Simulation studies and spectroscopic measurements of a position sensitive detector based on pixelated CdTe crystals

Abstract

Simulation studies and spectroscopic measurements are presented regarding the development of a pixel multilayer CdTe detector under development in the context of the COCAE project. The instrument will be used for the localization and identification of radioactive sources and radioactively contaminated spots. For the localization task the Compton effect is exploited. The detector response under different radiation fields as well as the overall efficiency of the detector has been evaluated. Spectroscopic measurements have been performed to evaluate the energy resolution of the detector. The efficiency of the event reconstruction has been studied in a wide range of initial photon energies by exploiting the detector's angular resolution measure distribution. Furthermore, the ability of the COCAE detector to localize radioactive sources has been investigated.

Simulated Performance of Algorithms for the Localization of Radioactive Sources from a Position Sensitive Radiation Detecting System (COCAE)

“…Towards the development of the COCAE instrument, apart the detailed simulation studies, two prototype integrated circuits have been developed, the pixelization of CdZnTe 75mm wafers has been successfully implemented and diode type single electrode detectors with high energy resolution have been developed. Furthermore, experiments with a precursor detector setup consisting of a stack of 3 CdTe hybrid pixel detectors are underway [7].…”

“…To model the realistic energy resolution of the COCAE instrument, the simulated energy depositions have been smeared according to a Gaussian distribution. Its FWHM has been determined using data from real measurements [7] taken by a mono-crystal CdTe Schottky diode, which is under development within the COCAE project, illuminated by various radioactive sources.…”

The COCAE Detector: An Instrument for Localization—Identification of Radioactive Sources

“…The detector is modeled with the aid of MEGAlib [7] and Geant4 [8]. The response of the detector has been studied [9] using a point gamma ray source with isotropic emission from 60 keV up to 2000 keV placed in front of the detector on its axis of symmetry. The best Compton sequence reconstruction efficiency achieved in the simulation study is presented in Fig.…”