Value-Assigned Pulse Shape Discrimination for Neutron Detectors

Using the waveforms from a digital electronics system, an offline analysis technique on pulse shape discrimination (PSD) has been developed to improve the $n$-$\gamma$ separation in a bar-shaped NE-213 scintillator that couples to a photomultiplier tube (PMT) at each end. The new improved method, called the "valued-assigned PSD" (VPSD), quantifies the separation between neutrons and gamma rays. Position dependence of PSD can be taken into account and automated using VPSD method. The resulting $n$-$\gamma$ identification is much improved when compared to the traditional technique that uses the geometric mean (GM) of light outputs from both PMTs. This technique has been applied successfully to a recent experiment to better extract the neutron spectra for understanding the nuclear equation of state (EoS).