正由于铅对γ射线的屏蔽效果非常明显，而含硼聚乙烯又是对中子漫化吸收的理想材料，所以在同时存在中子和γ场的场所。

Is due to the lead of gamma ray shielding effect is very obvious, and boron polyethylene is ideal materials for neutron absorbed moderation, so in the place of neutron and gamma field at the same time, from around to ensure the safety of the staff, the commonly used mixed materials such as lead, boron, polyethylene shield.