X-RAY SPECTRAL ELEMENT

PROBLEM TO BE SOLVED: To obtain an X-ray spectral element with high reflection and high resolution by combining an element of which atomic number is smaller by 1 or 2 than the specific element with an artificial multilayer film, when specific characteristic X-ray caused by a specific element is extracted. SOLUTION: The part of artificial multilayer film of an X-ray spectral element has tungsten (W) on the first layer 10 and boron carbide (B4 C) on the second layer 12. The thicknesses of the first layer 10 and the second layer 12 are respectively 3 to 4 nanometers, which are layered by 50 to 200 times. On the surface of the artificial multilayer film, a nickel surface layer 14 is formed. This X-ray spectral element is to extract only CuKα-ray, and by forming nickel layer 14, X-rays of wavelength side shorter than the CuKα-ray can be absorbed effectively with the nickel layer 14.