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Muon Detector Could Thwart Nuclear Smugglers
Ben Sullivan writes "Cosmic rays that bombard Earth could help catch smugglers trying to bring nuclear weapons into the U.S. Los Alamos scientists say they've developed a detector that can see through lead or other heavy shielding in truck trailers or cargo containers to detect uranium, plutonium or other n-bomb materials. Their technique, muon radiography, is reportedly far more sensitive than x-rays, with none of the radiation hazards of x-ray or gamma-ray detectors now used at border crossings. From Science Blog."
than what these guys used.
This has been around for years - and the BBC reported it (in spite of it being old news) about 2 weeks ago.
Yeah, right. It will harmlessly pass through a bag of water like a human body, because water is such a lousy material at stopping radiation. That's why it's not used in nuclear reactors or cosmic ray detectors...
Even though its old news, maybe we should still keep our eye on the rise of cancer cases coming from the border areas now.
Life is too short for a 40 hour work week.
We should have seen it coming: tin foil hats are useless now...
... for the muon-detector-industry.
As for delivering delivering plutonium to the US, it seems using trucks isn't necessary at all, this seems much more practical.
"Money is a sign of poverty." - Iain Banks
The reason muons don't stop inside our bodies is because they (a) don't interact with atomic nuclei much and (b) are quite heavy.
So there are lots of different particles, like protons and neutrons or electrons, that you could use.
But protons bounce off atomic nuclei because they see something called the "strong force". This means they stop very quickly.
On the other hand, electrons don't see the strong force, which means they don't bounce off the atomic nuclei much at all. In fact, electrons spend all their time bouncing off the electrons that whizz round the outside of the atom.
The thing is though that electrons are much lighter than protons, so even though they only see the electrons in the atom, they still bounce right off them. The same goes with photons (e.g. light, x-rays).
This means that the electrons (and x-rays) get stopped very quickly too.
So both the electrons and protons get stopped very quickly, which means they deposit much more energy inside you = nasty radiation damage!
Muons, OTOH, will zip straight through as they don't see the atomic nuclei and are relatively heavy. This means they do less radiation damage, and you need fewer of them.
This is why you can get away with using atmospheric muons. It also explains why the atmospheric muons are there in the first place - all the other particles get stopped in the atmosphere.*
*Except some special particles called neutrinos - but let's not go there.
Here's a general particle physics wikipedia
. . . COOL STINKIN' BEANS.
It's amazing how many solutions there are to a given problem, like the problem of "seeing" through things.
Troy, inventor of such far-out yet functional devices like the bear encounter suit and fire paste, has finally flipped out, or maybe he's on to something.
The natural move from my point of view is to look at mu-N interactions, where a muon blows apart a nucleus in the target material, producing a shower of excited nuclear fragments and neutrons. Heavy materials such as plutonium will have a much different cascade signature than relatively light things like iron, so it may be possible to develop a quite specific finger-printing mechanism that would be hard to work around. With a muon detector on top to act as a trigger, and some combination of gamma and neutron detectors nearby, this is might be able to both speed up processing and improve accuracy dramatically.
Of course, terrorists could always fall back to the obvious plan B: smuggling the weapon in hidden in a bale of marijuana.
--Tom
Blasphemy is a human right. Blasphemophobia kills.
We can now see through lead? I feel my childhood collapsing around me... Science has just surpased Superman
Radiological Alarm!
... we've the story being forwarded of one of our coworkers stopped at the border coming into the US from Canada for the very thing you say isn't possible.
:)
Seeing as how he is a rather highly placed and takes a rather cynical view of the government leads me to believe his story about being yanked out of the Customs line and asked to undergo a radiological exam (geiger counter?).
Apparently he had been surrounded by officers since he'd gotten onto the bridge- don't ask me how because the next few cars were waved thru without an inspection (unverified).
I guess radioactive Iodine is easier to find