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More Evidence for Tabletop Fusion
heptapod writes "Researchers at Purdue University have statistically significant evidence that their tabletop fusion experiments were successful. Yiban Xu's experiment different from an earlier Oak Ridge experiment using a different and cheaper source of neutrons than Oak Ridge's pulse neutron generator. Surpassing break-even point still eludes the grasp of science."
Statistical evidence of fusion at this level is indeed impressive; however, while fusion experiments such as this others remain below the break-even point, they shall yet be little more than a labtable source of neutrons. We await developments from the latest in the field.
It's possible to build boosted fission primaries with fission efficiency up to about 50%. Such have been built and weaponized. Modern US devices have less efficiency (around 15%, in rough terms) because they are designed to use as little fissile material as possible and to be one-point safe, and also to have limited overall fission yield. Those requirements lead to less efficient weapons than are possible and were used in the past.
Second, fusion, stages can be both highly efficient (50% or more of the possible fusion energy content) and have very high multiplication ratios of input to output energy (factor of 25 is possible, with factors of 8-15 in deployed US weapons), even before you double it again with a fissionable tamper third stage.
Look at references like the Nuclear Weapons FAQ at http://nuclearweaponarchive.org/
Once you build a Farnsworth Fusor, you have a tabletop nuclear fusion device. Which part of "Fusor" was unclear?
If all you want is neutrons and to violate your local Nuclear-Free Zone, just stop at that point...
You are so wrong it's not even funny.
The industrial revolution started because of forest depletion in England which meant that they had to switch to coal. In order to get to the coal they invented the steam engine to pump water out of mines and lift people into and out of them. The invention of the steam engine had the wonderful side effect of bringing forth the industrial revolution from which we all benefited.
If you want to read about the reasons for societal development and collapse by a academic whose works on civilization have stood the test of time and explain the Roman, Mayan, Mezoamerican and Egyptian collapses all with the same theory I suggest you read Tainter's collapse of complex societies. The west has saved itself from collapse for longer than any other civilization out there because we have had the wonderful luck to constantly innovate ourselves out of the corners we get into. There were many times throughout the Renaissance and the industrial revolution that European society could have collapsed but we always managed to pull ourselves out of it via technolgy.
5+ standard deviations against the control is interesting. Should be easy to reproduce. (or not).
"A language that doesn't affect the way you think about programming, is not worth knowing" - Alan Perlis
You can get tabletop fusion with a TV high voltage supply, a glass bulb, some wire, and deuteriums gas. That's been known for decades and is used as a neutron source commercially. People build those things for science fairs. It's called the "Farnsworth Fusor" (I know, in light of Futurama it sounds like a joke, but the fictional character was named after the real one).
Why don't we all have flying cars, then? Because you can't get a net energy gain with the Farnsworth Fusor--it seems to be impossible in general to do so, the numbers just don't work out.
Of course, even if you do make it efficient, it's not exactly "clean energy": even with so-called aneutronic fusion, a few percent of the fusion reactions will generate neutrons, which, for realistic power generation, results in a neutron flux that causes the power generation to be quite dirty. Not as dirty as fission--disposal should be easier--but don't expect something harmless you can just run in your basement.
So, tabletop fusion isn't really anything impressive: there are probably lots of ways of getting fusion on your tabletop. The question is how you make it efficient enough to useful amounts of energy out of it. And cavitation seems no more promising there than inertial confinement in the Farnsworth Fusor. But maybe if enough people keep playing around with this, someone will get lucky and find something that works.
About coal being worse than nuclear, I have not the best references, but here are a few:
/ FS-163-97.html / colmain.html
http://geology.cr.usgs.gov/energy/factshts/163-97
http://www.ornl.gov/info/ornlreview/rev26-34/text
http://yarchive.net/nuke/coal_radiation.html
Remember the year 2000? They promised us flying cars. They delivered the PT Cruiser...