Storage characteristics of mixtures of KCl:Eu 2+ phosphors and polyethylene powder by irradiation of fast neutrons

Storage characteristics of mixtures of polyethylene powder and photostimulable phosphors such as KCI:EuH with low gamma-ray sensitivity were investigated in order to improve the spatial resolution when the mixtures were applied to fast neutron imaging. The maximum photostimulated luminescence yields were obtained at a KCI:EuH weight ratio of about 0.8 when the mixtures were irradiated by fast neutron with an energy of 14.8 MeV. These experimental results well agreed with theoretical predictions by Monte Carlo simulation using PHITS code. Estimated spatial resolution of the optimal mixture sample was 0.068 mm that was better than that obtained by conventional methods where the radiators are set in front of the phosphors. These mixtures will be usable for fast neutron imaging.