Objective to understand the 5% boron polyethylene (atomic number %) shielding fast neutron shielding effect, use californium - 252 (^ 252 cf) and americium - beryllium (241 am - Be ^) standard neutron source, respectively for the fast neutron shielding is studied in this protective effect. Method 3. The 2cm thick boron polyethylene plate is cut in diameter 5. 5cm, thickness of 3. Superposition of 2 cm round to test samples, the samples for different thickness of ionizing radiation in the national defense science and technology industry - level metering station with 252 cf and ^ ^ 241 am - Be standard neutron source illuminate, the boron polyethylene slabs with different thickness were measured the fast neutron transmittance. The results showed that the thickness of boron polyethylene plate was 3. 2 cm, to ^ 241 am - Be source of neutron shielding efficiency of 47. 7% of ^ 252 cf source neutron shielding efficiency is 60%, the boron polyethylene plate thickness to 12. 8 cm, to ^ 241 am - Be source neutron shielding efficiency was 91%, that's right. 252 ^ 252 cf source neutron shielding efficiency. 5%, the thickness of the boron polyethylene plate is 22. 4 cm, on ^ 241 am - Be source of neutron shielding efficiency for 97. 9%, to 252 ^ 252 cf neutron shielding efficiency of the source. 2%. Conclusion the boron polyethylene plate is an efficient neutron shielding material for neutron and neutron radiation shielding. 

    目的為了解5％含硼聚乙烯（原子數％）屏蔽快中子的防護效果，用锎-252（^252Cf）和镅-鈹（^241Am—Be）標準中子源分別對其屏蔽快中子的防護效果進行了實驗研究。方法將3．2cm厚的含硼聚乙烯板裁成直徑5．5cm，厚度3．2cm的圓形待測樣品，疊加為不同的樣品厚度，在國防科技工業電離輻射-級計量站用^252Cf和^241Am—Be標準中子源照射，分別測量不同厚度的含硼聚乙烯板對其快中子的透射率。結果結果表明，該含硼聚乙烯板厚度為3．2cm時，對^241Am—Be源中子屏蔽效率為47．7％，對^252Cf源中子屏蔽效率60％，該含硼聚乙烯板厚度為12．8cm時，對^241Am—Be源中子屏蔽效率為91％，對。^252Cf源中子屏蔽效率95．5％，該含硼聚乙烯板厚度為22．4cm時，對^241Am—Be源中子屏蔽效率為97．9％，對^252Cf源的中子屏蔽效率98．2％。結論該含硼聚乙烯板是-種高效的防中子屏蔽材料，可有效用于中子和中子、γ混合輻射場中的中子輻射屏蔽防護。