Slashdot Mirror
Nuclear Fusion Real Soon Now
Mr. A. Coward writes "Researchers at the
National Ignition Facility are attempting to produce nuclear fusion. They'll focus 192 amplified lasers on a pellet of frozen hydrogen. 'NIF experiments will be the first to create fusion that gives off more energy than it takes in.' That will have to be quite a bit, since it will take 500 trillion watts to ignite the pellet in the first place. The facility has been plagued with delays, and so far only 4 of the 192 lasers have been completed. Researchers believe they will first achieve fusion sometime around 2014."
SimCity said they should be avaliable around 2020, right? I love games that tell the future
Since when did Real Soon Now translate to 10yrs+ ... ?
In 1960 we where gong to have fusion in 1980.
In 1980 we where going to have fusion in 2000.
In 2004 we'll have it in 2014.
Things are starting to look optimistic!
Do you have any idea the difference between power and energy? 500 trillion watts for a period of a few billionths of a second is not a lot of energy, brainiac. You could probably get more out of a potato battery.
At least cold fusion did not cost that much.
So when was the break even point that they recover all the money that has been spent developing it?
Umm, fusion is most certainly NOT impossible. Stand outside tomorrow around noon and look up at the sky. See that big burning thing that hurts your eyes? That's a nuclear fusion reaction.
Sounds like an arsonists' boot camp :S
There's supposed to be an earth shattering kaboom!
Ahh, hasn't break even been passed experimentally quite some time ago?
m l
http://www.jaeri.go.jp/english/fusion/fusion.ht
This claims break even in 1996, and 1.25 power increase in 1998 in the JT-60 tokamak..
And this article seems to be stating they plan to hit breakeven in 2014 or further out.. hmmm.. perhaps they mean some special kind of break even, like the first ones using our method, or in the US, or something like that..
That would probably be the first to create a net increase in energy using fusion. Either that, or those fusion scientists are pretty good fakers over the last few decades.
Call me when FusionSE is released and it's small enough to power my laptop.
'NIF experiments will be the first to create fusion that gives off more energy than it takes in.'
Just sounds like my design plans for a perpetual motion machine. Can I borrow your snake oil for the bearings.
Obligatory nit-pick. The article implies that about 10 Joules of energy hits the pellet. No mention of the laser system's efficiency.
The cost of the lasers and the associated ancillary paraphernalia associated with the fusion plant. If the cost per kWh from the setup and maintenance of the equipment needs to be x cents / kWh and using renewable / clean sources of electricity can generate at x/5 cents / kWh then it wont fly.
Great to see that it is now thought probable that fusion can actually be an energy producer though.
"And we have seen and do testify that the Father sent the Son to be the Savior of the World" 1 John 4:14
Researchers believe they will first achieve fusion sometime around 2014.
What about my flying cars? I was promised flying cars!
A programmer is a machine for converting coffee into code.
National Ignition Facility home page
National Ignition Facility project status and photo gallery with lots of pictures
LLNL Science on High Energy Lasers
I know that it makes sense to at least do something so that we continue to learn, but sometimes it seems like they need to do more thinking and less building.
Sometimes it's best to just let stupid people be stupid.
Fusion happens commonly in research labs. What hasn't happened yet, is getting more energy out than it took to create the fusion, in a controlled, energy-generating environment.
http://www.llnl.gov/nif/construction/photoshow.htm l
sale of foil hats will be at an all time high
We'll certainly need the power of fusion for it.
Let's see...
Assuming that '500 trillion' means 500 x 10^12 watts... They said it would be for a 'few billionths' of a second: maybe 2 x 10^-9 seconds?
Am I counting wrong, or does that come out to about a million watt-seconds, or 0.277 kilowatt-hours?
I consume more energy than that makin' coffee.
Never attribute to malice that which can be explained by mere idiocy.
so what industry do you work in that will create something that changes life as we know it in less than 10 years or so?
As Mr. Potts says, Watts are a unit of power. 500 trillion Watts is the power being put into the reaction by the lasers. Energy is not the same thing as power. Power is energy divided by time.
According to the article, the beams will be fully on "only for a few billionths of a second". For a naive estimate of the total energy being output by the lasers, we can simply multiply (500 GW) * (2 ns).
