A Simplified Digital Charge Collection (SDCC) method of discrimination between neutron and gamma pulses in an organic scintillator is presented and compared to the Pulse Gradient Analysis (PGA) discrimination method. Data used in this research were gathered from events arising from the ⁷Li(p,n)⁷Be reaction detected by an EJ-301 organic liquid scintillator recorded with a fast digital oscilloscope. Time-of-Flight (TOF) data were also recorded and used as a second means of identification. The SDCC method is found to improve on the figure of merit (FOM) given by PGA method at the equivalent sampling rate.

The design, build and test of a digital analyzer for mixed radiation fields is described. This instrument has been developed to provide portable, real-time discrimination of hard mixed fields comprising both neutrons and γ rays with energies typically above 0.5 MeV. The instrument in its standard form comprises a sensor head and a system unit, and affords the flexibility to provide processed data in the form of the traditional scatter-plot representation separating neutron and γ -ray components, or the full, sampled pulse data itself. The instrument has been tested with an americium-beryllium source in three different shielding arrangements to replicate the case in which there are only neutrons, only γ rays and where both neutrons and γ -rays are present. The instrument is observed to return consistent results.