20 Mev 电子直线加速器实验室辐射屏蔽防护设计

为防止电子直线加速器产生的各种辐射所造成的有害生物效应,加速器实验室应采用一系列措施,对韧致辐射x线及光中子进行屏蔽防护。实验室应按最优化设计原则,既保证防护要求又降低造价和提高空间利用率。对宽角度轫致辐射光子的屏蔽,应考虑加速器工作负荷因子w,x射线束定向因子U,和有关人员居留因子T。对散射光子的屏蔽,根据Braestrup和Wyckoff的近似方法进行设计。在对南京大学20 Mev电子直线加速器实验室设计中: 1.采用了局部铅屏蔽室,使有用束外的初级x线减弱至10~(-4)左右。 2.舍弃迷宫,采用加强屏蔽门措施。 3.设置了一系列与出束联锁的声、光报警装置和烟控防火报警设备。文章还给出了有关设计公式、图表和数据。

A DESIGN OF RADIATION SHIELDING AND PROTECTION FOR 20Mev ELECTRON LINEAR ACCELERATOR LABORATORY

In order to prevent all kinds of radiation produced by electron linear accelerator from bringing about harmful effect on creatures, we adopt some measures to shield bremsstrahlung X-rays and photoneutron in the design of accelerator. Designs of the laboratory must follow the optimum principle which satisfies the need of protection and reduces the expense and increases the utilization ratio of space. W must consider the accelerator work load factor W, orientation(use) factor U and the occupancy factor T of related persons so as to shield the photons produced in wide-angle bremsstrahlung, In the design of the LINAC laboratory of Nanjing University. 1. we adopt the partial shield lead cell, so that the primary X-ray outside the useful beam decreases to about 10~(-4). 2. we abandon the labyrinth and adopt the measure of strengthening the shielding door. 3. we set a series of optical and acoustic warning system interlocked with the beam and fire-alarm equipments which can be triggered by smoke. This paper also presents related formulas, figures and details