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Amateur Scientists Seek Fusion Reaction
ElvaWSJ writes "A small subculture of amateur physicists and science-fiction fans — fewer than 100 worldwide — are building working nuclear-fusion reactors at home. The designs are based on the work of Philo T. Farnsworth, an inventor of television, from the 1960s. Some of these hobbyists hope similar reactors can one day power the planet, but so far they consume more energy than they create."
Can a string theorist explain why this won't work?, in simple terms please.
Does anyone remember the "radioactive boyscout"?
David Hahn to make his own reactor (breeder, i think). He accumulated quantities of radium and tritium from smoke detectors and lantern mantles in a shed. The DOE had to lock down his parents whole house and yard to clean it up.
David Haun
"A small subculture of amateur physicists and science-fiction fans -- fewer than 100 worldwide -- are building working perpetual motion devices at home. The designs are based on the work of Albert Michelson, co-proponent of luminiferous aether theory, from the 1890s. Some of these hobbyists hope similar devices can one day power the planet, but so far they consume more energy than they create."
Good article.
All known hydrogen fusion reactions produce strong neutron fluxes. Strong enough to kill, and death by radiation poisoning is not my idea of a fun time.
Ooh, moderator points! Five more idjits go to Minus One Hell!
Delendae sunt RIAA, MPAA et Windoze
No, this really works as advertised. It's a high school science faire level of complexity and cost (if you're willing to deal with stray neutrons). For practical reasons, it can't be made to produce more energy than it consumes, is all. The principles have been known since the 20s. Robert Bussard (of Bussard Ramjet fame) had patents on it.
Its for the tinkerer who wishes to learn more about high vacuum pumps (absorption, ion, vane, turbo...), vacuum chamber design (welding, management of outgassing...), low pressure measurement, low pressure gas flow, high voltage (flybacks, diode stacks, corona discharge, flashover...), particle detectors (scintillators, avalanche photodiodes, image intensifiers, calibrated op amps...), instrument design (fast ADCs, multi-channel analyzers...), oh and some cool stuff related to nuclear physics thrown in. Most of us can't buy all the gear, so we make it all from scrounged parts. And learn a tremendous amount of related engineering in the process. Look at it this way - its like the difference between building an RC car and rebuilding a classic car - anyone can toss together a kit, but if you want to learn how to restore an older car you end up learning dozens of skills you didn't realize you need. Its one of the most interesting educational projects in modern science that isn't illegal (yet).
Focusing on Farnsworth fusors in an article written in part about fusion as a possible energy source seems as poorly researched as writing about steam engines in an article about internal combustion. The polywell seems be the heir apparent for serious work in energy out of the fusor lineage.
But the stray neutrons (or other energetic particles, depending on the reaction) are the real problem with fusion as a power source. To quote TFA:
Fusion advocates say reactors would be relatively clean, generating virtually no air pollution and little long-lived radioactive waste. Today's nuclear power plants, in contrast, are fission-based, meaning they split atoms and create a highly radioactive waste that can take millennia to decompose.
The spent fuel from a fission reactor is just not that hard to deal with - park it in a contianment area as robust as the reactor itself for 5-10 years, and you're left with not-very-much not-very-radioactive waste that could be easily disposed of, if it weren't so valuable that we insist on keeping it instead.
It's the rest of the reactor that's the serious problem. Depending on the reactor design, quite a bit of the reactor structure can become radioactive over time.
Fusion is going to have the same problem. Even if you have a reactor vessel the size of a washing machine, you're going to need significant shielding, an energy transfer mechanism (water leading to a turbine or something), structural elements, etc. Surem the problem with spent fuel goes away, but the problem with speant reactors remains. Not something you'd want in everyone's basement.
Socialism: a lie told by totalitarians and believed by fools.
Sweet. They built a time machine.
I don't think anyone building these expects to ever have a net power output from them -- that's not the point. The point is to be able to say you built a fusion reactor, or as others have said to generate isotopes for other experimenting, etc.
IMO, a more important area of amateur and admittedly fringe scientific research around fusion and fusion-like reactions is the several hundred teams that still continue to this day to investigate what the heck is going on with low temperature fusion. Tons of progress is being made in the field, and some reasonable theories are starting to form. There's a lot of unknowns, but helium is regularly produced, neutrons are regularly produced and more interesting from a theoretical standpoint, lots of atoms are changing from one element to another...
Its like the 1700's experimenting with chemistry. Lots of people doing lots of very cool and interesting experiments and getting lots of very interesting results, even if we (humanity, not me personally) still don't quite get it.
IMO, its an aspect of science we miss in the modern world. These days we just assume we understand things pretty well and experimenting is about engineering or proving a theory. Its cool there are still areas of fundamental science experimentation going on where we just don't get what is happening and have no idea what might happen with the next variant.
Are these the same yahoos that post videos of "perpetual" motion machines on Youtube?
No. Wikipedia is your friend.
Farnsworth - Hirsch - Meeks fusors are quite real and effective. They're easy to build even by hobbyists using readily obtainable parts. Commercial versions serve as controllable neutron sources. Fusion neutron output of up to a trillion per second has been reported and rates in the billions per second are easily obtainable. To date it is estimated that Farnsworth-Hirsch-Meeks fusors have produced far more total fusion neutrons than all other non-bomb fusion devices combined.
Downside is that they involve ions moving in a trajectory past a metal electrode, which they must pass without hitting many thousands of times on the average before they participate in a fusion reaction. Hitting the electrode loses the energy used to create the ion and attempt to confine it, dumping the energy as heat in the electrode. Getting the electrode to be sufficiently "transparent" to achieve breakeven seems to be a lost cause.
