In this new Application Note (AN3250) Pulse Shape Discrimination between neutrons and gamma rays in liquid scintillators is studied by using DPP-PSD firmware running on CAEN digitizers. The dependence of the Figure of Merit on the digitizer sampling rate and resolution is experimentally determined.
Based on "Pulse shape discrimination with fast digitizers", L. Stevanato et al, NIMA 748 (2014) 33-38, DOI: 10.1016/j.nima.2014.02.032
For the measurements reported in this application note, a liquid scintillator coupled to a 12 dynode photo-multiplier (PMT) has been used. The anode signal was directly processed by a set of CAEN digitizers running DPP-PSD firmware:
Pulse Shape Discrimination (PSD) is a technique widely used in both basic and applied research. One of the most common PSD applications is the discrimination between neutrons and gamma rays in fast neutron measurements. During the last years, Pulse Shape Discrimination has been significantly improved thanks to the use of fast digitizers and Digital Pulse Processing (DPP). The digital approach, therefore, replaced in many cases those analog systems that have been developed and successfully operated for several decades.
Digital Pulse Processing offers many advantages in respect to the traditional systems. The detector signals can be processed on real time by the FPGAs housed in the digitizers. This allows for higher trigger rates because no conversion time is needed to digitize the input pulses and perform the analysis. The setup is considerably easier and more compact since the detector can be directly connected to the digitizer and no other electronic module is needed for the data acquisition. Finally, when the on-line analysis is not sufficient, the raw digitized signals can be used for a refined off-line analysis.
