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Bubble Fusion Results Replicated
Anonymous Coward writes "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. Interesting stuff, read about it
here."
Previous slashdot articles
Thursday January 20: Fusion Using Sonic Compression
Monday April 19 2004: Bubble Fusion Results Replicated by 4 Institutions
That's a cool idea, but what would be the efficiency of that process? Earlier experiments used a 14MeV neutron beam to generate microscopic nucleation points which sonoluminescent fusion expanded and collapsed, releasing 2.5 MeV neutrons. I'm not ready to say "bubble fusion" can't be used to generate power, but I think it's important to consider it an area for pure research at the moment without any immediate application. This problably will not lead to fusion power plants, unfortunately.
That doesn't, mean the subject should be ignored, just that folks shouldn't get their hopes up over this process. (Added for the benefit of clueless ACs who might have difficulty with reading and comprehension.)
True, with one caviat - this approach to fusion requires the substance (acetone really, not water) to stay liquid. So you have to use the heat energy to boil some other working fluid. The only real hard part is that the acetone (at least at this point) needs to be cool. That can probably be fixed via high pressure, but the low temperature aspects may limit usefulness.
On the other hand, there are always alternatives. It can probably be used very soon in low temperature environments.
while (sig==sig) sig=!sig;
No, the goal is to capture the kinetic energy of the moving neutrons, which is turned into heat, which is then translated to mechanical motion, which turns a generator, which generates electricity, if the heat is not used outright on its own.
Even in a thermoelectric battery, powered by the heat generated typically from plutonium decay, the heat induces a potential difference between two different metals, which is then captured. You get the same thing if you take a chunk of the two metals and heat it with a torch.
Neutrons may be "ionizing" radiation, but that's because they might knock molecules or atoms into pieces. Gamma rays are ionizing radiation because they are at a high enough energy so that if a molecule absorbs a gamma photon, it has to get rid of that acquired energy somehow, so it splits. Gamma rays are so feared because they penetrate so deep into susceptible materials, like mammalian flesh. Neutron-decay stuff isn't so bad to the body, unless you ingest it somehow. Alpha- and Beta-decay stuff is relatively benign.
Because neutrons are 0 charge, they don't inherently create or induce electrical potentials in materials on their own by their motion.
Ion flow doesn't really happen, either. It's electron flow (really, electron "hole" flow) that is electricity.
I don't think it's that simple. First, I believe this experiment used acetone for the liquid medium, and I'm not certain that it's behavior in a steam turbine system is satisfactory. Second, there is the question of energy density. Sure, they're seeing bubbles that exhibit sonoluminescence, but are they seeing enough bubbles to heat the fluid to the point that it can drive a steam turbine?
And even if they are, which I don't think is the case (the flashes last only 35 picoseconds), will the system be efficient enough to exceed break-even? I can boil water on my electric stove to drive a steam turbine, but not at sufficient power to run the stove.
It's news because the replicated findings are finally getting printed in a peer-reviewed journal, Physical Review E. The press release means that the authors say they did it, it means little until it get accepted by a journal. Do I think this is the wave of free energy? No but as far as a pure science aspect, it is interesting. Several assupmtions still need to be worked out anyways with the calculated temperature. Assumptions always need tested... Phys. Rev. E 69, 036109 (2004) http://link.aps.org/abstract/PRE/v69/e036109doi:10 .1103/PhysRevE.69.036109