Sub-Millimetre Linear Array Detectors Based on High-Flux CdZnTe Detectors

In the framework of the Avatar X project, we developed sub-millimetre CdZnTe linear arrays for high-flux spectroscopic X-ray imaging up to 150 keV. As widely demonstrated, CdZnTe (CZT) is one of the key materials for the development of room temperature X-ray and gamma ray detectors and great efforts have been made on both the device and the crystal growth technologies. Recently, new CZT materials with hole mobility-lifetime product enhancements have been fabricated for high-flux measurements (high-flux HF-CZT detectors). In this work, we will present the results of spectroscopic and imaging investigations on new HF-CZT detectors with linear pixel anodes, recently developed at IMEM-CNR Parma, Italy. CZT linear arrays with pixel pitches of 500 μm and inter-pixel gap of 25 μm were developed. The X-ray response of the detectors was measured taking into account the mitigation of the effects of incomplete charge collection, pile-up, charge sharing and high flux radiation induced polarization phenomena. Preliminary tests showed good room temperature energy resolution FWHM of 3 % (1.8 keV) at 59.5 keV at high bias voltage operation (>5000 V/cm). We foresee sub-keV energy resolution using dedicated front-end ASICs.