, which should improve its efficiency by a factor of 6, which helps, but that hardly puts a major dent in the short fall.

Oh, and the laser currently is as large as a sports stadium, and can only fire a few shots a day, instead of hundreds per second (a 1,000,000-1 repetition rate shortfall) and the fusion target is made out of gold and costs $10,000 per shot (the amortized cost per shot given the cost of the whole facility to do it is on the order of a million dollars). Factoring in the enormous decrease in target costs (factor of 100,000 say) and size of the laser (lets say a factor of 10,000 to fly it), we are looking at a figure-of-merit short fall of something like 20 orders of magnitude to turn the concept into reality. But other than that laser fusion works just fine.

Re: WHAT radioactive materials?

[ceoyoyo]

You seem to be referring to the US National Ignition Facility. It was built at very large scale in an attempt to produce net energy positive fusion and also to simulate nuclear weapon implosions.

The Boeing concept is for an engine powered by fission, initiated by neutrons produced by a small fusion reaction. The fusion part is like the spark plug in a car - it doesn't produce significant energy itself, it's just a way to initiate and control the main reaction.

Inertial (laser) confinement fusion works fine on smaller scales as a neutron source. Here's a paper talking about using it for a cheap, bench top neutron source: http://iopscience.iop.org/0029...

Great

[thinkwaitfast]

Now we won't have laser ignited fusion powered aircraft for another 20 years.

Re: Great

[Anonymous Coward]

What happened to the days when you had to go to the parent office with a working model? sigh

https://s-media-cache-ak0.pinimg.com/736x/bd/fc/31/bdfc319da05e929e87b6b88f1b4a759e.jpg

Re: Great

[redwraith94]

Maybe they have. They are after all a defense contractor, and if something like this was working it wouldn't be not classified.

Moon plane

[Anonymous Coward]

Maybe better as an engine on the moon, where you farm the deuterium from the sun.

Re:Moon plane

[reve_etrange]

The fusion is used to generate electricity. It still uses a turbine.

Re:Moon plane

[brambus]

You're mistaking deuterium (H^2) for tritium (H^3), which is still the wrong thing to be looking for. Lunar regolith is frequently cited as a source of He^3 (Helium-3), which in some schemes would be a suitable fusion fuel, but Helium-3 fusion is so difficult to initiate and keep stable that it's just stuff of pure science fiction (I mean the fusion bit is science fiction, the Helium-3 part is real enough).

Re:Moon plane

[ColdWetDog]

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.

Re:Moon plane

[Rei]

Not to mention that there's tons of ways to make 3He here on Earth. Including the natural decay of tritium.

Re:Moon plane

[reve_etrange]

Oh, you're right. The first link makes that clear.

Even U238 isn't radioactive.

[Anonymous Coward]

Not radioactive.

Re:Even U238 isn't radioactive.

[beelsebob]

But the plutonium produced by firing neutrons into it is.

Re:Even U238 isn't radioactive.

[Anonymous Coward]

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.

Re:Even U238 isn't radioactive.

[HiThere]

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.

Re:Even U238 isn't radioactive.

[beelsebob]

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.

Re:Even U238 isn't radioactive.

[ColdWetDog]

This is in fact exactly the reaction used in the production of Pu239 for nuclear weapons.

Cool. Portable nuclear proliferation. Now that's progress.

Re:Even U238 isn't radioactive.

[fuzzyfuzzyfungus]

So, if we can get this to the right scale; we can have a 'sustainable bomber' capable of all steps from enrichment to warhead delivery! It's like a seat on the security council in one convenient package.

Re:Even U238 isn't radioactive.

[Type44Q]

Fuzz, I'm surprised you never heard of this...

Re:Even U238 isn't radioactive.

[Rei]

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 (quite low capture, cheap, but subpar at moderation).

Re:Even U238 isn't radioactive.

[Hartree]

"Not radioactive"

Not true.

It's an alpha emitter with a half life of 4.5 billion years.

Re:Even U238 isn't radioactive.

[WheezyJoe]

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 powerful enough neutron bombardment.

Re:Even U238 isn't radioactive.

[clovis]

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. The fast neutrons released by the fusion make U-238 fission. Because U-238 has no critical mass (and won't support chain reactions), you can layer on all you want. Most of the power does NOT come from energy released by the fusion component - it's job is to make fast neutrons to fission the U-238 jacket

Re:Even U238 isn't radioactive.

[redwraith94]

U238 is only used as the outer 'shielding' of Nuclear weapons as it when does absorb neutrons that are generated by the bomb detonating it creates a cascade of more neutrons generated than the just one that hit it, some of which go back toward the Lithium 6 Deuteride inner 'shielding'. This essentially 'reflects' neutrons back into the core, which can significantly increase the yield of a nuke. The Lithium 6 Deuteride is responsible for the 'Fusion boosted' part. The U238 just 'prevents' some of the neutrons from 'escaping'.

The technical term is neutron cross section: https://en.wikipedia.org/wiki/...

Re:Even U238 isn't radioactive.

[redwraith94]

Boronated parafin. Parafin by itself doesn't do much. It's the Boron that has the high 'neutron cross section'

Re:Even U238 isn't radioactive.

[redwraith94]

Pu239 isn't really all that nasty in smallish quantities. The half life is large at over 24,000 years. It is Alpha decay (a helium nucleus, which is effectively stopped by the dead layer of skin on our bodies.) It only becomes an issue when it is near a source of neutrons, since it will 'respond' by generating a cascade of many more neutrons than each one that is absorbed.

It's natural decay can provide this source of neutrons hence you don't want to be near a large of enough quantity of it, as it will be generating a lot of neutrons from the 'chain reaction'.

So if all of it is in a sphere in the middle of the room, stay the hell away from it. If the same quantity is scattered as shot across the floor, it's not such an issue.

Re:Even U238 isn't radioactive.

[redwraith94]

Iron is the most stable nuclide (with Nickel being a close second), so creating elements above them requires energy. Not all heavier elements are radioactive though. The higher the ratio of neutrons to protons, the more likely the element is to be radioactive. There are so called 'islands of stability', just like with electron shells. Then there are also the double magic nuclei. I think that effect is the most interesting thing I have seen in all of Physics:

https://en.wikipedia.org/wiki/...

One of those higher magic numbered nuclei (elements we have not detected yet) are probably the fuel that the Annunaki used in their spaceships to enslave humanity 241,000 years ago...Just sayin.

Re:Even U238 isn't radioactive.

[redwraith94]

By far the majority of the power comes from the Lithium 6 Deuteride fusion booster, that sits between the U238 outer shell, and the actual core. The U238 helps, but it is not the most significant boost. The U238 is actually meant to create more neutrons in order to seed more Fusion; so that not as much of the fusion 'fuel' is lost to the explosion. I suspect it was also because after enrichment they have all of this 'depleted uranium' lying around, so why not put it to good use? It may only be a 40% boost (I don't know the actual number), but it is free!

Re:Even U238 isn't radioactive.

[redwraith94]

"Practically Not radioactive"

FTFY

Re:Even U238 isn't radioactive.

[oobayly]

Yes it is, it has a half life of 4.468 billion years and undergoes alpha decay.

Re:Even U238 isn't radioactive.

[forand]

I think you misread something. Pu239 synthesis doesn't include beta capture. U239 is unstable and EMITTS a beta similarly for Np239. Beta (electron) capture would lead to a lower atomic number:
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.

Re:Even U238 isn't radioactive.

[Rei]

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.

Re:Even U238 isn't radioactive.

[Rei]

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..

Re:Even U238 isn't radioactive.

[newslash.formatblows]

Could you be thinking of this one? http://nucleardata.nuclear.lu....

Re:Even U238 isn't radioactive.

