摘要 |
An apparatus for X-ray analysis by means of a focusing optical system according to the Rowland geometry. The apparatus is arranged to operate with a fixed measuring channel, the X-ray detector (14, 16) occupying a fixed position. In order to compensate for mechanical tolerances and a spread in the period of the analysis crystal (12) (a multilayer mirror), it is necessary to rotate the crystal slightly, after which the X-ray beam to be analyzed is no longer completely incident on the detector (14, 16). In accordance with the invention, the analysis crystal (12) is readjusted by coupling the rotation of the crystal to a displacement of the crystal in conformity with the Rowland geometry. The detector need not be displaced for as long as the angle of incidence of the X-rays to be analyzed on the analysis crystal remains small, for example <30°. It is also possible to select another wavelength to be examined, it then being merely necessarily to displace the detector along a straight line passing through the entrance slit. A guide for such a rectilinear displacement can be more readily realized than a mechanism for following the exact detector path for the Rowland geometry.
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