A fast digital timing and analysis system based on real-time dCFD technique for nuclear physics experiments

In this paper a fast digital real-time spectrometer was developed for timing and analysis of nuclear pulse signals. The hardware system design and algorithm implementation with field-programming gate array (FPGA) and digital signal processor (DSP) were introduced. The performance of the digital constant fraction discrimination (dCFD) platform was experimentally tested with Agilent 80 MHz function/arbitrary waveform generator and LaCl3:Ce3+ scintillator detector for Na-22 positron annihilation gamma spectroscopy. The amplitude and time information of gamma photon was online obtained. The energy resolution could be 5.525% and the timing resolution 293.75 ps, the system error estimation of dCFD approach was also studied. The results showed that this spectrometer achieved a timing resolution close to that of traditional CFD timing resolution with a more simplified system structure.