Neutron imaging with Medipix-2 chip and a coated sensor

Neutron transmission radiography can serve as a complementary diagnostic method to X-ray radiography. The hybrid pixel detector device Medipix-2 with a silicon sensor chip (256×256 square pixels of 55 μm size) can be adapted for neutron detection by deposition of a converter layer onto its surface. Thermal neutrons are converted in the layer into secondary radiation which is detected by the pixel detector. Spatial resolution, detection efficiency and other properties were simulated for different converter materials and verified experimentally. The performance of the imager was compared with several types of neutron imaging systems. The results demonstrate superior properties of the Medipix-2 based neutron imager namely in terms of spatial resolution, linearity and dynamic range. The system is very promising in applications such as neutron micro-tomography.