Multiple scattering Compton camera with neutron activation for material inspection

We designed a multiple scattering Compton camera (MSCC) based on a lanthanum bromide (LaBr3:Ce) scintillator to detect neutron-activated prompt gamma-rays for material inspection. The system parameters such as detector thickness and inter-detector distances were optimized on the basis of figure of merit (FOM). The FOM was maximized when the inter-detector distance and detector thickness were 18 cm and 1.5 cm, respectively. Under the optimized conditions, energy spectra and spatial images were obtained to identify various substances, and the results matched well with theoretical data. The probability of multiple Compton scattering was higher than that of conventional Compton scattering at high energies (~MeV), which proved the effectiveness of MSCC to detect prompt gamma-rays. Simulations with realistic conditions showed the feasibility of using the MSCC investigate of materials in field applications.