Synthesis of plastic scintillation microspheres: Alpha/beta discrimination

• Plastic scintillation microspheres for α/β discrimination have been synthesised.
• The energy transfer process in PSm with different compositions has been investigated.
• The α/β discrimination capabilities of two commercial detectors have been evaluated.
• 2% and 0.5% of misclassifications for β and α radionuclides have been achieved respectively.

Plastic scintillation microspheres (PSm) have been developed as an alternative for liquid scintillation cocktails due to their ability to avoid the mixed waste, besides other strengths in which the possibility for alpha/beta discrimination is included. The aim of this work was to evaluate the capability of PSm containing two combinations of fluorescence solutes (PPO/POPOP and pT/Bis-MSB) and variable amounts of a second organic solvent (naphthalene) to enhance the alpha/beta discrimination. Two commercial detectors with different Pulse Shape Discrimination performances (Quantulus and Triathler) were used to evaluate the alpha/beta discrimination. An optimal discrimination of alpha/beta particles was reached, with very low misclassification values (2% for beta particles and 0.5% for alpha particles), when PSm containing PPO/POPOP and between 0.6 and 2.0 g of naphthalene were evaluated using Triathler and the appropriate programme for data processing.