Figure 3: Reactor geometry, data and image simulations.

(a) Photograph of the TRIGA reactor core taken from the top of the reactor pool. The fuel elements are visible in the centre of the photograph. The probe location would be to the lower left of the photograph. (b) Example of experimental data collected by the probe at 40 kW reactor power. The neutron and gamma-ray data were collected simultaneously. (c) Colour schematic of the view from the probe at the image origin. This image was used as an underlay to the radiation images as a reference to the surrounding structure including concrete (grey), light water (blue), graphite (black) and enriched-uranium fuel rods (purple). Distortion of these features is due to the preservation of the spherical image output. (d) Simulated images of the neutron and gamma-ray fields emitted by the core produced using the pin-hole camera function in MCNP5. The schematic shown in c has been used as an underlay for reference to the surrounding structure. These data have been self-normalized in each case.