Performance of Larger-Volume 40 × 40 × 10- and 40 × 40 × 15-mm³ CdZnTe Detectors

The dimension of 20 × 20 × 15 mm
³
has been selected as standard pixelated CdZnTe detector size for many years. Energy resolution of 0.31% full-width at half-maximum (FWHM) at 662 keV for single-pixel events was achieved in one of the best direct-attachment detectors based on VAD_UM v2.2 application-specific integrated circuit (ASIC). Energy resolution under 0.40% was obtained for most of the direct-attachment detectors. The consistent good performance drives the desire to build larger crystals. The increment of size is beneficial in many aspects, such as higher detection efficiency, better imaging performance, better spectroscopic resolution, and potentially lower cost. This article presents the performance of recently delivered 40 × 40 × 10 and 40 × 40 × 15-mm
³
CdZnTe crystals manufactured by Redlen Technology and Kromek Group. The result will be analyzed and the feasibility of mass producing 40 × 40-mm
²
crystals will be discussed.