HgI2 As X-Ray Imager: Modulation Transfer Function Approach

The Modulation Transfer Function (MTF) of Polycrystalline Mercuric Iodide based flat panel x-ray detectors is simulated as a function of spatial frequency. A simplified mathematical model for MTF is applied on four different published prototypes of Polycrystalline Mercuric Iodide. Our aim was to fit curve from MTF model with the curve from experimental data. The result of simulation from theoretical model shows a good agreement with the measured data. We have found that deep-trapping,K-fluorescence,dependence of dark current on temperature and exposure time are the most possible reasons for the slight mismatches between two curves. In addition, the mobility-lifetime product for best curve fitting was also examined for each prototype.