[Anonymous Coward]

In the real world where you don't have a U238 that stays pure indefinitely, but instead forms a sort of equilibrium with its decay products on the order of months after being refined, you end up with something several times more radioactive than the original pure U239, and emitting betas and gammas too. It makes a great calibration source for various beta and gamma spectroscopy equipment, and that is only with a small sample as opposed to the many kilograms that are used in various fusion-fission hybrid designs.

You seem to be confusing a simple ideal case with what is actually the practical side of things.

Re:Even U238 isn't radioactive.

[ebvwfbw]

Reason why he posted as AC. He's full of it. It has a half life and is radioactive. I'd offer to put a half Lbs under his pillow and dare him to keep it there for half a year. He won't be around anymore. It's not like you're going to die within an hour radioactive. It's still "hot". I think I still have some dishes around that are "hot".

Re:Even U238 isn't radioactive.

[HiThere]

Sorry, but for a moderator you don't want to absorb the neutrons, you want to slow them down. So scratch the boron.

Re:Even U238 isn't radioactive.

[clovis]

By far the majority of the power comes from the Lithium 6 Deuteride fusion booster, that sits between the U238 outer shell, and the actual core. The U238 helps, but it is not the most significant boost. The U238 is actually meant to create more neutrons in order to seed more Fusion; so that not as much of the fusion 'fuel' is lost to the explosion. I suspect it was also because after enrichment they have all of this 'depleted uranium' lying around, so why not put it to good use? It may only be a 40% boost (I don't know the actual number), but it is free!

You are right and I was wrong when I said: "Most of the power does NOT come from energy released by the fusion component ". I was talking off the top of my head from what I remembered from Richard Rhodes books. That only describes certain older weapons.

So, I do more reading. Proportion of yield depends upon design (duh), and in modern weapons (such as W-80 and W-88) it's closer to 50/50 fusion/fission contribution to energy.
Anyway, the li6 deuteride and U-238 work together. Both are critical to making the secondary stage work. The Li6-D provides fast neutrons to fission the U-238, and the U-238's fission's neutrons converts the Li6 to tritium for fusion and both boost the yield. The primary fission device has a yield of only 5-10 kT, so most of the yield comes from the fusion-fission secondary stage.
Although the hydrogen isotopes fusion provides more energy per weight, the U238- fission provides 8 times more energy per volume than the fusion component. In most modern weapon delivery systems, the size is more important than the weight.
Also, it appears that now-a-days the US is using highly enriched uranium, HEU, instead of natural U-238 for additional yield-boosting.

absolute BS

[frovingslosh]

Once again we have a patent issued for something that wasn't built, can't be built and likely will never be built. Boeing has no idea how to build a fusion engine, and if they could then they could and should build a ground based fusion power plant based on their magic technology. 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.

Re:absolute BS

[gweihir]

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.

Re:absolute BS

[msobkow]

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.

Re:absolute BS

[Anonymous Coward]

This has nothing to do with fusion power generation. We've been building fusion/thermonuclear weapons for a long time. This is basically an 'engine' which sets off a tiny thermonuclear bomb behind itself over and over again to propel itself forward. The basic design concept goes back to the sixties, and is quite workable. There is no technical reason it couldn't be built now, only political ones.

Re:absolute BS

[binarylarry]

Yeah, damn those shark activists

Re:absolute BS

[gstoddart]

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

[HiThere]

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.

Re:absolute BS

[meglon]

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.

Re:absolute BS

[Anonymous Coward]

GOD BLESS YOU, yes that's exactly what this is.

"If there is a God, then God is great, otherwise fuck it."

Re:absolute BS

[sumdumass]

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.

Re:absolute BS

[frovingslosh]

Please don't inflict your religious blessings on me.

Re:absolute BS

[gstoddart]

LOL ... is that a real fact, or one of those stupid internet facts?

Re:absolute BS

[khallow]

I'll beseech Eris on your behalf for an anti-blessing to counter the blessing. No charge.

Re:absolute BS

[penguinoid]

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.

Re:absolute BS

[Anonymous Coward]

GP poster is named "sumdumass", what do you think?

Re:absolute BS

[Anonymous Coward]

It's in the Smithsonian, which typically doesn't print rubbish. The fact that carrots improve eye health (and hence eyesight) was confirmed science, but they didn't do squat for night vision (that's the myth part). The myth existed due to misunderstandings of what "improved eyesight" entails.

In WWII they release misinformation in an attempt to forestall the discovery that the allies had radar. However, the myth existed as an old wive's tale before. In addition, the sugar shortages led to a popularity campaign to boost carrot consumption, which apparently they had in excess in storage.

WWII propoganda campaing popularized the myth that carrots help you see in the dark

Re:absolute BS

[joe_frisch]

Even some sort of peer review to say that you have at least solved the key problems.

Re:absolute BS

[Anonymous Coward]

If you give the lawers enough money, they can do anything.

Re:absolute BS

[redwraith94]

We don't actually know that for certain:

http://aviationweek.com/techno...

Re:absolute BS

[redwraith94]

That depends; is your name Podkletnov?

Re:absolute BS

[redwraith94]

I guess those carrots were grown with special tritium water?

Re:absolute BS

[redwraith94]

could be classified.

Re:absolute BS

[redwraith94]

That makes me think of the buzz bomb videos on youtube, can you imagine a fusion / fission version of that? It would have to be deafening.

So we had to limit this device to 230 decibels, A weighted. Stupid FAA. It'll only physically rip you pieces 150 yards out....No, no the hearing protection, don't bother...Yes, yes I'm sure.

Re:absolute BS

[dissy]

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 previously arranged)

One will not get far in life pissing off the only person with a functional fusion device, and there is next to nothing that could be done to stop them :P

Re:absolute BS

[redwraith94]

That isn't correct. While in a reactor Plutonium, or Uranium (fission) will produce more energy than fusion per nucleon, that is the average energy over the life of all of the decay products:

http://periodictable.com/Isoto...

The majority of the decay products takes far longer than a full second to be produced, so they aren't relevant to the detonation, or the brisance of the device.

http://www.kayelaby.npl.co.uk/...

In the environment of a reactor, you can simply wait long enough, and extract the full energy as Plutonium is converted between a dozen different elements, but in a bomb, speed is king, so the slow fission products don't add meaningful amounts of force, or power to the explosion. Fusion boosters don't have a critical mass, so you can pack in as much of them as you want.

Re:absolute BS

[Anonymous Coward]

It's called first to file.

And Europe's been following that system longer than the US...

Re:absolute BS

[Dr. Spork]

I actually think this is great. After all, the patent expires in what, 25 years? I doubt a single engine will be built in that time, but forever afterwards, this idea in the public domain. Consider the alternative, if someone waited to patent this thing until applications were actually ready. Then the patent would prevent competitors from entering the market. But because Boeing hasn't waited, it has basically ensured that nobody will use patent law to put the brakes on innovation when we get around to actually making serious spaceships - which is what this propulsion system is obviously for.

Re:absolute BS

[CrimsonAvenger]

We hid our radar capabilities in the early days of the cold war

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.

Re:absolute BS

[Anonymous Coward]

A functional Fusion device is not a magic wand.

Sorry.

Re:absolute BS

[meta-monkey]

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.

Re:absolute BS

[sumdumass]

Another posted pointed out to me that it was the brits in world war two not the cold war. In my civil air patrol days of the mid 1980s as a cadet (before i discovered the preacher's daughter and drugs/alcohol) I'm pretty sure i was told it was the cold war but i or the guy telling the story could be wrong.

Of course we heard a lot of stories. Part of the experience probably had more primitive camping than the boy scouts wished for in training for the search and rescue (sar) portion. But the CAP, as part of it's mission was propaganda er educating the public.

Re:absolute BS

[Anonymous Coward]

See National Ignition Facility before posting what is possible. But I doubt they can patient the whole process since it was created by U.S. Government grants.

