应用箔活化法,选用Dy、Lu、Eu、Au4种探测片,测量了重水零功率堆中心处的热中子通量谱。在堆的边缘构造一个重水区域作为参考谱区,通过测量该区Au的镉比,得出参考谱的超热中子份额。在选定的堆功率下,同时辐照2片相同种类的探测片,其中一片放在堆中心处,另一片放在参考谱区。由 Using the foil activation method, four kinds of detection sheets, Dy, Lu, Eu and Au, were selected to measure the thermal neutron flux at the center of the zero-power reactor. A heavy water zone was constructed on the edge of the heap as the reference spectral zone. The superheated neutron fraction of the reference spectrum was obtained by measuring the cadmium ratio of Au in this zone. At the selected stack power, two identical probes of the same type are irradiated simultaneously, one on the center of the stack and the other on the reference spectrum. by