Fig. 1. Moderated energy spectrum of ²⁵²Cf neutron source (a), and response curve of ³He detector (b)

Fig. 2. Schematic diagram of test platform

Fig. 3. Schematic of the interaction between thermal neutrons (a), epithermal and fast neutrons (b) and materials to be tested

Fig. 4. Schematic diagram of testing process for thermal neutron shielding performance of testing materials (a) Counts measurement setting, (b) Incident neutron spectrum, (c) Response curve of ³He detector, (d) Detector counts, (e) Calculation of thermal neutron shielding rate

Fig. 5. Diagram of collimating neutron beam launcher

Fig. 6. Simulation results of thermal neutron fluence rate (a) and thermal neutron share (b) of collimated neutron beam, and the product of thermal neutron fluence rate and thermal neutron share (c)

Fig. 7. Thermal neutron shielding rate of target samples to be tested (a) Iron plates, (b) Graphite plates

Fig. 8. Thermal neutron shielding rate of target samples to be tested under different filters

Fig. 9. Thermal neutron shielding rate of materials to be tested under different detection systems

Fig. 10. Thermal neutron shielding rate of materials under different neutron emissivity

Fig. 11. Thermal neutron shielding rate of materials with different distance to detector

Fig. 12. Thermal neutron shielding rate of materials to be tested at different distances from the center of the detector to the center line of the beam

Fig. 13. Thermal neutron shielding rate of materials to be tested under different neutron source types and test platforms