Bussard's family of Polywell fusion machine designs apparently started as an attempt to steer the ions around the inner electrode of a Farnsworth-Hirsch-Meeks machine using a magnetic field. But it has since developed into a different (though related) principle: Use the magnetic field from the self-shielding magnet/electrodes to confine electrons (which are much easier to handle), creating a high-density space charge in the center of the machine. Use the electrostatic field of the electrons to attract and confine the ions in this region at high density and temperature, resulting in fusion. The magnetic field still shields the inner structures and the field is convex toward the plasma, limiting the plasma instabilities the plague "conventional" fusion machines.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
No, no, no. It's not "almost" fusion. It is fusion. It is almost a fusion generator. That doesn't mean fusion isn't occurring. It means that the reaction is not self-sustaining. There's a huge difference. Saying that it isn't fusion is like saying that a match placed in a sealed jar and set ablaze using a laser isn't really fire because it consumes all the oxygen and burns out and there's no way to add more oxygen....
Check out my sci-fi/humor trilogy at PatriotsBooks.
Now if they could put it in the form of a suppository...
not plane, nor bird, nor even frog...
" The designs are based on the work of Albert Michelson, co-proponent of luminiferous aether theory, from the 1890s."
It's worth reminding people that, whatever his original views of luminiferous aether, Michelson was one of the great experimentalists of the 19th century and his name is most firmly associated with the experiment that's widely credited with experimentaly destroying the credibility of aether theories.
(It's still possible to come up with aether theories even with the Michelson-Morley results (and the results of hundreds of other people who replicated and refined that result), but it's much more difficult, and the resulting theories end up rather hard to credit.) I assume that the original use of the word "proponent" was a typo).
http://www.geoffreylandis.com
As someone who has worked in fusion, there is significant radiation created by the process. The larger reactors can't run on the ideal deuterium/tritium mixture because it would irradiate entire cities while the reactor burned. I would not want a small one in my garage. The reactor I worked on was in a concrete bunker a fair distance away from any people. It was also the size of a large house.
If you want to live in the future and be on the cutting edge of science, go to grad school and study physics (you're never too old). There are not enough people seriously studying fusion. You'll get paid to work on reactors (big or small) which may have a commercial future. We wear snarky shirts that no one understands too.
Why isn't this tagged with "goodnewseveryone"?
Robert Bussard (of Bussard Ramjet fame) had patents on it.
The patents apply to a fancier version called the Polywell. Polywell attempts to cut losses to the point where net power is possible. As far as I know, no hobbyist has attempted that one yet. It's a much more expensive design that, depending on the fuel, would generate truly lethal doses of neutrons, and would need lots of shielding.
If we just gathered together enough matter, it would start fusing on its own through gravitational force. Using this method, we could create a gigantic fusion reactor in space, and then collect its radiation and convert it to electricity. It would be kind of like harnessing the solar power of the sun...oh wait...
But the stray neutrons (or other energetic particles, depending on the reaction) are the real problem with fusion as a power source.
That actually depends on what your fuel source is. The common science fair level project uses hydrogen (not deuterium, even), and produces, IIRC, neutrons. There are other fuels possible, and some don't produce much of anything nasty. IIRC, Lithium 3 on one side and Lithium 4 on the other produces stable helium isotopes, and electricity, and absolutely nothing else.
There are still issues with fuel that misses other fuel striking internal components of the reaction chamber, which can produce some radioactivity, but getting to the self-sustaining point will also greatly reduce this sorts of unwanted collisions and ther resulting radioactive byproducts.
Actually, Bussard was trying to use a Boron-11 fuel matrix that doesn't release neutrons in the same fashion as Deuterium fusion does. One of the reasons for this is precisely to help cut down on the neutron flux coming from the reactor.
His design goal was to use it as a direct drop-in replacement for boilers at coal-fired power plants, using similar sorts of shielding and precautions as would be already in place for such a facility. Water in the boiler itself would offer what extra protection would be needed, and radiation levels for released radioactive products would be lower than would be typical for a coal plant as well.
FYI, coal plants release far more radioactive waste per kWh generated than the worst and most inefficient nuclear power plants... with perhaps the singlar exception of Chernobyl. Even that I'm not 100% certain of.
This said, you are correct that the fusion rate in a Polywell is something of a much greater concern if you actually got one going, and would be leathal if it used traditional fusion fuel targets.
up to 500 micro-sieverts each hour
1 sievert (SV) = 100 rem So, we're talking about tens of milli-rems per hour. Great. You get cosmic radiation at a higher rate than that by flying on an airliner.
a no-dive zone was self imposed by Greenpeace's radio-protection officer
Yeah, like that means anything. Just more food for the FUD.
French Environment and Health Ministries commissioned an official epidemiological study of leukaemia around La Hague
Over ten years ago, studying a quickly-appearing illness. No results? No surprise.
Measurements taken by OPRI near the beaches detected no radioactivity above the natural radioactivity level
See? Greenpeace has no substance to their argument.
I'll admit that no plant should circumvent the guidelines, nor should they then hide that fact. But the facts are that the safety guidelines are many times more strict for nuclear power than for any other type of power. I don't mean precautionary measures, I mean environmental impact. Coal plants release many times more radiation, spreading it over large areas via their smokestacks, than nuclear plants could even dream of. Even wind power has a greater carbon impact than nuclear power -- from start to finish, including building infrastructure, mining uranium, and handling the waste. Again, La Hague seems to be acting in an unethical manner, but I just can't stand all the ignorance about nuclear power.