Re:absolute BS

[KGIII]

I believe it should have been described more specifically as their way of creating indecision to help keep the knowledge of Chain Home a secret. The Germans did not know what the Chain Home system was actually doing. They bombed a couple (which were easily replaced and had redundancy built in for Home Office communications - a neat way of doing it) and then gave up which indicates that they really did not have any clue what the purpose was.

On the opposite end of the spectrum SAS crossed the channel to investigate some radio emitters. However, those were used for targeting and not for plane spotting.

Had the Germans known what the Chain Home system was they would have bombed the hell out of them, and likely been successful, which would have likely caused the War Over Europe to go differently.

It is hard to say, as all such intelligence things are, how well they can quantify the results. Current historians attribute it, as near as I can tell, to a simple intelligence oversight on the part of the Germans. They had the technology, they were even using it in their night fighters, but did not really use it on their end as well as they could have during the earliest stages of the bombing campaigns. What they had, to help them out at first, was a lot of people with communications gear who were able to spot aircraft invasions. Technology improved at a very rapid rate during that period. It seems some of the greatest technological advances come during times when we are trying our hardest to either hurt or be prepared to hurt another human being. If we put the same amount into learning how to not... Well...

Re:absolute BS

[Anonymous Coward]

Or maybe with a grace period of 1-2 years. Obtaining parts for making the prototype can require giving the idea away, so this should not prevent you from getting a patent if it has actual merit.

Re:absolute BS

[Megol]

Nope, fission produces x-rays and neutrons that compacts and then ignites the fusion stage. The fusion stage can in turn be used to ignite a fissile stage (using depleted uranium as the bomb casing) but that's optional, produces more fallout and isn't a vital part of the design.
A thermonuclear bomb get most energy through the fusion process as initiated by a fission device.

Re:absolute BS

[Chelloveck]

You forget that unlike copyright, patents actually expire after 20 years. This invention is unworkable now, and is unlikely to be workable within the lifetime of the patent. But, the patent can be considered prior art when someone finally does figure out how to make one of these. In the best case this will be an unencumbered technology by the time it's ready to be used. (Yes, I know that's an idealistic statement, and that anyone actually doing this will be able to file dozens of patents regarding the implementation details. But no one should be able to claim that the basic idea is innovative again.)

Re:absolute BS

[Anonymous Coward]

I have heard that several such patents actually do exist, as well as perpetual motion machines. They are not very discriminating when awarding patents.

Of course, I could just go try to research to validate this hearsay, but I'm too lazy.

Fusion or Fission?

[spooje]

If it's fusion as opposed to fissions wouldn't the fuel be some hydrogen isotope?

Re:Fusion or Fission?

[brambus]

The most commonly assumed because it's of the easiest to initiate fusion reactions is D-T fusion. The "T" stands for radioactive tritium, i.e. the H^3 isotope.

Re:Fusion or Fission?

[meglon]

H2+H3=H+He basically. But, the fusion part isn't what the counter argument is talking about.

Bullshit worries...

[gweihir]

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.

Fusion vs fission

[GrumpyDiver]

The moment the word "nuclear" is mentioned people go crazy. This is fusion where tritium pellets are bombarded with lasers to fuse into helium. The concept works in the lab, but the the amount of energy generated is pretty low when compared to the energy required to drive the lasers. It is NOT fission, the process used in current nuclear power plants where uranium or plutonium is split into radioactive particles with long half lives. Chances are pretty good that this patent will expire well before the process becomes viable (if this ever occurs). Yawn!

Re:Fusion vs fission

[thinkwaitfast]

That's why I don't worry about this stuff too much. By the time anyone builds it, the patent will have long expired. In the worse case scenario, we get fusion powered aircraft (implying, the problems associated with fusion have been largely solved) and we'll have to fly in Boeing aircraft (oh no).

Re:Fusion vs fission

[meglon]

If you had read the counter argument, you'd see that their concern is with the U239 that's created when the U238 inner sheath is bombarded by neutrons from the actual fusion blast... which is what causes the heat that's used. While yes, h2+h3=H+He is basic fusion, the counter article is talking about the U239... which is radioactive.

That aside, i think the counter argument is a bit premature, as the engine itself is a pipe dream at this point.

Re:Fusion vs fission

[PPH]

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.

Re:Fusion vs fission

[edjs]

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.

Alien Technology

[Anonymous Coward]

1947 Two Alien Spacecraft crashed at a ranch near Roswell, New Mexico
1950 The first production flat panel display was the Alien tube, developed in the early 1950s and produced in limited numbers in 1958.
1960 The first laser was built in 1960 by Theodore H. Maiman at Hughes Laboratories
etc etc etc

Re:Alien Technology

[Hartree]

But what about Alienware computers?

I'm not saying it's aliens, but...

Re:Alien Technology

[Anonymous Coward]

Tonight I saw a UFO light show in the sky , it moved faster than any drones but maybe not as fast as high rpm engines alongwith highend rocketry special effects

Another useless patent

[Anonymous Coward]

Fusion fission hybrids don't appear to work. Because math. https://en.m.wikipedia.org/wiki/Nuclear_fusion-fission_hybrid

Quote of the day

[P1h3r1e3d13]

Sustainable fusion reactions aren't quite reality yet.

Businessisider.com down?

[grimJester]

I can't imagine the actual technology is real, but apparently the interest is real enough.

Re:Businessisider.com down?

[HiThere]

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.)

Haha

[Anonymous Coward]

Haha hahahaha

ahahahhahahahaha

This is a rocket engine, for space, you idiots.

[Anonymous Coward]

It's not an "aircraft engine". You can look at the patent yourself.

It's an open-cycle nuclear rocket engine that sprays fusion neutrons and tritium all over the place and has no significant containment for neutron-activated materials or fission fragments. OF COURSE it's not for use in Earth's atmosphere.

This is a made-up story. The jet-engine-shaped diagrams in the press are not in the patent.

Re:This is a rocket engine, for space, you idiots.

[Anonymous Coward]

It sounds a lot like the Queller Drive from the Space:1999 episode Voyager's Return.

Could Be Worse

[Anonymous Coward]

It sounds better than some previous ideas...

That's grade A #1 BULLSHIT!

[AndyKron]

How can you patent something you can't even get working? That's grade A #1 BULLSHIT!

Re:That's grade A #1 BULLSHIT!

[ebvwfbw]

How can you patent something you can't even get working? That's grade A #1 BULLSHIT!

You're not familiar with the patent system, are you?
If they're getting a patent on it, you can bet it works. Otherwise there's no reason to get one. Now they can use it for 17 years. Why start a clock when you can't use it? That's one side, on the other the patent examiners will grant almost anything. They've been made fun of for years. Hey - let's patent the wheel again!

With their track record.

[fahrbot-bot]

First lithium-ion battery fires, now this. What could go wrong?

Sounds great

[Anonymous Coward]

I'm sure the patent office asked them to provide a working model for something so ahead of what everybody else can actually build.

The alternative is a joke at best of more likely, a sad commentary on the competence and common sense of patent examiners.

The Fictional Radioactive Materials

[Crashmarik]

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.

Re:The Fictional Radioactive Materials

[Shakrai]

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.

If you can develop a working fusion engine you'll have so much fucking money that it won't matter. Seriously, you'll be able to swim in your money like Scrooge McDuck. I highly doubt that Boeing's patent is a deal-breaker for the person that's smart enough to solve this engineering challenge. "Aww, shucks, I was going to change the course of human civilization but now I've got lawyers and paperwork to deal with. Screw it, I'm gonna go watch American Idol."

Re:The Fictional Radioactive Materials

[Crashmarik]

Dude that's the problem they won't own it.

Re:The Fictional Radioactive Materials

[Rei]

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.

Re:The Fictional Radioactive Materials

[sjames]

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.

Re:The Fictional Radioactive Materials

[camperdave]

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.

Re:The Fictional Radioactive Materials

[Khashishi]

Don't worry about it; the patent will expire by the time a working model is built.

Re:The Fictional Radioactive Materials

[redwraith94]

It may actually not be patentable; I haven't bothered to read the patent. There are too many of those damned things.

