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Bubble Fusion Results Replicated by 4 Institutions
Trackster writes ""TROY, N.Y. - Physical Review E has announced the publication of an article by a team of researchers from Rensselaer Polytechnic Institute (RPI), Purdue University, Oak Ridge National Laboratory (ORNL), and the Russian Academy of Science (RAS) stating that they have replicated and extended previous experimental results that indicated the occurrence of nuclear fusion using a novel approach for plasma confinement." Here's another link in case EVWorld gets burned."
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Ever feel the warmth of the sun? Lots comes of nuclear fusion.
We hear, every so often, that "nuclear fusion has occurred", and nothing ever comes of it. It either can't be replicated or is impractical for power generation.
Would anyone care to enlighten me as to when we'll see anything come of this promising technology, and when people will stop pussyfooting around and just increase the scale a little bit?
The trouble with fusion reactor experiments (of the tokamak kind) is that they are tremendously expensive and lengthy to build. After the previous generation of European experiments (JET) there supposed to be something like a seven-year gap before ITER would become available. IIRC the US pulled funding on their independent fusion programme, but eventually decided to join ITER too; its pretty much the only tokamak game in town.
However, due to its cost, ITER has always been mired in politics (even the site hasn't been chosen yet - 5 years after the project was supposed to have started) and this leads to more delays and increased costs.
Plasma theorists also have to find something else to do (and alternate funding) between each round of testing; seven years is a long time and people leave the subject, retire, etc, never too return. You'd be a very brave man to pin your career hopes on ITER being built on time. This then causes manpower difficulties for the project when it finally gets into gear, which then suffers more delays and overruns, etc, as postdoc researchers are trained up.
In short; expect progress when ITER is build, but don't hold your breath.
200 Hz pulses of neutrons and tuned ultrasound create cavities and grow bubbles in deuterated acetone which grow from 60 nanometers to 6 millimeters. At this point, they implode within nanoseconds, reaching estimated temperatures of 10^7 Celcius/Kelvin and 10^9 atmospheres (sea level) and releasing energy: tritium (hence fusion), light photons (sonoluminescence), gamma rays, and more neutrons. "Because the bubbles grow to such a relatively large size before they implode, their contraction causes extreme temperatures and pressures comparable to those found in the interiors of stars." "In future versions of the experiment, the tritium produced might then be used as a fuel to drive energy-producing reactions in which it fuses with deuterium."
Wouldn't it be funny if the sheer acreage of acetone tank required to produce a watt o power makes it less economical than covering that same area with solar panels?
Eat at Joe's.
> I can't think of any technology that has successfully spanned this many decades from proof-of-concept to practical reality.
How about The Marquand Logic Machine?
That's a pretty impressive scaling up over the last 12+ decades.
Operator, give me the number for 911!
Also, fusion is not the wonderous clean energy source it's made out to be, because any type of fusion that's realistically possible outside of a star also produces neutrons, which activate the reactor materials leading to significant amounts of radioactive waste. That said, the waste problem is not so severe as with fission plants because generally isotopes with short halflifes are produced.
For more information about fusion in general and amateur efforts in particular - I'm building a tabletop reactor - check out http://www.fusor.net/
"Studies have shown that people who eat peanuts live longer than those who do not eat."
It's cold in the sense that you don't have to have huge containment systems to avoid heat death from your sonofusion experiment. You can run this stuff on a regular lab table.
Actually, D-T has a larger interaction cross-section by two orders of magnitude up to very high temperatures (~100 keV), so you would get a considerably higher yield for the same energy input. However, tritium is not as practical in a lab setting because:
1) it's a beta emitter (thus more paperwork)
2) it's more difficult to acquire
Plus, it's easier to shield the 2.45 MeV D-D neutrons than the screaming 14.1 MeV D-T neutrons.
For a commercial power plant, you need 10s or 100s of megawatts. For home, probably less than 10 kilowatts peak, less than that if I have a flywheel or other way to store power for peak demand periods? Call it 4-5 orders of magnitude saved. There are some additional potential savings in a distributed system; you can in principle do away with the transmission losses we suffer in the current power grid. Given that it's fusion, I do wonder about the point raised in other threads about how long it would take for my home fusion reactor to become a problem neutron source...