Fig. 1. Diagram of one-dimensional location principle of a neutron source (a) and photo of a NI6612 timing-counter (b)

Fig. 2. 3D distribution of reaction points and location resolution diagram in different neutron emission modes(a) 3D distribution of a collimated thermal neutron beam, (b) Position resolution of a collimated thermal neutron beam, (c) 3D distribution of 4π emission thermal neutrons, (d) Position resolution of 4π emission

Fig. 3. 3D top view of thermal neutron reaction sites for tube diameters of 1.27 cm (a) and 5.08 cm (b)

Fig. 4. Relationship of polyethylene thickness with detection efficiency (a) and position resolution (b)

Fig. 5. Neutron counting peak diagram of ³He tubes with polyethylene thicknesses of 0 cm (a) and 5 cm (b)

Fig. 6. Neutron meter value (a) and peak value of TDOA (b) at different X-axis coordinates of the source

Fig. 7. Relationship between X-axis coordinate of the source and TDOA

Fig. 8. Effect of polyethylene thickness on neutron counting

Fig. 9. Diagrams of neutron waveform at different source locations in the active region(a) x=0 cm, (b) x=40 cm, (c) x=80 cm

Fig. 10. Neutron counting peak diagram for various source-tube distances (a) y=15 cm, (b) y=20 cm

Fig. 11. Positioning-deviation diagram of each point in each experimental group

Fig. 12. Comparison between calibration value and experimental mean value at different locations