A CdZnTe coplanar-grid detector array for environmental remediation

A portable, room-temperature gamma-ray spectrometer is being developed for use in environmental remediation activities. Good energy resolution and high-detection efficiency are achieved using an array of CdZnTe coplanar-grid detectors. The array is of modular design, which allows for the stacking of an arbitrary number of detectors, as well as for the easy exchange of detectors for repairs if needed. Each element of the array consists of a 1 cm3 detector and low-power readout electronics. Each detector module including the electronics fits within a small footprint of 1.4 cm×1.4 cm, thus allowing the detectors to be closely packed. A compliant detector-mounting scheme has been developed to protect the detectors from mechanical shock and vibration expected in field use. A prototype 2×2 array has been constructed and evaluated. The design of the detector, detector module and test results from the array are presented.