EXPLORATORY STUDIES ON NEUTRON RADIOGRAPHY WITH A SMALL NEUTRON SOURCE USING A NUCLEAR SCINTILLATION IMAGING TECHNIQUE

Neutron radiography based on mobile neutron sources need optimum utili zation of available neutron fluxes which are usually lower compared to those available from reactors. For optimum utilization of such low fl ux devices, a sensitive neutron imaging technique is required. Such a neutron imaging system based:on a (LiF)-F-6-ZnS scintillator screen ha s been developed using a pair of image intensifier tubes and a charge coupled device. This detector system has been employed to study the fe asibility of neutron radiography using low neutron fluences. The main feature of this imaging system is its ability to detect individual neu tron scintillation events with a higher degree of spatial resolution. In order to test the efficiency of this imaging system, a small scale moderator-collimator assembly was designed using a Pu-Be neutron sourc e of strength approximate to 2 x 10(7) n/s. Details of this imaging sy stem and results of some exploratory experiments for low fluence neutr on imaging are presented in this paper.