Experimental studies and simulations of spallation neutron production on a thick lead target

An intensive beam of 660 MeV protons from the Dubna Phasotron was directed towards a thick, lead target (not surrounded by shielding or neutron reflector) for 10 minutes. Detectors and iodine samples were placed around the target. The neutron field and the transmutation of 129I were studied by the Activation Analysis Method. MCNPX v.2.4.0 was used to simulate the experimental setup. The results of the simulations were compared to the experimental values, and the influence of the setup parts to the neutron field was explored.