TY  - RPRT
TI  - Calculations of fluence rates of unscattered x- and gamma-ray photons emerging from model spheres of special nuclear material 
AU  - Seltzer, Stephen
PY  - 2009
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - NIST IR 7557
DO  - 10.6028/NIST.IR.7557
ER  -