Year
1997
Abstract
Large-volume, CdZnTe, gamma-ray spectrometers (up to 2 cm3) that operate at room temperature with excellent resolution and peak shape have been demonstrated. CdZnTe has the potential to replace sodium iodide and germanium for gamma-ray spectroscopy in a number of safeguards applications, particularly portable measurements of nuclear material. At Los Alamos, we are investigating the application of this new detector technology to nuclear material safeguards and nonproliferation. In this paper, we examine several methods to improve the performance of coplanar-grid detectors, including analog pulse-processing, surface passivation, and cooling. To aid in the design and characterization of these detectors and in the development of spectrum analysis methods, we have developed a general, physics-based model to predict the response of roomtemperature semiconductor detectors. We are using the model to optimize electrode design and substrate geometry. A comparison between the performance of coplanar-grid designs on cylindrical and rectangular substrates is presented.