Performance of a pixel detector suited for slow neutrons

Semiconductor pixel radiation detector systems have recently made significant progress achieving excellent spatial resolution, high sensitivity, wide dynamic range and low noise. The hybrid silicon pixel device of Medipix type developed at CERN was originally designed for position sensitive single X-ray photon detection. We have adapted this device to a position sensitive detector of slow neutrons by covering the detector surface with a 6LiF neutron converter. Neutrons are converted to tritons and alpha particles which are subsequently detected by the silicon pixel detector. The basic parameters of such a pixel neutron sensitive device were investigated using thermal neutron beams. Tests for neutron imaging applications and comparison with currently used devices for neutron radiography (CCD camera with scintillator, imaging plates) were performed. The aim of this article is to demonstrate the exceptional good spatial resolution for neutrons (up to 8.5 lp/mm in the case of Medipix-2 option), reasonable neutron detection efficiency with very low sensitivity to background gamma radiation, low noise, perfect linearity and wide dynamic range. Results and future prospects are presented in this article.