Development of a wide-range paired scintillator with optical fiber neutron monitor for BNCT irradiation field study

Ishikawa, Masayori*; Kumada, Hiroaki; Yamamoto, Kazuyoshi ; Kaneko, Junichi* ; Bengua, G.*; Unesaki, Hironobu*; Sakurai, Yoshinori*; Tanaka, Kenichi*; Kosako, Toshiso*

A wide range thermal neutron detector was developed based on the Scintillator with Optical Fiber (SOF) detector which has been previously used for thermal neutron monitoring during boron neutron capture therapy irradiation. With this new detector system we intended to address the issues of real-time thermal neutron flux measurement and the simultaneous measurement of a wide range of thermal neutron flux in a BNCT irradiation field which were difficult to implement with the gold wire activation method. A good agreement between the thermal neutron flux measured by the gold wire activation method and the paired SOF detector system was observed. However, measurements which would normally take a few days to perform with the gold wire activation method were obtained in just about 15 min using the SOF detector system. We also confirmed the dynamic range of linearity for the SOF detector system to be in the order of magnitude of 1e-4.