CZT semiconductor radiation sensor for high energy gamma rays

Cadmium zinc telluride (CZT) radiation detectors are usable at room tempera ture because of sufficient band gap energy (2 eV). Very pure crystals have become available thanks to recent improvements in the crystal growth method . However, the sensitivity is low for high energy gamma rays over 1 MeV. In this study, in order to develop a new radiation sensor which consisted of stacked CZT crystals to make it sensitive to high energy gamma rays over 1 MeV, the sensitivity was calculated with the Monte Carlo simulation code EG S4 considering the charge carrier mobility. The basic performance of a CZT detector was investigated experimentally to examine the feasibility in nucl ear power plants. The sensitivity was nearly constant with increasing tempe rature of CZT crystals to 100 degrees C. The energy resolution and noise ch aracteristics were confirmed to be fully satisfactory as those for radiatio n sensors.