Fig. 1. Schematic of VSANS spectrometer's layout

Fig. 2. Schematics of the detector's head (a) and mechanical structure (b)

Fig. 3. Movable platform for the optical test

Fig. 4. Plot of the optical attenuation length

Fig. 5. Principle diagram of WLSF's mechanical bending loss test

Fig. 6. Spectral comparison diagrams before and after mechanical bending (in air)

Fig. 7. Principle diagram of the SiPM's gain test

Fig. 8. Charge spectrum of the SiPM

Fig. 9. Plot of SiPM's gain test results

Fig. 10. Plots of SiPM's thermal noise test results (a) The variation of Hamamatsu's SiPM output signal with increasing temperature, (b) The variation of Sensl's SiPM output signal with increasing temperature

Fig. 11. Snapshot of the detector prototype

Fig. 12. Photo self-developed readout electronics boards

Fig. 13. Schematic diagram of the detection efficiency experiment

Fig. 14. Snapshot of boron-containing aluminum plate with "CSNS" slits

Fig. 15. Comparison plot of the neutron wavelength spectra

Fig. 16. Plot of the detection efficiency test results

Fig. 17. Plot of the two-dimensional imaging test result