Spectrum of gamma-rays from nuclear reactions with fast neutrons on cadmium measured by the time-of-flight method is analyzed. Impact of neutrons re-scattered on the experimental facilities and surroundings down to thermal energies is considered for indoor experiments. New unfolding procedure is proposed and used for determination from experimental amplitude spectrum of the gamma spectrum induced by fast neutrons only. The flux of the thermal neutrons is estimated by MCNP code. Spectrum of gamma ray from Cd induced by fast neutrons is corrected and its systematical uncertainties are estimated. The re-calculated gamma-spectrum is smaller than previous one and in the energy range ∼ 3.5÷6.5 MeV the differences between these spectra can reach ∼ 30%. Two wide peaks are observed as before in exponentially dropping yield for gamma-ray energies near neutron separation energy (∼ 4.5÷10 MeV) but with lesser intensities.

分析了用飞行时间法测量的与中子在镉上的快速中子核反应产生的伽马射线的光谱。室内实验考虑将中子重新散射到实验设备和周围环境直至热能的影响。提出了一种新的展开程序，并将其用于仅由快中子引起的伽马谱的实验振幅谱进行测定。热中子的通量通过MCNP代码估算。校正了由快中子诱发的Cdγ射线谱，并估计了其系统不确定性。重新计算的伽马光谱小于前一个，并且在约3.5÷6.5 MeV的能量范围内，这些光谱之间的差异可以达到约30％。