Development of quick measurement method with high position resolution of neutron flux distribution by using light fiber painted with scintillator

A new method for neutron flux distribution measurement in a very narrow gap was developed, which made it possible to measure the distribution very quickly and with high position resolution by using optical fiber whose tip was painted with a mixture of ZnS(Ag) scintillator, LiF and adhesive paste. The detector can be inserted into a gap with 1-3mm width. Position resolution is about 1mm. In Kyoto University Critical Assembly, it was possible to measure thermal neutron flux distribution in several minutes over ∼100cm. The measurements of fast neutron and γ-ray distributions were also possible with this method. (author)