  A digital pulse shape discrimination system based on a programmable module
NI-5772 has been established and tested with EJ-301 liquid scintillation
detector. The module was operated by means of running programs developed in
LabVIEW with the sampling frequency up to 1.6GS/s. Standard gamma sources 22Na,
137Cs and 60Co were used to calibrate the EJ-301 liquid scintillation detector,
and the gamma response function has been obtained. Digital algorithms for
charge comparison method and zero-crossing method have been developed. The
experimental results showed that both digital signal processing (DSP)
algorithms could discriminate neutrons from gamma-rays. Moreover, the
zero-crossing method shows better n-{\gamma} discrimination at 80 keVee and
lower, whereas the charge comparison method gives better results at higher
thresholds. In addition, the figure-of-merit (FOM) of two different dimension
detectors were extracted at 9 energy thresholds, and it was found that the
smaller one presented a better n-{\gamma} separation property for fission
neutrons.
