An Optimized D-T neutron Generator Shielding for Prompt Gamma Ray Neutron Activation Analysis of Light Elements

We present an MCNP analysis of optimal gamma-detector shielding materials and their thicknesses for 14 MeV D-T neutron generator for detection of light elements by prompt gamma ray neutron activation analysis. Tungsten seems to be the best choice for the primary neutron-beam shielding of a minimum thickness, but copper and iron represent an economically acceptable alternative. To shield the gamma detector against gamma rays produced from neutron interactions in the laboratory walls another shielding made from lead is necessary.