摘要
提出了具有角分布辐射源的屋顶厚度计算方法，计算了Ｌ－６０００ＨＲＯ１５ＭｅＶＸ射线直线加速器在离源ｄｓ＝２０ｍ处，由天空回散照射产生的剂量当量率降低到２．５×１０－３ｍＳｖｈ－１时，所需的混凝土屋顶厚度为３１ｃｍ，最优化的屋顶厚度为５０ｃｍ，竣工后检测，周围环境剂量当量率为本底水平，达到了可以合理达到的尽量低的水平。用本方法计算的屋顶屏蔽厚度，既有足够的安全水平，又能节省投资。
Presents a methods for calculation of the thickness of a concrete roof for shielding the angularity distributed X ray radiation produced by a L 6000HRO 15MeV X ray Linear Accelerator.The required roof thickness was found to be 31 cm in order to ensure the dose equivalent rate to be 2.5×10 -3 mSv·h -1 at an observation point 20 m away from the machine.This radiation comes mainly from skyshine.The thickness of that concrete roof was further optimized and found to be 50 cm.The dosimetric measurements made after the accelerator building had constructed showed that the shielding design was safe and econonic,and the skyshine radiation had been decreased to a level as low as reasonably achievable.
出处
《北京大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
1998年第4期453-460,共8页
Acta Scientiarum Naturalium Universitatis Pekinensis
关键词
X射线
直线加速器
屋顶厚度
辐射防护
X ray
linear accelerator
calculation of roof thickness
optimization
skyshine
concrete
