Investigation of digitally sampling scintillation pulses in energy determination in PET

In this paper, we investigate the use of digitally sampling scintillation pulses techniques in energy determination in positron emission tomography (PET). We employ a dataset in the digital library, which has been built in previous work, to explore the effect on energy resolution in terms of integral interval and sampling rate. We investigate the effect on energy resolution with various integral interval by means of absolute amplitude and relative amplitude. In addition, we simulate that analog-to-digital converters (ADCs) work either in free running mode or trigger sampling mode to evaluate the effect on energy resolution with various sampling rates. Our results show that energy resolution is not significantly affected by sampling rates higher than 250 MSps, and it is improved rapidly with sampling rate increasing when sampling rate between 50 MSps and 250 MSps. Energy resolution is also improved with sampling duration increasing, and it is slightly affected by sampling duration more than 60 ns for LSO scintillation pulses without shaper processing. These results illustrate that, it is feasible to implement digitally sampling scintillation pulses without any shaper processing. Therefore, our results have then demonstrated the promising use of digitally sampling scintillation pulses techniques in energy determination in PET.