中文摘要：

中子密度的连续指示和它变化的率为反应堆的安全开始和操作是重要的。因为任何一个都不能很好为反应堆的安全开始和操作为即时或平的超级时间的计算发达数字方法满足需要，完成这的最好的方法是获得中子动力学方程的分析答案在实践。在这份报纸，有一个组的点动力学方程的一个精确分析答案推迟了中子，体外的中子来源被建议在中子密度计算变化，在的地方从 subcritical 阶段的整个过程到批评并且 supercritical 阶段为步反应插入被考虑。精确分析答案能也被用作采用解决生硬中子动力学方程的所有数字方法的一个基准。

英文摘要：

The continuous indication of the neutron density and its rate of change are important for the safe startup and operation of reactors. The best way to achieve this is to obtain analytical solutions of the neutron kinetics equations because none of the developed numerical methods can well satisfy the need for real-time or even super-time computation for the safe startup and operation of reactors in practice. In this paper, an accurate analytical solution of point kinetics equations with one-group delayed neutrons and an extraneous neutron source is proposed to calculate the change in neutron density, where the whole process from the subcritical stage to critical and supercritical stages is considered for step reactivity insertions. The accurate analytical solution can also be used as a benchmark of all numerical methods employed to solve stiff neutron kinetics equations.