Wavelength-dispersive X-ray spectrometer

A wavelength-dispersive X-ray spectrometer of a straight moving ray-collection type, the spectrometer being fitted to an X-ray microarea-analyzer such as an electron probe microanalyzer, said X-ray spectrometer comprising:

• a curved analyzing crystal having a crystalline lattice plane curved to have a curvature equal to the diameter of a Rowland circle in a direction of angular dispersion;
• and
• limitation means mounted integrally with the curved analyzing crystal, the limitation means acting to limit at least one of an incident region of a surface of the analyzing crystal on which incident X-rays impinge and an exit region of the surface of the analyzing crystal from which diffracted X-rays exit toward an X-ray detector such that only X-rays diffracted by an effective diffractive region of the surface of the analyzing crystal are detected by the X-ray detector in response to variation of the effective diffractive region of the surface of the analyzing crystal contributing to actual diffraction when a spectral analysis position of the X-ray spectrometer varies.