Studies on fast neutron imaging with a pixelated stilbene scintillator detector

For simultaneous imaging with fast neutrons and gammas we have developed a 16-pixel detector that uses the organic scintillator stilbene as active material. Sixteen stilbene cuboids of size 5×5×25mm3 are arranged in a 4 × 4 grid and read out by silicon photomultipliers. The usage of stilbene allows to distinguish neutron and gamma signals via pulse shape discrimination techniques. In this paper, attenuation measurements and first tomographies of objects containing aluminum and PMMA are presented. Fast neutrons and gammas are delivered by an Americium–Beryllium source. The performance of the tomographic reconstructions with neutrons and gammas is evaluated. It is shown that the combination of the two images can improve the material distinction in the reconstructed object.