Re: Sr/Y-90

Now I'm intrigued, or maybe confused myself.

In answer to the statement below, a very old reference I have

(Scintillation Spectrometry, 2nd edition, R.L. Heath, 1964!) lists a

production mechanism as Zr-90(n,p)Y-90m. It could also be a direct product

from fission (i.e., not indirect through Sr). I do know that the existance

of the metastable state doesn't necessarily mean that Sr-90 decays by that

pathway to any significant degree. I'm still pretty sure that there are

NOT two easily detectable gammas emitted for each Sr-90 beta decay,

otherwise detecting and quantifying Sr-90 would be a much easier job than

it is for people who must do it routinely.

I don't have immediate access to the latest reference mentioned, but it

would be rather odd for an error of that magnitude to have been printed and

repeated in all the references I do have (Rad Health handbook, Kocher's

Radioactive Decay Data Tables, etc.) which all say Sr-90 decays essentially

100% to Y-90, not Y-90m.

I'm surprised some real heavyweight expert has not jumped into the

discussion by now to put us all to shame.

V. King

Idaho Falls

...<<if Sr-90 does NOT decay to Y-90m, then where in the world does the

Y-90m

come from? Out of thin air?...

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