Performance of 1 cm × 1 cm × 1 cm pixelated CdZnTe gamma detectors

We present results for 1 cm × 1 cm × 1 cm pixelated CdZnTe gamma detectors with coarse segmentation. Large pixelated CdZnTe detectors are important for spectroscopic and imaging applications requiring sensitivity for higher gamma energies. For each gamma interaction, we process signals from all pixels and from the common electrode, and employ correction techniques developed at Soreq NRC for improving the energy resolution and the photopeak efficiency. For irradiation with an uncollimated ¹³³Ba source, we obtain a combined pad spectrum with energy resolution of ∼5% full width half maximum (FWHM) for the 81-keV peak and ∼1.5% FWHM for the 356-keV peak. We show spectra for two selected detectors, one with (μτ)_e = 7.3 × 10^-3 cm²/v, and one with (μτ)_e = 2.9 × 10^-3 cm²/v. We discuss the importance of detector material with high electron (μτ)_e for thick pixelated detectors. The experimental results are compared to theoretical simulations. These simulations contribute to our understanding of large pixelated detectors and provide a tool for designing new pixelated detector configurations.