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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. --
Damn, clicked the wrong thing. How do I delete my own message?
"Your having a bad day when the voices in your head put you on hold"
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.
You can't. But if you say you're a physicist, it'll be on topic.
Just because.
15 years? Nothing to actually show? How many Mercedes have I bought for managers with that money? I bet they could have sent everyone in my state to university for what they spent on this useless twaddling.
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.
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.
In the interests of non-US folks, why was he called The Gipper? Googling didn't help, everyone just assumes everyone knows what it means. I Googled for GOP, that worked. So....
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.
blast a pellet of frozen hydrogen isotopes, turning it into a tiny (and thus safe) hydrogen bomb.
You mean "nuclear fusion"?
"a laser-ignited H-Bomb would be more or less clean"
Well, yeah - on the other hand, if you had lasers large enough to create a sizable fusion reaction, you could just point them at whatever you want to destroy instead.
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.
Perhaps perfection is not really necessary! After all, you only need look at a star, any star, try our sun, for a perfect picture of a working fusion engine that is a really messy eater!
We know more than we understand our these fusion processes, and that lack of understanding challenges us. Back in 1962, we in the United States tried to get a 50 MT fusion device to work and failed. The result was the first in a series of 'nuclear' control treaties. The Soviets had succeeded in operating a 30 MT device and were promissing to follow that up with larger tests. In order to stall this, we finally agreed to these treaties as a public figleaf to cover a hidden failure. That failure and possibly others have forced suceeding American administrations to agree to more and more of the same old wine in new bottles while feverishly working within the framework of all the 'nooks and crannies' of the terms of these in order to make what progress in the understanding of it all. Chances are even extraterrestrials have had a hand in this as well even if only passively by reverse engineering of crashed space shuttles, the only craft obviousely available to us.
This has born some fruit. Look at the shape of the 'stealth' fighter the F-117!. A close look at it shows it could hide a saucer shape. Not all those F-117's will be the real deal, only a few; but something made a 9000 mph radar track that Tariq Aziz of Iraq mentioned in 1991. If we have such a plane, then the shuttle is window dressing and any money spent on it is a waste! It also would mean that those 7 astronauts on the Columbia did not have to die, but did die so the government could continue to hide a very big secret from the world. Maybe the Soviets knew of this as well. Why would communists voluntarily step out of power and literally fade into the woodwork of Russian society for no obvious and sufficient public reason? Doctrinaire communists have been historically the most truculent and stubborn and confrontational movers for change in world society in the written history of man. Why would they leave without a reason or a fight in country after country, especially in Russia?