Characteristics of optically stimulated luminescent dosimeter of beryllium oxide in BNCT irradiation field

The irradiation fields in boron neutron capture therapy (BNCT) consist of neutrons with a wide energy range and undesired high-intensity γ-rays. As the thermoluminescent dosimeter (TLD) used for BNCT dosimetry is out of production, a new type of γ-ray dosimeter is required for the quality assurance (QA) of the treatment. Therefore, in this study, an optically stimulated luminescent dosimeter (OSLD) made of BeO ceramic was selected and its use in the field of BNCT was investigated. The performance of the dosimeter was tested and the effect of a thermal neutron on the γ-ray dose obtained by the OSLD was measured. The OSLDs had a good γ-ray dose linearity of approximately 300 mGy corresponding to the dose in the quality assurance procedure of BNCT, and the thermal neutron sensitivity of the OSLD was less than that of TLD.