Performance measurement of the SOF detector for boron neutron capture therapy

Komeda, Masao   ; Kumada, Hiroaki; Ishikawa, Masayori*; Nakamura, Takemi  ; Yamamoto, Kazuyoshi ; Matsumura, Akira*

In this report, deterioration of a SOF detector that can measure thermal neutron in real time was investigated in irradiation experiments. Sensitivity of a SOF detector decreased by 2.0% after an irradiation of about 4 hours. Then thermal neutron fluence was approximately 2.010 (n/cm). And after the SOF detector was used for about 2 months, sensitivity decreased to 42%. Then thermal neutron fluence was approximately 6.410 (n/cm). Supposing that thermal neutron fluence is 210 (n/cm) on the surface of a patient at a BNCT, sensitivity of a SOF detector is considered to be decreased by approximately 0.3% at a BNCT. Therefore it is considered that countermeasure against deterioration is necessary for using a SOF detector at BNCT in the future.