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Detecting DU at a distance via beta particle emission.   Message List  
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Detecting DU at a distance via beta particle emission.

 
DU (Depleted Uranium) is uranium with the majority of the U-235 removed, leaving behind U-238 and U-234.
I prefer to think of DU as refined U-238. The metal has many industrial and scientific uses, mainly because of its high density, being 1.7 times as dense as lead. A few using would be counterweights and radiation shielding. DU is used in projectiles because of its unique density, pyrophoricity and "self-sharpening" characteristics.
 
The only progeny present that can be detected at a distance would be Pa-234m, a beta emitter.
With a maximum energy of  2.28 MeV, the betas would travel approximately 20-25 feet in air, using the rule of thumb of 10-12 feet per MeV.
A sensor would have to be appreciably closer than the maximum distance to detect the beta particles.
 
Because of self-shielding, DU metal's surface beta rate is in ratio of the surface size, not the thickness or
volume of the sample. In other words a thin sheet would have the same beta surface emission rate as a thick sheet.
Indeed, DU Slabs are used in the lab to calibrate probes.
 
The best "calculations" are done in the lab with a DU slab and a detector! Using a 2 pound cylinder of DU metal and
a pancake probe, about 6 feet is as far as you can get and still obtain usable (statistically significant) readings. Any closer and the readings
ramp up quickly. With a 100 Cm^2 alpha-beta scintillator on a Thermo ELECTRA alpha-beta meter, the range is extended to about 10 to 12 feet.
 
Geo


Mon Jan 7, 2008 5:10 pm

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Detecting DU at a distance via beta particle emission. DU (Depleted Uranium) is uranium with the majority of the U-235 removed, leaving behind U-238 and U-234....
Geo>K0FF
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Jan 7, 2008
5:12 pm
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