National Ignition Facility is Firing Up 58
VernonNemitz writes "Over near San Francisco in California, USA, the Lawrence Livermore National Laboratory is starting to reach the end of 15 years of development work on the National Ignition Facility. The goal is to use 192 high-powered laser beams to blast a pellet of frozen hydrogen isotopes, turning it into a tiny (and thus safe) hydrogen bomb. Currently 4 of the lasers have been commissioned for use in tests; the eventual goal is to get more energy out of the exploding pellet than is dumped into it. Personally I think they'd have an easier time of it if they combined different ideas, but what do I know?"
Science (Score:5, Insightful)
I don't think that the goal is simply to generate lots of electricity, but rather to setup and run an experiment that could teach them new things. (Oh, and generate oodles of research papers.)
Usually, in these kinds of basic "understanding" tests (which is still where we really are in terms of our understanding of quantum effects), you don't want to combine multiple strategies
WHAT quantum effects ? (Score:1)
That is what is usually called "science".
Usually, in these kinds of basic "understanding" tests
That is what is usually called a "scientific experiment".
(which is still where we really are in terms of our understanding of quantum effects)
WTF are you talking about ? This is dense plasma physics, at these energies the only quantum effects are atomic, QED, and, hopefully, nuc
Re:WHAT quantum effects ? (Score:1)
The first principle for quantum mechanics, the wave equation is not well understood. Its not an obvious axiom like those of Euclid. We are still learning new things from it by interpreting it (similar to the way Einstein had to interpret Newton's concept of inertia to develop specia
Re:WHAT quantum effects ? (Score:1)
The first principle for quantum mechanics, the wave equation is not well understood.
It is understood well enough to numerically predict the atomic, nuclear and radiation physics for the particles envolved in the relevant energies.
For the purpose of the experiment at hand, this is as much as a physicist needs.
Additionally the
w.r.t. general QCD and nuclear physics - agreed. However, for the purposes of DT f
Re:Science (Score:1)
It's called fusion and is, among many, thought to be the future of power generation, safe, cheap and clean.
Basically, you contain a small hydrogen plasma fusion reaction and gain massive amounts of energi.
This all depends on them actually making it work, of course - they're looking at production in 2040 or so
The Gipper (Score:2)
Calling President Reagan "the Gipper" was for his supporters a way of evoking the moral courage of the character portrayed in the movie while for his detractors it was a way to suggesting that Reagan was no more than a minor movie actor.
Really Firing Up? (Score:4, Interesting)
From what little I understood, it was an extremely challenging, perhaps even overly ambitious effort to get all 192 lasers to be sufficiently well-focussed in a perfect sphere and with perfect timing, perfect power levels etc.
Have any hard promises or milestones been met about Tera-Watt-seconds/mm^3 that the hohlraum will experience?
It's a very hard problem. I would guess it would take even more time and money than it has already.
Fluid dynamic instabilities, too (Score:5, Informative)
From what little I understood, it was an extremely challenging, perhaps even overly ambitious effort to get all 192 lasers to be sufficiently well-focussed in a perfect sphere and with perfect timing, perfect power levels etc.
It's more than just that. These lasers are used to irridate the outer hell of a spherical metal shell surrounding layers of "stuff" and, ultimately, a deuterium-tritium pellet at the very center. The lasers vaporize the outer hull of the metal tamper, causing near-instantaneous stresses in the remaining metal. This causes a spherical shockwave to form and begin to implode. As it passes through the inner layers of the target, microscopic manufacturing imperfections in the spherical layers (you can never create a perfectly sphere layer) lead to instabilities in the shock wave as it passes from material to material. Fluid dynamic instabilities such as Richtmyer-Meshkov and Raleigh-Taylor causes the spherical symmetry of the shockwave and the layers to break down. Gross mixing of the layers occurs and the shockwave doesn't implode to a nice point like one would hope. Therefore, no fusion of the deuterium and tritium.
Little is known about how to control these instabilties. So even if you got all the lasers to work correctly to form a perfect shockwave, the travel of this wave through the imperfectly-created layers ultimately causes the reaction to break down anyhow.
It's a very hard problem. I would guess it would take even more time and money than it has already.
You said it. Some would argue that because of the above listed problems that magnetically-confined fusion is the way to go. But that approach has its own set of problems.
GMD
Re:Fluid dynamic instabilities, too (Score:4, Interesting)
NIL isn't a facility for researching fusion power: it's designed for nuclear weapons research, even though no one says that in public (it's said more often in private).
The enormous technical difficulties involved in getting fusion from this method, much less positive energy returns, is one pointer to this fact; compare it to magnetic confinement, which has produced fusion though not positive energy returns. However, nuclear weapons researchers have spent years looking for more controlled circumstances under which to study how fusion occurs in bombs. After the US signed the CTBT, this need became more urgent, thus we're seeing it get built.
Yes yes.... (Score:2, Interesting)
For those who are missing it, a laser-ignited H-Bomb would be more or less clean. The conventional method of igniting an H-Bomb requires an A-Bomb, which spews fallout. A clean H-Bomb wouldd just take a city or installation out without ruining the land and water.
Hawks in the government hope a clean fusion bomb would allow moving past the era of nuclear weapons as deterrents into the era of
Re:Yes yes.... (Score:2)
No, it would not be appreciably cleaner than a conventional H-Bomb. The bulk of the fallout comes from the jacket in the second fission cycle which is compressed from the outside by the primary and from the inside by the fusion cycle. The jacket
Re:Yes yes.... (Score:2)
> the primary) - fusion (of the core of the
> secondary) - fission (of the jacket of the
> secondary).