Now, this yields a quantity with dimensions of energy: (500 GW) * (2 ns) = (1 kJ). To get a handle on this, it is the amount of energy that is output in heat and light by a 100W light bulb shining for ten seconds.
For a scenario Slashdotters are familiar with, it's the amount of heat generated by a 1 GHz Athlon thunderbird in 12 seconds.
Let's see, we get fusion in abou 10 years. That's 2014. Maybe 10 years later, we have a terrible disaster. That's 2024. So in 2044, I'm predicting we get a slashdot story about a cute biker chick riding around "ghost town," or what used to be Livermore, California.
Actually, once you've generated it and it puts out more than it received, you can recycle the process indefinitely. then its a matter of harnessing the output effeciently AND saving enough of the overage to eventually set a second chain of lasers firing, then in a few years the power output will grow exponentially and poof, free energy, mass space exploration, colonization, pure research civilization, galactic domination, intergalactic war with insect race, universal domination, peace and love and enlightenment, fin.
its kinda like putting a million bucks in the bank and living off the interest, but also putting aside enough of the interest to increase your returns.
This is my sig. There are many like it, but this one is mine.
April 1st isn't until Thursday.
This announcement was supposed to come out simultaneously with the "verified" claim to have found Methane on Mars, and with Condoleeza Rice's hillarious admission of guilt before the 9/11 commission, all on Thursday. Now you've ruined it.
The good and new comes from no quarter where it is looked for, and is always something different from what is expected.
Power is not the same as energy. It is energy per unit time. It is rubbish to say there will have to be a large energy output because the input power is high. By way of example, 500 trillion watts for a femtosecond = 500 joules. This is not an unreasonable amount of energy, contrary to the attempt to imply otherwise by shouting '500 trillion'.
Controlled fission is pretty common--you know, a regular nuke plant. And artificially created fusion that yields more energy than was put into it used to a regular thing--then they made those bomb tests illegal.
Got my SI prefixes wrong. 500 trillion * 1 femto second is 0.5W. My mistake. The correction is in favour of my argument though!
I thought all you had to do to get fusion (though not break-even yet, I think) is shake some heavy acetone.
Simple Unexpected Concrete Credible Emotional Stories
Date an English major.
I'd rather not. I never went for the Army type.
Actually, if you read the article 2014 is someone else's estimate, and the scientists hope for results substantially sooner.
/.er actually read the article?
I know, I know, suggest a
Ooh, a sarcasm detector. Oh, that's a real useful invention.
Indeed. For more information on this, you could do worse than starting here: fusion.org.uk
so, in 10 years these guys can potentially solve the world's energy problems and help stop the devastation non-renewable fuels are doing to the environment.
or, you can build us a couple of new bridges.
hmmm...
I know a number of people working on NIF and hear of its progress every few months. It's been plagued with problems largely due to budgeting, as scandals have hit the lab and much of the money was funneled out. The LLNL management was largely replaced due to these activities and for a while the entire laboratory was on the brink of being shutdown.
The four beams mentioned in the summary are really just a testbed. In the previous system, Nova, there was a smaller machine called Novet that had the same purpose. I always forget the newer machine's name, but this is standard practice versus a major delay. NIF is behind the original schedule, but that's due to problems (e.g. lens issues) and technical challenges always faced in such large R&D projects.
From what I hear, things will be going pretty well from now on. Since this is an international effort (led by the US), other countries are building their own versions. France has similar system that was brought up last year with help from LLNL personnel and has allowed the lab to avoid many of the same pitfalls the French have faced.
My main contribution to this thread is simply that NIF doesn't seem to be heading towards cancellation, like many government projects. The people behind it are extremely competent and far smarter than I am. The scandals are behind them and will be making steady progress. It's a really, really impressive effort.
"Open Source?" - Press any key to continue
However, is artifically created fission possible, so far it hasn't been.
Assuming you meant fusion instead of fission (which is how current nuclear plants work):
Sure it is, you ever heard of a "Hydrogen Bomb?"
What hasn't been done yet, is create a sustainable / controllable fusion reaction in a lab. If that ever happens, then we are on the way to being able to harness fusion for energy production, commercially.
