Characteristics of an Integrated Germanium Detector Based

An integrated gamma ray spectrometer, incorporating a germanium detector with integral mechanical cooling, digital signal processing electronics, MCA, and communications has been developed. It is intended as a modular subsystem for wide application, including use in stationary or mobile systems for the detection of radioactive materials. The requirements for this application are good low and medium energy detection efficiency and excellent spectral peak resolution. In a situation where either the spectrometer or the material is moving, the Field of View (FOV) determines the time the material contributes to the spectrum. The absolute efficiency and background determine the minimum detectable or identifiable quantity for the material in the FOV. To characterize the expected performance, the absolute efficiency was measured for a single unit for energies from 59 keV to 1.8 MeV. The horizontal FOV was measured for several source positions in the pedestrian portal configuration. The vertical FOV, important to determine the detector spacing, was also measured. The background was measured in a typical pedestrian portal situation. The measurements presented show this unit can be applied to a wide variety of monitoring situations.