Thermal neutron imaging through XRQA2 GAFCHROMIC films coupled with a cadmium radiator

A simple and inexpensive method to perform passive thermal neutron imaging on large areas was developed on the basis of XRQA2 GAFCHROMIC films, commonly employed for quality assurance in radiology. To enhance their thermal neutron response, the sensitive face of film was coupled with a 1 mm thick cadmium radiator, forming a sandwich. By exchanging the order of Cd filter and sensitive film with respect to the incident neutron beam direction, two different configurations (beam-Cd-film and beam-film-Cd) were identified. These configurations were tested at thermal neutrons fluence values in the range 109-1010 cm−2, using the ex-core radial thermal neutron column of the ENEA Casaccia - TRIGA reactor. The results are presented in this work.