The Neutron Detectors group at the Physics Institute III B, RWTH Aachen University, develops pixelated detectors for fast neutron imaging applications with compact neutron sources, e.g. Americium-Beryllium (AmBe) or neutron generators. The detectors use specialized scintillators such as stilbene that enable to distinguish neutron and gamma induced signals via Pulse Shape Discrimination, coupled to SiPMs. Therefore, these detectors allow for simultaneous investigation of objects with fast neutrons and gammas.
After the successful development and test of a single-pixel prototype, we have currently a 16-pixel detector prototype available. The prototype consists of 16 stilbene cuboids of size 5x5x25 mm³ arranged in a 4x4 grid, coupled to a 4x4 SiPM array. In the future, it is planned to construct larger detector arrays with custom-made readout electronics developed together with the ZEA-2, FZ Jülich.
In this presentation, detector characterization measurements as well as radiographic and tomographic test measurements, using an AmBe neutron source, a D-D neutron generator and a Cs-137 gamma source, will be shown. Also, results from a detailed Geant4 simulation that helps us better understand the interactions in detector, object of interest and surroundings and study different setups, will be presented.