Comparison with NIST attenuation coefficients

[Norm Buchanan]

Hello Everyone,

I am a new user to egs and I have a question about a problem I am having.
I appologize if this is obvious. I am trying to duplicate the NIST total
attenuation coefficient values for photons in copper down to an energy say
10 keV. I do this by simply examining the number of "untouched" photons
coming out the back of a 1cm thick piece of copper. I get good agreement
obove 1 MeV but continuously worse results as I go lower in energy. I
thought perhaps I need to turn on some interaction that is by default
turned off, but nothing I try is working. Perhaps someone could suggest a
solution to help me understand my problem? Thank you in advance.

Norm Buchanan Phone: (780) 492-7901
www.phys.ualberta.ca/~buchanan/ FAX: (780) 492-3408
Centre for Subatomic Research Edmonton, Canada
University of Alberta T6G-2N5