Re: Estimation of the activity of uranyl nitrate

[Michael McNaughton <mcnaught@lanl.gov>]

At 11:28 AM 2/26/01 -0600, you wrote:
>One of our pathology laboratories had held some few tens of grams of uranyl
>nitrate

John, now that it's lunch time, I am going to expand on my earlier, brief
response.

U-238 decays to Th-234, Pa-234m, and U-234. Because of its long half life,
very little of the U-234 has time to decay, so you don't see significant
decays of U-234; for the same reason, you don't have significant amounts of
decay products beyond U-234. 

There are about 10 times as many betas emitted as gammas. Furthermore, your
contamination detector is much more efficient for betas than for gammas.
Therefore, you detect mostly betas. Most of these are from Pa-234m, and
have a maximum energy of 2.29 MeV. The exact number you detect will depend
on the thickness of the vial.

mike
Mike McNaughton
Los Alamos National Lab.
email: mcnaught@LANL.gov or mcnaughton@LANL.gov
phone: (505)667-6130
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