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Amateur Scientists Seek Fusion Reaction
Posted by
kdawson
on Mon Aug 18, 2008 09:37 PM
from the things-that-hopefully-do-not-go-boom dept.
from the things-that-hopefully-do-not-go-boom dept.
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."
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Firehose: Amateur Scientists Seek Fusion Reaction by Anonymous Coward
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Can a String Theorist? (Score:5, Funny)
Re:Can a String Theorist? (Score:5, Funny)
Because for every hobbyist who builds one of these hoping to get more power than they put in, there's someone in the background playing a violin...
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Re:Can a String Theorist? (Score:5, Insightful)
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Re:Can a String Theorist? (Score:5, Funny)
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Re:Can a String Theorist? (Score:5, Insightful)
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whatcouldpossiblygowrong (Score:5, Informative)
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 [wikipedia.org]
Re:whatcouldpossiblygowrong (Score:5, Informative)
Hahn was arrested [nwsource.com] last year for trying to steal smoke detectors from his apartment complex.
Judging from his mugshot [blogspot.com] he looks to be suffering the effects of radiation exposure.
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Amateur Scientists Seek Perpetual Motion Device (Score:5, Funny)
Good article.
Re:Amateur Scientists Seek Perpetual Motion Device (Score:5, Insightful)
*Arapidlyspinningblackholesayswhat?
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What could possibly go wrong? (Score:5, Interesting)
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.
Not power generators (Score:5, Insightful)
Despite the fact that this is a link to a non-technical publication's website, the Farnsworth Fusor [wikipedia.org] is a real fusion device and works basically how they describe it. What it is not, however, is anticipated to ever be a viable power source, and there are significant theoretical hurdles to prevent it from being viable relative to other approaches (and when you make any kind of fusion reactor seem plausible in comparison, you're probably not going anywhere). In my experience, most hobbyists are well aware of this and just enjoy the tinkering.
The primary functions of a fusor are 1) Generate neutrons 2) Look really cool 3) Kill you with extremely high voltages if you screw up.
Why didn't they mention the polywell? (Score:5, Interesting)
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 [talk-polywell.org] seems be the heir apparent for serious work in energy out of the fusor lineage.
Philo T. Farnsworth (Score:5, Interesting)
.
Best book [eht.com] on the early days of television that I have read. The above quote is from page 126.
WMD (Score:5, Funny)
In other news, a small subculture of amateur neoconservatives are building working homemade tanks, fighter jets and cruise missiles in order to seek out and destroy these Weapons Of Mass Destruction before its too late and a mushroom cloud appears in somebody's basement
As others have said ... (Score:5, Insightful)
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.
Fusion? BAH!!! (Score:5, Funny)
Re:Good grief... (Score:5, Informative)
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.
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Re:Good grief... (Score:5, Informative)
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.
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Re:Good grief... (Score:5, Informative)
Are these the same yahoos that post videos of "perpetual" motion machines on Youtube?
No. Wikipedia is your friend. [wikipedia.org]
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. [wikipedia.org]
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Real fusion (Score:5, Informative)
There was an article by Tom Ligon in Analog back in September 1998-- it's available on the web [fusor.net] if you're interested in more details.
This is pretty cool. I love amateur science.
With that said, note that there is a vast difference between merely demonstrating fusion, and producing usable power by fusion, roughly similar to the gap between the glow of your old radium watch dial, and a nuclear bomb. But if the hobbiests can learn to scale it up... now, that would be cool.
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Widely used in medicine and research (Score:5, Interesting)
Farnsworth fusors are widely used in medicine and research as an easily controlled and cheap source of neutrons.
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Re:Really? (Score:5, Interesting)
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).
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Re:Radioactive Trajedy (Score:5, Funny)
Sweet. They built a time machine.
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Re:Fusion? Pah! I've done them better! (Score:5, Funny)
Burger King and Taco Bell? You could do so much better. Let me help.
Step 1: Broccoli and Cheese soup. Crush some Oyster Crackers into it and DON'T forget the Tabasco sauce.
Step 2: Pork and Beans. 1 Can. Always a classic.
Step 3: ONE foot-long-cheap-ass Don Miguel burrito (the spicy red one). Can be purchased at any fine 7-11 anywhere. Only ONE. Trust me.
Step 4: 5 Hardboiled eggs with salt and pepper.
Step 5: Steamed Cabbage and 2 raw onions with plenty of butter.
Step 6: A single large bag of Funyuns.
Do all of this within 3 1/2 hours. Sit on the couch and wait about another 2-3 hours. Hold everything in till about 6 hours after you started.
You know that saying "killed the dog"? Well if you have pets, I don't recommend this.
DISCLAIMER: If you have any kind of a heart condition, or if anyone else in the house has one DO NOT ATTEMPT THIS.
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Re:by working you mean failing (Score:5, Insightful)
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....
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