Fig. 1. A detector package of CCD236
Each detectoris divided into four quadrants

Fig. 2. The RSP of CCD236 detector

Fig. 3. Schematic diagram and picture of some device of spectrum measurement

Fig. 4. Spectrum of background

Fig. 5. Spectrum measurement of ⁵⁵Fe X-ray source and iteration results
The blue dotted line and red star dotted line are the iteration results without and with the background, respectively

Fig. 6. Curve of convergence factor ε with iteration times

Fig. 7. Curve of FWHM with iteration times

Fig. 8. Results of ⁵⁵Fe spectrum iterative inverse

Fig. 9. Experimental and convolution spectrum. The spectra are normalized by area

Fig. 10. Spectrum measurement of material by CCD236 detector; The spectrum is normalized by area