用Monte Carlo方法设计X射线均整器  

Monte Carlo design of X-ray flattening filters

作　　者：李泉凤[1] 严慧勇[1] 

机构地区：[1]清华大学工程物理系,北京100084

出　　处：《清华大学学报（自然科学版）》2003年第6期732-734,共3页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(10135040)

摘　　要：在以电子直线加速器为X射线源的工业CT和辐射治疗中,需要较均匀的X射线剂量率空间分布。利用MonteCarlo方法,设计了6MeV和9MeV的X射线均整器。对9MeV的X射线均整器进行了实验。实验结果表明:在距靶1m处测得均整后0°处的剂量率约为均整前的74%,7.5°处的剂量率约为0°处的69%。满足Varian标准。该均整器在满足平坦度要求的同时提高X射线剂量利用率,不经过打磨便可得到较好的均整结果。Monte Carlo simulations were used to obtain spatially uniform distributions of the Xray dose rate for industrial computerized tomographys and for radiotherapy with an electron Linac as the Xray source. 6 MeV and 9 MeV Xray flattening filters were designed using the Monte Carlo method. Experimental results with the 9 MeV Xray flattening filter showed that at 1 meter away from the target, the 0° dose rate after flattening was 74% of the dose rate before flattening and the dose rate at 7.5° was 69% of the dose rate at 0°. These results satisfy the Varian Standard. The flattening filter improves the Xray dose usage rate and satisfies the flatness requirement without grinding. 

关 键 词：X射线均整器 MonteCarlo方法 电子直线加速器 剂量率 空间分布 

分 类 号：TL53[核科学技术—核技术及应用]