// TODO: Insert Cool Sig
Nothing is wrong with this statement. You are probably referring to the Law of Conservation of Energy, which states, more or less, that energy cannot be created or destroyed. The confusion with nuclear reactions, fission and fusion, is that the reaction liberates energy stored in the nuclei of the reactants. No energy is being created, but more energy (hopefully) is harnessed than was used to start the reaction.
Think of a spark plug in a piston engine. It releases a fairly small amout of energy to start a reaction that releases a larger amount of energy stored in the fuel/air mixture.
Fusion will be a Good Thing once the bugs are ironed out.
The fact that the lasers use 500 trillion watts is not related at all as to whether this is the first fusion plant 'that gives off more energy than it takes in', since watts is not a measure of energy, rather, of power (energy/time).
Bzzt, thanks for playing. Most hydrogen bombs have a yield breakdown of about 85% fission to 15% fusion (fission is a much better producer of blast and fire), but in the 1960s there were the Bassoon Tests, which used hydrogen bombs where virtually 100% of the blast yield came from fusion.
So yes, we have the capability to artificially create fusion. We've had it for decades.
go easy on him--if he's a real /. geek he hasn't seen the sun in a while
it's the law of conservation of matter *and* energy...
t ar_6.html
A quick lesson in where the extra energy comes from in a fusion reaction: http://observe.arc.nasa.gov/nasa/exhibits/stars/s
I'll sig you upside the head!
Compare this to the efforts of JET the Joint European Torus project, which achieved breakeven (Q=1) during 1997 (good explanation of fusion milestones here). JET's successor, ITER aims to achieve Q of at least 10, paving the way for commercial-scale power generation.
The only thing that worries me about ITER is the level of bureaucracy exhibited, but perhaps this is to be expected from a multi-national consortium.
ITER are standing on the shoulders of giants, NIF are discussing specifications for a step-ladder.
That's correct, but it is also bleeding a huge amount of mass so it is not a case of getting something for nothing.
That's what my set of encyclopedias from 1968 say about the new "Stellarator" reactor they're building over at Stanford... "Within 10 or 20 years." But cynicism aside, there's no denying we've made great progress. From energy output/input ratios of .00001 to .3 and .4 since fusion research began.
My thought is that if you want a way to get unbelievable energy intensities, use the big fusion reactor in the sky. Launch a gossamer thin sheet of aluminized mylar, spin it into a disk, and use a minimal amount of structure to form it into a parabolic mirror. If you use a 500 meter radius piece, that's a constant 740 megawatts focused on the pinhead-sized object of your choice. If you need more, just launch a bigger piece of aluminized mylar.
It strikes me that trying to create a fusion reactor is an awful waste of time, effort and money when there's one just just across the road (in space terms) that we can use for free!
If all the money that's been poured into fusion research so far had been poured into making those "cheap" solar arrays they keep telling us are "just around the corner" then we'd all have roofs made of the stuff that would make us energy self-sufficient and we'd even be driving electric cars that were powered by the sun.
It seems stupid to try and reinvent the wheel (fusion) when nature has done such a wonderful job about ninety quintillion times over and we can harness the power of at least one of those natural fusion reactors very safely.
It is much more real - the availability of new power plants depends on combinations of:
:)
1) Mayor Rating
2) Number of high-wealth residents
3) Total power requirements
4) Total number of high-tech industry
5) Total energy demand
Same is true for all other nice things you get in that game. However, it's impossible to do that in one city, it just stagnates. The interaction between bordering cities it crucial. You basicaly get a region where you develop tens of cities, and RCI demand in one city affects the neighbour. The "deals" thing is same as in SC 3000, i.e. they can sell each other services. It's neat to have one "garbage" city, because that's really the only thing you can not get rid of safely in this game - only two options - garbade dump or waste-to-energy plant, both affect neighbours. Of course you can still have garbage island
Also, you can no longer build perfect city.
Sorry, I couldn't resist...
We've had fusion weapons since the '50s... they're called thermonuclear bombs.
At this point, research into fusion *power* probably isn't going to increase their effectiveness much more.
Right now, the big areas of superweapon research are biotech and nanotech. Mmmm, grey goo.
"We have to go forth and crush every world view that doesn't believe in tolerance and free speech." - David Brin
You mean the moon? It really doesn't hurt my eyes though. It does make me want to howl...
