Performance evaluation of large area three-dimensional CdZnTe drift strip detectors

What do medical imaging and astronomy have in common? Whether it is detecting tumors or observing colliding neutron stars, both fields can benefit from the same sensor technology. When observing radiation in the MeV band (0.1 to 100 MeV) from celestial sources, one faces challenges such as low flux, limited interaction probability, three energy loss processes, and a high background radiation rate. Present MeV band observatories suffer from poor sensitivity, and new state-of-the-art detector technology will be a key contributor to improve the sensitivity of future observatories. The detector group at DTU Space at the Technical University of Denmark (DTU) has developed a three-dimensional (3D) CdZnTe drift strip detector technology to meet the demands of future high-energy detectors. This advancement also shows potential application for emerging low-dose molecular breast imaging systems for breast cancer diagnosis. We present the results of the large area 3D CdZnTe drift strip detectors (4×4×0.5 cm3) developed in a collaboration between DTU Space and Kromek. We find the spatial resolution of these modules to be <0.6 mm in the x- and z-axes, and we measure the spectral resolutions to be <7% full width at half maximum (FWHM) at 122 keV, <1.4% FWHM at 661.6 keV, and 1% FWHM above 1460 keV.