Prompt gamma activation analysis - neutron imaging instrument on the China Mianyang research reactor

To meet the application demand for simultaneous structure inspection and elemental analysis, research on neutron imaging-driven prompt gamma activation analysis instrument is of great significance. Relying on the China Mianyang Research Reactor, the China Academy of Engineering Physics proposed the physical design of the PGAA -NT apparatus, carried out Monte Carlo simulations, signal commissioning and experimental tests, and successfully established an experimental facility that couples PGAA with neutron imaging. In terms of characterisation, the beam parameters, background features, Compton-suppression performance, wide-energy-range detection efficiency, and imaging spatial resolution of the instrument were accurately measured. The instrument exhibits the low background (full spectrum <200 cps at 1.5 × 108 n·cm−2s−1), high energy resolution (2 keV at 1.332 MeV), high imaging spatial resolution ( <10 µm) and millimetre-scale activated analysis volume. It provides a neutron measurement platform that combines three-dimensional structure detection with position-sensitive elemental analysis. This instrument fills the gap in China’s PGAA-NT field, with performance reaching the international advanced level.