There has been much progress with the plasma focus fairly recently. Taken from the Focus Fusion website:
In recently completed test experiments, the researchers were able to achieve temperatures that reached up to two billion degrees in some shots of the plasma focus device, well surpassing previous records of 520 million degrees achieved by the commonly used tokamak device. The much larger and more expensive tokamak has been cornerstone of the US fusion program for 25 years.
The plasma focus functions in a fundamentally different way from other fusion devices. Tokamaks and most other fusion devices use powerful magnets to attempt to stabilize the plasma - the extremely hot, electrically conducting gas in which the fusion reactions occur. This task has been likened to lifting gelatin with rubber bands. Instead, the plasma focus takes advantage of the natural instabilities of the plasma, so that the plasma's own magnetic fields compress it and heat it. "The plasma focus works with the plasma, not against it," says Lerner.
Perhaps someone with the foresight to see the best path for future power generation can fund this research fully and cease our pseudo problems concerning concerns about future energy sources. The solution is apparent.
Case 1:
Article: "When all 192 lasers in the NIF are operating, they'll focus 500 trillion watts (everything after this point is non-existent) - more than 1,000 times the power generated in the United States - on their target, albeit only for a few billionths of a second."
Slashdotter: "500 trillion watts?! You gotta be fuckin' kidding! You're gonna blow up California!"
Case 2:
Article: "When all 192 lasers in the NIF are operating, they'll focus a few kilojoules worth of energy on a hydrogen pellet..."
Slashdotter: "WTF is this all about? Is this good? Or is it whack?"
Case 3:
Article: "With this (Dr. Evil style)LA-SER device, we're gonna get FU-SION using less energy then what your Prescott has consumed while you're reading this piece of crap!"
Slashdotter: "I, for one, welcomes our new fusion power overlord! l33t!!!!"
It's interesting that the NIF first full light is now pushed back to 2014. There's a small chance we may just beat them to ignigion.
I work at the Omega Laser(still the most powerfull in the world at 60 Terawatts! ya!) and there is currently construction going on here to complete what is called Omega EP(extended performance) by ~2007. Omega EP will produce an astounding 2.6 PETAWATTS(million billion watts!!) of power for a around a picosecond (so about 2-3 Kilojoules per shot which is much less than the NIF's megajoule scale shots) making it, by far the worlds most powerfull laser when complete. The new laser will use what's called chirped pulse amplification to produce its incredibly high petawatt scale power.
Using the current 60 beam 60 Terawatt (~30Kj) laser to compress a pellet of hydrogen fuel and then just before the moment of maximum inward compression and then stagnation; the EP petawatt beam will fire, producing an instant injection of Mev scale electrons directly into the center of the collapsing target and hopefully producing high fusion yeilds and perhaps even approaching ignition. The Gekko XII laser in Japan with its 500 terawatt scale CPA lser has validated this scheme, which is called "fast ignition", reporting that with the CPA laser used at maximum compression with their 12 beam 40 terrawat laser they've achieve an increase in neutron output(fusion yield) by 1 to 2 orders of magnitude...Can't wait till we can fire ours up!
- "Hear that?! The percolations are imminent! Cease your ingress!"
Nope. The fission reaction is just used to kick off the fusion reaction. Here, read this:
http://people.howstuffworks.com/nuclear-bomb9.htm
// TODO: Insert Cool Sig
I'm sorry, I just can't let this go uncorrected. A fusion power plant is incapable of 'meltdown' in any way, shape or form. Fission plants can meltdown because they contain all of their fuel within the reactor vessel (think "all my gas is stored in my engine"). A fusion plant, on the other hand has its fuel piped to the reaction chamber ("my gas is in my gas tank, at the other end of the car"). At any given point there will be less than 10mg of plasma in the reaction vessel. This is not enough to damage the vessel, let alone melt anything at all.
As if! First you have to teach the sharks to fly!
Karma: It's all a bunch of tree-huggin' hippy crap!
Perhaps we should send a couple of settlers to the capitol and use them to help finish this Great Wonder!
*Points at big glowing spherical fusion plant in the sky*
;).
