Fig. 1. Outline diagram of vacuum ultraviolet spectroradiometer

Fig. 2. Off‑axis aspherical double reflection ultraviolet optical system

Fig. 3. Performance test of vacuum ultraviolet filter

Fig. 4. Reflectivity of the mirror at incident angles of 15 ° and 45 °

Fig. 5. Simulation curves of influence of MgF₂ protective layer thickness on aluminum mirror reflectivity

Fig. 6. Internal structure diagram of MCP-PMT

Fig. 7. Dark current curve of MCP-PMT over time

Fig. 8. Dark current graph as a function of vacuum

Fig. 9. Curve chart of signal to noise ratio as a function of bias voltage

Fig. 10. Photocathode sensitivity curves

Fig. 11. Photo of vacuum chamber

Fig. 12. Simulation nephogram of static displacement and stress of vacuum chamber

Fig. 13. Simulation nephogram of stress and static displacement of upper cover of cabin

Fig. 14. Chart of spectral radiance test result

Fig. 15. Responsiveness curve near the center wavelength of 121.2 nm

Fig. 16. Responsiveness curve near the center wavelength of 135.6 nm

Fig. 17. Responsiveness curve near the center wavelength of 160 nm

Fig. 18. Responsiveness curve near the center wavelength of 180 nm

Fig. 19. Responsiveness curve near the center wavelength of 200 nm

Fig. 20. Spectroradiometer working wavelength signal-to-noise ratio curve