Charge-Sharing Detection Method Using Semiconductor Detectors with Different Electron and Hole Mobilities

Abstract

The significance of X-ray spectral information is steadily growing. However, pile-up is becoming a pertinent problem at high dosage levels. Additionally, attempts to mitigate pile-up by reducing the surface area of the detector result in charge sharing, making accurate spectrum determination complicated. When materials such as cadmium telluride are employed as detectors, a significant disparity in the mobility of electrons and holes can lead to pulses in the opposite direction across multiple electrodes. We propose to identify charge-sharing events by detecting these opposing pulses. We found that eliminating events associated with negative pulses from the spectrum reduced the full width at half maximum of the peak from 15.9 to 14.4 keV. The proposed method improves the accuracy of spectral measurements under high flux to reduce the effect of charge sharing in single-point spectral measurements.