Fig. 1. Neutron capture cross-section of oxygen and silicon

Fig. 2. Comparison of γ-flux between the truncated group and the control group

Fig. 3. Three-dimensional geometric model of surface nuclear radiation scene

Fig. 4. Vertical cross-sectional diagram of surface nuclear radiation scene model

Fig. 5. Neutron source energy spectrum

Fig. 6. Schematic diagram of the top view structure (left) and cross-section (right) of the annular detector

Fig. 7. Comparison of secondary γ-ray dose rates at the Earth’s surface

Fig. 8. Comparison of secondary γ-ray dose rates at the sea surface

Fig. 9. Comparison of secondary γ-ray dose rates at the surface of concrete