Re:The Fictional Radioactive Materials

[Crashmarik]

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.

Re:The Fictional Radioactive Materials

[Anonymous Coward]

Of course, now so-said "anyone" is seriously looking into fusion techniques, cause Boeing took some time and money to try to patent a concept. They just make these ideas legitimate.

Really, if Boeing didn't patent, this 'well known' laser fusion technique, it would be sitting on some professor's self... until someone has a breakthrough technique... by chance (i.e. Moore's Law).

Instead, Boeing patenting their idea (hence if you come up with a better mouse trap--spoils to you) sort of validates/legitimized the concepts & they are ready for real application and mainstream use.

The patent system actually goes both ways folks. Yes, folks will 'game the system' (e.g. patent trolls), but it does act not only as a inventive repository, but also a business/economic validation tool.

Re:The Fictional Radioactive Materials

[Anonymous Coward]

Doesn't need working fusion to make this work.

The 'fusion part just needs to generate enough neutrons to cause controlled fission in the uranium, we can do that now.

I suspect that's actually the future of fusion anyway, doesn't look like pure fusion will scale well and the waste heat to energy output ratio is horrible.

Re:The Fictional Radioactive Materials

[Anonymous Coward]

precisely

They go to court, they prevent your exports and imports, they deny you the right to sell your product because you haven't got a license!

Or for a billion dollars you could sell them all your work and your problems go away!

Forget that boeing will run off and make a hundred billion selling the engine off your efforts.

Re:The Fictional Radioactive Materials

[Antique Geekmeister]

By patenting it, they control _research_ on it and closely related work for the next 20 years. Patents are written by the attorneys to cover as much of the related work and developments as possible.

Re:The Fictional Radioactive Materials

[camperdave]

In the 1950s, we weren't 20 years from practical barcode technology. We had computers running off of punched paper tape. Barcodes werre not much of a stretch. Practical nuclear fusion reactors are well over 20 years away, especially a type light enough to power an airplane.

Re:The Fictional Radioactive Materials

[Crashmarik]

So you support granting patents for technologies that don't exist and will require tremendous of effort to make work ?

Re:The Fictional Radioactive Materials

[tehcyder]

If I'd invented this world-changing technology (and I was American) I'd just bugger off to Russia or China and tell Boeing to sue my hairy balls.

Re:The Fictional Radioactive Materials

[camperdave]

No. Rather the contrary. Patents should be for well defined, actual inventions, not vague notions.

As far as Jerome Lemelson and the barcode patent are concerned, all the supporting technology was in place. We had computers. We had devices that read instructions and data from paper tape. We had devices that could sense light levels. Maybe he did put two and two together. I don't know.

My point, though, is this: Since patents only last 20 years, there's no point in patenting something that is 30 years out. You can't make any money on it. But Boeing is taking out patents. So, the only conclusion is that Boeing has stumbled onto an idea that will make fusion engines a practical reality before the patent runs out.

Re:The Fictional Radioactive Materials

[Crashmarik]

As far as Jerome Lemelson and the barcode patent are concerned, all the supporting technology was in place

That's nice, but what you are endorsing is no different than domain name squatting.

Here is another great example of a patent awarded for something that had the ability to be made but had no implementation.

https://en.wikipedia.org/wiki/...

Do you really want to say BT should have had the rights to every url on the internet ?

Re:The Fictional Radioactive Materials

[crunchygranola]

...You can't make any money on it. But Boeing is taking out patents. So, the only conclusion is that Boeing has stumbled onto an idea that will make fusion engines a practical reality before the patent runs out.

Here's another conclusion - Boeing has decided that the publicity for this patent is worth the cost of filing it. Or that the corporate inventor and patent attorneys find that this is a good way to keep their jobs funded (not exclusive with the previous possibility). Somehow these seem far more likely than a secret new technology nobody else has dreamed of (and is not evident in the actual patent).

Re:The Fictional Radioactive Materials

[camperdave]

As far as Jerome Lemelson and the barcode patent are concerned, all the supporting technology was in place

That's nice, but what you are endorsing is no different than domain name squatting.

You didn't read my comment properly, so let me reiterate:

Patents should be for well defined, actual inventions, not vague notions.

Tired of anti-nuclear editors on Slashdot!

[Prune]

And of course, one of the links cited is a story in CounterPunch that extensively quotes a Greenpeace official. What is CounterPunch, you might ask? First line in the Wikipedia article about it:

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.

Re:Tired of anti-nuclear editors on Slashdot!

[Hartree]

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

[kenwd0elq]

The basic concept is similar to Freeman Dyson's Project Orion https://en.wikipedia.org/wiki/... which makes any patent subject to prior art claims. If they're patenting a specific technique, then good for them!

i.e. they invented a theory

[Anonymous Coward]

Once upon a time you had to actually invent and make a working prototype, which had the effect of removing impossible ideas and pinning the vague patent language to a more concrete thing.

Instead we have this silliness.

spacecraft propulsion

[Anonymous Coward]

The basic idea of the patent (fusion pellets sent out the back triggered by lasers) has been proposed in some form as a future method of propulsion for spacecraft.

I would think the patent would expire (20 years) well before this method of propulsion would be used in outer space, but maybe not. Maybe Boeing plans to do a bunch of R&D on very advanced spacecraft propulsion. Perhaps instead Boeing is filing this patent to try to block or set back other companies in their potential very advanced spacecraft propulsion R&D.

Wikipedia on Project Orion using nuclear pellet propulsion in space.
https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

Re:spacecraft propulsion

[cheesybagel]

Actually this is more like Project Daedalus in that it uses ICF to a degree.

Re:spacecraft propulsion

[oobayly]

But do you need to pay royalties if you're only doing R&D?

Re:Fusion or Fission? Neither.

[leftover]

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.

So *many* mistakes in the article

[tlambert]

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 exposed to fast neutrons.

Note that these are *FAST* neutrons; to turn U-238 into Pu-239 requires *SLOW* neutrons. Even if some idiot put the one foot of paraffin required into the combustion chamber between the U-238 and the fusion reaction, it'd be burn out immediately by the temperatures involved (which is why we use reactor reactors to make Pu-239, and not straight Beryllium/Polonium or other less conventional neutron sources).

Basically, if one of these crashed, it would result in a bunch of inert wreckage, just like any other plane crash, although instead of starting a fire or anything, the pellet storage, if breached, would boil off (meaning the hydrogen isotopes would "heat" up to the point they became gas, not that anything would be hot).

In other words, no radiation anywhere.

P.S.: To the idiots who claim "this is how we make Pu-239 today" -- no, we do not use neutrons from fusion reactions to make Pu-239; also, if it were that easy to make Pu-239 *on purpose*, as opposed to *as a by-product of a design intended to avoid its production entirely*, Iraq would have had nuclear weapons already.

Inertial confinement fusion

[technosaurus]

ICF has already been demonstrated to work, however the laser density and strength has limited the efficiency. Perhaps the "Rocket City Rednecks" can bust out their weaponised blu-Ray player arrays and put them to a peaceful purpose.

So *many* mistakes in your post:

[Hartree]

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 alpha particle emitter with a half life of 4.5 billion years. (Agreed, it's not highly radioactive, but it certainly is radioactive. U235 is more highly radioactive.)

I'm hardly an alarmist about nuclear technology and am a strong supporter of nuclear power, but blatant mistakes in your post don't help the argument in favor of it.

Re:So *many* mistakes in your post:

[tlambert]

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/

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.

Re:So *many* mistakes in your post:

[Antique Geekmeister]

> As previously noted: the Tritium will remain cryogenically suspended, or it will "boil off". It's not an issue.

Keeping tritium around as a fuel source means keeping quite radioactive fuel, in significant quantities, aboard the aircraft and in storage for the aircraft. "cryogenic suspension" is expensive to maintain. If the suspension fails, it will disperse into the local atmosphere, combine with free oxygen locally, and contaminate the whole area, especially if there is any fire involved in the containment failure.

