Basic study on a LiF-Eu:CaF2 mixed powder neutron scintillator

Abstract We developed a mixed powder neutron scintillator as a novel neutron detection material. Since LiF-Ag:ZnS mixed powder, which is a widely used mixed powder neutron scintillator, is opaque owing to the extremely high refractive index of Ag:ZnS, the scintillator thickness is limited. We proposed the use of LiF-Eu:CaF 2 mixed powder, where both LiF and Eu:CaF 2 have almost the same refractive index, as a roughly transparent mixed powder neutron scintillator. Although the just mixed LiF-Eu:CaF 2 powder is opaque, it can become translucent by filling the gap in the powder with a liquid glass resin as a refractive index buffer. As a result, we observe a peak shape in the pulse height spectrum obtained from the LiF-Eu:CaF 2 mixed powder scintillator when irradiating thermal neutrons.