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National Ignition Facility is Firing Up
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?"
Personally I think they'd have an easier time of it if they combined different ideas, but what do I know?
...
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
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.
"Provided by the management for your protection."
This reminds me of buring ants with a magnifying glass. Scaled up a few times, and modified to be useful and all, but still the same root coolness (if you're a geek) multiplied.
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!"
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rld ...
... give us plenty time to strap one on in Baikonur and escape the planet as it gets sucked up by "Black Hole San Francisco".
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.
; -- the corruption of government starts with its secrets. a truly free people keep no secrets. --
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
watch this
in the sky continues to burn 24x7 at no cost, most of its energy completely unused
... turning it into a tiny (and thus safe) hydrogen bomb.
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.
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
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
Is it really wise to do this near a major earthquake fault? I mean if it gets a little bit out of alignment, or they load just a little too much hydrogen or something, all of California could end up in the ocean.
Not that that would necessarily be a bad thing, but....
Why this article makes me some faded memories about HalfLife entering my mind?
"Freeman, put the probe into beam, do you understand me?"
There you are, staring at me again.
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 nuclear weapons as a real force.
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).
I couldn't think of a sig.
15 years? Nothing to actually show?
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 probably close to a trillion in it, and only 4 of those 192 lasers have actually been "commissioned"? And it takes 8 hours to recharge them for the next shot? Aww c'mon folks, this project is being done for lots of reasons, but there is no way in hell you can convince me it will ever produce 10x the energy being put in per shot of the lasers. For those that are convinced its for weapons research, you may be somewhat correct, but how are you going to pack that up into a container small enough to deliver to the target?
That thing has turned into a WPA project for otherwise un-employed atomic researchers. But thats a bit of an understatement since the WPA paid subsistence wages in the time of the depression 70 years ago. Now the workers are driving a Lexus or Mercedes. Since its my taxpayer dollars being used to buy that Lexus, am I entitled to drive it? Nahh, donbesilly.
Somethings dreadfully wrong with this picture IMNSHO. Personally, this is the project that should have been canceled back when the SSC was shot down. I feel we would have received far more knowledge and data from the SSC by now, and probably would have done it on 10% of the money this thing has sucked up so far, with no profitable end in sight. They always have to build the next one 10x bigger to 'test their theories', promising that someday it will break even.
It may happen, but I'd have to live another 70 years to see it. That would make me 140, and they will still be playing in the fusion sandbox.
We don't need to test this theory any more, mark it as a failure and start looking for an even better idea.
And of course don't forget that the instant any such operation starts to do better than breakeven, you can take it to the bank that the California nimby's will get it canceled.
Cheers, Gene
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, nuclear-fusion physics: the first principles for all are rather well understood.
In the immortal words of A. nonymous: Don't talk nuclear when you don't know shit
Working for necessity's mother.
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 how to control (puting aside the nutronic difficulty).
Working for necessity's mother.
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.
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.
New NIMBY slogan: Jimmy Neutron Go Home!
Nearly fifty percent of all graduates come from the bottom half of the class!
From that, I take it that you are one who would vote no (regardless of its fueling method) on an electricity generating facility in your state/county. And then you have the gall to yelp when the rolling blackouts hit again this summer. Or when the price of importing power skyrockets because the Enrons of this world see a profit opportunity.
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 be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
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 designs, especially fusion bomb designs, are a bit too clever. Back when bomb design was an active field, when top people went to Los Alamos and Lawerence Livermore, there was a tendency to overdesign. Pushing for the highest possible yields from the smallest warheads provided useful work for many bright people. But trying to reach that level of cleverness with today's second and third tier people is hard. Especially when you can't test.
Hence the "National Ignition Facility". Part of the idea is to make bomb design without testing easier. And part of the idea is simply to keep physicists busy, so they're around when needed.
Physicists are part of the stockpile, you see.
There is only a slight chance of a resonance cascade scenario.
Actually, I was just trying to be funny. Clearly I need to work on my delivery...
Nearly fifty percent of all graduates come from the bottom half of the class!