Re: 90-Y counting in Beta/Gamma Counters

[LIPTONW@dteenergy.com]

I would guess that you're seeing bremsstrahlung from the high energy beta's 
(2.28 MeV max) from the Y-90.  The serum probably has a higher atomic
number, 
resulting in more bremsstrahlung production.   
 
The opinions expressed are strictly mine. 
It's not about dose, it's about trust. 
 
Bill Lipton 
liptonw@dteenergy.com 
 
You wrote: 
 
Hello All, 
    I am looking for some help regarding counting samples of 90-Y in a = 
beta counter and gamma Counter. We counted 3 samples of 90-Y of similar = 
activity in a beta counter and gamma counter in similar geoemtry/vials. = 
One sample contained 90-Y in saline, the other 2 contained 90-Y in serum = 
(at different concentrations). The numbers looked reasonable from the = 
beta counter. However, when the samples were counted in a gamma counter, = 
the serum sample yielded higher counts than the saline sample. the = 
experiment was repeated several times with similar results. Does anyone = 
have an expalantion as to why the serum samples would yield hugher = 
counts in the gamma counter as opposed to the saline sample? Any help is = 
greatly appreciated. Thanks in advance. 
Truly yours, 
Bob Dunn 
rso.gscancer@worldnet.att.net 

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