Fig. 1. SXFEL test facility in the SSRF campus

Fig. 2. Schematic layout of SXFEL test facility

Fig. 3. Schematic of the undulator system for HGHG cascade

Fig. 4. Gain curve and output spectra of 8.8 nm cascaded HGHG-FEL. (a) Gain curve; (b) output spectra

Fig. 5. Schematic of the undulator system for EEHG-HGHG cascade

Fig. 6. Gain curve and output spectra of the first stage EEHG. (a) Gain curve; (b) output spectra

Fig. 7. Second stage gain curve of EEHG-HGHG cascade

Fig. 8. Schematic of the undulator system for single stage EEHG

Fig. 9. Gain curve (20^th harmonic) and radiation spot (30^th harmonic) of single-stage EEHG. (a) Gain curve; (b) radiation spot

Fig. 10. Injector of the SXFEL test facility

Fig. 11. Laser heater. (a) Sketch; (b) physical photograph

Fig. 12. X-band linearizer

Fig. 13. Movable magnetic bunch compressor. (a) Sketch; (b) physical photograph

Fig. 14. Longitudinal phase space and current distribution of electron beam at the linac exit. (a) Without X-band linearizer; (b) with X-band linearizer

Fig. 15. C-band linac

Fig. 16. C-band deflecting cavity at the exit of the SXFEL linac and the measured longitudinal beam phase space distribution. (a) C-band deflecting cavity; (b) longitudinal beam phase space distribution

Fig. 17. U235 undulators installed in tunnel

Fig. 18. Cavity beam position monitor. (a) Photograph of the monitor; (b) resolution evaluation result

Fig. 19. X-band deflecting structures installed in the SXFEL test facility. (a) Photograph; (b) measured beam phase space when lasing

Fig. 20. High resolution X-ray spectrometer in diagnostic beam line. (a) Photograph; (b) measured spectrum

Fig. 21. Schematic of the SXFEL user facility