Re:So *many* mistakes in your post:

[angel'o'sphere]

As previously noted: the Tritium will remain cryogenically suspended, or it will "boil off". It's not an issue.

The first issue is: you falsly claimed tritium would not be radioactive.
The second issue is: rescue personnel and crash survivours will inhale the "boiling off" tritium, so it is an issue.

Re:So *many* mistakes in your post:

[Anonymous Coward]

But you know, feel free to get all pedantic,

You quite clearly said tritium is not radioactive, which is quite false. Changing that to it will disperse easily doesn't change how wrong what you said. Furthermore, while a lot can disperse, hyrdogen isotopes have an issue with tending to bond to metals and stick around places you don't want. This has been a serious design issue with fusion projects already, where you can find a lot of literature with estimates of needing hundreds to thousands of times more tritium in the system than just for the reaction, because most of it will end up bound to inner surfaces of the system. While in day to day work with regular hydrogen, no one really cares if a gram or two sticks around (except maybe hydrogen embrittlement issues), that is a significant issue in managing tritium inventory.

As for U-238: cadmium and Neodymium have the same level of "danger" as U-238,

Also, you quite explicitly said U238 is not radioatice, which is also flat out false. Not only that over the course of a couple months, unless you continually refine the U238, you will build up a decay products that will have comparable activity as the original U238, and these include beta and gamma decays. When you start dealing with kilogram levels of U238, that involves multiple MBq of activity of alphas, betas, and gammas each, and that is not a trivial amount of radioactivity. It is manageable, but you're dealing with far more than just a smoke detector.

For someone complaining about people hanging on technical details, you seem to be thinking in terms of textbook definitions and properties of U238 instead of thinking in terms of what happens in the real world, where it is no longer just a simple alpha source (speaking from experience using it to calibrate beta and gamma spectrometers...).

Answer

[Anonymous Coward]

The heaviest concentration radioactive material would be in a container that can withstand reentry.

Re:Answer

[Anonymous Coward]

All excess lift should be used for putting radioactive materials into solar impact.

And how large will this be?

[clovis]

Here is the actual patent:
http://pdfpiw.uspto.gov/.piw?P...

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 a circle.

Or, it suggests we can use "light-emitting diode (LED) driven Alexandrite lasers" instead of free-electron lasers.
Or maybe a flash lamp driven ruby laser. No kidding.

And then the patent says that the fast neutrons from the Deuterium-Tritium fusion will cause the U-238 to fission and explode.
Again, quoting from the patent:
"The secondary explosion recompresses more of the Deuterium and Tritium, causing more fusion energy to be released beyond the 'breakeven' level vaporizing the remaining pellet materials of the propellant 18c of FIG 4 and increasing the overall thrust and exhaust velocity. Use of this embodiment reduces exhaust molecular weight, and increases exhaust velocity and specific impulse."

I did not mistype that.

I'm wondering how large it will be.
AFAIK, this is what a laser fusion device looks like, except that this one isn't ready for prime-time.
https://lasers.llnl.gov/media/...
Nor this one:
http://www.washington.edu/news...
http://www.washington.edu/news...

I would go with the free-electron laser because this is clearly an attempt to make the largest possible engine for the least thrust.

Also, looking at the diagrams in the article, I don't see anything that suggests they've addressed the problem that hitting the pellet with a laser on one side simply causes the pellet be vaporized and driven away without fusion (somewhat like squeezing a watermelon seed). How can they grant patents from devices that cannot work as designed?

Flight

[Anonymous Coward]

Whoah wait a minute, just sounds hot. And unless the laws of physics have changed, its not very viable to carry radioactive material for flight propulsion.

Usage probable for FUTURE probes and MARS

[Anonymous Coward]

this patent is less about flight on earth or other worlds, and more about generating power and HEAT on other planets since NASA's supply of relevant nuclear batteries is depleted. Look at recent incidences with their probes freezing and not being operational for days, weeks, months at a time. This is the response to that, and it also provides a method of movement too. Nothing on a probe or spacecraft can be for just one usage. MARS and other projects need these kind of developments to be viable. Trucking tons of fuel millions of miles through space is not a viable option, tons of water is a better course for human life and radiation protection.

one half NIF

[paul mafinga]

LLNL scientists have a lot of patents on various parts of the NIF. This Boeing patent references some of them. The patent describes the lasers, hohlraum, DT pellets, etc.

In a way, they've cut the NIF chamber in half, and converted one half into a nozzle. Fig 1, 5 of the patent illustrate the classic spike and bell nozzles, respectively.

The design really seems like a novel adaptation of the NIF effort.

"If you can dream it, you can do it"
-- Walt Disney

Then again, all three scientists are from Southern California, the land of $ 60 recommendations and a sea of dispensaries.

The materials science isn't there

[cheesybagel]

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

[Karmashock]

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

[slashmydots]

I've heard of lasers used in high gap distance spark plugs. They're supposed to ignite more fuel faster than high voltage electrical sparks but I have my doubt. But seriously, fusion?! You lose magnetic containment for one second and that engine blows apart. Worst idea ever.

Re:sort of already exists

[angel'o'sphere]

The fusion is based on lasers, not on magnetic containment, you could at least read the summary.

Re:sort of already exists

[Anonymous Coward]

You lose magnetic containment for one second and that engine blows apart. Worst idea ever.

Not how magnetic confined fusion works, as in most cases if you lose the containment, it goes out like turning a fluorescent light bulb off. Worst case scenario involves dumping a lot of heat in an undesired location within the reactor... and by a lot I mean enough to do damage to the surface of expensive parts, but way, way too little to 'blow apart' the machine. Real life fusion isn't anything like the Spiderman movie.

Re:sort of already exists

[Anonymous Coward]

You lose magnetic containment for one second and that engine blows apart.

Look at this. Look at this stupid thing you wrote.

I hope for your sake that you never develop any self-awareness, because if you do you'll kill yourself out of shame.

I don't get it

[DrXym]

How are they going to suspend the sharks on the wings?

Re:I don't get it

[Anonymous Coward]

I believe the sharks are inside the plane, flying it.

Cool Lasers on a Plane

[Anonymous Coward]

This must be cold fusion. Attaching lasers on a plane is so cool.

Magical Pixie-dust Patents

[Dr.Dubious DDQ]

Some years back, I remember seeing a story (I think it was actually here on /.) that one of the big companies (Samsung?) had gotten a patent on teleportation.

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) 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 trying to justify their pay?

(From the link above:)"This application is a continuation of application Ser. No. 08/650,896, filed on May 17, 1996, (now abandoned) which was a continuation of application Ser. No. 08/519,620, filed on Sep. 25, 1995, (now abandoned) which was a continuation of application Ser. No. 07/977,748, filed on Nov. 16, 1992, (now abandoned), which was a continuation of application Ser. No. 07/816,528, filed on Dec. 30, 1991, (now abandoned), which was a continuation of application Ser. No. 07/640,550, filed on Jan. 14, 1991, (now abandoned), which was a continuation of application Ser. No. 07/177,550, filed on Apr. 4, 1991, (now abandoned) as international application serial No. PCT/DE87/00384, filed Aug. 29, 1987, claiming priority to foreign appl. No. P3629434.9, filed Aug. 29, 1986."

Deuterium or tritium

[Chris Mattern]

The article says the patent specifies deuterium or tritium. Only if the engine uses tritium will there be any radioactive fuel to be spread.

patents expire....

[Anonymous Coward]

Won't the patent be invalid/expired by the time this sort of technology is actually developed?

Patent reduces risk it will be built

[Mostly a lurker]

The patent has generated fears of what might happen if an aircraft containing radioactive material as fuel were to crash ...

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.

Neutron shielding?

