Pulse Shape Discrimination in Polysiloxane-Based Liquid Scintillator

This work analyses for the first time the time response of a recently developed polysiloxane based liquid scintillator, characterized by low toxicity and low volatility, with a special focus on the pulse shape discrimination capability of this material. With the aim of maximizing the neutron-gamma discrimination the fluorescence lifetime and the scintillation pulses have been studied at different primary dye concentrations, connecting the results to the energy transfer and to the formation of excimers inside the scintillating solution. Pulse shape analysis performed during the irradiation of the samples with a pulsed neutron beam allowed the definition of a figure of merit as an indicative parameter for the neutron-gamma discrimination, and the dependence of this parameter form radiation energy and PPO concentration has been analyzed in order to understand the critical points and optimize the performances of the material in view of its possible use with high radiation backgrounds