The use of pulse processing techniques to improve the performance of Cd1-xZnxTe gamma-ray spectrometers

Cd_1-xZn_xTe (CZT) has recently shown great promise for use as a room temperature gamma-ray detector material. The availability of large volume (>1 cm³) high resistivity CZT crystals has allowed the demonstration of detectors much larger than can be built with the similar material CdTe. However, CZT-like many other room-temperature materials-suffers from the poor transport properties of holes. The poor hole drift properties of CZT cause the characteristic “hole tailing” in gamma-ray pulse height spectra. We have applied pulse processing methods to reduce the hole tailing effects and improve the energy resolution of CZT detectors. We have used two signal processing methods to reduce hole tailing in CZT detectors: digital rise-time compensation and dual time-constant sampling. We discuss the implementation of these techniques, demonstrate results obtained in the laboratory, and compare the performance obtained with other detector systems