Investigation on thermal-neutron sensitivity of commercial BeO(Na) thermoluminescence dosimeter and development of thermal-neutron insensitive BeO(Na) phosphors encapsulated in quartz-capillary

BeO(Na) TLD on the market, UD-170 L, gives thermoluminescence response equivalent to irradiation with 3.2±0.5 cGy of 60Co γ-rays after irradiation with 1010 thermal neutrons per cm2. Because of this neutron sensitivity, UD-170 L is not suitable for measurement of γ-rays in γ-neutron mixed radiation from a nuclear reactor of Kinki University when we use it for radiobiological research. To reduce this troublesome sensitivity, we replaced the glass capillary used for UD-170 L with a quartz capillary. Quartz tube encapsulated BeO(Na) showed a markedly reduced response to thermal neutrons. (author)