Natural U check source

[Peter Fundarek <P.FUNDAREK@utoronto.ca>]

Does anyone know of a good source (no pun intended) for a natural U check source 
to be used for calibrating instruments for detecting alpha particles on wipes?  
We have an Eberline SPA-1A and need a calibration source before doing some 
swipe tests for loose alpha contamination.  The source should be no larger than 
25 mm diameter by 1.5 mm in thickness.  Active area should be 16 mm in diameter 
or larger.  We want to use natural U since that is what we will be looking for 
in the actual situation.

Any assistance would be appreciated.  Haven't had any luck with Eberline or 
their supplier.

*************************************
Regards,
Peter J. Fundarek
University of Toronto
CANADA
email:  p.fundarek@utoronto.ca
phone:  (416) 978-2374
fax:  (416) 971-1384
*************************************