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Teen Builds Nuclear Bomb Detector
DaneM writes "An enterprising teenage boy named Taylor Wilson, 17, has created a homemade, hand-held nuclear bomb detector. It utilizes a small fusion reactor that he made when he was 14, and detects nuclear materials by shooting neutrons at closed containers and exciting any nuclear materials inside — which, in turn, causes more radiation to be produced, and is detected by the device. This may provide a simpler, more effective alternative to searching containers visually, one-at-a-time. No information is given about how safe such a practice is. Taylor also has some choice things to say about how science is, in fact, very cool."
I assure you, the people at Nature already know about the Farnsworthâ"Hirsch fusor.
I assure you, Farnsworthâ"Hirsch fusors exist, fit the dictionary definition of "reactor", are well within the capabilities of teenagers to build, and do emit neutrons.
And I also assure you that when you bombard fissile material with neutrons, its rate of activity goes up, and that increase in activity makes it easier to detect the fissile material with radiation detectors.
The operating principle is given in the second sentence of the goddamn summary: Fire neutrons in, watch radiation from activation products. As others have pointed out, otherwise known as Neutron Activation Spectroscopy.
Taylor attends The Davidson Academy. A secondary school for profoundly gifted youth on the University of Nevada, Reno campus. My wife is his chemistry teacher. The Academy and University have a mutually advantageous relationship that allows motivated students like Taylor access to advanced resources not customarily accessible to the typical high school student.
You might have misunderstood me. I didn't mean passive neutron radiation detectors, I meant something like this kid built: an active scanner, that's capable of analyzing the contents of the crate without opening it (that's what the article implies). I go a bit further, the real news is not making this, it's how he crunches the data to get the contents from the reflected neutron flux/induced radiation pattern, whichever he uses.
A passive neutron scanner is all dandy and fine, but can be defeated with shielding. This active scanner, developed far enough for sensitivity/crunching capacity, could detect the presence of shielding (though not its contents), which itself would be grounds for suspicion. The passive scanner would just indicate a zero or very low flux, which might be mistaken for background radiation or other, similarly innocuous, explanation.
Chill the f*ck out, and respond civilly, I did not insult you.
Hyperbole: I use it liberally!
I would guess that it is a Farnsworth-Hirsch fusor which is a commercially produced device to produce free neutrons. In terms of application I'd be a little concerned what this device is used to probe. Neutrons are readily absorbed by many nuclei and can produce radioactive isotopes. So scanning an object will result in making it radioactive. While I would hope the number of neutrons required would be small, and so the activation minimal, this is still probably a concern for foodstuffs since radioactive material is a lot more dangerous inside the body than outside. Same applies for clothing too probably.
The other issue is that since a nuclear device is a sub-critical mass of fissile material bombarding it with enough neutrons may actually make it supercritical while it is in the beam if the beam balances the neutrons lost. This would let you "detect" the bomb put perhaps not in a very constructive way...although again I would guess that the number of neutrons used for scanning would probably be too small to do this.