Multielement CdTe stack detectors for gamma-ray spectroscopy

This paper describes the development of a field portable gamma-ray spectroscopy system based on multielement CdTe detectors. A stack of multiple planar detector elements is used, with each individual element thin enough for good charge transport but with the outputs summed so that the full volume is used. The detector elements are CdTe diodes mounted on a thermoelectric cooler, providing low noise and good charge transport with relatively simple electronics. It is anticipated that the detector will have a resolution of < 1% FWHM at 662 keV with a volume of at least 0.5 cm³ and that the approach will be suitable for production. To optimize the detector configuration, simulation software was developed and test devices fabricated. This paper will present simulation results and experimental data obtained using multielement detectors.