辐照处理托帕石光谱学分析和放射性检测

Spectroscopic analysis and radioactivitydetection of topaz by irradiation

选取经未知方法辐照处理的托帕石样品,γ能谱仪测试结果表明其放射性与自然环境本底辐射相当,不会对人体产生新的危害。用直线电子加速器对样品进行辐照处理,射线能量为10 MeV,剂量为21 kGy、14 kGy和7 kGy,辐照前后托帕石样品颜色变化明显,均由较浅的蓝色变为较深的褐黄色。对辐照后的样品进行放射性检测,其放射性与环境本底辐射相当,说明在该条件下经过直线电子加速器辐照处理的托帕石不具放射性。对二次辐照处理后的样品再次进行热处理,样品的褐黄色均明显褪色。经紫外-可见-近红外光谱测试发现,样品致色成因为色心致色。

Topaz samples treated by unknown irradiation process were tested using Gamma-ray spectrometer.Results showed that the radioactivity of the treated topazs is equivalent to the natural background radiation,thus do not cause additional health risks to human body.For the purpose of verifying this result,the topaz samples were divided into 3 groups and were re-irradiated by electron accelerator at the radiation energy of 10 MeV,while their radiation doses of the 3 groups were 21 kGy,14 kGy and 7 kGy respectively.After irradiation,the color of all topaz samples changed significantly from light blue to brown-yellow.The radioactivity of the topazs after irradiation treatment remained equivalent to the natural background radiation,indicating that the topazs irradiated by electron accelerator under such condition is not radioactive.The brown-yellow color of the re-irradiated topazs faded obviously after a following heat treatment.The UV-Vis-NIR spectra showed that the color change of the topazs was caused by the color center.