Development of an optical fiber type detector using a Eu:LiCaAlF6 scintillator for neutron monitoring in boron neutron capture therapy

We have developed a small neutron detector probe as a thermal neutron flux monitor for boron neutron capture therapy. The detector consists of an optical fiber and a small Eu:LiCaAlF6 scintillator. In order to improve neutron-gamma ray discrimination capability, we use the small-size scintillator, whose size is controlled to be smaller than fast electron range produced by gamma-rays and larger than the range of charged particles induced by 6Li(n,t) reactions. We confirmed the improved neutron-gamma ray discrimination capability by comparing the detector responses between a small-size scintillator and a slab one. We also evaluated the neutron sensitivity of the fabricated optical fiber type neutron detector to be 2×10−4 cm2.