Pixellized CdTe MeV-camera for flash radiography

Abstract We are developing a new, well spatially resolved (millimetric resolution), high sensitivity and high quantum detectivity, large size pixellized CdTe(Zn) camera for high energy (> 1 MeV) flash radiography applications. Energy deposition Monte Carlo simulations (MCNP4, CYLTRAN) predict the Line Spread Function (LSF) and the Modulation Transfer Function induced by this energy spread in pixellized detectors. They give also the quantum efficiency, which provides a theoretical limit for the sensitivity when we assume a low noise charge read-out. We present also the first experimental results which confirm the interest of a such detector for the MeV flash radiography: the measured sensitivity is better than 1 μGy (20 MeV - 35 ns - pulsed generator with 5 cm lead source filtration).