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Laser Fusion Put On a Slow Burn By US Government
gbrumfiel writes "Those hoping to laser their way out of the energy crisis will have to wait a little longer. The U.S. government has unveiled its new plan for laser fusion, and it's not going to happen anytime soon. It all comes down to problems at the National Ignition Facility (NIF), the world's most powerful laser at Lawrence Livermore Lab in California. For the past six years researchers at NIF have been trying to use the laser to spark a fusion reaction in a tiny pellet of hydrogen fuel. Like all fusion, it's tougher than it looks, and their campaign came up short. That left Congress a little bit miffed, so they asked for a new plan. The new plan calls for a more methodical study of fusion, along with a broader approach to achieving it with the NIF. In three years or so, they should know whether the NIF will ever work."
what lie? the lab and government make no secret work done there in both fields, controlled fusion and thermonuclear bomb research.
Besides being an ugly word it is imposing a sort of emotional response to something that is more practical and dare scientific.
At the end of the day we have created fusion. Most of it came through bombs, but from a scientific standpoint we know about fusion.
This is about creating a clean, reliable, cost effective energy solution.
There should not be hard feelings or even a feeling of failure. The idea was sound enough to look into. Maybe it's just not practical. No use throwing good money after bad or crying over spilled milk.
If you want to get an understanding of the state of fusion research, you need to look at this graph. Fusion power is not unreasonable, nor even very far out of reach. This interview is good reading as well.
If we want to get serious about global warming, we could do worse than funding more fusion research.
All thermonuclear weapons are fusion bombs. They have been built since the late 50s. The designs have been refined, but we don't need to research much there. The bombs we have are powerful enough for all intents and purposes.
Please uprate previous comment. It is not a troll. The NIF project is funded primarily by the NNSA, the part of the Department of Energy which deals with the science & engineering of nuclear weapons. The DoE does not dispute this, it just likes to de-emphasize the reality of the primacy of the weapons effort.
The design of the experiment and system matches the thermonuclear secondaries for weapons. Contrary to some people's belief, the nuclear physics is not difficult---it is the fluid mechanics and radiation transfer in extreme conditions which is the scientifically difficult part. (Radiation-driven secondaries are much much more difficult than fission primaries).
The primary purpose of the NIF is to gain experimental data to calibrate the simulation codes for nuclear weapons engineering & reliability in the absence of nuclear weapons testing.
There is a small energy related research project, but it is very very very far from practicality. There is little attention to actual engineering issues, compared to say ITER (magnetic confinement fusion) project, which is pretty heavily focused on engineering practicalities. Lasers are horribly inefficient energy transfer if you care about power breakeven but much better for making clean data for weapons code calibration. Most of the funded experimental runs will be for weapons, not energy research.
In any case, neither inertial confinement nor magnetic confinement fusion will be used as a power source with customers for at least 60-100 years.
We already know how to make nuclear reactors---and if we are not funding and churning out high-quality modular fission reactors now, it's foolish to think about fusion.
It's where 99.9% of the energy on this planet has come from and where 99.9% will ever come from. Sooner or later it's going to have to be our primary source.
So what your saying is the future lies in fusion?
Tiny compared to most things on day-to-day human scales. Here's an image of the pellet.
As for the reaction itself (and I probably have this wrong, so please correct me if you discover so) it would, best-case, generate 100-150 MJ, but I read the target chamber's design only allows for 45 MJ (realistic expectations, I suppose?) That amounts to 11 kg of TNT (yes this is all paraphrased from Wikipedia.) Certainly tiny by the standards of fusion/fission, but quite huge considering the pellet above.
This might not seem like much, but it is a demonstrative design. Going for designs that would produce a practical commercial system at appreciable outputs would have been astronomically more expensive. Better to prove the concept first. Still more, this is a dual purpose facility; it's primary objective is stockpile stewardship. The potential for fusion research for commercial purposes is just added value.
Demented But Determined.
It's not about increasing the power of new bombs, it's about increasing their reliability / taking care of old bombs without needing to do nuclear tests.
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What lie. It's says so right in the article.
You read the article? Security breach!
Have gnu, will travel.
Hello, I'm sorry to say this, but aneutronic fusion is probably never going to be a practical energy source.
There's a reason D-T fusion is the focus. One problem is that all the aneutronic fusion reactions involve higher-Z (higher atomic number) nuclei. Higher Z nuclei have worse energy loss via Bremsstrahlung radiation than the D-T or D-D reactions. In a plasma hot enough to sustain fusion reactions, the electrons and ions are banging against each other, and every hit potentially makes X-rays or gamma rays, converting thermal energy into light. In a reasonable-sized thermal plasma, these photons pretty much just leave without interacting again, thus cooling the plasma.
People have calculated that the energy loss rate from Bremsstrahlung in a thermal plasma composed of atoms capable of doing aneutronic fusion would exceed the rate that the fusion reactions would heat it. Thus, the plasma would cool right off, the flame would in effect "go out" because it would lose heat faster than it created heat via fusion.
In a star, this works out, because a star is so very, very big that the photons from Bremsstrahlung are re-captured within the star: i.e., the heat can't escape because of sheer mass in the way. We're never going to pull that size and density off in a lab or an engineering installation.
Now, if you can somehow arrange for the plasma to NOT be thermal, you may be able to beat this issue. However, keeping a plasma from thermalizing requires a large energy input, and is very hard to arrange for and preserve long enough to get energy from fusions. Inertial confinement might work (laser or Z-pinch or the like), there you potentially have very high densities for maybe "long enough" for Bremsstrahlung not to eat your lunch: I don't know. However, both laser and Z-type installations seem very hard engineering problems.
The wikipedia on "aneutronic fusion" discusses these issues some as well.
Anyway, that's one reason most are happily ignoring aneutronic fusion entirely. Another is that much higher temperatures are required for the aneutronic fusion reactions, and we haven't even got D-T going yet and that is the lowest temperature fusion reaction. D-T is where I would put my money, too, given the results of the physics calculations.
--PM