摘要
利用蒙特卡罗方法和^(252)Cf中子源研究了在准直热中子入射束下,15%~30%(质量分数)碳化硼含量的Al-B_4C复合材料的中子吸收系数和宏观截面。结果表明,Al-B_4C复合材料的中子吸收系数随碳化硼含量增加而增大,相同碳化硼含量的材料其中子吸收系数随厚度的增加按指数规律变化;^(252)Cf中子源测试得到的中子吸收系数比0.0253eV单能热中子计算得到的吸收系数低0.5%~4.3%;Al-B_4C复合材料的宏观截面随着碳化硼含量的增加呈线性递增的关系,而且理想热中子0.0253eV下的递增率(0.97925cm^(-1)/%)大于^(252)Cf中子源构建0~1eV中子下的递增率(0.58537cm^(-1)/%)。
The Monte Carlo method and a ^252Cf neutron source device were used to investigate the neutron absorption coefficient and the macroscopic cross-section of Al-B4 C composite materials with the boron carbide content of15 wt.%-30 wt.%,under the thermal neutron collimatied beam.The results showed that the neutron absorption coefficient of the Al-B4 C composite materials increased with the increasing content of B4 C.When the content of B4 C was determined,the neutron absorption coefficient changes with the variation of thickness of materials according to the index law.The neutron absorption coefficient of Al-B4 C composite materials tested by ^252Cf neutron source was 0.5%-4.3%lower than calculated value from 0.0253 eV single thermal neutron.The macroscopic cross-section of Al-B4 C composite materials showed a linear increasing relationship with the increase of boron carbide content.Furthermore,the change rate of macroscopic cross-section of the composite materials obtained from 0.0253 eV neutrons（0.97925cm^-1/%）was larger than that of ^252Cf neutron source（0.58537cm^-1/%）.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2016年第16期21-25,30,共6页
Materials Reports
基金
中国工程物理研究院军民两用重大项目(JMZD200903)
