直线加速器8 MV X射线能谱及结构研究  

Investigation of 8 MV X-rays energy spectrum structure of medical linear accelerator

作　　者：白彦灵[1] 肖雪夫[2] 邵文成[1] 

机构地区：[1]哈尔滨医科大学附属第三医院放射物理科,150081 [2]中国原子能科学研究院辐射计量测试部,北京102413

出　　处：《中华放射肿瘤学杂志》2012年第2期181-184,共4页Chinese Journal of Radiation Oncology

基　　金：黑龙江省自然科学基金资助项目（A200805）;黑龙江省教育厅科技资助项目（11531282）

摘　　要：目的研究医用直线加速器8MVX射线的能谱结构，简化能谱结构的描述方式。方法采用蒙特卡罗通用程序Geant4，对加速器产生的X射线能谱角分布和能谱结构进行研究。结果通过对X射线能谱结构的调试形成具体加速器的虚拟X射线源，采用蒙特卡罗Gean4程序计算得出在该虚拟源辐射场中水模体内不同照射野的百分深度剂量以及照射野内不同深度处Profile剂量曲线与测量结果精确吻合。结论放疗中具有相同能量的X射线都具有非常相近的能谱和能谱角分布，剂量学特性的细节差异反映了能谱角分布的细节差异。对利用测量剂量曲线快速建立源模型有着非常重要的意义。Objective To study the spectrum structure of X-ray and simplify the description method of it. Methods By the general program of Monte Carlo Geant4 to study X-ray spectrum structure and angular distribution of X-ray energy spectrum. Results The results of percentage depth doses and profile curves at different depths of any radiation fields in water phantom calculated by Monte Carlo Geant4 were consistent with the measurements. Conclusions In radiotherapy, X-ray with same nominal energy have very similar dosimetry characteristics, this indicates they have very similar energy spectrum and angular distribution of spectrum, the differences of dosimetric details reflect the different details of the X-ray spectrum structure and angular distribution of X-ray energy spectrum. These studies have very important significances to rapidly build precise virtual source modeling for Monte Carlo calculation based on dose curves measurements in water phantom.

关 键 词：直线加速器 X射线能谱 角分布 蒙特卡罗 

分 类 号：TH774[机械工程—仪器科学与技术]