缓发中子计数法定量<sup>235</sup>U、<sup>239</sup>Pu初步研究

缓发中子计数法定量²³⁵U、²³⁹Pu初步研究

摘要: 利用缓发中子计数法对²³⁵U-²³⁹Pu混合物中²³⁵U和²³⁹Pu含量的快速测定进行了初步研究。在中国原子能科学研究院30 kW微型反应堆(简称微堆)垂直孔道辐照²³⁵U、²³⁹Pu以及²³⁵U-²³⁹Pu混合物样品30 s，冷却2 s，用缓发中子探测器测量100 s，得出²³⁵U和²³⁹Pu的探测限分别为0.14和0.18 μg；探测器效率为0.015 0±0.001 0；当²³⁵U和²³⁹Pu质量比m(²³⁵U)/m(²³⁹Pu)=1.2时，²³⁵U、²³⁹Pu含量计算值与标称值的相对偏差分别为0.8%和6.9%。

Abstract: The preliminary study on the measurements of ²³⁵U and ²³⁹Pu in ²³⁵U-²³⁹Pu mixture using delayed neutron counting method was introduced. All samples were irradiated for 30 s at China Institute of Atomic Energy, cooled for 2 s, and counted for 100 s using a delayed neutron detector. It is found that the detection limits of ²³⁵U and ²³⁹Pu are 0.14 and 0.18 μg for ²³⁵U and ²³⁹Pu, respectively. The detection efficiency for delayed neutron is 0.015 0±0.001 0. The relative deviations between calculated mass and measured mass of ²³⁵U and ²³⁹Pu are 0.8% and 6.9%, respectively, for m(²³⁵U)/m(²³⁹Pu) of ²³⁵U-²³⁹Pu mixture sample is 1.2.