[seven of five]

This thing is going to be kicking out probably hundreds of kW to maybe MW of neutrons with passengers a few meters away.

Obligatory Gerry Anderson reference

[Anonymous Coward]

Will it make all sorts of weird sounds to alert the audience that exotic propulsion is being employed?

Interesting talk-polywell discussion here...

[seven of five]

http://talk-polywell.org/bb/vi...

It's project Pluto again, with 100% more fusion?

[Ihlosi]

https://en.wikipedia.org/wiki/...

On earth.

[Ihlosi]

I really can't think that Boeing would be so daft as to think that anyone would ever use this on Earth.

Project Pluto was supposed to be used on Earth. You know, if the Americans can't have it, then at least the commies wouldn't have it, either.

https://en.wikipedia.org/wiki/...

Fusion not Fission

[Anonymous Coward]

Wow, just wow. They vote, drive heavy equipment, and make more dummies just like them...

lets count the ways this is idiotic

[cinnamon colbert]

1) Fusion powered airplanes; right
anytime anyone on /. makes a comment about how some other group of people are stupidly wasting time on some idiotic idea....

2) Garbage patent
to secure a patent,the invention has to be "enabled"

3)counterpunch is the absolute bottom of the barrel in webcrap
if you can't write, and you have a particularly stupid piece of inane word salad you want on the web, counterpunch is where you would go after your essay was rejected by everyone else (ok National Review on line and Mark Levin are worse, but they are both pathological)

Re:lets count the ways this is idiotic

[CustomSolvers2]

I also see a very relevant and not-idiotic-at-all output: lots of worthy comments.

Re:lets count the ways this is idiotic

[PPH]

2) Garbage patent
to secure a patent,the invention has to be "enabled"

From the USPTO website:

"The specification must include a written description of the invention and of the manner and process of making and using it, and is required to be in such full, clear, concise, and exact terms as to enable any person skilled in the technological area to which the invention pertains, or with which it is most nearly connected, to make and use the same."

Lets see someone build a fusion propulsion engine. I'll be amazed.

Lets see the USPTO actually enforce their own requirement as a condition of granting a patent. My amazement will be multiplied tenfold.

Fusion is not currently possible

[CustomSolvers2]

There are quite a few worthy fusion/fission-related comments to this article, but it seems that certain idea is not completely clear to everyone: we haven’t ever built a working fusion reactor. Currently there is a (theoretically) serious attempt which is supported by various countries (and by lots of money) call ITER; although it is still a mere theoretical prototype. In fact this project has been systematically delayed during the last years.

A quick overview of how this reactor is expected to work:
1. Reaching an extremely temperature (i.e., the one in the sun), which will instantaneously melt any known material.
2. Containing the aforementioned hot plasma (i.e., self-sustained fusion chain reactions) with magnetic fields and with a very efficient refrigeration system.
3. Getting just a tiny fraction (i.e., what is required to boil water) of all this heat to generate electricity.

Thus, the main problem is that the required heat (the energy used to provoke the first fusion reaction) is so high that provokes quite a few other problems, like confining the hot plasma and extracting only what is required or even having a device able to generate so high temperatures

All these problems are logically much less relevant at much smaller scales (at the microscopic level), where the only successful fusion reactions have precisely occurred; and even at that tiny level, it is very difficult to create a self-sustained reactions generating more power than what is being put in (to not mention all the aforementioned issues associated with so high temperatures).

I have proposed an example in one my comments above which I will repeat here: looking forward to getting any reliable reference to a single successful experiment creating a macroscopic-relevant fusion reaction, like heating a cup of coffee during 5 minutes. I think that such a thing hasn’t ever occurred, but I would love to be proven wrong. Please, provide relevant references to support all your claims on the can-be-done front.

Re:Fusion is not currently possible

[CustomSolvers2]

I don't mind the no-editing-after-posting Slashdot peculiarity; even think that it is good for someone like me (usually performing lots of editions after submitting any online text). Unfortunately, now I am quite tired and couldn't avoid some errors. Sorry and lesson learned (last late post in Slashdot).

Re:Fusion is not currently possible

[Anonymous Coward]

but it seems that certain idea is not completely clear to everyone: we haven’t ever built a working fusion reactor.

Numerous fusion reactors have been built on different scales, from tabletop ones to ones like TFTR that involved 10s of MW of fusion power. The hard part is not getting hydrogen isotopes to fuse, but doing so efficiently enough that you output more power than you put in. Only a small number of reactors have gotten close one of the definitions of breakeven.

although it is still a mere theoretical prototype

I'm not sure what you mean by "theoretical" as it is quite the opposite, an experimental setup, and following a long line of previous experiments that show a continuing trend of improvements.

even having a device able to generate so high temperatures

Multiple university sized projects already can reach temperatures higher than the center of the Sun. Reaching the temperature is not difficult, it is doing so efficiently and sustainable. Unfortunately, the reaction inside the sun is quite slow by power generating standards, just takes place over an astronomically large volume. So production reactors will be running nearly an order of magnitude hotter than the center of the Sun.

All these problems are logically much less relevant at much smaller scales (at the microscopic level),

Actually, a lot of these problems are much more relevant at smaller scales, because there are massive economies of scales involved, which is why projects have been getting bigger with every iteration. Shrinking things down involves much higher gradients which drive instabilities, much higher fluxes that damage components, etc.

Please, provide relevant references to support all your claims on the can-be-done front.

I'm sorry, but when you make statements that look like you haven't even taken the time to look at a Wikipedia level description of fusion power, I don't know why you would expect others to do the work of digging out references for you. Considering there is already much written about this out there, even on just Wikipedia (with references...), it becomes difficult to expect you will take the time to actually use a provided reference.

Re:Fusion is not currently possible

[CustomSolvers2]

Numerous fusion reactors have been built on different scales.

As requested, please provide reliable references supporting your claims. Just one example with relevant macroscopic effects would be more than enough to me (although well... depending upon the exact conditions the expression "fusion reactor" might not be too accurate).

I'm not sure what you mean by "theoretical".

I meant that they have a very nice theory and are working on implementing it; but with no tangible results so far (other than delays).

Multiple university sized projects already can reach temperatures higher than the center of the Sun. Reaching the temperature is not difficult

By applying these ideas, I might also say: as far as there are many people capable to run 100m in less than 10sec, getting this performance is very easy and thus we can safely assume that lots of people should be able to run 200m in 20sec, 400m in 40sec, etc. That is: the fact of being able to generate certain temperature under very specific conditions (independently upon the number of successful events) does not mean that having this performance is easy or acceptable in any situation (and what is more important: keeping these temperatures for as long as required or starting/stopping the process at will).

Actually, a lot of these problems are much more relevant at smaller scales

?! So... are you saying that the tests are being made under the hardest conditions? Then, why not starting at the macroscopic level right away and creating actually relevant fusion reactions? I do certainly not understand what you are exactly trying to defend/criticise here.

I'm sorry, but when you make statements that look like you haven't even taken the time to look at a Wikipedia level description of fusion power

While studying for my MS in Industrial Engineering specialising in energy, I had quite a few nuclear engineering related subjects. On the other hand, I do understand that many people have a much better knowledge than me on this matter (mainly by bearing in mind that this happened 10 years ago and never worked on it); these people do not even need to have a relevant background on associated issues, like physics or engineering or even basic power-plant knowledge. In any case, the way in which your whole message is written tells me that your knowledge in this specific field/engineering/physics is not too deep; could you please talk a bit about your exact background (are you at the Wikipedia level?).

Sorry but I will not answer any other comment on these lines. I don't want to get involved in this kind of discussions where anything can be claimed based on nothing. My initial request was very clear: please, support all your claims against what I am defending (and what I consider basic understanding of this matter) with reliable references.

