## 医用直线加速器辐射防护与评价

Title  Radiation Protection and Evaluation of Medical linear Accelerator
Abstract
Objective Calculate the dose rate of protective door and shielding wall of a room with 15MV medical linear accelerator.Base on the dose rate to evaluate the annual effective dose equivalent of radiological workers and the surrounding public. And complete the environmental impact assessment of the accelerator. Methods Choose Varian Clinac iX 15 MV Medical linear Accelerator of The first People's hospital in Yancheng city as the research object. According to the recommendations and requirements of the imminent national standard GBZ /T 201.2, use corresponding formulas and medical accelerator practical parameters to evaluate and analyse the radiation protection ability of the room.  Results  The largest instantaneous dose rate of room's shielding wall is 2.49μSv/h, and the instantaneous dose rate of protective door is 1.84 u Sv/h. The largest annual effective dose equivalent of radiological workers is 1.58 mSv, and public's annual effective dose equivalent is 0.156 mSv.  Conclusions  The shielding ability of the linear accelerator room can satisfy the requirements of the national standard. Therefore，the design scheme of the room is feasible. This linear accelerator can be put into medical application when other auxiliary and safety measures are completed. 源自/六^维:论"文;网(加7位QQ3249~114 www.lwfree.cn
Keywords Medical linear accelerator; Shielding calculation; Dose evaluation; Environmental impact assessment

1  引言 1
2  医用直线加速器 2
2.1  简介  2
2.2  工作原理2
2.3  治疗过程 3
2.4  主要污染物4
2.5  污染防治措施5
3  环境影响评价 6
3.1  项目简介 6
3.2  环境现状调查6
3.3  环境问题及保护目标 10
3.4  评价标准10
3.5  机房屏蔽核算及剂量评价12
3.5.1  机房墙体屏蔽设计核算14
3.5.2  机房入口防护门屏蔽核算20
3.5.3  感生放射性污染24
3.5.4  保护目标剂量评价24
3.5.5  安全防护措施评价25

1  引言

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