Single neutron pixel detector based on Medipix-1 device

Abstract

Neutron transmission radiography (neutronography) is based on the application of the universal law of attenuation of radiation passing through matter. Thanks to different values of neutron and X-ray attenuation coefficients in matter, neutronography can produce contrast images of materials, which are roentgenographically indistinguishable (typically materials containing light element; like Hydrogen, e.g. plastics or biological samples). Reliable performance of neutron detecting device is essential for the acquisition of high quality neutronograms. Nowadays promising digital detector systems such as Medipix are available and make possible real time imaging with high sensitivity and broad dynamic range. A single neutron pixel detector based on a single X-ray photon pixel detector device Medipix-1 is presented. Thermal neutrons are converted in a /sup 6/LiF layer. Tritons and alpha particles are subsequently detected by a silicon pixel detector (64 /spl times/ 64 square pixels, 170 /spl mu/m /spl times/ 170 /spl mu/m each), which is connected to the Medipix-1 readout chip. Spatial and time resolution, detection efficiency and other detector properties are determined and compared with Monte-Carlo simulations. Several images of real objects demonstrating the capabilities of the technique will be presented.