Re:Fusion is not currently possible

[CustomSolvers2]

I am including below these lines a comment I wrote above as a reply to another person (providing links to various fusion reactors). I think that these ideas are also helpful here to adequately explain my exact position on the fusion-reactors front: ----------------- To avoid future misunderstandings, here you have a set of more detailed (perhaps too evident at some point; but will surely avoid misterpretations) ideas:

- What we want fusion for? For somehow emulating what the current fission reactors (logically by bearing in mind the multiple differences between both phenomena) are doing; more specifically, to emulate the stable (and not-too-high-temperature) heat generation outputted by the fission reactions. Why the fission reactors have to generate stable (and not-too-high-temperature) heat? Because all the fission-based power plants (equivalently to what is expected to happen with the future(?) fusion ones) are based on a very simple but perfectly working idea: the electricity is generated from the rotation of a turbine; this turbine has to be regularly rotating for as long periods as possible (because we need all the possible electricity and more); this rotation is achieved by boiling water, phenomenon which happens only its temperature is within certain pretty small range (a bit below/above 100C). The current nuclear (fission) plants get this stable source of heat (with not-too-high-temperature) by taking advantage from what the fission reactions generate. This generated temperature is quite low and that’s why it represents a good source of energy on this context (i.e., a good waiter-boiler). You also don’t need too much energy to start the fission reactions; in fact: you don’t need to start them too often (almost never), this is the beauty of the chain fission reactions and that’s why this form of energy (independently upon the associated dangers) is very efficient and that’s why the nuclear fission plants are the most powerful ones.

- The fusion reactors are expected to apply exactly the same ideas than the fission ones; because the fusion reactions are also expected to generate a regular source of heat (which is basically what we want). The problem is that this time, starting the process (and maintaining it) is not so easy. Additionally the temperature of the generated heat is so high that provokes lots of problems. Creating a chain reaction in fission is very easy; you can see it as a pool (billiard) game: you through a ball which hits another one, which hits the wall, which hits another one After the process is started, it will continue for really long. In fact, without chain reactions nuclear energy would make any sense (= couldn’t considered a form of energy) as far as the heat generated in just one event (fission/fusion) is not too relevant. When you say that fusion hasn’t reached the break-even or that you have put in x and it can only generate x-1, you are not defining a form of energy, but a form of consumption (equivalently to the water which is expected to be boiled).

- Thus, when I talk about fusion I understand a form of energy capable to deliver what is expected, that is: generating heat (at an adequate temperature) for a long enough period of time (to boil water which will then generate electricity). If you are able to fuse two nuclei, excellent; if these first two nuclei generate enough heat to automatically provoke the fusion of the neighbour ones (and so on and so forth), excellent too; if you need lots of energy to perform these fusions but you create a properly working framework, excellent. But don’t call it form of energy if it does not behave as what is traditionally called form of energy (in this context: stable water boiler). If after years (and years and years) the maximum you get (after having spent imaginably high amounts of money) is some nuclei to fuse, a system able to generate and contain the disproportionately high required temperatures, and even get some chain reactions for some seconds Be very proud of

Re:Fusion is not currently possible

[Anonymous Coward]

While studying for my MS in Industrial Engineering specialising in energy, I had quite a few nuclear engineering related subjects. On the other hand, I do understand that many people have a much better knowledge than me on this matter (mainly by bearing in mind that this happened 10 years ago and never worked on it); these people do not even need to have a relevant background on associated issues, like physics or engineering or even basic power-plant knowledge. In any case, the way in which your whole message is written tells me that your knowledge in this specific field/engineering/physics is not too deep; could you please talk a bit about your exact background (are you at the Wikipedia level?).

Funny how you demand references from other people, but act like we should depend on your above average background as you've never provided any references to your claim. And you were given the exact name of a major 15+ year experiment, if that is not enough of a reference, then maybe you should be posting on a technical forum, or at least shouldn't act like you have some knowledge of the subject. On top of that this is one of a dozen of large scale projects of similar design leading up to ITER, a half dozen of which are still running now (e.g. JET, EAST, DIII-D, KSTAR, Tore Supra, ASDEX, among many more), plus a couple dozen medium scale projects and other large scale projects of competing design.

Seriously, stating that such things don't exist is on par trying to discuss operator system design and saying no *NIX operating system exists outside of academic labs, and trying to blame lack of such knowledge because no one ever took the time to link you to one of many Linux distros or to a commercial UNIX. You can't blame that on lack of links, but only on never having read on a topic (and unfortunately, many nuclear engineering courses say little to nothing about fusion, as only a tiny number of nuclear engineers work on fusion related topics). Coincidentally, MWs of fusion power are also about the same age as Linux, if not a bit older going back to the 80s... so it is not like in either case you can blame it on being 10 years out of date.

And by the way, my background is in plasma physics, with experience working on four different medium and large scale projects... you claim to be lecturing others on the basics of a subject that you seem to have so little knowledge of, you don't realize it. Either you're still being disingenuous and trolling, or due to an unfortunate variation of Poe's law, have no idea how many wrong ideas and red flags you've through out and can't possibly tell why people would get indignant at your projected confidence.

Re:Fusion is not currently possible

[Anonymous Coward]

Eh, wrote the comment a couple hours ago but had a 5 minute time out after having posted to another story, and left my desk instead of waiting. I should have refreshed when I came back to see other comments, but hit submit instead...

Re:Fusion is not currently possible

[Anonymous Coward]

The “we have fusion power since long time ago” is completely wrong;

I can't find any one on this whole page of comments who has used that phrase. I can only find a couple comments that mention previous experiments have produced X amount of fusion power (one of which near the top has a wrong number). Fusion power is defined as the amount of energy per time released by fusion reactions in the experiment, is not a statement about how much electrical energy has been dumped back on to the grid, etc. Besides, your original post said, " macroscopic-relevant fusion reaction," when I think most would consider MW of reactions to be quite macroscopic.

A practical fusion reactor does not require a completely self-sustaining chain reaction to run, only that there is enough of an excess of power coming out compared to what goes in to account for conversion inefficiencies (and to overcome economic costs). This is usually expressed in terms of the fusion Q factor, which compares how much power is produces by fusion reactions to how much heating is inputted into the system (it does not include conversion inefficiencies or power to magnets, the latter of which is less for superconducting systems). A complete chain reaction would be an infinite Q, while practically speaking a Q of 20-30 would be enough for an electrical power plant. Trying to force a comparison to the chain reaction within a fission reactor will end up with a broken analogy that does you no good.

A better comparison of progression is the Lawson criterion which has basically experienced exponential improvement over the years. This is not like someone improving the efficiency of an switching power supply and thinking, "Hey, a little harder and we can get more electricity out than we put in." But it on the basic principles of the reaction, it is matter of incremental improvements needed to get out more than being put in.

During 5 seconds, you have everything under control; let’s wait another 10 years to reach the 10 seconds threshold .

Multiple tokamaks (e.g. Tore Supra and SST-1) already can operate in the time scale of multiple minutes, with ITER planning on 1000 s, to be followed by DEMO with continuous operation.

If this really interests you, may instead of assuming analogies of fission works or going off of some video, you should at least pick up the basics, like at least the first chapter of Tokamaks by Wesson which just covers the basic of fusion reactions and what is needed for a reactor. Although just about any plasma physics textbook has a chapter on that.

Re:Fusion is not currently possible

[CustomSolvers2]

(Seriously, last set of answers to you because you are not the kind of person I want to discuss with).

