活化法测量中子能谱实验中反应率及初始谱的检验

摘要

Neutron spectrum in irradiation chamber of Xi′an pulsed reactor was measured with activation meth-od.The activity of foils was measured and analyzed.The analysis revealed that one of the measured reaction rates is not accurate.Further investigation was carried out, and then a method of qualitative analysis of the ex-perimental data was summarized:After finite iterations, the reliability of the data can be assessed, according to the departure of the ratio of calculated reaction rate to experimental reaction rate from 1.After the data selec-tion, the spectrum can be unfolded.Furthermore, the influence of different initial spectrum on the results was analyzed.The larger the difference between the initial spectrum and the reality, the more obvious influence of cross section of the resonance range on the results.In view of this, a method is proposed to determine the suita-bility of the initial spectrum.%利用活化法对西安脉冲反应堆辐照腔进行了中子能谱测量。对活化片的测量数据进行了分析，发现其中一个反应道的反应率测量值不准确，并以此为切入点展开深入研究，总结出评定实验数据的定性分析方法：在有限次迭代后，通过对各反应道反应率计算值与实验值之比与1的偏离程度判断实验数据的置信度，进行实验数据取舍后再进行解谱。此外，分析了不同初始能谱对解谱结果的影响。结果表明：初始能谱与实际能谱偏差越大，共振区的截面数据对结果的影响越明显。为此，提出了一种判断初始能谱是否合适的方法。