【摘要】 用多箔法测定热中子堆内活性区和反射层内的全能区中子通量谱。选择26种探测器,把10^-4eV至20MeV的整个能区分为640群,考虑箔自身吸收和散射,按群内中子是单能的计算14种热与中能探测器的自屏因子。按各箔截面互相一致适用原则选择活化反应截面。文中给出计算得的通量谱和谱误差。还给出两测点的“宏观谱量”,包括热中子通量,中子温度,费米谱量,偏离费米谱指数和快中子积分通量。检验了反应率、截面和初始通量谱对解谱的灵敏度。在初始谱变化较大的情况下都获得大体一致的结果。在能量<0.01eV与约10～500keV的两个能区,探测器响应均不灵敏,亦获得合理的通量谱分布。更多还原

【Abstract】 The neutron flux spectra in the core and the reflector of the thermal reactor are measured by multiple foil method. There are 26 kinds of foil detectors selected for the measurements. The neutron energy-range from 10^-4 eV to 20MeV is divided into 640 groups. In consideration of neutron capture and scatter of foil itself. The neutron self-shielding factors for 14 kinds of thermal and intermediate foils are calculated by single neutron energy approach in each group. The energy-dependent activation cross sections of each detector are selected under the requirement of good accuracy and consistency between foils. The results of computed flux spectra and their errors are given, "The macroscopic spectral values", i.e. thermal neutron fluxes, neutron temperatures, values of Fermi-spectrum, Fermispectrnm deviations and integral fast neutron fluxes are given at two measured positions too. The reaction-rates, the uncertainties of cross sections and initial flux spectrum used in the iteration VS. the sentivity of flux spectrum are tested. In the cases of a rather large change of initial flux spectrum the roughly consistent results are obtained. Rather reasonable distributions of flux spectra are also obtained in two energy ranges, one is 0.01 eV, where cross sections of the foils are almost 1/ν, and the other is about 10～500keV, where all foils are insensitive.更多还原