In 4 billion years when that sucker goes red-giant we'll see what it can't meltdown
I like my Earth's extra-crispy.
Oops I misspoke, I meant to say the Omega laser is actually the most ENERGETIC UV laser in the world at ~30Kilojoules/shot, Not the most powerfull, as there are a few other chirped pulse lasers with higher powers out there but not higher energies(most can only do a few hundred J per shot though this is still enough to do direct laser induced nuclear reactions).
- "Hear that?! The percolations are imminent! Cease your ingress!"
Yes, a world of happiness and leisure... for everyone except the poor sucker who has to keep pushing the frozen hydrogen pellets into the lasers.
Hope he's got real thick gloves.
One god, one market, one truth, one consumer.
Skycar
How am I supposed to fit a pithy, relevant quote into 120 characters?
Ok, i blame my blindness on you. I've not been in the sun for weeks.. AND NOW LOOK AT ME! And now, back to the matter at hand. Nulcear fusion is possible. have a nice day :)
I'm glad that progress is being made but I have to ask:
How good are (computer) simulations at modeling this? I mean the NIF and presumably you are going to spend billions to essentially run experiments. I assume this means that simulations of the physics are not good enough to predict what is the best design. So, what's the problem? Is there a fundamental lack of knowledge (quantum/relativistic effects/high energy densities) at these regimes or are your equations good but you just don't have the computing power to solve them? Because we might see PetaFLOP computers before we see PetaWATT lasers!
Also do you know if Magnetic confinement schemes also have simulation problems?
(BTW I met the exec. dir. of the Max Planck inst. in Plasma phys. while on the TGV last year, he seemed quite optimistic that magnetic confinement was going to be producing results "real soon now";)
Essentially that's true, I suppose. NOVA was around 100 Terawatts per shot (I've heard it was capable of 100 Kilojoules per shot but I suspect it was actually less). NOVA only had 10 beams though and this ended up creating huge problems. When a pellet was imploded on NOVA the beam/beam instabilities and nonuniformity of the irradiation on target caused very large hydrodynamic instabilities as it imploded (Rayleigh-Taylor instability mostly) which spoiled the fusion reaction before it could really start.
The Omega laser with its 60 beams produces much higher irradiation uniformity and even though it's lower power than NOVA(which was decomissioned in '99) it holds the record for neutron production in a shot at something like 5X10^13 neutrons, indicating a much 'cleaner' convergence and fusion burn. There were several lasers at LLNL before the NOVA laser with various names like Janus, Argus and Shiva, which all used the fundamental frequency of Nd:glass lasers at 1064 nanometers(infrared) and the great contribution in the early '80s to ICF laser fusion by the Omega guys was the idea to convert this IR to its third harmonic at ~351 nanometers in the UV. This greatly increased laser absorption efficiency on target and consequently increased target compression pressures/temperatures accordingly. Allmost all high power Nd:glass lasers use this technique today.
- "Hear that?! The percolations are imminent! Cease your ingress!"
This only counts the energy of the laser beams. Unfortunately, getting the deuterium (heavy hydrogen) out of ordinary water requires a huge amount of energy, relative to what will be produced by the fusion of the same amount of deuterium undergoing fusion. This expense doesn't figure into the equation for "breaking even."
Worse, this isn't even deuterium-deuterium fusion they are trying to achieve. It's the "easier" to accomplish deuterium-tritium fusion. Tritium is not even a component of natural hydrogen (it decays with a lifetime of only a couple of years). Tritium must be manufactured, atom by atom. The amount of energy that is needed for this is even larger that for extracting deuterium, and of course it also doesn't figure into the energy budget equation. It's unlikely that d-t fusion will ever produce commertially usable energy. And we are truly a long way from d-d fusion in the lab breaking even (and that's without counting the energy for getting the fuel in the first place).
The ideal reaction to use of course would be proton-proton fusion, which powers the sun. Proton is the nucleus of the normal, "light" hydrogen, so it costs very little (relatively speaking) to extract it from water. But this reaction has never been observed in a lab, and it's probably unrealistic to expect something like that to happen in this century.
Sorry...
You imply that maser is a neolgism, while laser is not. The maser actually was created before the laser so shouldn't you say, "visual light maser"? ;-)
Debunking the "59 Deceits"
We're getting a new solar heater for our house and it costs several thousand dollars. It will take a decade or more to recoup the costs in cost savings.
