Active and non destructive quantification of highly shielded fissile materials using photofission

Sets of photo fission experiments have been conducted at the 10 MeV LINAC of EBC, Kharghar. Natural Uranium and Thoria samples in pure and mixed form were used in experiments. The aim of the experiments is to evolve and establish the active interrogation technique. Delayed neutron and delayed gamma decay data was acquired and analysed. By this method the relative proportions of mixed fissile material was detected with 20% error. The absolute efficiency of neutron detection system was theoretically estimated by modelling the system in FLUKA and experimentally measured using 252Cf source of known yield. Using nuclear data and FLUKA simulated results minimum detection efficiency of the system was estimated and compared the results with the experimentally observed values. In future it is proposed to conduct experiments using mock hull drum. Effect of shield will be studied by enclosing the fissile material in known density of shielding. The fundamental data evolved from the photo fission experiments will be employed in development of active interrogation system in actual applications