^(238)U/^(235)U裂变截面比与俘获裂变截面比测量分析

Measurement and Analysis of Fission Cross Section Ratio and Capture-Fission Cross Section Ratio of ^(238)U/^(235)U

在中国实验快堆(CEFR)中直接测量238 U的截面数据较困难且误差较大,但可通过测量其与235 U的截面比值来获取238 U的相关数据。本工作采用活化法测量238 U与235 U的裂变截面比及俘获裂变截面比(即σf8/σf5与σ8c/σf5),获取238 U的截面数据并与MCNP计算结果进行比较。结果表明,CEFR的轴向转换区或反射层位置为最佳增殖区域。

It was inconvenient to measure the cross section data of 238U directly and there usually exists deviations in the results.The cross section data could be obtained with good precision by the measurement of the cross section ratio between 235U and 238U,and compared with calculation result of MCNP.The results show that the optimal breed region is the axial blanket area or the reflective area.