Patent Number: 
Section: abstract

A channel-cut monochromator has at least two kinds of reflecting surface pairs processed on a common single crystal block. Each reflecting surface pair has a first and a second reflecting surfaces between which X-rays are reflected even-number times. The channel-cut monochromator can be rotated around an axis of rotation perpendicular to a reference plane so as to switch the reflecting surface pair which reflects X-rays. An X-ray beam incident on any reflecting surface pair or its extension line is tangent to a common imaginary circle whose center coincides with the axis of rotation. With this structure, the switchover of the reflecting surface pair is accomplished by only the rotation of the channel-cut monochromator around its axis of rotation, so that various X-ray beams reflected by various Miller indices can be taken out selectively. The channel-cut monochromator may have a direct path through which an X-ray beam passes in no contact with any reflecting surface. The channel-cut monochromator may be made of silicon or germanium single crystal and may have preferably five or more kinds of reflecting surfaces, for example, for {220}, {400}, {422}, {511} and {111} reflection. Further, at least one of reflecting surface pair may have one or two asymmetrical reflecting surfaces.