Cnpc-specific anti-neutron polyethylene board boron carbide polyethylene board, cnpc-anti-neutron protection source oil cover, anti-neutron pad are all using boron carbide polyethylene board.
The slowing down of hydrogen in the polyethylene ball plays a major role. After the neutron is slowed down, it is mainly the reaction of low-energy neutron to hydrogen. The greater the thickness, the stronger the hydrogen slowing down and absorption, which is reflected in the increase of the amplitude of the hydrogen reaction peak.
In boron - containing polyethylene spheres, the main absorption is boron. The reaction section of boron to low-energy neutrons is relatively large. Before the reaction of hydrogen occurs, low-energy neutrons have been completely absorbed by boron. The protective effect of boron-containing polyethylene to neutrons is up to the requirement when the mass percentage is 10, the thickness is 15cm. If the boron content or thickness is increased, the integral leakage of neutron is basically unchanged.
中石油专用防中子聚乙烯板 碳化硼聚乙烯板，中石油防中子防护源油盖、防中子垫板等均是采用碳化硼聚乙烯板。
聚乙烯球中氢的慢化起主要作用，中子被慢化后，主要是低能中子对氢的反应。厚度越大，氢的慢化、吸收越强，表现在氢的反应峰值的幅度增大。
而在含硼聚乙烯球中，主要是硼起吸收作用。硼对低能中子的反应截面比较大，在还没有发生氢的反应之前低能中子基本已被硼完全吸收，含硼聚乙烯在质量百分比为10﹪、厚度为15cm时，含硼聚乙烯对中子的防护效果已达到要求。在此基础上再增加含硼量或者厚度，中子的积分泄露量基本不发生变化。