Modifications of the beam profile in the new inclined crystal geometry

The new inclined crystal geometry has been successfully used in high heat load X-ray monochromator tests. The important aspect of this geometry is that from a diffraction point of view, when properly aligned, it is a symmetric Bragg reflection; i.e., b=ki x n/kout x n = -1. An interesting result of this geometry is that with a single reflection from an inclined crystal the output X-ray beam shape changes dramatically, while maintaining the same beam cross sectional area. For example, a parallel 8 keV input X-ray beam using Si(111) reflection, with an inclination angle of 70.50, the output beam size is compressed by about a factor of 5.6 in one direction and expanded by the same factor in the other direction. This geometry can therefore be used to alter the source line profile of in house X-ray generators, and in some cases to better match the sample size and the X-ray beam. The effect of this geometry on beam profiles, beam divergences and acceptance angles will be discussed. (orig.)