10 MeV电子加速器出束能量参数测量及其初步应用

Measurement of energy parameters and preliminary applications of 10 MeV linear accelerator electron beam

为完善设备检测用参数,进一步改善辐照加工工艺,对10 MeV电子加速器电子束能量和剂量参数进行了详细测量和分析。首先利用国标铝片叠层法测量了加速器最概然能量值和平均能量;其次采用聚丙烯塑料板、装饰低密度板、聚氯乙烯(Polyvinyl chloride,PVC)泡沫板和PVC亚克力板共4种典型的密度不同的均匀材料,测量并分析了电子束的最佳穿透深度和深度剂量分布曲线。结果表明:电子束的平均能量为9.42 MeV,略小于最概然能量(10.01 MeV),加工工艺制定以平均能量为计算依据更合适;材料密度越低其剂量不均匀性越大,上述四种材料对应的不均匀度值分别为1.20、1.28、1.34和1.46;这与γ辐照情况相反。通过经验拟合法得到穿透深度与材料密度、剂量不均匀度与材料密度的关系函数,对制定和提高规范化辐照加工具有积极意义。

In this study,the values of electron beam energy and dose parameters of a 10 MeV electron accelerator were measured and analyzed in detail in order to optimize the parameters used for equipment detection and improve the existing irradiation processing technology.First,the values of most probable energy and the average energy of the accelerator were estimated using the national standard aluminum lamination method.Then,the optimal penetration depth and depth dose distribution curves of the electron beam in four typical uniform materials of varying densities-PP(Polypropylene)plastic board,decorative low density board,PVC(polyvinyl chloride)foam board,and PVC acrylic board were measured and analyzed.The results demonstrated that the average energy of the electron beam was 9.42 MeV,which is slightly less than the most probable energy of 10.01 MeV,and it was concluded that the average energy is more suitable for the formulation of processing technology.Further,the dose uniformity ratio(DUR)was observed to be inversely proportional to the density of the medium,and their ratio values are 1.2,1.28,1.34,and 1.46 for the above four materials.it is opposite to gamma radiation situation.The relations between penetration depth and material density,and dose uniformity ratio and material density,were obtained via the empirical fitting method,which exhibit positive consequence with respect to the formulation and improvement of standardized irradiation processing.