In recent years there has been an increased interest in the use of a medium resolution semiconductor CdZnTe (CZT) detector for gamma-ray spectroscopy and in safeguards applications. However, due to the different mobility and lifetime of electrons and holes in the crystal’s sensitive volume, a CZT detector shows an asymmetrical peak characterized by low-energy tailing.
The type and settings of the electronics used to process the signal can have an impact on the observed peak shape, e.g. the slope of low-energy tail and the resolution. In this work, we study impact of the shaping time parameter on the slope of low-energy tail and the resolution using two different types of signal processing instrumentation.
A 500 mm3 CZT detector was tested with different settings of the shaping time parameter on analogue and digital instrumentation. The best setting was chosen upon the impact on the slope of low-energy tail and the resolution. The best results on both types of instrumentation were compared. Digital MCA-527 instrumentation with 1.2 µs shaping time setting showed the lowest slope of low-energy tail and the smallest impact on resolution.