Comparison of neutron/gamma dose estimates: ion-chamber measurements vs. Monte Carlo calculations

Ion-chamber measurements in a water phantom irradiated by neutrons from the Gas Target Neutron Source have been completed at depths of 3.5, 7.5, 10, 15 and 20 cm. It is now possible to construct a three-dimensional dose profile for both neutron- and gamma-absorbed doses. A novel way of correcting for the displacement of water by the ion chambers and GM counter was utilized. Comparison of these results with previous Monte Carlo calculations indicates problems with neutrons scattered within the irradiation room.