Gamma-ray and neutron radiography as part of a pulsed fast neutron analysis inspection system

A gamma-ray and neutron radiography system has been developed to provide us eful supplemental information for a Pulsed Fast Neutron Analysis (PFNA) car go inspection system. PFNA uses a collimated beam of pulsed neutrons to int errogate cargoes using (n, gamma x) reactions. The PFNA source produces bot h gamma rays as well as neutrons. The transmission of both species through the cargo is measured with an array of plastic scintillators. Since the neu tron and gamma-ray signals are easily separated by arrival time a separate image can be made for both species. The radiography measurement is taken si multaneously with the PFNA measurement turning PFNA into an emission and tr ansmission imaging system, thus enhancing the PFNA radiography system. (C) 1999 Elsevier Science B.V. All rights reserved.