With fission and fusion the idea is to take a relativly small amount of energy to start a chain reaction that releases a very large amount of energy.
There is a solar array by the university but it's unsightly. We just don't have the stuff to make solar cells efficient enough to be practical. We can't very well be driving along at 20 miles per hour with 200 square feet of solar cells on the roof of the car that only has room for half a person.
Using the sun directly as a power source isn't looking very promising. So we make use of it instead to grow crops and whatnot. It's not like the sun's power is just going to waste. Trying to use it make electricity just isn't working out. The sun seems to be a screwdriver that we're attempting to pound nails in with.
Maybe one day we'll find a material that reaches a practical amount of efficency for solar cells. In the mean time we need power and fussion and fission are the most practical and cost effective.
Ben
Work Safe Porn
-
Migma fusion
- Inertial electrostatic confinement
- Muon-catalyzed fusion
- Antimatter-catalyzed fusion
- Cold fusion
It would also be nice if the fusion effort was run by scientists and engineers instead of politicians and bureaucrats. Check out this stupidity:In related news, NIF has ordered 192 sharks.
If you insist on using solar power, a better solution would be harnessing wave energy and sub-oceanic thermal differentials. Those oceans out there are already soaking up 70% of the solar energy that hits the earth. Why pave the land with solare panels?
Boss: When do you expect to finish the project?
Me: Hmmm, lemme see, I think I'll finish it by year 2014, and then it may not work.
Boss: OK, here's your paycheck. By the way, we've approved that $20M yearly budget increase.
Boy, wouldn't that be sweet? Software industry is a wrong domain to work in right now. Those bloodsucking PHBs demand results every freaking week.
any physicist worth his salt knows this one..
"plasma fusion is 20 years away. and it will always be."
notice how grammer is not a necessary component of a physicists salt content ^_^
Marty McFly: So does it run on regular unleaded gasoline?
Dr. Emmett Brown: Unfortunately no, it needs something with a little more kick - plutonium.
Marty McFly: Plutonium... wait, are you telling me that this sucker is nuclear?
Dr. Emmett Brown: No no no, this sucker's electrical, but it requires a nuclear reaction to generate the 1.21 gigawatts of electricity I need.
Marty McFly: Doc, you don't just walk into a store and buy plutonium... did you rip that off?
Dr. Emmett Brown: Shhhhhh. Of course. From a group of Libyan nationalists. They wanted me to build them a bomb, so I took their plutonium and in turn, gave them a shiny bomb-casing filled with used pinball machine parts.
-- There is no spoon. Only fork.
I am a physicist - but I have not read these articles - I'll wait for it to be published in Nature. My recollection of the experiment that achived breakeven some years back was that they measured the power in after losses due to generating the plasma, that is to say that there was more energy out than was in the plasma to begin with, but not more than was needed to generate the plasma. The analogous case of the laser method would be like saying that we generated more energy from fusion than we put in via photons from the lasers - but since the lasers are only 2% efficient in generating the photons it is not quite what you need for commercial energy generation. As for fusion energy from bombs, there was a nice study done at Stanford (IIRC) about the economics of simply setting off bombs in a deep hole and using the residual heat to power a steam turbine. According to the study this would be economical, you just neeed to convince your neighbors it is ok to do. As for having to have a huge hole, consider that at LANL people were designing steel containment vessals for small yield tests so that the cost of the hole could be amortized over several tests. In this case the problem was not the blast so much as the molten steel melting a hole in the bottom of the containment vessal at the end of the test.
I believe that's frikkin' shark.
Oh, and before you think to answer ... zip it!
I feel fantastic, and I'm still alive.
Unfortunately, politicians get in the way of scientific research, and in the last 25 years in particular here in the UK, blue-sky research has been cut in preference to that which looks promising from a commercial point of view. The accountants rule. Unfortunately, this reduces science to mere "refinement of engineering" at the expense of radical new and exciting discoveries and knowledge; and they wonder why no one wants to be a scientist any more.
