自屏蔽电子加速器的辐照室屏蔽设计

Shielding Design of Irradiation Chamber of Self-shielding Electron Accelerator

电子加速器运行时,在辐照室内,若高能电子被屏蔽体或束下物阻挡,则会产生韧致辐射,即X射线,容易对辐照室周围环境造成辐射污染。目前,市场上的自屏蔽加速器通常以钢板作为屏蔽材料,X射线通过钢板时以近似指数衰减,随着钢板厚度的增加,当量剂量率逐渐下降,当屏蔽达到一定厚度时,辐照室外参考点处当量剂量率下降到小于剂量限值,在满足国家环保要求的同时,最大限度地节约成本。

When the electron accelerator is running,in the irradiation room,if high-energy electrons are blocked by shields or under-beams,bremsstrahlung radiation namely X-rays will be generated,which is likely to cause radiation pollution to the surrounding environment of the irradiation room.Currently,self-shielding accelerators on the market usually use steel plates as shielding materials,X-rays decay approximately exponentially when passing through the steel plate,as the thickness of the steel plate increases,the equivalent dose rate gradually decreases,when the shielding reaches a certain thickness,the equivalent dose rate at the reference point outside the irradiation room drops to less than the dose limit,which can save costs to the greatest extent while meeting national environmental protection requirements.