Re: error propagation for % enrichment

[FASeiler@aol.com]

Hi All and a belated Happy New Year to all RADSAFERS,

The error propagation is indeed not straightforward.  Apart from the mess 
with mass% etc., there is a restrictive condition in the sum of all 
percentages being 100.
This can be approached by first using this condition to eliminate one of the 
percentages, and then the expression can be treated as a function of 
independent variables in the usual manner. By the way, Duane, your letter 
offers an alternative to the explicit error propagation formulae in form of a 
Taylor series, but it also needs to operate not on the original formula but 
on the one in which one percentage has been eliminated.  I don't know the 
expression  for the result you are seeking, but it is probably simple enough 
so that you can do either algebraic propagation or a Monte Carlo simulation.  
The nice thing about the algebraic form is that you can see what is 
contributing how much. If you should need refs. for the Taylor series, please 
let me know.

Best regards,
Fritz

**************************************

P.S. Please do not use this AOL-address, I hardly ever use it for new e-mail, 
I use it      as my backup file!  Sometimes, I have to go through AOL to send 
e-mail, but I     rarely check it.

***************************************
Fritz A. Seiler
Sigma Five Asssociates
P.O. Box 1709
Los Lunas, NM 87031-1709, USA
tel.  505-866-5193
fax. 505-866-5197
e-mail: faseiler@nmia.com

***************************************
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html