On the evaluation of the absolute photon energy of Cu$ K\alpha _{\mathrm{,}}\beta $ lines using 4-crystal X --ray spectrometer

A 4-crystal X-ray spectrometer was designed based on a 2-crystal X-ray spectrometer to be able to perform the absolute measurement of Bragg angle. This basic thought based on 2 crystals dates back to the times to A.Compton etc.[ Sci.Rev.Inst.,\textbf{2},365(1931), Phys.Rev.\textbf{47},882(1935) ]. Because a distortion to give the crystal by the adhesive when a crystal was glued, greatly affected the X-rays profile, we changed it to the channel cut crystal without a free distortion as for having made each crystal of 2-crystal a channel cut. The influence of the foot in the spectral profile is more suppressed because four times of reflections reflect it. It is a high resolution so as not to need to consider instrumental function by the reflection degree that a specific atomic analysis can be executed with the chemical state which it is possible for making the placement of the 4-crystal ($+$,$+)$ setting [Phys.Rev.\textbf{49},14(1936), Phys.Rev.A65,042502(2002)]. This type of spectrum device is first time in the world. Because the absolute measurement of 2$\theta $ angles is enabled by ($+$,-) and ($+$,$+)$ setting from the center of gravity position of the rocking curve and the center of gravity position of the X-rays spectrum, we may measure the absolute value of the X-ray photon energy. Because we evaluated the energy of the Cu $K\alpha $,$\beta $ lines, we report it.