Performance of a new CdZnTe portable spectrometric system for high energy applications

A new CZT portable spectrometric system called OMEGA has been developed at CEA/LETI for high-energy applications like spent fuel assay in response to needs in the nuclear industry. The CZT OMEGA system has been designed to operate at room temperature under water. It is based on a single 10 × 10 × 10 mm³ CZT detector associated with a single electronics channel. In order to improve performance, the CZT OMEGA system uses advanced technologies including: a new electrode design based on the capacitive grid Frish method to obtain maximum sensitivity from the 10 × 10 × 10 mm³ CZT detector, a single hybrid preamplifier to reduce noise, a specially designed electronics board to enhance count rate capabilities and electron bi-parametric (BP) correction (pulse height versus rise time spectrum) to improve both energy resolution and detection efficiency. This paper reports the most recent results obtained with the CZT OMEGA spectrometric system at high energy (¹³⁷Cs and ¹⁵²Eu sources) at both low and high count rate: spectrometric performance shows an energy resolution of 1 % FWHM at 662 keV (0.8% at 1408 keV) from 1 kcps to 50 kcps, deteriorating to 2 % FWHM at 200 kcps.