Performance of the Zero-Dead-Time Mode of the DSPEC Plus

Gamma ray spectroscopy systems have dead time losses during data collection due to pulse processing in the electronics. Several methods have been developed in the past to recover from dead time losses. These include live-time clocks and loss-free counting. The live-time clock (LTC) extension technique (where the counting time is extended to compensate for the lost counts) gives accurate results for samples where the total count rate (dead time) is constant during the measurement. The Harms Westphal loss-free counting (LFC) method gives better results when the counting rate varies significantly during the acquisition period. However, this LFC method does not give the uncertainty of the spectral counts. Thus, the analysis of the spectral data with uncertainty calculations can't be done. The ORTEC DSPECTM implements a digital “zero dead-time” (ZDT) method for loss free counting that also gives the uncertainty for each channel in the ZDT spectrum. Data will be presented to show that the new method gives the correct peak area for changing count rates in different conditions.