Analysis of time correlations for high sensitivity measurements

This work illustrates the development of an alpha spectroscopy system dedicated to the measurement of surface contaminations in materials used for low-background radioactive experiments. The system described is sensitive to trace levels of natural radionuclides. The operating principle is based on the simultaneous measurement of time and energy for each detected particle. A dedicated selection algorithm is developed to identify events in defined temporal relationships, so as to highlight cascade decays in natural radioactive chains. The shown results highlight the potential of the technique in reducing the radioactive background and revealing contamination otherwise not observable with usual analysis techniques.