252Cf随机脉冲源方法测量球形钚系统瞬发中子衰减常数

²⁵²Cf随机脉冲源方法由早期的重复脉冲源方法演变而来，是测量核系统瞬发中子衰减常数α的有效方法。采用该方法测量了钚球装配31 mm、29 mm厚钢反射层核系统的α，在有效信号和噪声的比例为1∶1的情况下，得到的瞬发中子衰减谱信噪比为7∶1，最小二乘拟合结果依次为2.25 μs^-1和3.00 μs^-1，拟合误差为±0.02 μs^-1。与Rossiα方法的测量结果进行了比较，两种测量方法的结果差异小于1.3%。

Using 252Cf as Randomly Pulsed Neutron Source for Prompt Neutron Decay Measurements on Subcritical Plutonium Sphere

The randomly pulsed neutron method with ²⁵²Cf, which evolved from repeated pulsed-neutron method, is effective on prompt-neutron decay constant measurements. Because it’s based on time-correlated accordance, the influence of the background rays could be suppressed effectively. Using this method, subcritical measurements were performed on an alpha-phase plutonium sphere reflected by 31 mm thick and 29 mm thick steel. The proportion of useful signal and background was 1∶1 in the experiments, but in the prompt neutron decay spectrum the proportion of time-correlated signal and background was 7∶1. The prompt neutron decay constants of the measurements were 2.25 μs^-1 and 3.00 μs^-1 and the fitting error was ±0.02 μs^-1. Comparing with the results by Rossiαmethod, the difference is less than 1.3%.