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Using Radio Waves to Detect Explosives
deadmantyping writes "A Japanese research group published a paper describing a method to detect explosives in luggage using radio waves. The method relies upon nitrogen nuclear quadrapole resonance (NQR) and is able to distinguish between different white powders, whereas currently used x-ray technology is not."
SO will it detect Cocaine, herion, anthrax, flour? What if I add some gun powder to my Coke?
Cool! When can the new technology allow us to walk through the security with dignity again?
In Soviet Washington the swamp drains you.
What if a crazy man just straps some bombs on, walks up to the security checkpoint and sets himself off? There's no security check to protect the first security check. Better add one.
...and recurse.
Demented But Determined.
what happens if the crazy terrorist (er.. freedom fighter) decides to make a trigger which works off of radio waves (or whatever particular radio wave) said name future machine may use?
Given the availability of both clocks and button, it seems unlikely to come up often.
I remember hearing warnings about having transmitters near my explosives, something about accidentally triggering professional grade gear;
Exposing high strength radio waves to homemade devices might result in detection by detonation.......
Unix, an obscure operating system developed by bored researchers in an attempt to get a better game playing experience.
It appears to be a slightly more advanced system than SNUPA http://www.abc.net.au/quantum/stories/s112369.htm developed at the University of Melbourne, which I believe didn't differentiate between different explosive compounds.
A game has objectives and is competitive, anything else is just play
A little oxidized iron, a little aluminum powder, a tiny amount of binder, press, and you have the makings of some attractive plaques or statuary. A bit of magnesium wire and a battery and you have everything you need to start a large mass of aluminum burning. Spectacularly.
Good thing none of the Bad Guys have the brains of a flatworm. Or at least, that's what our whole air travel security strategy assumes.
Lacking <sarcasm> tags,
so this is called nuclear magnetic resonance spectroscopy.
Doing it with a gradient field and a special pulse sequence lets you get the
vibrational amplitudes of your protons based on their position within the gradient field.
That's what gets you MRI images. Before MRI images, nuclear spectroscopy was used to
resonate the "nucleus" of atoms/molecules/conglomerations of molecules at varying radio-frequencies to see if there was any resulting resonance and output RF (radiofrequency) signal.
Protons resonate at 2.4 GHz approximately (which is the frequency used in microwaves to resonate the H's in the {H}_2{0} molecules in your food and heat it.
...using explosions to detect radio waves.
https://www.eff.org/https-everywhere
And not all nitrogen containing explosives are white powders. :)
Computational Chemistry products and services.
Nothing (plausible) can detect everything that might be explosive, Actually even what an explosive is can be kind of ambiguous; still I've read that terrorists are more likely to use peroxide based explosives rather than nitrate based explosives. I see the nitrogen nuclear quadrupole resonance as have more potential in finding IED in the road beds in places like Iraq.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Ron Sager and Alan Sheldon of Quantum Design used a SQUID in 1992 for detecting the NQR response of ammonium perchlorate (~38kHz), so the Japanese group isn't even the first to use SQUIDs for NQR...
A Shadeless room is a brighter room.
NQR detectors tend to be relatively slow to examine an area, and a very important factor in Iraq is a fast rate of advance. NQR might work for airports, but other systems -- like metal detectors and backscatter radars -- work better when you need to go fast. The military mostly looks at NQR as a confirmation technology for other detectors and not as the first line of explosive threat detection. (Google "NQR rate of advance" for various papers and studies on the issue.)
I have a much simpler method: if america doesn't like country X it follows that X has explosives...
The MAFIAA is a bunch of mindless jerks who will be the first up against the wall when the revolution comes
guarding the planes. To hell with the people on the ground. Why do you think that security is set up in the MIDDLE of the airport? What if a bad guy wanted to kill people in the terminal? Wide open. That is why in Israel, the security is at the front gate., not the flight gate.
Luggage probably does not burn very well. The suitcase and its contents are mostly fabric / leather / plastic of some type. ( think about what you packed last time... ) Most clothing has passed some kind of won't-sustain-combustion test, and that in the presence of lots of oxygen at or near sea level. Leather won't sustain a fire on its own. Plastics, who knows? But few are highly exothermic.
And add to that the fact that there is not a whole lot of air available in the luggage container - it's mostly luggage. Even if there is enough fuel to sustain a low-temp fire, it soon suffocates itself. The only jet that has crashed in the last few decades due to a cargo fire was because there was an oxygen tank in the luggage.
Also, according to federal law, all luggage compartments on commercial airliners are required to have fire-resistant walls.
Snicker....
As was pointed out by 'Entrope', NQR is probably not the best choice for detecting roadside IED's - there are other methods better suited for rapid scanning. What NQR would be good for is confirming whether or not a non-conducting anomaly picked up ground penetrating radar contains explosives.
You are correct in stating that NQR would be ineffective against peroxide explosives. The explosives that NQR is especially effective at detecting are also the ones with essentially zero vapor pressure that give problems for trace detectors.
A Shadeless room is a brighter room.