(LiF)-Li-6 Oleic Acid Capped Nanoparticles Entrapment in Siloxanes for Thermal Neutron Detection

The good light output of siloxane based scintillators as displayed under gamma-rays and alpha particles has been exploited here to obtain clear and reliable response toward thermal neutrons. Sensitization towards thermal neutrons has been pursued by adding (LiF)-Li-6 in form of nanoparticles. Aiming at the enhancement of compatibility between the inorganic nanoparticles and the low polarity, siloxane based surrounding medium, oleic acid-capped (LiF)-Li-6 nanoparticles have been synthesized by thermal decomposition of Li trifluoroacetate. Thin pellets siloxane scintillator maintained their optical transmittance up to weight load of 2% of Li-6. Thin samples with increasing Li-6 concentration and thicker ones with fixed Li-6 amount have been prepared and tested with several sources (alpha, gamma-rays, moderated neutrons). Light output as high as 80% of EJ212 under irradiation was measured with thin samples, and negligible changes have been observed as a result of (LiF)-Li-6 addition. In case of thick samples, severe light loss has been observed, as induced by opacity. Nevertheless, thermal neutrons detection has been assessed and the data have been compared with GS20, based on Li glass, taken as a reference material.