Fig. 1. Schematic of soft X-ray flat-field spectrometer with the spectral range of 0.8-6.0 nm

Fig. 2. Imaging property of soft X-ray flat-field grating. (a) Focal curves; (b) spectral line width

Fig. 3. Principle schematic of fabricating soft X-ray flat-field gratings

Fig. 4. Effect of the subarea number of fused silica mask written by EBL on the spectral broadening

Fig. 5. Effect of the coefficient error δ1 of the groove density distribution equation of an EBL-written fused silica mask on focal curve

Fig. 6. Effects of the coefficient errors of the groove density distribution equation of an EBL-written fused silica mask on spectral line width. (a) Error δ1; (b) error δ2; (c) error δ3; (d) errors of δ1, δ2 and δ3

Fig. 7. Effect of the displacement of substrate center on spectral imaging character. (a) Focus plane; (b) spectral line width

Fig. 8. Schematic of the relative attitude angular of mask and grating substrate

Fig. 9. Effects of the main parameter errors of NFH on spectral line width. (a) R error; (b) θ error; (c) h error; (d) δ error

Fig. 10. Effects of different combinations of the alignment errors of the NFH optical configuration on spectral line width. (a) Serious broadening; (b) mutual compensation

Fig. 11. Compensation of spectral line width by the fabrication error of EBL with NFH