广西医用电子加速器验收检测泄漏辐射水平分析

目的：验收、检测广西地区医用电子加速器，分析其泄漏辐射水平，为估算放射职业人员、患者辐射防护剂量水平和制定放射防护控制策略提供依据，为医院的放射治疗质量控制提供指导。方法：对广西29台医用电子加速器进行验收、检测。使用热释光剂量计（TLD）测量加速器的泄漏辐射水平；使用中子测量仪测量中子的泄漏辐射水平，结合国家标准对其进行分析与评价。结果：加速器透过限束装置的辐射泄漏率最大值≤1.2%，平均值≤0.65%；距电子轨道1 m处辐射泄漏率最大值≤0.46%，有用线束中心轴2 m圆平面内辐射泄漏率最大值≤0.19%，平均值≤0.09%；标称能量≥10 MV的加速器，其电子轨道1 m处中子的辐射泄漏率最大值≤0.032%，有用线束中心轴2 m圆平面内中子的辐射泄漏率最大值≤0.028%，平均值≤0.014%。结论：所检测设备的泄漏辐射水平均在国家标准控制范围内，医用加速器的泄漏辐射水平是设备防护性能的重要指标，在其投入使用前必须通过验收，以确保医疗质量和安全。

Acceptance testing analysis on leakage radiation levels sets of medical electron accelerators in Guangxi

Objective： To analyze the leakage radiation levels of medical electron accelerators by acceptance test, aiming to estimate the radiation protection dose level of the radiation occupation personnel and patients, and to Provide basis for the establishment of radiation protection control strategy, also to guide the Radiotherapy quality control for the hospital. Methods： Twenty-nine sets of medical electron accelerators were tested in GuangXi from 2007 to 2013, and studied with some equipment including thermo luminescence dosimeters （TLD） and Neutron dosimeter to obtain leakage radiation doses of X-ray and Neutron respectively. The data were analyzed and appraised with relative standards. Results： The radiation leakage rate maximum of the beam limiting device is ≤1.2%, the mean value of which is ≤0.65%. In addition, the maximum leakage rate is≤0.46%at a distance 1m from electron orbit;leakage rate maximum is≤0.19%within the 2m plane from useful harness inner circle, its mean value is≤0.09%;for nominal energy≥10MV accelerator, the neutron leakage rate maximum at the position 1m away from the electronic track is≤0.032%. Neutron leakage rate maximum is ≤0.028% within 2m round plane of the useful beam central axis. It means value is ≤0.014%. Conclusion： The detection device leakage radiation levels are within the control of the national standard, leakage radiation levels of medical accelerator is an important index in the protection performance of equipment, in order to ensure the medical quality and safety, the device must pass the acceptance test before be put into use.