Stick Men
They've tried this quite a bit but it's not easy to get pipes drilled down far enough to get at that heat. The cost of the pipe placement is very high and you quickly eat up all the available heat. Rock transfers heat very poorly so you basically cool off the rock right around the tube and it'll take years for the surrounding heat to diffuse back in.
Alternately, you could just find porous rock, run water through the cracks and collect the hot water that comes up. This has the advantage of less expensive drilling and large surface areas. The problem is that the water either tends to vanish down some crack or come back with lots of dissovled minerals that cause all sorts of corrosion and mineral buildup problems.
They even did a plowshare program in the 60's where they detonated underground nukes in rock to try and extract the thermal energy but it ran into the same sorts of problems.
In places like Iceland where the lava comes up to you, geotehrmal works. Pretty much everywhere else, it's not workable. If it were, we'd be using it.
It's always amazing how the people in charge (or that sponsor the project) seem to 'forget' this little detail. But, in fact, the critics are right. Billions and billions are wasted, on something that they know full well will never amount to a working fusion reactor that actually delivers energy to the market. The design (and goals, btw) are extremely unsuited to accomplish that, especially compared to the JET-project - http://www.jet.efda.org/ - (or actually the ITER-project).
And all the 'new things that have been learned' does not weigh up against the billions spend on it. The REAL reason (which they never mention) that they have gone through with this, is because of military pressure and animousity between the EU and USA on some key issues. Because, while a tokamak design yields the best results and opportunities for actual energy-output in a sustained, marketable way, the laser-pellet system is a lot more usefull in one respect: the study and experimentation of atomic/hydrogen fussions as they occur in bombs (explosive output). THAT is why they went for that project, because for usefull civilian experimentation, other ways of attaining nuclear fusion are far better suited.
Strange how you never seem to hear that aspect from the scientists/politicians involved.
--- "To pee or not to pee, that is the question." ---
Fusion power generation, as currently being developed is nothing like this. It's still a sensible investment for the next few centuries and as a step to better things, but it's not the panacea you suggest and you harm the credibility of science and technology by claiming it is.
Likely 21st century fusion power plants will burn tritium and deuterium. While both are isotopes of hydrogen and deuterium is acceptably common in the universe (1 in 10000 or so atoms if I recall correctly) we are not burning hydrogen. Tritium is radioactive with a 12 year half-life, so is basically not found in the universe except where it is being formed (in stars mostly). To make commercial quantities of it, you irradiate lithium 6 with neutrons producing helium and tritium. Lithium is reasonably common on Earth, but not super-abundant. The costs of extracting and purifying lithium, and in particular lithium 6 are not negligible, although we are unlikely to run out for a while.
So, effective fuel is lithium and deuterium. Both are reasonably plentiful, but neither is cost-free.
Now the tricky bit. The deuterium-tritium reaction produces a helium nucleus (alpha-particle) which is no problem and a neutron. We need a decent proportion of those neutrons to breed more tritium, but inevitably, some of them will end up hitting things other than the lithium target. When they do, they tend to make what they hit radioactive. Thus, once your reactor has been running for a few years, all of the inner structure, the lithium tanks and so on, are medium-level radioactive waste. The neutron irradiation also weakens these structures, so they need periodic replacement. Gigawatt for Gigawatt, it's a lot less radioactive waste than a fission reactor produces (and no plutonium to manage), but its not nothing, and the cost of the equipment and expertise to manage this periodic replacement with acceptable staff safety and so on is also not nothing.
Water, by the way, is not a byproduct of fusion reactors.
The final issue is safety. Here the big win is that there are no realistic disaster scenarios on the scale of a fission reactor melt-down or someone using reactor-produced plutonium to make a fission bomb. There are all the hazards common to fossil fuels and fission associated simply with running a large industrial plant -- things falling on people, leaking chemicals, etc. A tritium leak is still a real hazard, and a molten lithium leak or fire would be pretty unpleasant, and the medium-level waster would need to be managed, but it is a lot better than fission.
So, not a panacea, but a likely move forward, and I don't think we do any good by describing it as a panacea and rasing false expectations.
Break even and ignition are two separate things. Break even means that the total fusion energy produced exceeds the energy put into heating the ingredients. I think JET achieved break even in a tokamak, and it's even easier in laser fusion.
