基于新型空气等效材料的治疗水平电离室研究

发布时间：2018-02-02 20:51

本文关键词： 石墨烯空气等效电离室能量响应　出处：《中国测试》2017年08期 　论文类型：期刊论文

【摘要】：针对目前使用的治疗水平电离室石墨帽有效原子序数偏低,且易碎等问题,研究以空气电子密度、等效原子序数、反应截面为基础,模拟计算出空气等效材料的有效原子权重及质量配比。采用高纯石墨烯粉末作为基材,添加纯度为99.9%的偏氟材料,高温融化搅拌高压压制成空气等效板材,该材料导电率为0.03 S/cm,质量密度为1.8 g/cm~3。以该空气等效板材为基础,设计加工一种新型的0.6 cm~3治疗水平电离室,并采用不同材质的收集极做能响实验,确定收集极的材质。通过实验证明,该电离室漏电(零点漂移)为0.15%,测量重复性为0.07%,示值非线性为0.27%,X能量响应为1.63%,X/γ能量响应为-0.48%,杆旋转为0.46%,满足JJG 912——2010《治疗水平电离室剂量计》对电离室的要求。
[Abstract]:Aiming at the problems of low effective atomic number of graphite cap in the treatment level ionization chamber and its fragility, the paper studies the basis of the air electron density, equivalent atomic number and reaction cross section. The effective atomic weight and mass ratio of the air equivalent material were simulated and calculated. The high purity graphene powder was used as the base material and the metafluorine material with purity of 99.9% was added into the air equivalent plate by melting and stirring at high temperature and high pressure. The conductivity of the material is 0.03s / cm and the mass density is 1.8g / cm ~ 3.Based on the air-equivalent plate, a new 0.6 cm~3 therapeutic horizontal ionization chamber is designed and manufactured. Determine the material of the collector. The leakage current (00:00 drift) of the ionization chamber is 0.15, the repeatability of measurement is 0.07, the nonlinear value of the ionization chamber is 0.27 and the energy response is -0.48, the rod rotates to 0.46, which meets the requirements of JJG 912-2010 level ionization chamber dosimeter for the ionization chamber.
【作者单位】：中测测试科技有限公司;四川中测辐射科技有限公司;
【基金】：国家重大科学仪器设备开发专项(2013YQ090811)
【分类号】：R730.55
【正文快照】： 0引言目前,放射治疗是治疗恶性肿瘤的重要手段之一[1],主要是采用直线加速器或者钴机产生的高能光子(X、γ)和高能电子来治疗恶性肿瘤。国际辐射单位和测量委员会ICRU第24号报告提出:原发肿瘤根治剂量的不确定度应低于±5%[2]。因此剂量的精准是进行放射治疗最基本的要素;绝对

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