Funny how you demand references from other people, but act like we should depend on your above average background as you've never provided any references to your claim

What is the exact problem between the reality (= the current conversation which you can read as many times as you wish) and the weird conclusions you draw and the pointless replies you write? At what point have I demand anything?! You were the one doubting about my knowledge and I have told you about my knowledge. I have merely forwarded such a request back. I have ever doubted about anything you said (despite the subtle difference that I am a logged-clearly-identified user and you are discussing as an anonymous coward): you didn’t say plainly anything. You are now doubting about what I am saying?! Seriously, what is wrong with you?

you were given the exact name of a major 15+ year experiment

Have you even gone to the University? For what would an engineer want to know the names of experiments about something of no practical use (not for engineering, not for anyone)? In Industrial Engineering (in Spain, 10 years ago), I got my BS in Mechanical Engineering without hearing a word about nuclear fusion (not even fission). When studying for my MS (4th & 5th), precisely specialising in energy (i.e., power plants and engines) and despite having quite few fission-, power-plant- and electricity-generation-related subjects I didn’t hear a word about fusion, other than side comments on the lines of “never has been done”, “impossible dream”, “during over the last 40 years, many people have promised fusion in 10 years times”, etc. The only time when I studied something related to abstract physics theories was in an introductory subject (which was precisely criticised because of being unnecessarily abstract and useless; BTW I got 9.5 over 10) mentioning Relativity and Quantum Mechanics (BTW perhaps you want to know my opinion about the first one, I call it: “Critical Analysis of the Main Premises of Special Relativity: Lorentz & Minkowski”). Why? Because engineers do not care about these things, because the actual applicability of these theories is none (please, refer to the aforementioned critical analysis)!
I wasn't here talking as an expert in fusion, because I am not (I don't even believe that it is possible). I was talking on account of my knowledge (the one I got in the University and in some later researches because I like the field; but not fusion; nuclear engineering and fission and actually-applicable physics); was sharing what I think that has been done and can be done. I said it very clearly: correct me if I am wrong, but support your claims with reliable references. Why? Because I have a solid enough knowledge to know that certain things haven't happen yet (and what is required to make them happen is so complex and so expensive that are extremely unlikely to happen within the quite a few next years). Or by using other words: I don’t need to be an expert magician to discuss about magic existence. In fact, most of people defending that magic does not exist are not magicians; why would be otherwise? And you are blaming me for not knowing magic? No, I don’t know magic, why should I?

(e.g. JET, EAST, DIII-D, KSTAR, Tore Supra, ASDEX, among many more), plus a couple dozen medium scale projects and other large scale projects of competing design

I talked about this in my comment below (which I think you have also answered; will look at it right after finishing this comment). These are experiments at universities. You can call them reactors because this is the usual name for the container where (nuclear) reactions happen. But you shouldn’t use this term directly (your beloved Wikipedia uses the expression “test reactor”; everything is fine as far as t

Re:Fusion is not currently possible

[CustomSolvers2]

You know about this thing of time zones and time difference, don't you? Is this the kind of thing that a person (well... presumably; an anonymous coward can be many things :) I am joking, don't get angry just for this) with background in plasma physics can know? I am in Spain; the last time I checked this comment was 10pm my time; in any case, why should I come here to answer you immediately?! Why you think that anything you say is relevant? I am systematically defining all what you are saying as nonsense and telling you that "will stop answering you because doesn't make any sense to me"; isn't this enough to understand that your opinion is not important to me? This is kind of funny, because now I am living in a small town in the middle of nowhere, where people show an equivalent behaviour: they seem to think that their opinions have an intrinsic value no matter how many times you say them "what you are saying do not make any sense to me". They are also very nervous and impatient. Anyway...

Re:Fusion is not currently possible

[CustomSolvers2]

Fusion power is defined as the amount of energy per time released by fusion reactions in the experiment,

Nice thing to know. So nothing to do with a standard nuclear (fission) plant, where the power is measured by the electricity being generated. That is: your fusion "reactors" (or test reactors or expensive toys) are measuring the generated power in a completely different way than what is standard (and actually relevant; as far as the whole point of fusion is generating electricity). Is not this a somehow-misleading way to refer to very important concepts? on one hand, you are using the same word (reactor) to refer to two different realities; on another hand, you are measuring different variables but using the same name (generated power).

Besides, your original post said, " macroscopic-relevant fusion reaction," when I think most would consider MW of reactions to be quite macroscopic

Lots of misunderstandings over here, that's why I thought that writing the aforementioned clear-enough summary was required. With macroscopic relevant I mean something which has an actual effect at the macroscopic level, like heating a cup of coffee during 5 minutes. Playing around with atoms is required, but it is just a pre-step. For example, in fission: you have to firstly have control over the fission reactions (start and terminate them at will), then convert the outputted energy in what you want (i.e., source of heat able to keep the temperature in a water tank with certain dimensions at around 100C) and finally make sure that the whole process is stable and regular enough (like a switch you can set on and off to get what you want). With macroscopic effects I meant having a preliminary version (needing whatever crazily big resources are required) of a system capable to perform all the steps until the end, that is: actually generating a usable source of heat. Making sure that the atoms behave as you want is one of the intermediate steps and what I call "microscopic level" as far as my cup of coffee can still not be heated.

A practical fusion reactor does not require a completely self-sustaining chain reaction to run,

Such a statement sounds very compatible with the fusion theory and reality (= labs completely focused on making sure that the first steps work well enough, still very far away from caring about the actual applicability of these first steps), but unfortunately extremely incompatible with the actual reality of electricity generation. As explained in my previous point, what a fusion reactor is expected to do (at least, ITER the first real fusion reactor) is applying the Rankine cycle (the one used in all the fission plants) which expects a regular source of heat at certain temperature. Regular means over months (I think that the standard fission plants are stopped just once or perhaps twice a year just for security reasons; what means that the chain reactions are automatically happening during all that time); you cannot have a power plant generating electricity at irregular intervals. I think that ITER expects to reach more or less self-sustained chain reactions, equivalently to what happens in fission reactors, basically because this is what is required: a regular (over months) source of heat keeping the temperature of the water in a tank within a very narrow range. I am afraid that you cannot get that with "shots" of extremely hot reactions, which can be repeated once every x minutes. Or even in case of getting such a situation (still quite far from that anyway), the resulting system would be extremely inefficient in comparison with any other fuel. Note that additionally to requiring sun-like temperatures to start the process, you have to spend resources on containing the hot plasma (to eventually refrigerate it) and to convert the high temperatures into the target one of around 100C. The only way to make such a crazily inefficient system to be more or less acceptable would be by relying on self-sustained reac

Re:Fusion is not currently possible

[CustomSolvers2]

Sorry, I answered this one also without thinking to much and right after completing my long answer to your comment above. Better read firstly my answer to your last message below (my tone is more relaxed).

Re:Fusion is not currently possible

[CustomSolvers2]

Better read firstly my answer to your last message below (my tone is more relaxed).

Oh, yeah, what a disaster THAT would be...

[TaleSpinner]

> if an aircraft containing radioactive material as fuel were to crash, spreading such fuel across the crash site

Everyone knows how dangerous deuterium can be. Why it's one common component in dihydrogen oxide, which kills more people every year than any other chemical substance ever invented. http://www.dhmo.org/facts.html

Really?

[SuperDre]

the dumb greenpeace moron in the article is comparing the Solar Impulse 2 to a real engine that could power an airliner... Solar Impulse 2 can barely lift itself and a pilot, how is that supposed to support a big jumbo jet with 300 passengers and/or cargo... Solar energy is far from viable (at the moment/decade) for use in commercial flight..

Also nowhere is mentioned that the engine is actually going to be used in commercial flight...

Nuclear airplanes led to the investigation of LFTR

[Anonymous Coward]

Without the air force wanting a fully nuclear airplace, LFTR and molten salt reactors would NEVER have been investigated at all.

Now, while it's crazy to use fission on an aircraft, and the nuclear airplane project was eventually cancelled (for obvious reasons) I fully support LFTR and molten salt reactors for power production, because they are fail safe by design, can use existing stockpiles of spent nuclear fuel as fuel (thus reducing this 'waste'), and have zero risk of nuclear proliferation. This is exactly the type of reactor Iran should be researching. And it should be the reactor of choice for replacing existing and building new. China is researching this tech NOW.

And, folks, if we had unlimited power, we could actually USE that power to produce regular aircraft fuel, or equivalents, and effectively have carbon-neutral airplanes.