Schematic diagram of the flat crystal spectrometer for the Shanghai EBIT. Here is only a simple side view and the diffraction plane is oriented to be perpendicular to the electron beam. The crystals and the CCD are all put inside the vacuum chamber. A fully automatic control system is used to rotate the crystals and the CCD.
Slit image result by Gaussian fitting of the measured data. The width of the x-ray emitting area is around after analyzing the fitting data.
(a) The CCD image of lines by the diffraction of LiF(200), Si(220), and . (b) Lorentzian fitting of the two lines in the CCD. The data were averaged over 300 selected rows of the CCD image. Since the fitting figures of three crystals are similar, here only the fitting data of LiF(200) are given. The residual shows the complex of the x-ray emission from characteristic lines.
(a) The CCD image of the online test. Each time we took a 2 h long acquisition and totally we accumulated for 26 h. After adding all the data together, it can be clearly seen that there is one line in the middle of the CCD image. (b) Lorentzian fitting of the data. The data were summed of 1300 selected rows of the CCD image. The rest rows were ignored because we found the line was a little inclined and some bad pixels in the bottom of the CCD. The FWHM of the peak is around 12 pixels and the resolving power of this peak is around .
Parameters and results for LiF(200), Si(220), and with Ti emission.
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