Ignition means that the energy being produced by fusion and re-absorbed in the plasma is keeping it hot enough to keep on fusing with no external energy inputs until some other factor (like running out of fuel or the plasma blowing itself apart) intervenes. This has only been acheived in bombs.
As an analogy consider trying to light a recalcitrant campfire. Break even is when the total energy produced by your buring wood before it sputters out exceeds the energy put in by the match. Ignition is when it keeps burning on its own.
A candle flame reaches c. 1400K but can be touched briefly without injury or even pain. Touching boiling water at only 373K, however, will cause burns - the boiling water is more dense and contains more heat than the plasma of a candle flame.
The plasma in a fusion reactor is even less dense by a few orders of magnitude, and even though its temperature is in the hundreds of millions of K, its energy is still tiny.
Now the volume of plasma in the JET tokomak is c. 150 cubic meters. Let's assume a viable commercial reactor will be three times as big, with a plasma volume of 450m^3. The density of the plasma is c. 0.001g/m^3, so there will be a total of 0.45g of active plasma in the vessel. This plasma has a temperature of c. 2e8K. The specific heat of hydrogen is 14 J/gK[1], so the total energy of the active plasma is 1.2e9 J.
Looks like a lot, doesn't it? However, in terms of heat, a joule is tiny. This amount of energy is sufficient to boil 6 tons of water, or to raise the temperature of JET's iron core by roughly 1K. So, quite a way short of melting the reactor, let alone the entire facility.
As for a chain reaction back to the "storage area", forget it. For fusion to occur, the plasma must be contained. No containment => no plasma => no fusion. You can't contain a plasma in a pipe. Sure, you can keep it from getting out, but as soon as it touches the wall of the pipe, it cools down and is no longer a plasma, just a hot gas orders of magnitude away from fusion.
[1]Yes, I know about changes to H2 specific heat with temperature - orders of magnitude is all the precision we need here.
Here's the Google cache of the article.
Obama's legacy: (N)othing (S)ecure (A)nywhere and (T)error (S)imulation (A)dministration
Get as many people together as you can, with laser pointers and a hydrogen filled balloon.
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Luck is just skill you didn't know you had.
I'm placing my bets on this guy doing it first or some other amateur tinkerer. I hate to mention the billions of dollars wasted on tokamak "make it bigger and it will work" technology that completely does a reverse 180 from Farnsworth's discovery of potential wells where smaller is better (most people can't vacuum out the inert neutrons quick enough). I'd like to mention that nobody has yet met the fusor challenge, amateur or professional. Produce enough excess energy to light a 60watt lightbulb. I believe there's a million or two dollars out there as a reward if I'm not mistaken.
My father is a Nuclear Engineer. He had this to say about the article:
There are two major approaches to fusion: Inertial Confinement and Magnetic Confinement. The facility at Livermore discussed in this article is part of the inertial confinement effort. I visited this facility quite a few years ago when they were building the NOVA facility which was mentioned in the article. The basic idea is to compress and heat a target pellet and hope that it stays together long enough to fuse before blowing apart - hence the "inertia" in its name. My personal opinion is that this method has less chance of being used for commercial electricity production than magnetic confinement fusion concepts. I think that this method has a pretty good chance to form the basis of some fantastic weapon for attacking threats coming from space. Once the tecnical hurdles are crossed, fusion will still face a huge economic problem. The facilities, either magnetic or inertial, have huge construction costs. I do believe that we will persevere and cross all of these hurdles. One driving force is happening now. The price of gas is going up. When other forms of energy get prohibitively expensive, the governments of the world will increase their support for fusion research and the problems will be solved. Fusion has considerable advantages of limitless cheap fuel, very low and easily managed radioactive waste products, very safe facilities, and no chance of proliferation of weapons-grade material. It will be great when we are able to achieve it, but I'm not expecting that to happen very soon. I once bet a colleague that we would see a commercial fusion power plant before I retired. I will concede that I have lost that bet. I hope that we will see it before my children are all retired but I'm not very confident even of that.
About 23 years too late. The Berkeley Tokomak achieved break-even, as published in "Fusion" Magazine, back in 1981. One of the people involved was Dr. Dr. John Coonrod, who was also involved in building the first whole-body CAT scanner.
-- Terry