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。

"measurement of leakage energy spectrum of boron containing polyethylene ball under d-t neutron irradiation" experiment using polyethylene ball&boron containing polyethylene ball under d-t neutron irradiation leakage energy experiment shows that the slowing down of hydrogen in polyethylene ball plays a major role,&the slowing down of neutrons is mainly the reaction of low-energy neutrons to hydrogen. the greater the thickness, the greater the slowness&absorption of hydrogen.
in boron - containing polyethylene spheres, boron plays a major role in absorption. the reaction section of boron to low-energy neutrons is relatively large. before hydrogen reaction, the low-energy neutrons have been completely absorbed by boron. when the mass percentage of boron containing polyethylene is 10 ‰&the thickness is 15cm, the protective effect of boron containing polyethylene to neutrons has reached the requirements. if the boron content/thickness is added on this basis, the neutron integral leakage amount will not change.