Digital Gamma-Neutron Discrimination with Organic Plastic Scintillator EJ 299-33

The neutron / gamma pulse shape discrimination (PSD) is measured for the newly dis- covered plastic scintillator EJ 299-33 using a fast digitizer DDC10. This plastic scin- tillator (EJ 299-33) discovered by Lawrence Livermore National Laboratory(LLNL) is now commercially available by Eljen Technology. Some of its properties include light output emission efficiency of 56 / 100 (of Anthracene), wavelength of maximum emis- sion of 420 nm, C:H ratio of 1:1.06 and density of 1.08 g / cm 3 . The PSD between neutrons and gamma rays in this plastic scintillator is studied using a 5.08-cm diameter by 5.08-cm thick sample irradiated by a neutron-gamma source AmBe-241 and em- ploying charge integration method. The results show that EJ 299-33 has a very good PSD, having a figure of merit of approximately 0.80, 2.5 and 3.09 at 100 KeVee, 450 KeVee and 750 KeVee light outputs respectively. The performance of this new material is compared to that of a liquid scintillator with a well proven excellent PSD performance NE213, having a figure of merit of 0.93, 2.95 and 3.30 at 100 KeVee, 450 KeVee and 750 KeVee respectively. The PSD performance of EJ 299-33 is found to be comparable to that of NE 213