The proposed laser-ignited bomb would, of course, be pure fusion. The resulting relative cleanliness is one of the advantages.
> This last step accounts for the majority of the
> yield.
The ability to produce very low yield bombs is the other advantage.
Re:Fluid dynamic instabilities, too (Score:2)
I read that yesterday, and thought, "wow, that's a wonderfully visceral description!" To create an Hellishly hot outer layer in order to create a truly Infernal level of heating and compression inside.
Looking again today, I guess it was supposed to be "outer hull" or "outer shell". But I still like the image of using lasers to irradiate the hell out of something.
Re:Really Firing Up? (Score:1)
I can't help it. (Score:2, Funny)
What restraint they must have in not playing a very expensive version of the old game "lets put stuff in dad's vise and crush it!"
Physics: The Most Trustworthy Religion in The Wo.. (Score:2, Funny)
I hope they're gonna give us plenty of warning when they fire that thing up, over here in Trans..beria
All 'that free energy' has gotta come from somewhere.
meanwhile, the big fusion reactor (Score:4, Interesting)
Re:meanwhile, the big fusion reactor (Score:2)
Re:meanwhile, the big fusion reactor (Score:2)
Re:meanwhile, the big fusion reactor (Score:2)
How about Waterworld? We can build a great big dam and create people with webbed feet.
Re:meanwhile, the big fusion reactor (Score:2)
Re:meanwhile, the big fusion reactor (Score:2)
Re:meanwhile, the big fusion reactor (Score:5, Funny)
Yeah, but look how many cases of cancer it's causing. It can't be stored safely because it will remain radioactive for billions of years. There is no realistic plan for decomissioning. Some research implicates it in global warming and it's known to cause destructive storms. Concentrated exposure has been shown to cause smoking and charring in ants.
Other reactors of the gas-core gravitationally confined design have been known to explode, causing great environmental damage.
As soon as someone gets around to filing and reviewing an Environmental Impact Statement, we'll have to shut down that huge nuclear reactor in the sky and replace it with alternatives that environmentalists can accept.
Solar fusion reactor (Score:4, Insightful)
Think about it -- the Sun has an estimated 10 billion year Main Sequence lifetime, of which it has used up 5 billion years. Also consider that over the Main Sequence lifetime it cannot achieve anywhere near complete burnup of the hydrogen and you can figure that the amount of hydrogen burnt per year is measured in parts per trillion.
There are heavier stars that burn their hydrogen much more quickly, and it is good for us that the Sun is so thrifty, but if you could duplicate the conditions in the core of the Sun, it wouldn't make for an economical energy source in an Earth-based power plant.
Now that's an encouraging link... (Score:3)
Cute link for the "tiny, safe hydrogen bomb"! Or perhaps they mean that the image is actual size? Cool -- the New Millenium version of an old favorite [lavaworld.com].
Re:My tax dollars hard at work (Score:2)
Yeah, thats my take on this. I read up on it over a decade back and saw that it had scaling problems out the yang. We're talking timeing accuracies for all beams measured in the amount of time it takes light to move less than a millimeter, and getting 192 lasers marching in that degree of lockstep on a repeatable basis strikes me as some theoretical guys idea, one who has never found out hot to get his hands dirty with the tools.
Here it is, nearly 15 years and proba
Re:My tax dollars hard at work (Score:2)
Re:My tax dollars hard at work (Score:2)
When playing the game, one must be willing to pay for the priviledge, or not play. How you pay for it is your choice, TANSTAAFL.
Cheers, Gene
"There are four boxes to
Re:My tax dollars hard at work (Score:2)
I just applied to them for a job (Score:1, Interesting)
It is an internal posting. Unix and OS X support. Hope I get it. Could be really interesting. I know people who work there and have toured it as it was built. I was a real kick to see the sphere lifted into the building. One hell of a crane!
ac
Hmmmm..... (Score:2)
Not that that would necessarily be a bad thing, but....
Re:Hmmmm..... (Score:2)
Re:Hmmmm..... (Score:3, Funny)
Anyway the San Andreas is the wrong kind of fault for that.
Wouldn't it be hilarious if the fault really DID let go... and all the rest of the USA (or better yet, North America) slid beneath the waves?
Re:Hmmmm..... (Score:2, Insightful)
Already experienced... (Score:1)
"Freeman, put the probe into beam, do you understand me?"
Tiny,.. (Score:1)
and thus safe Hydrogen bomb?
Did they just say a safe hydrogen bomb? Are they serious? When is any kind of bomb safe?
Besides, the reaction that occurs in the fusion chamber of the power center is not a bomb, it is controlled fusion, much more elegant (and more expensive).
Tiny, safe bomb is accurate. (Score:3, Informative)
Besides, the reaction that occurs in the fusion chamber of the power center is not a bomb, it is controlled fusion, much more elegant (and more expensive).
In ICF the goal is a submilimeter scale thermonuclear explosion. A tiny bomb is indeed an accurate description.
It is indeed safe b/c the quantities are small: nuclear energy density is ~10^6 higher than chemical, so if one explodes 10^-6 the amount of, say, coal that is burned in a usual generator in a second, one gets the same power, which we know
This is part of "stockpile stewardship" (Score:2)
How do you recruit new ones? The job requires a PhD in a specialized area of physics. It requires someone who's willing to devote their life to doing something many people disapprove of, and which is a dead end job as well.
There's an additional problem that's not well known. Existing US bomb
Its very safe (Score:1)