薄膜型^(90)Sr放射源制备工艺研究

Study on Preparation of Strontium-90 Radioactive Source

目的为了获取与^(90)Sr同位素电池匹配的放射源,研发一种在指定非金属衬底材料上制作薄膜型^(90)Sr放射源的工艺。方法双环己烷-18-冠醚-6是一种既可配位锶离子,又具有良好抗辐照性能的分子,采用配位法将硝酸锶负载在该冠醚分子上,并溶解于高分子成膜剂中,在衬底材料上滴加后,自然晾干制备成含锶膜层。对制备结果进行了IR、TG、DSC、EDS、元素分析表征,考察了膜与衬底材料之间在经过116 k Gy剂量的γ辐照前后的结合力。结果该工艺实现了锶加载率大于93%,辐照后薄膜振荡掉粉率的增加小于1.3%。示踪实验表明,薄膜中表征锶分布不均匀性的相对标准偏差在7%左右。结论该工艺能够在衬底材料上获取^(90)Sr放射性薄膜,膜与衬底之间结合牢固,锶分布均匀性满足相关行业标准。

Objective In order to match with ^90Sr isotope batteries, ^90Sr radioactive sources on the appointed nonmetallic material are needed. Therefore, a new preparation method of ^90Sr radioactive sources was studied. Methods Dicyclohexano-18-crown-6 could not only coordinate with strontium ion but also had good resistance to radiation. The coordination technology was used to load the strontium nitrate on the crown molecule, then the product was dissolved in a functional polymer. After dropping the liquid containing strontium onto the appointed nonmetallic material, the film was dried at room temperature. The films were characterized by IR, TG, DSC, EDS and elemental analysis. Also, the binding properties between the film containing strontium and the substrate material were investigated before and after being experienced by the 7 irradiation of a total dose of 116 kGy. Results The loading rate of strontium was greater than 93 %. Compared with post-irradiation, the increased oscillation dropping powder rate of pre-irradiation was less than 1.3%. The results from tracing experiments showed that the relative standard deviation of the distribution of strontium in the surface of films was about 7%. Conclusion The process can obtain the strontium radioactive film on the appointed nonmetallic material, and the film is combined with substrate firmly. Strontium distribution uniformity satisfies relevant industrial standards.