Cadmium-Zinc-Telluride photon detector for epithermal neutron spectroscopy-pulse height response characterisation

The Resonance Detector Spectrometer was recently revised for neutron spectroscopic studies in the eV energy region. In this technique one makes use of a photon detector to record the gamma emission from analyser foils used as neutrongamma converters. The pulse-height response of a Cadmium-Zinc-Telluride photon detector to neutron capture emission from 238U and 197Au analyser foils was characterised in the neutron energy range 1-200 eV: The experiment was performed on the VESUVIO spectrometer at the ISIS neutron-pulsed source. A biparametric data acquisition, specifically developed for these measurements, allowed the simultaneous measurements of both the neutron time of flight and g pulse-height spectra. Through the analysis of the g pulse-height spectra the main components of the signal associated with resonant and non-resonant neutron absorption were identified. It was also shown that, in principle, energy discrimination can be used to improve the signal to background ratio of the neutron time-of-flight measurement.