The_Davster - 23-5-2009 at 19:22
Some odd/interesting things found browsing youtube.
First is a farnsworth fusor which I do not doubt the authenticity of as I posted a story a while back about a high-school kid who built one.
http://www.youtube.com/watch?v=OSg2neElOTw&feature=relat...
Second is either a well done forgery(in the same vein as the explosive binary putty that went around a while ago) or is actually someone who used "The
radioactive Boyscout" as a how-to manual.
http://www.youtube.com/watch?v=i0TlECFbjvM
Third is supposedly a homemade reactor, but video and detail is poor. Not sure what was done here.
http://www.youtube.com/watch?v=-YLVw004lE0&feature=relat...
In any case I was amused for a while. The radioactive boyscout-esque one does concern me a bit...
Sauron - 23-5-2009 at 19:32
A fusor is a neutron generator IIRC but not I think a THERMAL neutron generator (fast neutrons) and again IIRC that makes a whole lot of difference.
Not my area of course.
The individual you refer to accumulated some alpha and beta emitters like radium, americium etc, contaminated his property and himself. Note however
that these are not fissile materials and thusm any purported reactor is not really a nuclear reaction in any sense that is generally ascribed to the
term.
You may argue that any appartus for conducting any type of reaction of a radionucleide is a "nuclear reactor" but to do so is to deprive the term of
any real meaning. I am not sure what rhe "boy scout" wanted to do or thought he was doing but I can safely say that he never got anywhere near
anything fissile, nowhere near criticality and nowhere near a fast neutron flux.
Tell me if I am full of shit.
Fusors employ D2 as fuel gas. A D+D fufion to He-3 generates a neutron of 2.5 MeV. In comparison a D+T fusion to He-4 generates a neutron of 14.1 MeV
but, is T2 (tritium) available to hobbyists> I think it requires a NRC license, nicht wahr? And I am still fuzzy about fast vs slow neytrons. I
read that fusors even the industrial sort as manufactured by NSD-Fusion are relatively low powered compared to solid target type neutron generators.
And amateur fusors, even further down the scale.
Pardon my ignorance but what can one do with the neutron flux in a hobbyist or industrial fusor? I can only think of a few things that are done in
reactor fluxes:
1. Transmute isotopes
2/ NAA neutron actication analysis
3. Cooking colored (semiprecious stones to enhance their value (but this makes them radioactive! Unethical and unsafe.)
1 is a potential nightmare if it is efficient, imagine amatuer Po production. Although they would likely kill themselves trying to do the
radiochemistry without a hot cell and waldos.
2 seems unlikely and 3 a bad idea.
Anything else?
[Edited on 24-5-2009 by Sauron]
Arrhenius - 24-5-2009 at 10:54
A Farnsworth-Hirsch fusor can't really be used to make new isotopes with the neutrons formed. My understanding is that the 'fast' neutrons it creates
can't really undergo nuclear reactions, and they're rather difficult to slow down. In a breeder reactor, various moderators are used for this
purpose. I believe GE builds this type of ion confinement fusor as a neutron source for imaging purposes. I don't think there's really any danger of
forming heavy radioisotopes with this type of fusor.
No way is tritium available to hobbyists. It's hellishly expensive, too. ]
I like the Trigga breader reactor videos! 
I can't get enough of the blue glow
(forget what it's called...) They have one at my uni, but I don't think they'll let me in to check it out, haha!
http://www.youtube.com/watch?v=uxVPVv3mSP8
bfesser - 24-5-2009 at 11:03
Čerenkov radiation
[Edited on 5/24/09 by bfesser]
Sauron - 24-5-2009 at 11:06
The blue glow is the interaction of air with Cherenkov radiation. A photonic byproduct of neutron flux.
Waffles - 25-5-2009 at 17:14
The latter two are hilarious, the last one especially. Shittiest bullshit artist in the history of bullshit artists:
•"dude im the son of the website united nuclear i know what im doing im not a idot k?"
•"no i dont it was not easy and still isnt who said it was easy? i am taking school right now and becoming a nuclear phisisist u know .... i have
autism and i suck at spelling and math but this kind of stuff such as mecanics and electricity i am gifted thankfully for"
The radioactive boyscout is actually the first cousin of one of my best friends- she says the family doesn't talk about him . In his case, he was just playing with too much radioactive crap and not containing
it properly in his efforts to make tiny (i.e. unusable) amounts of fissionable material. If he had gotten his shit together and built a home-made vent
hood and used reasonable containment, his passion could have become an incredible scholarship/fellowship rather than nationwide stigma and being
banned from every NRC site for life.
Sauron - 25-5-2009 at 19:21
There's a thread on David Hahn, why not go there>
This thread really is not about him.
Waffles - 26-5-2009 at 18:42
Hey man, you were the one that started talking about Hahn's apparatus. The point of my spiel was just that he WAS producing fissionable material, just
microscopic insignificant useless quantities.
There's a fair amount of interesting science/amateur chemistry/experiment stuff on Youtube, but the nuclear realm is a) mostly out of the home domain
of the standard Youtuber and b) not very conducive to video in the first place.
watson.fawkes - 26-5-2009 at 21:21
If you do want to try this at home, please see Techniques for nuclear and particle physics experiments, blurbed as "The book is based on a laboratory course in nuclear physics given to advanced
students." It's mostly about building detectors, not accelerators. Too bad about that death ray.
Sauron - 26-5-2009 at 22:56
Actually someone else brought up the felloe first. Read the thread.
It does not matter what Hahn wanted to do, the question is whether or not he could have made anything fissile. The fact is he did not, but had he
continued ? I tink the answer is NO and even if I was wrong, given the microscopic amounts, how would he have known?
I don't believe he had a gamma spectrometer handy. Or a neitron counter. Did he have a Geiger? Not that it would have told him mmuch.
Sauron - 27-5-2009 at 02:28
A somewhat fuller and more correct description of Cherenkov radiatopm is that it results from a charged particle, most usually an electron, travelling
through a medium such as air or water (in the broadest sense a dielectric but not a hard vacuum) at the speed of light. Since c > the apparent
speed of light in any given dielectric, the charged particle interacts many times with such dielectric.
This rffect can arise from conditions other than nuclear reactions such as in particle accelerators, and so is nt unique to a neutron flux, but it is
best known as the blue glow around a nuclear pile in operation.