An optimal solvent of liquid scintillator for fast-neutron imaging applications

For fast neutron detection and imaging applications in the inertial confinement fusion (ICF) experiments, a scintillator with high reflective index, good transparency in the wavelength range of the fluorescence emission spectra, fast decay component with a few nanoseconds decay time is required. In this work, when 2,5-diphenyloxazol and p-bis(o-methylatyryl)-benzene were used as the fluors of a liquid scintillator, three kinds of solvents including PX (p-xylene), PXE (l-phenyl-l-xylylethane) and DIN (di-isopropylnaphthalene) were selected to prepare a liquid scintillator. The wavelength-dependent attenuation length and the fluorescence emission spectra of liquid scintillator mixtures were measured by an UV-vis spectrometer and a FL spectrofluorimeter, respectively. The decay time of liquid scintillator was tested employing the time-correlated single photon counting (TCSPC) technique featured in high dynamic range of several orders of magnitude in light intensity. The experimental results indicated that the optimal solvent was PX from the point of energy transfer efficiency and optical properties.