Synthesis And Neutron- Gamma Ray Shielding Performance Of Bismuth Oxoborate

With nuclear energy more widely used in military and production,in view of the nuclear radiation to produce a variety of radiation rays(such as α、β、γ- rays, secondary γ- rays, and other charged particles and high-energy rays) protective work also appears more and more important. In many types of rays, γ-ray protection is particularly important, because, in general, the electromagnetic wavelength of theγ-rays is very short, with a strong penetrating ability, likely to cause the organism’s irreparable harm. Neutron is not charged which leads its fortissimo penetrating property. Once neutron enters organism, it will create serious injury which is bigger than other beams caused. The Bi3B5O12 is an important inorganic scintillator material, and studies have shown that: many special performance of the low-dimensional lead tungstate depends on its structure and morphology.This article synthesized Bi3B5O12 crystal with different luminous intensity and luminous center through high temperature self-propagating method and took Bi3B5O12 as the functional fillers to add to the natural rubber to form the Bi3B5O12/rubber compound materials which obtained good mechanics performance and protection performance of thermal neutron beams and low-energy gamma rays. By using XRD, SEM, fluorescence(PL), electronic universal testing machine and Na I(TI) detectors and BF3 technical detectors, the structure and property of microcrystals have been analyzed and the mechanical properties, low-energy γ-ray protective performance and thermal neutron absorption property of Bi3B5O12/rubber composite have been discussed. Among these, we also discussed the temperature increment influence on the Bi3B5O12 crystal growth inhibitory as well as the appearance effect on the photoluminescence performance influence. The result indicated that, when synthesized at temperature600℃, the luminous intensity was the strongest and sent out green light.After the temperature increasing, the photoluminescence intensity fell drastically and the luminescent center caused blue shift.Simultaneously this paper has reseached the effect of luminous intensity and activity of Bi3B5O12 functional fillers on its low-energy(59.5ke V) gamma ray shielding property and also has tested the monoenergetic thermal neutron beam absorption performance with the identical film. The result indicated that, the active Bi3B5O12 powders dispersed homogeneously in the natural rubber latex matrix.Mechanical performance of the Bi3B5O12/rubber composite was obviously higher than the pure natural rubber latex film. Bi3B5O12 crystals with better photoluminescence properties presented higherγ-ray shielding rates which reached the highest value of 20.97%(40wt% filler content). And good activity of Bi3B5O12 crystals which dispersed well in natural rubber latex will contribute to improvingγ-ray shielding rate. What’s more, the test result also indicated that the thermal absorption rate could reach 27.87%(40wt% filler content). All above, Bi3B5O12/rubber composite can both shield low-energy gamma rays(59.5ke V) and absorb the thermal neutron beams well.