Determination of 4.438 MeV γ-ray to neutron emission ratio from a 241Am–9Be neutron source

Gamma-ray (γ-ray) spectra of a 1.49×1011 Bq 241Am–9Be source and background were measured using a 2 in×2 in, NaI(Tl) detector. Backgrounds due to the neutron interactions and energy deposition were calculated with MCNP4C. By subtracting the backgrounds from the experimental spectra, the Sγ is obtained and the R=Sγ/Sn was estimated. The final result of R=Sγ/Sn=0.596 is in agreement with result reported in literature.