摘要
以侧窗式微型X射线管为例,采用蒙特卡罗(Monte Carlo)方法,对金刚石光学窗口的最优厚度进行了模拟研究。以管压为50 kV、管电流为1.0 mA的X射线管工况为例的模拟结果表明:增加金刚石窗口厚度,可使银靶的Kα特征X射线有效透射比和峰总比不断提高;在最优厚度为2.0 mm的条件下,高能X射线有效透射比为154.5%,K系特征X射线的透射比为74.5%,峰总比为27.9%。与铍光学窗口相比,在保证特征X射线透射比T相等的前提下,金刚石光学窗口有更高的有效透射比和峰总比,可以替代传统铍作为微型X射线管的光学窗口。
[Background]As a hot material,diamond has been widely used in various civil and military equipment with high hardness(Mohs hardness is 10),compressive strength(greater than 1.2 GPa),excellent thermal(thermal conductivity at room temperature is 20~22 W·cm^(−1)·K^(−1),thermal expansion coefficient at room temperature is only(1.1~1.3)×10^(−6)K^(−1)),optical(higher transparency to X-rays)and electrical properties.Traditional optical window material beryllium is harmful to the human body and industrial hazards,its hardness,thermal conductivity and the thermal expansion coefficient are much lower than that of diamond.[Purpose]This study aims to explore the performance of micro X-ray tube with diamond optical window by simulation,obtain the best thickness of diamond for X-ray tube optical window and its shielding effect against low,medium and high energy X-ray.[Methods]The Monte Carlo method was used to calculate the effective transmission ratio,peak back ratio and transmission ratio of characteristic X rays with diamond optical window in high energy region.The X-ray tube with 50 kV tube voltage and 1.0 mA tube current was taken as an example to determine the optimal thickness of diamond.[Results]Simulation results show that the Kαcharacteristic X-ray effective transmittance and peak to total X-ray ratio of the silver target increase continuously with the increase of the diamond window thickness,and the optimum diamond thickness is 2.0 mm.Under the optimal thickness of 2.0 mm,the effective transmittance is 154.5%,high-energy Xray transmittance is 74.5%,and the characteristic X-ray peak back ratio is 27.9%.[Conclusions]Diamond can be used as a substitute for beryllium optical windows and has good application prospect.
作者
邢义强
赵剑锟
李蔚成
刘义保
刘薇
姜爽
XING Yiqiang;ZHAO Jiankun;LIWeicheng;LIU Yibao;LIU Wei;JIANG Shuang(Fundamental Science on Radioactive Geology and Exploration Technology Laboratory,East China Institute of Technology,Nanchang 330013,China;School of Nuclear Science and Engineering,East China University of Technology,Nanchang 330013,China)
出处
《核技术》
CAS
CSCD
北大核心
2021年第4期8-14,共7页
Nuclear Techniques
基金
放射性地质与勘探技术国防重点学科实验室开放基金(No.RGET1912)
国家重大仪器专项(No.2017YFF0106503)
国家自然科学基金(No.11805032、No.41804114)
教育部产学合作协同育人项目(No.202002088002)资助资助。
