Performance of styrene polymerized plastic scintillator with micropixel avalanche photodiode

This paper presents the performance of polystrene based plastic scintillator produced in Turkish Energy, Nuclear and Mineral Research Agency (TENMAK). The scintillator is manufactured using thermal polymerization of commercially available styrene monomer doped with first and second fluorescent dyes. The absorption spectrum of the scintillator exhibited two absorption bands at 225 nm and 340 nm, with an absorption edge observed at 410 nm. The wavelength of the emitted light was measured in the range of 400–800 nm, with a maximum intensity at 427 nm. Internal conversion electrons from the ¹³⁷Cs source were used to evaluate the characteristics of the new scintillator, particularly its light yield. As the light readout the MAPD-3NM type silicon photomultiplier array (4 × 4) with an active area of 15 × 15 mm², assembled using single MAPDs with an active area of 3.7 × 3.7 mm², was used. The light yield of the scintillator was determined to be 6134 photons/MeV. In addition, the efficiency of the scintillator for gamma rays with an energy of 662 keV was found out to be approximately 1.8%. CmBe neutron source was employed to evaluate its fast neutron detection performance. However, neutron/gamma discrimination using pulse shape discrimination (charge integration) method was not observed. The results demonstrate the potential of produced plastic scintillator for various applications, particularly in radiation monitoring and detection systems.